PHARMACEUTICAL GLASS COATING FOR ACHIEVING PARTICLE REDUCTION

BACKGROUND

1. Field

The present specification generally relates to pharmaceutical glass containers and, more specifically, to pharmaceutical glass containers which greatly reduce particle generation during processing, for example, during processing in pharmaceutical filling lines

2. Technical Background

Particle contamination, especially in parenteral drugs, poses a risk to patient safety and, despite being monitored closely during pharmaceutical manufacturing, glass and metal particles continue to be a leading cause of parenteral drug recalls. With traditional glass containers, glass-to-glass contact produces significant quantities of particle of various sizes in the most sensitive portion of the filling process (i.e., prior to container closure).

During processing in bulk, high speed pharmaceutical filling lines, conventional borosilicate glass containers are subjected to systematic glass to glass contact due to the handling method designs. Operations such as loading, accumulation, rotary drives, star wheels and singulation place containers under load while they are in contact with one another. A number of the operations take place following washing, but before capping where the container is susceptible to glass to glass to damage. Furthermore, the glass is depyrogenated and cleaned, further increasing the surface coefficient of friction and susceptibility and severity of the damage. The damage that is caused from glass to glass contact results in glass particle generation. Depending on the nature of the damage, impact loads and presence of pre-existing damage, glass particles ranging from 1 to 120 μm can be generated. If these particles are being generated in the filling line environment, there exists a risk that the particles can contaminate open containers. The design of the filling line area and laminar air flow does not fully prevent such airborne contamination.

The United States Pharmacopoeia (USP) has defined limits on allowable particle levels. The allowable level for visible particles is zero. Visible particles are defined by the ability for a certified operator to detect the particle in the solution with the unaided eye with specific lighting conditions. <USP 1 and USP 790>. Generally, particles in the 50 to 150 μm range is the threshold for reliable visible detection. USP has regulations for sub-visible particle levels as well. <USP 788> defines levels of 600 and 6000 particles per dose for particles size >25 μm and >10 μm respectively. Particle generation in pharmaceutical filling lines can make containers non-compliant with USP standards.

Accordingly, a need exists for improved pharmaceutical glass containers which reduce particle generation in pharmaceutical filling lines.

SUMMARY

Embodiments of the present disclosure are directed to pharmaceutical coatings, which prevent glass particles from being generated during processing, for example, during processing in the pharmaceutical filling line area. The coating additionally improves machinability during filling line processing and reduces catastrophic break events which tend to contaminate adjacent containers and the filling line environment.

According to one embodiment, a coated glass article is provided. A coated glass article comprising a glass body comprising glass and having a first surface and a second surface opposite the first surface, wherein the first surface is an exterior surface of the glass body, and a coating disposed on at least a portion of the exterior surface of the glass body. The coated glass article reduces particle generation when the coated glass article undergoes processing, wherein the coated glass article demonstrates at least a 50% reduction in average particle count for generated sub-visible glass particles compared to an average particle count of generated sub-visible glass particles by an uncoated glass article that undergoes processing, wherein the average particle count is computed using light obscuration according to United States Pharmacopoeia Standard 788.

According to another embodiment, the coated glass article comprises a glass body comprising glass and having a first surface and a second surface opposite the first surface, wherein the first surface is an exterior surface of the glass body, and a coating disposed on at least a portion of the exterior surface of the glass body, the coating comprising a polymer chemical composition. The coated glass article reduces glass particle formation caused by non-breakage inducing glass contact in pharmaceutical glass filling lines. The reduction in glass particle formation is defined as follows: wherein an average particle count of generated sub-visible glass particles having a size of 50 μm or less is below allowable levels defined by United States Pharmacopoeia Reference Standard 788, the average particle count being computed using light obscuration; and wherein the coated glass article demonstrates at least a 50% reduction in average particle count for generated sub-visible glass particles compared to an average particle count of generated sub-visible glass particles by an uncoated glass article in the pharmaceutical glass filling lines.

It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate the various embodiments described herein, and together with the description serve to explain the principles and operations of the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically depicts a cross section of a glass container with a low-friction coating, according to one or more embodiments shown and described herein;

FIG. 2 schematically depicts a cross section of a glass container with a low-friction coating comprising a polymer layer and a coupling agent layer, according to one or more embodiments shown and described herein;

FIG. 3 schematically depicts a cross section of a glass container with a low-friction coating comprising a polymer layer, a coupling agent layer, and an interface layer, according to one or more embodiments shown and described herein,

FIG. 4 shows an example of a diamine monomer chemical composition, according to one or more embodiments shown and described herein;

FIG. 5 shows an example of a diamine monomer chemical composition, according to one or more embodiments shown and described herein;

FIG. 6 depicts the chemical structures of monomers that may be used as polyimide coatings applied to glass containers, according to one or more embodiments shown and described herein;

FIG. 7 is a flow diagram of one embodiment of a method for forming a glass container with a low-friction coating, according to one or more embodiments shown and described herein;

FIG. 8 schematically depicts the steps of the flow diagram of FIG. 7, according to one or more embodiments shown and described herein;

FIG. 9 schematically depicts a testing jig for determining the coefficient of friction between two surfaces, according to one or more embodiments shown and described herein;

FIG. 10 schematically depicts an apparatus for testing the mass loss of a glass container, according to one or more embodiments shown and described herein;

FIG. 11 graphically depicts the light transmittance data for coated and uncoated vials measured in the visible light spectrum from 400-700 nm, according to one or more embodiments shown and described herein;

FIG. 12 graphically depicts the failure probability as a function of applied load in a horizontal compression test for vials, according to one or more embodiments shown and described herein;

FIG. 13 contains a Table reporting the load and measured coefficient of friction for Schott Type 1B glass vials and vials formed from a Reference Glass Composition that were ion exchanged and coated, according to one or more embodiments shown and described herein;

FIG. 14 graphically depicts the failure probability as a function of applied stress in four point bending for tubes formed from a Reference Glass Composition in as received condition, in ion exchanged condition (uncoated), in ion exchanged condition (coated and abraded), in ion exchanged condition (uncoated and abraded) and for tubes formed from Schott Type 1B glass in as received condition and in ion exchanged condition, according to one or more embodiments shown and described herein;

FIG. 15 depicts gas chromatograph-mass spectrometer output data for a APS/NOVASTRAT® 800 coating, according to one or more embodiments shown and described herein;

FIG. 16 depicts gas chromatography-mass spectrometer output data for a DC806A coating, according to one or more embodiments shown and described herein;

FIG. 17 contains a Table reporting different low-friction coating compositions which were tested under lyophilization conditions, according to one or more embodiments shown and described herein;

FIG. 18 contains a chart reporting the coefficient of friction for bare glass vials and vials having a silicone resin coating tested in a vial-on-vial jig, according to one or more embodiments shown and described herein;

FIG. 19 contains a chart reporting the coefficient of friction for vials coated with an APS/Kapton polyimide coating and abraded multiple times under different applied loads in a vial-on-vial jig, according to one or more embodiments shown and described herein;

FIG. 20 contains a chart reporting the coefficient of friction for vials coated with an APS coating and abraded multiple times under different applied loads in a vial-on-vial jig, according to one or more embodiments shown and described herein;

FIG. 21 contains a chart reporting the coefficient of friction for vials coated with an APS/Kapton polyimide coating and abraded multiple times under different applied loads in a vial-on-vial jig after the vials were exposed to 300° C. for 12 hours, according to one or more embodiments shown and described herein;

FIG. 22 contains a chart reporting the coefficient of friction for vials coated with an APS coating and abraded multiple times under different applied loads in a vial-on-vial jig after the vials were exposed to 300° C. for 12 hours, according to one or more embodiments shown and described herein;

FIG. 23 contains a chart reporting the coefficient of friction for Schott Type 1B vials coated with a Kapton polyimide coating and abraded multiple times under different applied loads in a vial-on-vial jig, according to one or more embodiments shown and described herein;

FIG. 24 shows the coefficient of friction for APS/NOVASTRAT® 800 coated vials before and after lyophilization, according to one or more embodiments shown and described herein;

FIG. 25 graphically depicts the failure probability as a function of applied load in a horizontal compression test for vials, according to one or more embodiments shown and described herein;

FIG. 26 shows the coefficient of friction for APS/NOVASTRAT® 800 coated vials before and after autoclaving, according to one or more embodiments shown and described herein; and

FIG. 27 graphically depicts the coefficient of friction for coated glass containers exposed to different temperature conditions and for an uncoated glass container;

FIG. 28 contains a Table illustrating the change in the coefficient of friction with variations in the composition of the coupling agent of a low-friction coating applied to a glass container as described herein;

FIG. 29 graphically depicts the coefficient of friction, applied force and frictive force for coated glass containers before and after depyrogenation;

FIG. 30 graphically depicts the coefficient of friction, applied force and frictive force for coated glass containers for different depyrogenation conditions;

FIG. 31 shows a schematic diagram of reaction steps of a silane bonding to a substrate, according to one or more embodiments shown and described herein;

FIG. 32 shows a schematic diagram of reaction steps of a polyimide bonding to a silane, according to one or more embodiments shown and described herein;

FIG. 33 graphically depicts the coefficient of friction, scratch penetration, applied normal force, and frictional force (y-ordinates) as a function of the length of the applied scratch (x-ordinate) for the as-coated vials of a Comparative Example;

FIG. 34 graphically depicts the coefficient of friction, scratch penetration, applied normal force, and frictional force (y-ordinates) as a function of the length of the applied scratch (x-ordinate) for the thermally treated vials of a Comparative Example;

FIG. 35 graphically depicts the coefficient of friction, scratch penetration, applied normal force, and frictional force (y-ordinates) as a function of the length of the applied scratch (x-ordinate) for the as-coated vials of a Comparative Example;

FIG. 36 graphically depicts the coefficient of friction, scratch penetration, applied normal force, and frictional force (y-ordinates) as a function of the length of the applied scratch (x-ordinate) for the thermally treated vials of a Comparative Example;

FIG. 37 graphically depicts the coefficient of friction, applied force and frictive force for coated glass containers before and after depyrogenation, according to one or more embodiments shown and described herein;

FIG. 38 graphically depicts the failure probability as a function of applied load in a horizontal compression test for vials, according to one or more embodiments shown and described herein;

FIG. 39 graphically depicts the coefficient of friction, applied force and frictive force for coated glass containers before and after depyrogenation, according to one or more embodiments shown and described herein;

FIG. 40 graphically depicts the coefficient of friction after varying heat treatment times, according to one or more embodiments shown and described herein, according to one or more embodiments shown and described herein;

FIG. 41 graphically depicts the coefficient of friction, applied force and frictive force for coated glass containers before and after depyrogenation, according to one or more embodiments shown and described herein;

FIG. 42 graphically depicts the failure probability as a function of applied load in a horizontal compression test for vials, according to one or more embodiments shown and described herein;

FIG. 43 shows a scanning electron microscope image of a coating, according to one or more embodiments shown and described herein;

FIG. 44 shows a scanning electron microscope image of a coating, according to one or more embodiments shown and described herein;

FIG. 45 shows a scanning electron microscope image of a coating, according to one or more embodiments shown and described herein; and

FIG. 46 graphically depicts the light transmittance data for coated and uncoated vials measured in the visible light spectrum from 400-700 nm, according to one or more embodiments shown and described herein.

FIG. 47 is a photograph of an uncoated borosilicate vial following a filling line trial.

FIG. 48 is a photograph of exemplary coated vials following a filling line trial, according to one or more embodiments shown and described herein.

FIG. 49A is an EDX plot of coated glass vial samples which undergo vial scratch testing as discussed in the Examples, according to one or more embodiments shown and described herein.

FIG. 49B is an Energy Dispersive X-ray Spectroscopy (EDX) plot of comparative uncoated glass vial samples which undergo vial scratch testing as discussed in the Examples.

FIG. 50 is a schematic depiction of a vial scratch test used to evaluate and characterize particle generation, according to one or more embodiments shown and described herein.

FIG. 51 is a particle distribution determined from a debris field produced from 1 mm scratches on uncoated vial samples at a scratch speed of 60 mm/min and scratch load between 1 to 30 N,

FIG. 52 is a particle distribution from a debris field produced from 1 mm scratches on uncoated vial samples at a scratch load of 30 N and a scratch velocity in the range of 6 to 120 mm/min.

FIG. 53 is an SEM image of a debris field produced as uncoated vial samples are subjected to a 30 N applied scratch load.

FIG. 54 is a Weibull plot showing the durability of coated glass cartridge samples following multiple scratches at loads of 1 to 30 N, according to one or more embodiments shown and described herein.

FIG. 55 is a Weibull plot showing the durability of a comparative silicone coated cartridge samples following multiple scratches at loads of 1 to 30 N.

FIG. 56 is an SEM image of a debris field produced when subjecting uncoated vials to a filling line trial.

FIG. 57 is a schematic illustration depicting moving vials sliding past vials constrained by the inner guide on a rotary accumulator table.

FIG. 58 is a schematic illustration depicting a screw feeder delivering vials that impact stationary vials on a stationary plate.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of pharmaceutical glass containers, examples of which are schematically depicted in the figures and described below. Such coated glass articles may be glass containers suitable for use in various packaging applications including, without limitation, as pharmaceutical packages. These pharmaceutical packages may or may not contain a pharmaceutical composition. Various embodiments of the low-friction coatings, glass articles with low-friction coatings, and methods for forming the same will be described in further detail herein with specific reference to the appended drawings. While embodiments of the low-friction coatings described herein are applied to the outer surface of a glass container, it should be understood that the low-friction coatings described may be used as a coating on a wide variety of materials, including non-glass materials and on substrates other than containers including, without limitation, glass display panels and the like.

Generally, a low-friction coating may be applied to a surface of a glass article, such as a container that may be used as a pharmaceutical package. The low-friction coating may provide advantageous properties to the coated glass article such as a reduced coefficient of friction and increased damage resistance. The reduced coefficient of friction may impart improved strength and durability to the glass article by mitigating frictive damage to the glass. Further, the low-friction coating may maintain the aforementioned improved strength and durability characteristics following exposure to elevated temperatures and other conditions, such as those experienced during packaging and pre-packaging steps utilized in packaging pharmaceuticals, such as, for example, depyrogenation, autoclaving and the like. Accordingly, the low-friction coatings and glass articles with the low-friction coating are thermally stable.

The low-friction coating may generally comprise a coupling agent, such as a silane, and a polymer chemical composition, such as a polyimide. In some embodiments, the coupling agent may be disposed in a coupling agent layer positioned on the surface of the glass article and the polymer chemical composition may be disposed in a polymer layer positioned on the coupling agent layer. In other embodiments, the coupling agent and the polymer chemical composition may be mixed in a single layer.

FIG. 1 schematically depicts a cross section of a coated glass article, specifically a coated glass container 100. The coated glass container 100 comprises a glass body 102 and a low-friction coating 120. The glass body 102 has a glass container wall 104 extending between an exterior surface 108 (i.e., a first surface) and an interior surface 110 (i.e., a second surface). The interior surface 110 of the glass container wall 104 defines an interior volume 106 of the coated glass container 100. A low-friction coating 120 is positioned on at least a portion of the exterior surface 108 of the glass body 102. In some embodiments, the low-friction coating 120 may be positioned on substantially the entire exterior surface 108 of the glass body 102. The low-friction coating 120 has an outer surface 122 and a glass body contacting surface 124 at the interface of the glass body 102 and the low-friction coating 120. The low-friction coating 120 may be bonded to the glass body 102 at the exterior surface 108.

In one embodiment, the coated glass container 100 is a pharmaceutical package. For example, the glass body 102 may be in the shape of a vial, ampoule, ampul, bottle, flask, phial, beaker, bucket, carafe, vat, syringe body, or the like. The coated glass container 100 may be used for containing any composition, and in one embodiment, may be used for containing a pharmaceutical composition. A pharmaceutical composition may include any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease. Examples of pharmaceutical compositions include, but are not limited to, medicines, drugs, medications, medicaments, remedies, and the like. The pharmaceutical composition may be in the form of a liquid, solid, gel, suspension, powder, or the like.

Now referring to FIGS. 1 and 2, in one embodiment, the low-friction coating 120 comprises a bi-layered structure. FIG. 2 shows a cross section of a coated glass container 100, where the low-friction coating comprises a polymer layer 170 and a coupling agent layer 180. A polymer chemical composition may be contained in polymer layer 170 and a coupling agent may be contained in a coupling agent layer 180. The coupling agent layer 180 may be in direct contact with the exterior surface 108 of the glass container wall 104. The polymer layer 170 may be in direct contact with the coupling agent layer 180 and may form the outer surface 122 of the low-friction coating 120. In some embodiments the coupling agent layer 180 is bonded to the glass wall 104 and the polymer layer 170 is bonded to the coupling agent layer 180 at an interface 174. However, it should be understood that, in some embodiments, the low-friction coating 120 may not include a coupling agent, and the polymer chemical composition may be disposed in a polymer layer 170 in direct contact with the exterior surface 108 of the of the glass container wall 104. In another embodiment, the polymer chemical composition and coupling agent may be substantially mixed in a single layer. In some other embodiments, the polymer layer may be positioned over the coupling agent layer, meaning that the polymer layer 170 is in an outer layer relative to the coupling agent layer 180, and the glass wall 104. As used herein, a first layer positioned “over” a second layer means that the first layer could be in direct contact with the second layer or separated from the second layer, such as with a third layer disposed between the first and second layers.

Referring now to FIG. 3, in one embodiment, the low-friction coating 120 may further comprise an interface layer 190 positioned between the coupling agent layer 180 and the polymer layer 170. The interface layer 190 may comprise one or more chemical compositions of the polymer layer 170 bound with one or more of the chemical compositions of the coupling agent layer 180. In this embodiment, the interface of the coupling agent layer and polymer layer forms an interface layer 190 where bonding occurs between the polymer chemical composition and the coupling agent. However, it should be understood that in some embodiments, there may be no appreciable layer at the interface of the coupling agent layer 180 and polymer layer 170 where the polymer and coupling agent are chemically bound to one another as described above with reference to FIG. 2.

The low-friction coating 120 applied to the glass body 102 may have a thickness of less than about 100 μm or even less than or equal to about 1 μm. In some embodiments, the thickness of the low-friction coating 120 may be less than or equal to about 100 nm thick. In other embodiments, the low-friction coating 120 may be less than about 90 nm thick, less than about 80 nm thick, less than about 70 nm thick, less than about 60 nm thick, less than about 50 nm, or even less than about 25 nm thick. In some embodiments, the low-friction coating 120 may not be of uniform thickness over the entirety of the glass body 102. For example, the coated glass container 100 may have a thicker low-friction coating 120 in some areas, due to the process of contacting the glass body 102 with one or more coating solutions that form the low-friction coating 120. In some embodiments, the low-friction coating 120 may have a non-uniform thickness. For example, the coating thickness may be varied over different regions of a coated glass container 100, which may promote protection in a selected region.

In embodiments which include at least two layers, such as the polymer layer 170, interface layer 190, and/or coupling agent layer 180, each layer may have a thickness of less than about 100 μm or even less than or equal to about 1 μm. In some embodiments, the thickness of each layer may be less than or equal to about 100 nm. In other embodiments, each layer may be less than about 90 nm thick, less than about 80 nm thick, less than about 70 nm thick, less than about 60 nm thick, less than about 50 nm, or even less than about 25 nm thick.

As noted herein, in some embodiments, the low-friction coating 120 comprises a coupling agent. The coupling agent may improve the adherence or bonding of the polymer chemical composition to the glass body 102, and is generally disposed between the glass body 102 and the polymer chemical composition or mixed with the polymer chemical composition. Adhesion, as used herein, refers to the strength of adherence or bonding of the low friction coating prior to and following a treatment applied to the coated glass container, such as a thermal treatment. Thermal treatments include, without limitation, autoclaving, depyrogenation, lyophilization, or the like.

In one embodiment, the coupling agent may comprise at least one silane chemical composition. As used herein, a “silane” chemical composition is any chemical composition comprising a silane moiety, including functional organosilanes, as well as silanols formed from silanes in aqueous solutions. The silane chemical compositions of the coupling agent may be aromatic or aliphatic. In some embodiments, the at least one silane chemical composition may comprise an amine moiety, such as a primary amine moiety or a secondary amine moiety. Furthermore, the coupling agent may comprise hydrolysates and/or oligomers of such silanes, such as one or more silsesquioxane chemical compositions that are formed from the one or more silane chemical compositions. The silsesquioxane chemical compositions may comprise a full cage structure, partial cage structure, or no cage structure.

The coupling agent may comprise any number of different chemical compositions, such as one chemical composition, two different chemical compositions, or more than two different chemical compositions including oligomers formed from more than one monomeric chemical composition. In one embodiment, the coupling agent may comprise at least one of (1) a first silane chemical composition, hydrolysate thereof, or oligomer thereof, and (2) a chemical composition formed from the oligomerization of at least the first silane chemical composition and a second silane chemical composition. In another embodiment, the coupling agent comprises a first and second silane. As used herein, a “first” silane chemical composition and a “second” silane chemical composition are silanes having different chemical compositions. The first silane chemical composition may be an aromatic or an aliphatic chemical composition, may optionally comprise an amine moiety, and may optionally be an alkoxysilane. Similarly, the second silane chemical composition may be an aromatic or an aliphatic chemical composition, may optionally comprise an amine moiety, and may optionally be an alkoxysilane.

For example, in one embodiment, only one silane chemical composition is applied as the coupling agent. In such an embodiment, the coupling agent may comprise a silane chemical composition, hydrolysate thereof, or oligomer thereof.

In another embodiment, multiple silane chemical compositions may be applied as the coupling agent. In such an embodiment, the coupling agent may comprise at least one of (1) a mixture of the first silane chemical composition and a second silane chemical composition, and (2) a chemical composition formed from the oligomerization of at least the first silane chemical composition and the second silane chemical composition.

Referring to the embodiments described above, the first silane chemical composition, second silane chemical composition, or both, may be aromatic chemical compositions. As used herein, an aromatic chemical composition contains one or more six-carbon rings characteristic of the benzene series and related organic moieties. The aromatic silane chemical composition may be an alkoxysilane such as, but not limited to, a dialkoxysilane chemical composition, hydrolysate thereof, or oligomer thereof, or a trialkoxysilane chemical composition, hydrolysate thereof, or oligomer thereof. In some embodiments, the aromatic silane may comprise an amine moiety, and may be an alkoxysilane comprising an amine moiety. In another embodiment, the aromatic silane chemical composition may be an aromatic alkoxysilane chemical composition, an aromatic acyloxysilane chemical composition, an aromatic halogen silane chemical composition, or an aromatic aminosilane chemical composition. In another embodiment, the aromatic silane chemical composition may be selected from the group consisting of aminophenyl, 3-(m-aminophenoxy) propyl, N-phenylaminopropyl, or (chloromethy) phenyl substituted alkoxy, acyloxy, halogen, or amino silanes. For example, the aromatic alkoxysilane may be, but is not limited to, aminophenyltrimethoxy silane (sometimes referred to herein as “APhTMS”), aminophenyldimethoxy silane, aminophenyltriethoxy silane, aminophenyldiethoxy silane, 3-(m-aminophenoxy) propyltrimethoxy silane, 3-(m-aminophenoxy) propyldimethoxy silane, 3-(m-aminophenoxy) propyltriethoxy silane, 3-(m-aminophenoxy) propyldiethoxy silane, N-phenylaminopropyltrimethoxysilane, N-phenylaminopropyldimethoxysilane, N-phenylaminopropyltriethoxysilane, N-phenylaminopropyldiethoxysilane, hydrolysates thereof, or oligomerized chemical composition thereof. In an exemplary embodiment, the aromatic silane chemical composition may be aminophenyltrimethoxy silane.

Referring again to the embodiments described above, the first silane chemical composition, second silane chemical composition, or both, may be aliphatic chemical compositions. As used herein, an aliphatic chemical composition is non-aromatic, such as a chemical composition having an open chain structure, such as, but not limited to, alkanes, alkenes, and alkynes. For example, in some embodiments, the coupling agent may comprise a chemical composition that is an alkoxysilane and may be an aliphatic alkoxysilane such as, but not limited to, a dialkoxysilane chemical composition, a hydrolysate thereof, or an oligomer thereof, or a trialkoxysilane chemical composition, a hydrolysate thereof, or an oligomer thereof. In some embodiments, the aliphatic silane may comprise an amine moiety, and may be an alkoxysilane comprising an amine moiety, such as an aminoalkyltrialkoxysilane. In one embodiment, an aliphatic silane chemical composition may be selected from the group consisting of 3-aminopropyl, N-(2-aminoethyl)-3-aminopropyl, vinyl, methyl, N-phenylaminopropyl, (N-phenylamino)methyl, N-(2-Vinylbenzylaminoethyl)-3-aminopropyl substituted alkoxy, acyloxy, halogen, or amino silanes, hydrolysates thereof, or oligomers thereof. Aminoalkyltrialkoxysilanes, include, but are not limited to, 3-aminopropyltrimethoxy silane (sometimes referred to herein as “GAPS”), 3-aminopropyldimethoxy silane, 3-aminopropyltriethoxy silane, 3-aminopropyldiethoxy silane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyldimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropyldiethoxysilane, hydrolysates thereof, and oligomerized chemical composition thereof. In other embodiments, the aliphatic alkoxysilane chemical composition may not contain an amine moiety, such as an alkyltrialkoxysilane or alkylbialkoxysilane. Such alkyltrialkoxysilanes or alkylbialkoxysilanes include, but are not limited to, vinyltrimethoxy silane, vinyldimethoxy silane, vinyltriethoxy silane, vinyldiethoxy silane, methyltrimethoxysilane, methyltdimethoxysilane, methyltriethoxysilane, methyldiethoxysilane, hydrolysates thereof, or oligomerized chemical composition thereof. In an exemplary embodiment, the aliphatic silane chemical composition is 3-aminopropyltrimethoxy silane.

It has been found that forming the coupling agent from combinations of different chemical compositions, particularly combinations of silane chemical compositions, may improve the thermal stability of the low-friction coating 120. For example, it has been found that combinations of aromatic silanes and aliphatic silanes, such as those described above, improve the thermal stability of the low-friction coating, thereby producing a coating which retains its the mechanical properties, such as coefficient of friction and adhesion performance following a heat treatment at elevated temperatures. Accordingly, in one embodiment the coupling agent comprises a combination of aromatic and aliphatic silanes. In these embodiments, the ratio of aliphatic silanes to aromatic silanes (aliphatic:aromatic) may be from about 1:3 to about 1:0.2. If the coupling agent comprises two or more chemical composition, such as at least an aliphatic silane and an aromatic silane, the ratio by weight of the two chemical compositions may be any ratio, such as a weight ratio of a first silane chemical composition to a second silane chemical composition (first silane:second silane) of about 0.1:1 to about 10:1. For example, in some embodiments the ration may be from 0.5:1 to about 2:1, such as 2:1, 1:1, 0.5:1. In some embodiments, the coupling agent may comprise combinations of multiple aliphatic silanes and/or multiple aromatic silanes, which could be applied to the glass container in one or multiple steps with or without organic or inorganic fillers. In some embodiments, the coupling agent comprises oligomers, such as silsesquioxanes, formed from both the aliphatic and aromatic silanes.

In an exemplary embodiment, the first silane chemical composition is an aromatic silane chemical composition and the second silane chemical composition is an aliphatic silane chemical composition. In one exemplary embodiment, the first silane chemical composition is an aromatic alkoxysilane chemical composition comprising at least one amine moiety and the second silane chemical composition is an aliphatic alkoxysilane chemical composition comprising at least one amine moiety. In another exemplary embodiment, the coupling agent comprises an oligomer of one or more silane chemical compositions, wherein the oligomer is a silsesquioxane chemical composition and at least one of the silane chemical compositions comprises at least one aromatic moiety and at least one amine moiety. In one particular exemplary embodiment, the first silane chemical composition is aminophenyltrimethoxy silane and the second silane chemical composition is 3-aminopropyltrimethoxy silane. The ratio of aromatic silane to aliphatic silane may be about 1:1. In another particular exemplary embodiment, the coupling agent comprises an oligomer formed from aminophenyltrimethoxy and 3-aminopropyltrimethoxy. In another embodiment, the coupling agent may comprise both a mixture of aminophenyltrimethoxy and 3-aminopropyltrimethoxy and oligomers formed from the two.

In another embodiment, the coupling agent may comprise a chemical composition that is an aminoalkylsilsesquioxane. In one embodiment the coupling agent comprises aminopropylsilsesquioxane (APS) oligomer (commercially available as an aqueous solution from Gelest).

In one embodiment, the aromatic silane chemical composition is a chlorosilane chemical composition.

In another embodiment, the coupling agent may comprise chemical composition that are hydrolyzed analogs of aminoalkoxysilanes such as, but not limited to, (3-Aminopropyl)silantriol, N-(2-Aminoethyl)-3-aminopropyl-silantriol and/or mixtures thereof.

In another embodiment, the coupling agent may be an inorganic material, such as metal and/or a ceramic film. Non-limiting examples of suitable inorganic materials used as the coupling agent include titanates, zirconates, tin, titanium, and/or oxides thereof.

In one embodiment, the coupling agent is applied to the exterior surface 108 of the glass body 102 by contacting with the diluted coupling agent by a submersion process. The coupling agent may be mixed in a solvent when applied to the glass body 102. In another embodiment, the coupling agent may be applied to the glass body 102 by a spray or other suitable means. The glass body 102 with coupling agent may then be dried at around 120° C. for about 15 min, or any time and temperature sufficient to adequately liberate the water and/or other organic solvents present on the exterior surface 108 of the glass container wall 104.

Referring to FIG. 2, in one embodiment, the coupling agent is positioned on the glass container as a coupling agent layer 180 and is applied as a solution comprising about 0.5 wt % of a first silane and about 0.5 wt % of a second silane (total 1 wt % silane) mixed with at least one of water and an organic solvent, such as, but not limited to, methanol. However, it should be understood that the total silane concentration in the solution may be more or less than about 1 wt %, such as from about 0.1 wt % to about 10 wt %, from about 0.3 wt % to about 5.0 wt %, or from about 0.5 wt % to about 2.0 wt %. For example, in one embodiment, the weight ratio of organic solvent to water (organic solvent:water) may be from about 90:10 to about 10:90, and, in one embodiment, may be about 75:25. The weight ratio of silane to solvent may affect the thickness of the coupling agent layer, where increased percentages of silane chemical composition in the coupling agent solution may increase the thickness of the coupling agent layer 180. However, it should be understood that other variables may affect the thickness of the coupling agent layer 180 such as, but not limited, the specifics of the dip coating process, such as the withdraw speed from the bath. For example, a faster withdraw speed may form a thinner coupling agent layer 180.

In another embodiment, the coupling agent layer 180 may be applied as a solution comprising 0.1 vol % of a commercially available aminopropylsilsesquioxane oligomer. Coupling agent layer solutions of other concentrations may be used, including but not limited to, 0.01-10.0 vol % aminopropylsilsesquioxane oligomer solutions.

As noted herein, the low friction coating also includes a polymer chemical composition. The polymer chemical composition may be a thermally stable polymer or mixture of polymers, such as but not limited to, polyimides, polybenzimidazoles, polysulfones, polyetheretheketones, polyetherimides, polyamides, polyphenyls, polybenzothiazoles, polybenzoxazoles, polybisthiazoles, and polyaromatic heterocyclic polymers with and without organic or inorganic fillers. The polymer chemical composition may be formed from other thermally stable polymers, such as polymers that do not degrade at temperatures in the range of from 200° C. to 400° C., including 250° C., 300° C., and 350° C. These polymers may be applied with or without a coupling agent.

In one embodiment, the polymer chemical composition is a polyimide chemical composition. If the low-friction coating 120 comprises a polyimide, the polyimide composition may be derived from a polyamic acid, which is formed in a solution by the polymerization of monomers. One such polyamic acid is NOVASTRAT® 800 (commercially available from NeXolve). A curing step imidizes the polyamic acid to form the polyimide. The polyamic acid may be formed from the reaction of a diamine monomer, such as a diamine, and an anhydride monomer, such as a dianhydride. As used herein, polyimide monomers are described as diamine monomers and dianhydride monomers. However, it should be understood that while a diamine monomer comprises two amine moieties, in the description that follows, any monomer comprising at least two amine moieties may be suitable as a diamine monomer. Similarly, it should be understood that while a dianhydride monomer comprises two anhydride moieties, in the description that follows any monomer comprising at least two anhydride moieties may be suitable as a dianhydride monomer. The reaction between the anhydride moieties of the anhydride monomer and amine moieties of the diamine monomer forms the polyamic acid. Therefore, as used herein, a polyimide chemical composition that is formed from the polymerization of specified monomers refers to the polyimide that is formed following the imidization of a polyamic acid that is formed from those specified monomers. Generally, the molar ratio of the total anhydride monomers and diamine monomers may be about 1:1. While the polyimide may be formed from only two distinct chemical compositions (one anhydride monomer and one diamine monomer), at least one anhydride monomer may be polymerized and at least one diamine monomer may be polymerized to from the polyimide. For example, one anhydride monomer may be polymerized with two different diamine monomers. Any number of monomer specie combinations may be used. Furthermore, the ratio of one anhydride monomer to a different anhydride monomer, or one or more diamine monomer to a different diamine monomer may be any ratio, such as between about 1:0.1 to 0.1:1, such as about 1:9, 1:4, 3:7, 2:3:, 1:1, 3:2, 7:3, 4:1 or 1:9.

The anhydride monomer from which, along with the diamine monomer, the polyimide is formed may comprise any anhydride monomer. In one embodiment, the anhydride monomer comprises a benzophenone structure. In an exemplary embodiment, benzophenone-3,3′,4,4′-tetracarboxylic dianhydride may be at least one of the anhydride monomer from which the polyimide is formed. In other embodiments, the diamine monomer may have an anthracene structure, a phenanthrene structure, a pyrene structure, or a pentacene structure, including substituted versions of the above mentioned dianhydrides.

The diamine monomer from which, along with the anhydride monomer, the polyimide is formed may comprise any diamine monomer. In one embodiment, the diamine monomer comprises at least one aromatic ring moiety. FIGS. 4 and 5 show examples of diamine monomers that, along with one or more selected anhydride monomer, may form the polyimide comprising the polymer chemical composition. The diamine monomer may have one or more carbon molecules connecting two aromatic ring moieties together, as shown in FIG. 5, wherein R of FIG. 5 corresponds to an alkyl moiety comprising one or more carbon atoms. Alternatively, the diamine monomer may have two aromatic ring moieties that are directly connected and not separated by at least one carbon molecule, as shown in FIG. 4. The diamine monomer may have one or more alkyl moieties, as represented by R′ and R″ in FIGS. 4 and 5. For example, in FIGS. 4 and 5, R′ and R″ may represent an alkyl moiety such as methyl, ethyl, propyl, or butyl moieties, connected to one or more aromatic ring moieties. For example, the diamine monomer may have two aromatic ring moieties wherein each aromatic ring moiety has an alkyl moiety connected thereto and adjacent an amine moiety connected to the aromatic ring moiety. It should be understood that R′ and R″, in both FIGS. 4 and 5, may be the same chemical moiety or may be different chemical moieties. Alternatively, R′ and/or R″, in both FIGS. 4 and 5, may include a hydrogen group instead of an alkyl moiety.

Two different chemical compositions of diamine monomers may form the polyimide. In one embodiment, a first diamine monomer comprises two aromatic ring moieties that are directly connected and not separated by a linking carbon molecule, and a second diamine monomer comprises two aromatic ring moieties that are connected with at least one carbon molecule connecting the two aromatic ring moieties. In one exemplary embodiment, the first diamine monomer, the second diamine monomer, and the anhydride monomer have a molar ratio (first diamine monomer:second diamine monomer:anhydride monomer) of about 0.465:0.035:0.5. However, the ratio of the first diamine monomer and the second diamine monomer may vary in a range of about 0.01:0.49 to about 0.40:0.10, while the anhydride monomer ratio remains at about 0.5.

In one embodiment, the polyimide composition is formed from the polymerization of at least a first diamine monomer, a second diamine monomer, and an anhydride monomer, wherein the first and second diamine monomers are different chemical compositions. In one embodiment, the anhydride monomer is a benzophenone, the first diamine monomer comprises two aromatic rings directly bonded together, and the second diamine monomer comprises two aromatic rings bonded together with at least one carbon molecule connecting the first and second aromatic rings. The first diamine monomer, the second diamine monomer, and the anhydride monomer may have a molar ratio (first diamine monomer:second diamine monomer:anhydride monomer) of about 0.465:0.035:0.5.

In an exemplary embodiment, the first diamine monomer is ortho-Tolidine, the second diamine monomer is 4,4′-methylene-bis(2-methylaniline), and the anhydride monomer is benzophenone-3,3′,4,4′-tetracarboxylic dianhydride. The first diamine monomer, the second diamine monomer, and the anhydride monomer may have a molar ratio (first diamine monomer:second diamine monomer:anhydride monomer) of about 0.465:0.035:0.5.

In some embodiments, the polyimide may be formed from the polymerization of one or more of: bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic dianhydride, cyclopentane-1,2,3,4-tetracarboxylic 1,2;3,4-dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, 4arH,8acH)-decahydro-1t,4t:5c,8c-dimethanonaphthalene-2t,3t,6c,7c-tetracarboxylic 2,3:6,7-dianhydride, 2c,3c,6c,7c-tetracarboxylic 2,3:6,7-dianhydride, 5-endo-carboxymethylbicyclo[2.2.1]-heptane-2-exo,3-exo,5-exo-tricarboxylic acid 2,3:5,5-dianhydride, 5-(2,5-Dioxotetrahydro-3-furanyl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride, isomers of Bis(aminomethyl)bicyclo[2.2.1]heptane, or 4,4′-Methylenebis(2-methylcyclohexylamine), Pyromellitic dianhydride (PMDA) 3,3′,4,4′-Biphenyl dianhydride (4,4′-BPDA), 3,3′, 4,4′-Benzophenone dianhydride (4,4′-BTDA), 3,3′, 4,4′-Oxydiphthalic anhydride (4,4′-ODPA), 1,4-Bis(3,4-dicarboxyl-phenoxy)benzene dianhydride (4,4′-HQDPA), 1,3-Bis (2,3-dicarboxyl-phenoxy)benzene dianhydride (3,3′-HQDPA), 4,4′-Bis(3,4-dicarboxyl phenoxyphenyl)-isopropylidene dianhydride (4,4′-BPADA), 4,4′-(2,2,2-Trifluoro-1-pentafluorophenylethylidene) diphthalic dianhydride (3FDA), 4,4′-Oxydianiline (ODA), m-Phenylenediamine (MPD), p-Phenylenediamine (PPD), m-Toluenediamine (TDA), 1,4-Bis(4-aminophenoxy)benzene (1,4,4-APB), 3,3′-(m-Phenylenebis(oxy))dianiline (APB), 4,4′-Diamino-3,3′-dimethyldiphenylmethane (DMMDA), 2,2′-Bis(4-(4-aminophenoxy)phenyl)propane (BAPP), 1,4-Cyclohexanediamine 2,2′-Bis[4-(4-aminophenoxy) phenyl]hexafluoroisopropylidene (4-BDAF), 6-Amino-1-(4′-aminophenyl)-1,3,3-trimethylindane (DAPI), Maleic anhydride (MA), Citraconic anhydride (CA), Nadic anhydride (NA), 4-(Phenylethynyl)-1,2-benzenedicarboxylic acid anhydride (PEPA), 4,4′-diaminobenzanilide (DABA), 4,4′-(hexafluoroisopropylidene)di-phthalicanhydride (6-FDA), Pyromellitic dianhydride, benzophenone-3,3′,4,4′-tetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 4,4′-(hexafluoroisopropylidene)diphthalic anhydride, perylene-3,4,9,10-tetracarboxylic dianhydride, 4,4′-oxydiphthalic anhydride, 4,4′-(hexafluoroisopropylidene)diphthalic anhydride, 4,4′-(4,4′-Isopropylidenediphenoxy)bis(phthalic anhydride), 1,4,5,8-Naphthalenetetracarboxylic dianhydride, 2,3,6,7-Naphthalenetetracarboxylic dianhydride, as well as those materials described in U.S. Pat. No. 7,619,042, U.S. Pat. No. 8,053,492, U.S. Pat. No. 4,880,895, U.S. Pat. No. 6,232,428, U.S. Pat. No. 4,595,548, WO Pub. No. 2007/016516, U.S. Pat. Pub. No. 2008/0214777, U.S. Pat. No. 6,444,783, U.S. Pat. No. 6,277,950, and U.S. Pat. No. 4,680,373. FIG. 6 depicts the chemical structure of some suitable monomers that may be used to form a polyimide coating applied to the glass body 102. In another embodiment, the polyamic acid solution from which the polyimide is formed may comprise poly (pyromellitic dianhydride-co-4,4′-oxydianiline) amic acid (commercially available from Aldrich).

In another embodiment, the polymer chemical composition may comprise a fluoropolymer. The fluoropolymer may be a copolymer wherein both monomers are highly fluorinated. Some of the monomers of the fluoropolymer may be fluoroethylene. In one embodiment, the polymer chemical composition comprises an amorphous fluoropolymer, such as, but not limited to, Teflon AF (commercially available from DuPont). In another embodiment, the polymer chemical composition comprises perfluoroalkoxy (PFA) resin particles, such as, but not limited to, Teflon PFA TE-7224 (commercially available from DuPont).

In another embodiment, the polymer chemical composition may comprise a silicone resin. The silicone resin may be a highly branched 3-dimensional polymer which is formed by branched, cage-like oligosiloxanes with the general formula of R_nSi(X)_mO_y, where R is a non reactive substituent, usually methyl or phenyl, and X is OH or H. While not wishing to be bound by theory, it is believed that curing of the resin occurs through a condensation reaction of Si-OH moieties with a formation of Si—O—Si bonds. The silicone resin may have at least one of four possible functional siloxane monomeric units, which include M-resins, D-resins, T-resins, and Q-resins, wherein M-resins refer to resins with the general formula R₃SiO, D-resins refer to resins with the general formula R₂SiO₂, T-resins refer to resins with the general formula RSiO₃, and Q-resins refer to resins with the general formula SiO₄(a fused quartz). In some embodiments resins are made of D and T units (DT resins) or from M and Q units (MQ resins). In other embodiments, other combinations (MDT, MTQ, QDT) are also used.

In one embodiment, the polymer chemical composition comprises phenylmethyl silicone resins due to their higher thermal stability compared to methyl or phenyl silicone resins. The ratio of phenyl to methyl moieties in the silicone resins may be varied in the polymer chemical composition. In one embodiment, the ratio of phenyl to methyl is about 1.2. In another embodiment, the ratio of phenyl to methyl is about 0.84. In other embodiments, the ratio of phenyl to methyl moieties may be about 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.3, 1.4, or 1.5. In one embodiment, the silicone resin is DC 255 (commercially available from Dow Corning). In another embodiment, the silicone resin is DC806A (commercially available from Dow Corning). In other embodiments, the polymer chemical composition may comprise any of the DC series resins (commercially available for Dow Corning), and/or Hardsil Series AP and AR resins (commercially available from Gelest). The silicone resins can be used without coupling agent or with coupling agent.

In another embodiment, the polymer chemical composition may comprise silsesquioxane-based polymers, such as but not limited to T-214 (commercially available from Honeywell), SST-3M01 (commercially available from Gelest), POSS Imiclear (commercially available from Hybrid Plastics), and FOX-25 (commercially available from Dow Corning). In one embodiment, the polymer chemical composition may comprise a silanol moiety.

Referring again to FIGS. 1 and 2, the low-friction coating 120 may be applied in a multi stage process, wherein the glass body 102 is contacted with the coupling agent solution to form the coupling agent layer 180 (as described above), and dried, and then contacted with a polymer chemical composition solution, such as a polymer or polymer precursor solution, such as by a submersion process, or alternatively, the polymer chemical composition layer 170 may be applied by a spray or other suitable means, and dried, and then cured at high temperatures. Alternatively, if a coupling agent layer 180 is not used, the polymer chemical composition of the polymer layer 170 may be directly applied to the exterior surface 108 of the glass body 102. In another embodiment, the polymer chemical composition and the coupling agent may be mixed in the low-friction coating 120, and a solution comprising the polymer chemical composition and the coupling agent may be applied to the glass body 102 in a single coating step.

In one embodiment, the polymer chemical composition comprises a polyimide wherein a polyamic acid solution is applied over the coupling agent layer 180. In other embodiments, a polyamic acid derivative may be used, such as, for example, a polyamic acid salt, a polyamic acid ester, or the like. In one embodiment, the polyamic acid solution may comprise a mixture of 1 vol % polyamic acid and 99 vol % organic solvent. The organic solvent may comprise a mixture of toluene and at least one of N,N-Dimethylacetamide (DMAc), N,N-Dimethylformamide (DMF), and 1-Methyl-2-pyrrolidinone (NMP) solvents, or a mixture thereof. In one embodiment the organic solvent solution comprises about 85 vol % of at least one of DMAc, DMF, and NMP, and about 15 vol % toluene. However, other suitable organic solvents may be used. The coated glass container 100 may then be dried at around 150° C. for about 20 minutes, or any time and temperature sufficient to adequately liberate the organic solvent present in the low-friction coating 120.

In the layered low-friction coating embodiment, after the glass body 102 is contacted with the coupling agent to form the coupling agent layer 180 and polyamic acid solution to form the polymer layer 170, the coated glass container 100 may be cured at high temperatures. The coated glass container 100 may be cured at 300° C. for about 30 minutes or less, or may be cured at a temperature higher than 300° C., such as at least 320° C., 340° C., 360° C., 380° C., or 400° C. for a shorter time. It is believed, without being bound by theory, that the curing step imidizes the polyamic acid in the polymer layer 170 by reaction of carboxylic acid moieties and amide moieties to create a polymer layer 170 comprising a polyimide. The curing may also promote bonds between the polyimide and the coupling agent. The coated glass container 100 is then cooled to room temperature.

Furthermore, without being bound by limitation, it is believed that the curing of the coupling agent, polymer chemical composition, or both, drives off volatile materials, such as water and other organic molecules. As such, these volatile materials that are liberated during curing are not present when the article, if used as a container, is thermally treated (such as for depyrogenation) or contacted by the material in which it is a package for, such as a pharmaceutical. It should be understood that the curing processes described herein are separate heating treatments than other heating treatments described herein, such as those heating treatments similar or identical to processes in the pharmaceutical packaging industry, such as depyrogenation or the heating treatments used to define thermal stability, as described herein.

The glass containers to which the low-friction coating 120 may be applied may be formed from a variety of different glass compositions. The specific composition of the glass article may be selected according to the specific application such that the glass has a desired set of physical properties.

The glass containers may be formed from a glass composition which has a coefficient of thermal expansion in the range from about 25×10⁻⁷/° C. to 80×10⁻⁷/° C. For example, in some embodiments described herein, the glass body 102 is formed from alkali aluminosilicate glass compositions which are amenable to strengthening by ion exchange. Such compositions generally include a combination of SiO₂, Al₂O₃, at least one alkaline earth oxide, and one or more alkali oxides, such as Na₂O and/or K₂O. In some of these embodiments, the glass composition may be free from boron and compounds containing boron. In some other embodiments the glass compositions may further comprise minor amounts of one or more additional oxides such as, for example, SnO₂, ZrO₂, ZnO, TiO₂, As₂O₃, or the like. These components may be added as fining agents and/or to further enhance the chemical durability of the glass composition. In another embodiment, the glass surface may comprise a metal oxide coating comprising SnO₂, ZrO₂, ZnO, TiO₂, As₂O₃, or the like

In some embodiments described herein, the glass body 102 is strengthened such as by ion-exchange strengthening, herein referred to as “ion-exchanged glass”. For example, the glass body 102 may have a compressive stress of greater than or equal to about 300 MPa or even greater than or equal to about 350 MPa. In some embodiments, the compressive stress may be in a range from about 300 MPa to about 900 MPa. However, it should be understood that, in some embodiments, the compressive stress in the glass may be less than 300 MPa or greater than 900 MPa. In some embodiments, the glass body 102 may have a depth of layer greater than or equal to 20 μm. The compressive stress may be measured at the outer surface or the inner surface of the glass body, and the depth of layer may be measured from the outer surface or the inner surface inward toward the bulk of the glass body. In some of these embodiments, the depth of layer may be greater than 50 μm or even greater than or equal to 75 μm. In still other embodiments, the depth of the layer may be up to or greater than 100 μm. The ion-exchange strengthening may be performed in a molten salt bath maintained at temperatures from about 350° C. to about 500° C. To achieve the desired compressive stress, the glass container (uncoated) may be immersed in the salt bath for less than about 30 hours or even less than about 20 hours. For example, in one embodiment the glass container is immersed in a 100% KNO₃salt bath at 450° C. for about 8 hours.

In one particularly exemplary embodiment, the glass body 102 may be formed from an ion exchangeable glass composition described in U.S. Pat. No. 8,551,898 and entitled “Glass Compositions with Improved Chemical and Mechanical Durability” assigned to Corning, Incorporated.

However it should be understood that the coated glass containers 100 described herein may be formed from other glass compositions including, without limitation, ion-exchangeable glass compositions and non-ion exchangeable glass compositions. For example, in some embodiments the glass container may be formed from Type 1B glass compositions such as, for example, Schott Type 1B aluminosilicate glass.

In some embodiments described herein, the glass article may be formed from a glass composition which meets the criteria for pharmaceutical glasses described by regulatory agencies such as the USP (United States Pharmacopoeia), the EP (European Pharmacopeia), and the JP (Japanese Pharmacopeia) based on their hydrolytic resistance. Per USP 660 and EP 7, borosilicate glasses meet the Type I criteria and are routinely used for parenteral packaging. Examples of borosilicate glass include, but not limited to Corning® Pyrex® 7740, 7800 and Wheaton 180, 200, and 400, Schott Duran, Schott Fiolax, KIMAX® N-51A, Gerrescheimer GX-51 Flint and others. Soda-lime glass meets the Type III criteria and is acceptable in packaging of dry powders which are subsequently dissolved to make solutions or buffers. Type III glasses are also suitable for packaging liquid formulations that prove to be insensitive to alkali. Examples of Type III soda lime glass include Wheaton 800 and 900. De-alkalized soda-lime glasses have higher levels of sodium hydroxide and calcium oxide and meet the Type II criteria. These glasses are less resistant to leaching than Type I glasses but more resistant than Type III glasses. Type II glasses can be used for products that remain below a pH of 7 for their shelf life. Examples include ammonium sulfate treated soda lime glasses. These pharmaceutical glasses have varied chemical compositions and have a coefficient of linear thermal expansion (CTE) in the range of 20-85×10⁻⁷° C.⁻¹.

When the coated glass articles described herein are glass containers, the glass body 102 of the coated glass containers 100 may take on a variety of different forms. For example, the glass bodies described herein may be used to form coated glass containers 100 such as vials, ampoules, cartridges, syringe bodies and/or any other glass container for storing pharmaceutical compositions. Moreover, the ability to chemically strengthen the glass containers prior to coating can be utilized to further improve the mechanical durability of the glass containers. Accordingly, it should be understood that, in at least one embodiment, the glass containers may be ion exchange strengthened prior to application of the low-friction coating. Alternatively, other strengthening methods such as heat tempering, flame polishing, and laminating, as described in U.S. Pat. No. 7,201,965, could be used to strengthen the glass before coating.

In one embodiment, the coupling agent comprises a silane chemical composition, such as an alkoxysilane, which may improve the adhesion of the polymer chemical composition to the glass body. Without being bound by theory, it is believed that alkoxysilane molecules hydrolyze rapidly in water forming isolated monomers, cyclic oligomers, and large intramolecular cyclics. In various embodiments, the control over which species predominates may be determined by silane type, concentration, pH, temperature, storage condition, and time. For example, at low concentrations in aqueous solution, aminopropyltrialkoxysilane (APS) may be stable and form trisilanol monomers and very low molecular weight oligomeric cyclics.

It is believed, still without being bound by theory, that the reaction of one or more silanes chemical compositions to the glass body may involve several steps. As shown in FIG. 31, in some embodiments, following hydrolysis of the silane chemical composition, a reactive silanol moiety may be formed, which can condense with other silanol moieties, for example, those on the surface of a substrate, such as a glass body. After the first and second hydrolysable moieties are hydrolyzed, a condensation reaction may be initialized. In some embodiments, the tendency toward self condensation can be controlled by using fresh solutions, alcoholic solvents, dilution, and by careful selection of pH ranges. For example, silanetriols are most stable at pH 3-6, but condense rapidly at pH 7-9.3, and partial condensation of silanol monomers may produce silsesquioxanes. As shown in FIG. 31, the silanol moieties of the formed species may form hydrogen bonds with silanol moieties on the substrate, and during drying or curing a covalent bond may be formed with the substrate with elimination of water. For example, a moderate cure cycle (110° C. for 15 min) may leave silanol moieties remaining in free form and, along with any silane organofunctionality, may bond with the subsequent topcoat, providing improved adhesion.

In some embodiments, the one or more silane chemical compositions of the coupling agent may comprise an amine moiety. Still without being bound by theory, it is believed that this amine moiety may act as a base catalyst in the hydrolysis and co-condensation polymerization and enhance the adsorption rate of the silanes having an amine moiety on a glass surface. It may also create a high pH (9.0-10.0) in aqueous solution that conditions the glass surface and increases density of surface silanol moieties. Strong interaction with water and protic solvents maintains solubility and stability of a silane having an amine moiety chemical composition, such as APS.

In an exemplary embodiment, the glass body may comprise ion-exchanged glass and the coupling agent may be a silane. In some embodiments, adhesion of the low-friction coating to an ion-exchanged glass body may be stronger than adhesion of the low-friction coating to a non-ion-exchanged glass body. It is believed, without being bound by theory, that any of several aspects of ion-exchanged glass may promote bonding and/or adhesion, as compared with non-ion-exchanged glass. First, ion-exchanged glass may have enhanced chemical/hydrolytic stability that may affect stability of the coupling agent and/or its adhesion to glass surface. Non-ion-exchanged glass typically has inferior hydrolytic stability and under humid and/or elevated temperature conditions, alkali metals could migrate out of the glass body to the interface of the glass surface and coupling agent layer (if present), or even migrate into the coupling agent layer, if present. If alkali metals migrate, as described above, and there is a change in pH, hydrolysis of Si—O—Si bonds at the glass/coupling agent layer interface or in the coupling agent layer itself may weaken either the coupling agent mechanical properties or its adhesion to the glass. Second, when ion-exchanged glasses are exposed to strong oxidant baths, such as potassium nitrite baths, at elevated temperatures, such as 400° C. to 450° C., and removed, organic chemical compositions on the surface of the glass are removed, making it particularly well suited for silane coupling agents without further cleaning. For example, a non-ion-exchanged glass may have to be exposed to an additional surface cleaning treatment, adding time and expense to the process.

In one exemplary embodiment, the coupling agent may comprise at least one silane comprising an amine moiety and the polymer chemical composition may comprise a polyimide chemical composition. Now referring to FIG. 32, without being bound by theory, it is believed that the interaction between this amine moiety interaction and the polyamic acid precursor of the polyimide follows a stepwise process. As shown in FIG. 32, the first step is formation of a polyamic acid salt between a carboxyl moiety of the polyamic acid and the amine moiety. The second step is thermal conversion of the salt into an amide moiety. The thirds step is further conversion of the amide moiety into an imide moiety with scission of the polymer amide bonds. The result is a covalent imide attachment of a shortened polymer chain (polyimide chain) to an amine moiety of the coupling agent, as shown in FIG. 32.

Referring collectively to FIGS. 7 and 8, FIG. 7 contains a process flow diagram 500 of a method for producing a coated glass container 100 having a low-friction coating and FIG. 8 schematically depicts the process described in the flow diagram. In a first step 502, glass tube stock 1000 formed from an ion-exchangeable glass composition is initially shaped into glass containers 900 (specifically glass vials in the embodiment depicted) using conventional shaping and forming techniques. In step 504, the glass containers 900 are loaded into a magazine 604 using a mechanical magazine loader 602. The magazine loader 602 may be a mechanical gripping device, such as a caliper or the like, which is capable of gripping multiple glass containers at one time. Alternatively, the gripping device may utilize a vacuum system to grip the glass containers 900. The magazine loader 602 may be coupled to a robotic arm or other, similar device capable of positioning the magazine loader 602 with respect to the glass containers 900 and the magazine 604.

In a next step 506, the magazine 604 loaded with glass containers 900 is transferred with a mechanical conveyor, such as a conveyor belt 606, overhead crane or the like, to a cassette loading area. Thereafter, in step 508, the magazine 604 is loaded into a cassette 608. The cassette 608 is constructed to hold a plurality of magazines such that a large number of glass containers can be processed simultaneously. Each magazine 604 is positioned in the cassette 608 utilizing a cassette loader 610. The cassette loader 610 may be a mechanical gripping device, such as a caliper or the like, which is capable of gripping one or more magazines at a time. Alternatively, the gripping device may utilize a vacuum system to grip the magazines 604. The cassette loader 610 may be coupled to a robotic arm or other, similar device capable of positioning the cassette loader 610 with respect to the cassette 608 and the magazine 604.

In a next step 510, the cassette 608 containing the magazines 604 and glass containers 900 is transferred to an ion exchange station and loaded into an ion exchange tank 614 to facilitate chemically strengthening the glass containers 900. The cassette 608 is transferred to the ion exchange station with a cassette transfer device 612. The cassette transfer device 612 may be a mechanical gripping device, such as a caliper or the like, which is capable of gripping the cassette 608. Alternatively, the gripping device may utilize a vacuum system to grip the cassette 608. The cassette transfer device 612 and attached cassette 608 may be automatically conveyed from the cassette loading area to the ion exchange station with an overhead rail system, such as a gantry crane or the like. Alternatively, the cassette transfer device 612 and attached cassette 608 may be conveyed from the cassette loading area to the ion exchange station with a robotic arm. In yet another embodiment, the cassette transfer device 612 and attached cassette 608 may be conveyed from the cassette loading area to the ion exchange station with a conveyor and, thereafter, transferred from the conveyor to the ion exchange tank 614 with a robotic arm or an overhead crane.

Once the cassette transfer device 612 and attached cassette are at the ion exchange station, the cassette 608 and the glass containers 900 contained therein may be preheated prior to immersing the cassette 608 and the glass containers 900 in the ion exchange tank 614. The cassette 608 may be preheated to a temperature greater than room temperature and less than or equal to the temperature of the molten salt bath in the ion exchange tank. For example, the glass containers may be preheated to a temperature from about 300° C.-500° C.

The ion exchange tank 614 contains a bath of molten salt 616, such as a molten alkali salt, such as KNO₃, NaNO₃and/or combinations thereof. In one embodiment, the bath of molten salt is 100% molten KNO₃which is maintained at a temperature greater than or equal to about 350° C. and less than or equal to about 500° C. However, it should be understood that baths of molten alkali salt having various other compositions and/or temperatures may also be used to facilitate ion exchange of the glass containers.

In step 512, the glass containers 900 are ion exchange strengthened in the ion exchange tank 614. Specifically, the glass containers are immersed in the molten salt and held there for a period of time sufficient to achieve the desired compressive stress and depth of layer in the glass containers 900. For example, in one embodiment, the glass containers 900 may be held in the ion exchange tank 614 for a time period sufficient to achieve a depth of layer of up to about 100 μm with a compressive stress of at least about 300 MPa or even 350 MPa. The holding period may be less than 30 hours or even less than 20 hours. However it should be understood that the time period with which the glass containers are held in the tank 614 may vary depending on the composition of the glass container, the composition of the bath of molten salt 616, the temperature of the bath of molten salt 616, and the desired depth of layer and the desired compressive stress.

After the glass containers 900 are ion exchange strengthened, the cassette 608 and glass containers 900 are removed from the ion exchange tank 614 using the cassette transfer device 612 in conjunction with a robotic arm or overhead crane. During removal from the ion exchange tank 614, the cassette 608 and the glass containers 900 are suspended over the ion exchange tank 614 and the cassette 608 is rotated about a horizontal axis such that any molten salt remaining in the glass containers 900 is emptied back into the ion exchange tank 614. Thereafter, the cassette 608 is rotated back to its initial position and the glass containers are allowed to cool prior to being rinsed.

The cassette 608 and glass containers 900 are then transferred to a rinse station with the cassette transfer device 612. This transfer may be performed with a robotic arm or overhead crane, as described above, or alternatively, with an automatic conveyor such as a conveyor belt or the like. In a next step 514, the cassette 608 and glass containers 900 are lowered into a rinse tank 618 containing a water bath 620 to remove any excess salt from the surfaces of the glass containers 900. The cassette 608 and glass containers 900 may be lowered into the rinse tank 618 with a robotic arm, overhead crane or similar device which couples to the cassette transfer device 612. The cassette 608 and glass containers 900 are then withdrawn from the rinse tank 618, suspended over the rinse tank 618, and the cassette 608 is rotated about a horizontal axis such that any rinse water remaining in the glass containers 900 is emptied back into the rinse tank 618. In some embodiments, the rinsing operation may be performed multiple times before the cassette 608 and glass containers 900 are moved to the next processing station.

In one particular embodiment, the cassette 608 and the glass containers 900 are dipped in a water bath at least twice. For example, the cassette 608 may be dipped in a first water bath and, subsequently, a second, different water bath to ensure that all residual alkali salts are removed from the surface of the glass article. The water from the first water bath may be sent to waste water treatment or to an evaporator.

In a next step 516, the magazines 604 are removed from the cassette 608 with the cassette loader 610. Thereafter, in step 518, the glass containers 900 are unloaded from the magazine 604 with the magazine loader 602 and transferred to a washing station. In step 520, the glass containers are washed with a jet of de-ionized water 624 emitted from a nozzle 622. The jet of de-ionized water 624 may be mixed with compressed air.

Optionally, in step 521 (not depicted in FIG. 8), the glass containers 900 are transferred to an inspection station where the glass containers are inspected for flaws, debris, discoloration and the like.

In step 522, the glass containers 900 are transferred to the coating station with the magazine loader 602 where the low-friction coating is applied to the glass containers 900. In some embodiments, the application of the low-friction coating may include the application of a coupling agent directly to the surface of the glass container and a polymer chemical composition on the coupling agent, as described above. In these embodiments, the glass containers 900 are partially immersed in a first dip tank 626 which contains the coupling agent 628 to coat the exterior surface of the glass containers with the coupling agent. Alternatively, the coupling agent may be spray applied. Thereafter, the glass containers are withdrawn from the first dip tank 626 and the coupling agent is dried. In some embodiments, such as embodiments where the coupling agent comprises one or more silane chemical compositions as described above, the glass containers 900 may be conveyed to an oven where the glass containers 900 are dried at about 120° C. for 15 minutes.

While the process schematically depicted in FIG. 8 includes a step of coating the outside of the glass containers with a coupling agent, it should be understood that this step is only used for those coating compositions in which a coupling agent is needed. In other embodiments of low-friction coatings in which a coupling agent is not needed, the step of applying the coupling agent may be omitted.

Thereafter, the glass containers 900 are conveyed to the coating dip tank 630 with the magazine loader 602. The coating dip tank 630 is filled with the polymer chemical composition coating solution 632 comprising a polymer chemical composition described herein above. The glass containers are at least partially immersed in the polymer chemical composition coating solution 632 to coat the polymer chemical composition onto the glass containers, either directly onto the exterior surface of the glass containers 900 or onto the coupling agent which is already coated on the glass containers 900. Thereafter, the polymer chemical composition solution is dried to remove any solvents. In one embodiment, where the polymer chemical composition coating solution contains NOVASTRAT® 800 as described above, the coating solution may be dried by conveying the glass containers 900 to an oven and heating the glass containers at 150° C. for 20 minutes. Once the polymer chemical composition coatings solution is dried, the glass containers 900 may (optionally) be re-dipped into the polymer chemical composition coating dip tank 630 to apply one or more additional layers of polymer chemical composition. In some embodiments, the polymer chemical composition coating is applied to the entire external surface of the container, while in other embodiments the low-friction coating is only applied to a portion of the external surface of the container. While the coupling agent and polymer chemical composition are described herein, in some embodiments, as being applied in two separate steps, it should be understood that in an alternative embodiment, the coupling agent and low-friction coating are applied in a single step, such as when the coupling agent and the polymer chemical composition are combined in a mixture.

Once the polymer chemical composition coating solution 632 has been applied to the glass containers 900, the polymer chemical composition is cured on the glass containers 900. The curing process depends on the type of polymer chemical composition coating applied to the coating process and may include thermally curing the coating, curing the coating with UV light, and/or a combination thereof. In the embodiments described herein where the polymer chemical composition coating comprises a polyimide such as the polyimide formed by the NOVASTRAT® 800 polyamic acid coating solution described above, the glass containers 900 are conveyed to an oven 634 where they are heated from 150° C. to approximately 350° C. over a period of about 5 to 30 minutes. Upon removal of the glass containers from the oven, the polymer chemical composition coating is cured thereby producing a coated glass container with a low-friction coating.

After the low-friction coating has been applied to the glass container, the coated glass containers 100 are transferred to a packaging process in step 524 where the containers are filled and/or to an additional inspection station.

Various properties of the coated glass containers (i.e., coefficient of friction, horizontal compression strength, 4-point bend strength) may be measured when the coated glass containers are in an as-coated condition (i.e., following application of the coating without any additional treatments) or following one or more processing treatments, such as those similar or identical to treatments performed on a pharmaceutical filling line, including, without limitation, washing, lyophilization, depyrogenation, autoclaving, or the like.

Depyrogenation is a process wherein pyrogens are removed from a substance. Depyrogenation of glass articles, such as pharmaceutical packages, can be performed by a thermal treatment applied to a sample in which the sample is heated to an elevated temperature for a period of time. For example, depyrogenation may include heating a glass container to a temperature of between about 250° C. and about 380° C. for a time period from about 30 seconds to about 72 hours, including, without limitation, 20 minutes, 30 minutes 40 minutes, 1 hour, 2 hours, 4 hours, 8 hours, 12 hours, 24 hours, 48 hours, and 72 hours. Following the thermal treatment, the glass container is cooled to room temperature. One conventional depyrogenation condition commonly employed in the pharmaceutical industry is thermal treatment at a temperature of about 250° C. for about 30 minutes. However, it is contemplated that the time of thermal treatment may be reduced if higher temperatures are utilized. The coated glass containers, as described herein, may be exposed to elevated temperatures for a period of time. The elevated temperatures and time periods of heating described herein may or may not be sufficient to depyrogenate a glass container. However, it should be understood that some of the temperatures and times of heating described herein are sufficient to depyrogenate a coated glass container, such as the coated glass containers described herein. For example, as described herein, the coated glass containers may be exposed to temperatures of about 260° C., about 270° C., about 280° C., about 290° C., about 300° C., about 310° C., about 320° C., about 330° C., about 340° C., about 350° C., about 360° C., about 370° C., about 380° C., about 390° C., or about 400° C., for a period of time of 30 minutes.

As used herein, lyophilization conditions (i.e., freeze drying) refer to a process in which a sample is filled with a liquid that contains protein and then frozen at −100° C., followed by water sublimation for 20 hours at −15° C. under vacuum.

As used herein, autoclave conditions refer to steam purging a sample for 10 minutes at 100° C., followed by a 20 minute dwelling period wherein the sample is exposed to a 121° C. environment, followed by 30 minutes of heat treatment at 121° C.

The coefficient of friction (μ) of the portion of the coated glass container with the low-friction coating may have a lower coefficient of friction than a surface of an uncoated glass container formed from a same glass composition. A coefficient of friction (μ) is a quantitative measurement of the friction between two surfaces and is a function of the mechanical and chemical properties of the first and second surfaces, including surface roughness, as well as environmental conditions such as, but not limited to, temperature and humidity. As used herein, a coefficient of friction measurement for coated glass container 100 is reported as the coefficient of friction between the outer surface of a first glass container (having an outer diameter of between about 16.00 mm and about 17.00 mm) and the outer surface of second glass container which is identical to the first glass container, wherein the first and second glass containers have the same body and the same coating composition (when applied) and have been exposed to the same environments prior to fabrication, during fabrication, and after fabrication. Unless otherwise denoted herein, the coefficient of friction refers to the maximum coefficient of friction measured with a normal load of 30 N measured on a vial-on-vial testing jig, as described herein. However, it should be understood that a coated glass container which exhibits a maximum coefficient of friction at a specific applied load will also exhibit the same or better (i.e., lower) maximum coefficient of friction at a lesser load. For example, if a coated glass container exhibits a maximum coefficient of friction of 0.5 or lower under an applied load of 50 N, the coated glass container will also exhibit a maximum coefficient of friction of 0.5 or lower under an applied load of 25 N.

In the embodiments described herein, the coefficient of friction of the glass containers (both coated and uncoated) is measured with a vial-on-vial testing jig. The testing jig 200 is schematically depicted in FIG. 9. The same apparatus may also be used to measure the frictive force between two glass containers positioned in the jig. The vial-on-vial testing jig 200 comprises a first clamp 212 and a second clamp 222 arranged in a cross configuration. The first clamp 212 comprises a first securing arm 214 attached to a first base 216. The first securing arm 214 attaches to the first glass container 210 and holds the first glass container 210 stationary relative to the first clamp 212. Similarly, the second clamp 222 comprises a second securing arm 224 attached to a second base 226. The second securing arm 224 attaches to the second glass container 220 and holds it stationary relative to the second clamp 222. The first glass container 210 is positioned on the first clamp 212 and the second glass container 220 is positioned of the second clamp 222 such that the long axis of the first glass container 210 and the long axis of the second glass container 220 are positioned at about a 90° angle relative to one another and on a horizontal plane defined by the x-y axis.

A first glass container 210 is positioned in contact with the second glass container 220 at a contact point 230. A normal force is applied in a direction orthogonal to the horizontal plane defined by the x-y axis. The normal force may be applied by a static weight or other force applied to the second clamp 222 upon a stationary first clamp 212. For example, a weight may be positioned on the second base 226 and the first base 216 may be placed on a stable surface, thus inducing a measurable force between the first glass container 210 and the second glass container 220 at the contact point 230. Alternatively, the force may be applied with a mechanical apparatus, such as a UMT (universal mechanical tester) machine.

The first clamp 212 or second clamp 222 may be moved relative to the other in a direction which is at a 45° angle with the long axis of the first glass container 210 and the second glass container 220. For example, the first clamp 212 may be held stationary and the second clamp 222 may be moved such that the second glass container 220 moves across the first glass container 210 in the direction of the x-axis. A similar setup is described by R. L. De Rosa et al., in “Scratch Resistant Polyimide Coatings for Alumino Silicate Glass surfaces” in The Journal of Adhesion, 78: 113-127, 2002. To measure the coefficient of friction, the force required to move the second clamp 222 and the normal force applied to first and second glass containers 210,220 are measured with load cells and the coefficient of friction is calculated as the quotient of the frictive force and the normal force. The jig is operated in an environment of 25° C. and 50% relative humidity.

In the embodiments described herein, the portion of the coated glass container with the low-friction coating has a coefficient of friction of less than or equal to about 0.7 relative to a like-coated glass container, as determined with the vial-on-vial jig described above. In other embodiments, the coefficient of friction may be less than or equal to about 0.6, or even less than or equal to about 0.5. In some embodiments, the portion of the coated glass container with the low-friction coating has a coefficient of friction of less than or equal to about 0.4 or even less than or equal to about 0.3. Coated glass containers with coefficients of friction less than or equal to about 0.7 generally exhibit improved resistance to frictive damage and, as a result, have improved mechanical properties. For example, conventional glass containers (without a low-friction coating) may have a coefficient of friction of greater than 0.7.

In some embodiments described herein, the coefficient of friction of the portion of the coated glass container with the low-friction coating is at least 20% less than a coefficient of friction of a surface of an uncoated glass container formed from a same glass composition. For example, the coefficient of friction of the portion of the coated glass container with the low-friction coating may be at least 20% less, at least 25% less, at least 30% less, at least 40% less, or even at least 50% less than a coefficient of friction of a surface of an uncoated glass container formed from a same glass composition.

In some embodiments, the portion of the coated glass container with the low-friction coating may have a coefficient of friction of less than or equal to about 0.7 after exposure to a temperature of about 260° C., about 270° C., about 280° C., about 290° C., about 300° C., about 310° C., about 320° C., about 330° C., about 340° C., about 350° C., about 360° C., about 370° C., about 380° C., about 390° C., or about 400° C., for a period of time of 30 minutes. In other embodiments, the portion of the coated glass container with the low-friction coating may have a coefficient of friction of less than or equal to about 0.7, (i.e., less than or equal to about 0.6, less than or equal to about 0.5, less than or equal to about 0.4, or even less than or equal to about 0.3) after exposure to a temperature of about 260° C., about 270° C., about 280° C., about 290° C., about 300° C., about 310° C., about 320° C., about 330° C., about 340° C., about 350° C., about 360° C., about 370° C., about 380° C., about 390° C., or about 400° C., for a period of time of 30 minutes. In some embodiments, the coefficient of friction of the portion of the coated glass container with the low-friction coating may not increase by more than about 30% after exposure to a temperature of about 260° C. for 30 minutes. In other embodiments, coefficient of friction of the portion of the coated glass container with the low-friction coating may not increase by more than about 30% (i.e., about 25%, about 20%, about 15%, or event about 10%) after exposure to a temperature of about 260° C., about 270° C., about 280° C., about 290° C., about 300° C., about 310° C., about 320° C., about 330° C., about 340° C., about 350° C., about 360° C., about 370° C., about 380° C., about 390° C., or about 400° C., for a period of time of 30 minutes. In other embodiments, coefficient of friction of the portion of the coated glass container with the low-friction coating may not increase by more than about 0.5 (i.e., about 0.45, about 0.04, about 0.35, about 0.3, about 0.25, about 0.2, about 0.15, about 0.1, or event about 0.5) after exposure to a temperature of about 260° C., about 270° C., about 280° C., about 290° C., about 300° C., about 310° C., about 320° C., about 330° C., about 340° C., about 350° C., about 360° C., about 370° C., about 380° C., about 390° C., or about 400° C., for a period of time of 30 minutes. In some embodiments, the coefficient of friction of the portion of the coated glass container with the low-friction coating may not increase at all after exposure to a temperature of about 260° C., about 270° C., about 280° C., about 290° C., about 300° C., about 310° C., about 320° C., about 330° C., about 340° C., about 350° C., about 360° C., about 370° C., about 380° C., about 390° C., or about 400° C., for a period of time of 30 minutes.

In some embodiments, the portion of the coated glass container with the low-friction coating may have a coefficient of friction of less than or equal to about 0.7 after being submerged in a water bath at a temperature of about 70° C. for 10 minutes. In other embodiments, the portion of the coated glass container with the low-friction coating may have a coefficient of friction of less than or equal to about 0.7, (i.e., less than or equal to about 0.6, less than or equal to about 0.5, less than or equal to about 0.4, or even less than or equal to about 0.3) after being submerged in a water bath at a temperature of about 70° C. for 5 minutes, 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, or even 1 hour. In some embodiments, the coefficient of friction of the portion of the coated glass container with the low-friction coating may not increase by more than about 30% after being submerged in a water bath at a temperature of about 70° C. for 10 minutes. In other embodiments, coefficient of friction of the portion of the coated glass container with the low-friction coating may not increase by more than about 30% (i.e., about 25%, about 20%, about 15%, or event about 10%) after being submerged in a water bath at a temperature of about 70° C. for 5 minutes, 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, or even 1 hour. In some embodiments, the coefficient of friction of the portion of the coated glass container with the low-friction coating may not increase at all after being submerged in a water bath at a temperature of about 70° C. for 5 minutes, 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, or even 1 hour.

In some embodiments, the portion of the coated glass container with the low-friction coating may have a coefficient of friction of less than or equal to about 0.7 after exposure to lyophilization conditions. In other embodiments, the portion of the coated glass container with the low-friction coating may have a coefficient of friction of less than or equal to about 0.7, (i.e., less than or equal to about 0.6, less than or equal to about 0.5, less than or equal to about 0.4, or even less than or equal to about 0.3) after exposure to lyophilization conditions. In some embodiments, the coefficient of friction of the portion of the coated glass container with the low-friction coating may not increase by more than about 30% after exposure to lyophilization conditions. In other embodiments, coefficient of friction of the portion of the coated glass container with the low-friction coating may not increase by more than about 30% (i.e., about 25%, about 20%, about 15%, or event about 10%) after exposure to lyophilization conditions. In some embodiments, the coefficient of friction of the portion of the coated glass container with the low-friction coating may not increase at all after exposure to lyophilization conditions.

In some embodiments, the portion of the coated glass container with the low-friction coating may have a coefficient of friction of less than or equal to about 0.7 after exposure to autoclave conditions. In other embodiments, the portion of the coated glass container with the low-friction coating may have a coefficient of friction of less than or equal to about 0.7, (i.e., less than or equal to about 0.6, less than or equal to about 0.5, less than or equal to about 0.4, or even less than or equal to about 0.3) after exposure to autoclave conditions. In some embodiments, the coefficient of friction of the portion of the coated glass container with the low-friction coating may not increase by more than about 30% after exposure to autoclave conditions. In other embodiments, coefficient of friction of the portion of the coated glass container with the low-friction coating may not increase by more than about 30% (i.e., about 25%, about 20%, about 15%, or event about 10%) after exposure to autoclave conditions. In some embodiments, the coefficient of friction of the portion of the coated glass container with the low-friction coating may not increase at all after exposure to autoclave conditions.

The coated glass containers described herein have a horizontal compression strength. Referring to FIG. 1, the horizontal compression strength, as described herein, is measured by positioning the coated glass container 100 horizontally between two parallel platens which are oriented in parallel to the long axis of the glass container. A mechanical load is then applied to the coated glass container 100 with the platens in the direction perpendicular to the long axis of the glass container. The load rate for vial compression is 0.5 in/min, meaning that the platens move towards each other at a rate of 0.5 in/min. The horizontal compression strength is measured at 25° C. and 50% relative humidity. A measurement of the horizontal compression strength can be given as a failure probability at a selected normal compression load. As used herein, failure occurs when the glass container ruptures under a horizontal compression in least 50% of samples. In some embodiments, a coated glass container may have a horizontal compression strength at least 10%, 20%, or 30% greater than an uncoated vial.

Referring now to FIGS. 1 and 9, the horizontal compression strength measurement may also be performed on an abraded glass container. Specifically, operation of the testing jig 200 may create damage on the coated glass container outer surface 122, such as a surface scratch or abrasion that weakens the strength of the coated glass container 100. The glass container is then subjected to the horizontal compression procedure described above, wherein the container is placed between two platens with the scratch pointing outward parallel to the platens. The scratch can be characterized by the selected normal pressure applied by a vial-on-vial jig and the scratch length. Unless identified otherwise, scratches for abraded glass containers for the horizontal compression procedure are characterized by a scratch length of 20 mm created by a normal load of 30 N.

The coated glass containers can be evaluated for horizontal compression strength following a heat treatment. The heat treatment may be exposure to a temperature of about 260° C., about 270° C., about 280° C., about 290° C., about 300° C., about 310° C., about 320° C., about 330° C., about 340° C., about 350° C., about 360° C., about 370° C., about 380° C., about 390° C., or about 400° C., for a period of time of 30 minutes. In some embodiments, the horizontal compression strength of the coated glass container is not reduced by more than about 20%, 30%, or even 40% after being exposed to a heat treatment, such as those described above, and then being abraded, as described above. In one embodiment, the horizontal compression strength of the coated glass container is not reduced by more than about 20% after being exposed to a heat treatment of about 260° C., about 270° C., about 280° C., about 290° C., about 300° C., about 310° C., about 320° C., about 330° C., about 340° C., about 350° C., about 360° C., about 370° C., about 380° C., about 390° C., or about 400° C., for a period of time of 30 minutes, and then being abraded.

The coated glass articles described herein may be thermally stable after heating to a temperature of at least 260° C. for a time period of 30 minutes. The phrase “thermally stable,” as used herein, means that the low friction coating applied to the glass article remains substantially intact on the surface of the glass article after exposure to the elevated temperatures such that, after exposure, the mechanical properties of the coated glass article, specifically the coefficient of friction and the horizontal compression strength, are only minimally affected, if at all. This indicates that the low friction coating remains adhered to the surface of the glass following elevated temperature exposure and continues to protect the glass article from mechanical insults such as abrasions, impacts and the like.

In the embodiments described herein, a coated glass article is considered to be thermally stable if the coated glass article meets both a coefficient of friction standard and a horizontal compression strength standard after heating to the specified temperature and remaining at that temperature for the specified time. To determine if the coefficient of friction standard is met, the coefficient of friction of a first coated glass article is determined in as-received condition (i.e., prior to any thermal exposure) using the testing jig depicted in FIG. 9 and a 30 N applied load. A second coated glass article (i.e., a glass article having the same glass composition and the same coating composition as the first coated glass article) is thermally exposed under the prescribed conditions and cooled to room temperature. Thereafter, the coefficient of friction of the second glass article is determined using the testing jig depicted in FIG. 9 to abrade the coated glass article with a 30 N applied load resulting in an abraded (i.e., a “scratch”) having a length of approximately 20 mm. If the coefficient of friction of the second coated glass article is less than 0.7 and the surface of the glass of the second glass article in the abraded area does not have any observable damage, then the coefficient of friction standard is met for purposes of determining the thermal stability of the low friction coating. The term “observable damage,” as used herein means that the surface of the glass in the abraded area of the glass article contains less than six glass checks per 0.5 cm of length of the abraded area when observed with a Nomarski or differential interference contrast (DIC) spectroscopy microscope at a magnification of 100× with LED or halogen light sources. A standard definition of a glass check or glass checking is described in G. D. Quinn, “NIST Recommended Practice Guide: Fractography of Ceramics and Glasses,” NIST special publication 960-17 (2006).

To determine if the horizontal compression strength standard is met, a first coated glass article is abraded in the testing jig depicted in FIG. 9 under a 30 N load to form a 20 mm scratch. The first coated glass article is then subjected to a horizontal compression test, as described herein, and the retained strength of the first coated glass article is determined. A second coated glass article (i.e., a glass article having the same glass composition and the same coating composition as the first coated glass article) is thermally exposed under the prescribed conditions and cooled to room temperature. Thereafter, the second coated glass article is abraded in the testing jig depicted in FIG. 9 under a 30 N load. The second coated glass article is then subjected to a horizontal compression test, as described herein, and the retained strength of the second coated glass article is determined. If the retained strength of the second coated glass article does not decrease by more than about 20% relative to the first coated glass article then the horizontal compression strength standard is met for purposes of determining the thermal stability of the low friction coating.

In the embodiments described herein, the coated glass containers are considered to be thermally stable if the coefficient of friction standard and the horizontal compression strength standard are met after exposing the coated glass containers to a temperature of at least about 260° C. for a time period of about 30 minutes (i.e., the coated glass containers are thermally stable at a temperature of at least about 260° C. for a time period of about 30 minutes). The thermal stability may also be assessed at temperatures from about 260° C. up to about 400° C. For example, in some embodiments, the coated glass containers will be considered to be thermally stable if the standards are met at a temperature of at least about 270° C. or even about 280° C. for a time period of about 30 minutes. In still other embodiments, the coated glass containers will be considered to be thermally stable if the standards are met at a temperature of at least about 290° C. or even about 300° C. for a time period of about 30 minutes. In further embodiments, the coated glass containers will be considered to be thermally stable if the standards are met at a temperature of at least about 310° C. or even about 320° C. for a time period of about 30 minutes. In still other embodiments, the coated glass containers will be considered to be thermally stable if the standards are met at a temperature of at least about 330° C. or even about 340° C. for a time period of about 30 minutes. In yet other embodiments, the coated glass containers will be considered to be thermally stable if the standards are met at a temperature of at least about 350° C. or even about 360° C. for a time period of about 30 minutes. In some other embodiments, the coated glass containers will be considered to be thermally stable if the standards are met at a temperature of at least about 370° C. or even about 380° C. for a time period of about 30 minutes. In still other embodiments, the coated glass containers will be considered to be thermally stable if the standards are met at a temperature of at least about 390° C. or even about 400° C. for a time period of about 30 minutes.

The coated glass containers disclosed herein may also be thermally stable over a range of temperatures, meaning that the coated glass containers are thermally stable by meeting the coefficient of friction standard and horizontal compression strength standard at each temperature in the range. For example, in the embodiments described herein, the coated glass containers may be thermally stable from at least about 260° C. to a temperature of less than or equal to about 400° C. In some embodiments, the coated glass containers may be thermally stable in a range from at least about 260° C. to about 350° C. In some other embodiments, the coated glass containers may be thermally stable from at least about 280° C. to a temperature of less than or equal to about 350° C. In still other embodiments, the coated glass containers may be thermally stable from at least about 290° C. to about 340° C. In another embodiment, the coated glass container may be thermally stable at a range of temperatures of about 300° C. to about 380° C. In another embodiment, the coated glass container may be thermally stable at a range of temperatures from about 320° C. to about 360° C.

The coated glass containers described herein have a four point bend strength. To measure the four point bend strength of a glass container, a glass tube that is the precursor to the coated glass container 100 is utilized for the measurement. The glass tube has a diameter that is the same as the glass container but does not include a glass container base or a glass container mouth (i.e., prior to forming the tube into a glass container). The glass tube is then subjected to a four point bend stress test to induce mechanical failure. The test is performed at 50% relative humidity with outer contact members spaced apart by 9″ and inner contact members spaced apart by 3″ at a loading rate of 10 mm/min.

The four point bend stress measurement may also be performed on a coated and abraded tube. Operation of the testing jig 200 may create an abrasion on the tube surface such as a surface scratch that weakens the strength of the tube, as described in the measurement of the horizontal compression strength of an abraded vial. The glass tube is then subjected to a four point bend stress test to induce mechanical failure. The test is performed at 25° C. and at 50% relative humidity using outer probes spaced apart by 9″ and inner contact members spaced apart by 3″ at a loading rate of 10 mm/min, while the tube is positioned such that the scratch is put under tension during the test.

In some embodiments, the four point bend strength of a glass tube with a low-friction coating after abrasion shows on average at least 10%, 20%, or even 50% higher mechanical strength than that for an uncoated glass tube abraded under the same conditions.

In some embodiments, after the coated glass container 100 is abraded by an identical glass container with a 30 N normal force, the coefficient of friction of the abraded area of the coated glass container 100 does not increase by more than about 20% during another abrasion by an identical glass container with a 30 N normal force at the same spot, or does not increase at all. In other embodiments, after the coated glass container 100 is abraded by an identical glass container with a 30 N normal force, the coefficient of friction of the abraded area of the coated glass container 100 does not increase by more than about 15% or even 10% during another abrasion by an identical glass container with a 30 N normal force at the same spot, or does not increase at all. However, it is not necessary that all embodiments of the coated glass container 100 display such properties.

Mass loss refers to a measurable property of the coated glass container 100 which relates to the amount of volatiles liberated from the coated glass container 100 when the coated glass container is exposed to a selected elevated temperature for a selected period of time. Mass loss is generally indicative of the mechanical degradation of the coating due to thermal exposure. Since the glass body of the coated glass container does not exhibit measureable mass loss at the temperatures reported, the mass loss test, as described in detail herein, yields mass loss data for only the low-friction coating that is applied to the glass container. Multiple factors may affect mass loss. For example, the amount of organic material that can be removed from the coating may affect mass loss. The breakdown of carbon backbones and side chains in a polymer will result in a theoretical 100% removal of the coating. Organometallic polymer materials typically lose their entire organic component, but the inorganic component remains behind. Thus, mass loss results are normalized based upon how much of the coating is organic and inorganic (e.g., % silica of the coating) upon complete theoretical oxidation.

To determine the mass loss, a coated sample, such as a coated glass vial, is initially heated to 150° C. and held at this temperature for 30 minutes to dry the coating, effectively driving off H₂O from the coating. The sample is then heated from 150° C. to 350° C. at a ramp rate of 10° C./min in an oxidizing environment, such as air. For purposes of mass loss determination, only the data collected from 150° C. to 350° C. is considered. In some embodiments, the low-friction coating has a mass loss of less than about 5% of its mass when heated from a temperature of 150° C. to 350° C. at a ramp rate of about 10° C./minute. In other embodiments, the low-friction coating has a mass loss of less than about 3% or even less than about 2% when heated from a temperature of 150° C. to 350° C. at a ramp rate of about 10° C./minute. In some other embodiments, the low-friction coating has a mass loss of less than about 1.5% when heated from a temperature of 150° C. to 350° C. at a ramp rate of about 10° C./minute. In some other embodiments, the low-friction coating loses substantially none of its mass when heated from a temperature of 150° C. to 350° C. at a ramp rate of about 10° C./minute.

Mass loss results are based on a procedure wherein the weight of a coated glass container is compared before and after a heat treatment, such as a ramping temperature of 10°/minute from 150° C. to 350° C., as described herein. The difference in weight between the pre-heat treatment and post-heat treatment vial is the weight loss of the coating, which can be standardized as a percent weight loss of the coating such that the pre-heat treatment weight of the coating (weight not including the glass body of the container and following the preliminary heating step) is known by comparing the weight on an uncoated glass container with a pre-treatment coated glass container. Alternatively, the total mass of coating may be determined by a total organic carbon test or other like means.

Outgassing refers to a measurable property of the coated glass container 100 which relates to the amount of volatiles liberated from the coated glass container 100 when the coated glass container is exposed to a selected elevated temperature for a selected period of time. Outgassing measurements are reported herein as an amount by weight of volatiles liberated per the surface area of the glass container having the coating during exposure to the elevated temperature for a time period. Since the glass body of the coated glass container does not exhibit measureable outgassing at the temperatures reported for outgassing, the outgassing test, as described in detail below, yields outgassing data for substantially only the low-friction coating that is applied to the glass container. Outgassing results are based on a procedure wherein a coated glass container 100 is placed in a glass sample chamber 402 of the apparatus 400 depicted in FIG. 10. A background sample of the empty sample chamber is collected prior to each sample run. The sample chamber is held under a constant 100 ml/min air purge as measured by rotometer 406 while the furnace 404 is heated to 350° C. and held at that temperature for 1 hour to collect the chamber background sample. Thereafter, the coated glass container 100 is positioned in the sample chamber 402 and the sample chamber 402 is held under a constant 100 ml/min air purge and heated to an elevated temperature and held at temperature for a period of time to collect a sample from a coated glass container 100. The glass sample chamber is made of Pyrex, limiting the maximum temperature of the analysis to 600° C. A Carbotrap 300 adsorbent trap 408 is assembled on the exhaust port of the sample chamber to adsorb the resulting volatile species as they are released from the sample and are swept over the absorbent resin by the air purge gas 410 where the volatile species are adsorbed. The absorbent resin is then placed directly into a Gerstel Thermal Desorption unit coupled directly to a Hewlett Packard 5890 Series II gas chromatograph/Hewlett Packard 5989 MS engine. Outgassing species are thermally desorbed at 350° C. from the adsorbent resin and cryogenically focused at the head of a non-polar gas chromatographic column (DB-5MS). The temperature within the gas chromatograph is increased at a rate of 10° C./min to a final temperature of 325° C., so as to provide for the separation and purification of volatile and semi-volatile organic species. The mechanism of separation has been demonstrated to be based on the heats of vaporization of different organic species resulting in, essentially, a boiling point or distillation chromatogram. Following separation, purified species are analyzed by traditional electron impact ionization mass spectrometric protocols. By operating under standardized conditions, the resulting mass spectra may be compared with existing mass spectral libraries.

In some embodiments, the coated glass containers described herein exhibit an outgassing of less than or equal to 54.6 ng/cm², less than or equal to 27.3 ng/cm², or even less than or equal to 5.5 ng/cm²during exposure to elevated temperature of 250° C., 275° C., 300° C., 320° C., 360° C., or even 400° C. for time periods of 15 minutes, 30 minutes, 45 minutes, or 1 hour. Furthermore, the coated glass containers may be thermally stable in a specified range of temperatures, meaning that the coated containers exhibit a certain outgassing, as described above, at every temperature within the specified range. Prior to outgassing measurements, the coated glass containers may be in as-coated condition (i.e., immediately following application of the low-friction coating) or following any one of depyrogenation, lyophilization, or autoclaving. In some embodiments, the coated glass container 100 may exhibit substantially no outgassing.

In some embodiments, outgassing data may be used to determine mass loss of the low-friction coating. A pre-heat treatment coating mass can be determined by the thickness of the coating (determined by SEM image or other manner), the density of low-friction coating, and the surface area of the coating. Thereafter, the coated glass container can be subjected to the outgassing procedure, and mass loss can be determined by finding the ratio of the mass expelled in outgassing to the pre-heat treatment mass.

Referring to FIG. 11, the transparency and color of the coated container may be assessed by measuring the light transmission of the container within a range of wavelengths between 400-700 nm using a spectrophotometer. The measurements are performed such that a light beam is directed normal to the container wall such that the beam passes through the low-friction coating twice, first when entering the container and then when exiting it. In some embodiments, the light transmission through the coated glass container may be greater than or equal to about 55% of a light transmission through an uncoated glass container for wavelengths from about 400 nm to about 700 nm. As described herein, a light transmission can be measured before a thermal treatment or after a thermal treatment, such as the heat treatments described herein. For example, for each wavelength of from about 400 nm to about 700 nm, the light transmission may be greater than or equal to about 55% of a light transmission through an uncoated glass container. In other embodiments, the light transmission through the coated glass container is greater than or equal to about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, or even about 90% of a light transmission through an uncoated glass container for wavelengths from about 400 nm to about 700 nm.

As described herein, a light transmission can be measured before an environmental treatment, such as a thermal treatment described herein, or after an environmental treatment. For example, following a heat treatment of about 260° C., about 270° C., about 280° C., about 290° C., about 300° C., about 310° C., about 320° C., about 330° C., about 340° C., about 350° C., about 360° C., about 370° C., about 380° C., about 390° C., or about 400° C., for a period of time of 30 minutes, or after exposure to lyophilization conditions, or after exposure to autoclave conditions, the light transmission through the coated glass container is greater than or equal to about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, or even about 90% of a light transmission through an uncoated glass container for wavelengths from about 400 nm to about 700 nm

In some embodiments, the coated glass container 100 may be perceived as colorless and transparent to the naked human eye when viewed at any angle. In some other embodiments, the low-friction coating 120 may have a perceptible tint, such as when the low-friction coating 120 comprises a polyimide formed from poly(pyromellitic dianhydride-co-4,4′-oxydianiline) amic acid commercially available from Aldrich.

In some embodiments, the coated glass container 100 may have a low-friction coating 120 that is capable of receiving an adhesive label. That is, the coated glass container 100 may receive an adhesive label on the coated surface such that the adhesive label is securely attached. However, the ability of attachment of an adhesive label is not a requirement for all embodiments of the coated glass containers 100 described herein.

Particle Reduction and Contamination in Pharmaceutical Containers

Moreover, the coated glass containers described above also reduce particle generation caused when pharmaceutical containers undergo processing.

As used herein, “processing” may encompass various steps for the pharmaceutical container after glass container production, wherein glass container production may involve glass melting, ion exchange strengthening, and glass coating. While many “processing” steps are contemplated under this definition, “processing” may encompass, for example, and not by way of limitation: 1) pharmaceutical filling line procedures, such as washing, conveying, singulating, aligning, depyrogenation, filling, stoppering and capping operations; 2) other thermal treatment procedures, such as lyophilization and autoclaving; and 3) the shipping and handling of the pharmaceutical containers whether filled or unfilled. In embodiments discussed below, “processing” involves the non-breakage inducing glass contact of pharmaceutical containers in pharmaceutical filling lines.

As used herein, “non-breakage inducing glass contact” involves interactions with glass containers or impact upon glass containers during processing which may cause unacceptable glass particle formation in conventional uncoated glass containers. Further, “non-breakage inducing glass contact” does not encompass glass interactions that cause a breakage event wherein one or more glass containers may crack or shatter. For example and not by way of limitation, “non-breakage inducing glass contact” involves glass interaction or impact with many contemplated objects, for example, glass to glass contact, or glass to metal contact. Additionally as described further below, “non-breakage inducing glass contact” may include impact on the glass container at various glass impact speeds and glass impact load forces. While non-breakage inducing glass contact can result in particulate generation without causing complete container breakage, it is understood that complete container breakage can also lead to generation of particulates in all size ranges.

The pharmaceutical filling line embodiments described as follows illustrate the particle reduction properties of the coated glass containers. As stated above, conventional bulk pharmaceutical filling lines for parenteral containers may comprise, but are not limited to, the steps of washing, conveying, singulating, aligning, depyrogenation, filling, stoppering and capping operations contained in a clean and sterile environment. The environmental control is designed to prevent visible and sub-visible particles from contaminating the drug product or container. As used herein, particles having a size (e.g., a diameter) larger than 50 μm are “visible” particles, while particles having a size of 50 μm or below are “sub-visible” particles that are difficult to see with the naked eye. Particles less than 10 μm which may find their way into the product solution are especially a concern for proteins or biologic products; whereas, particles between 10 and 50 μm must be monitored by all pharmaceutical manufacturers.

Isolator or barrier technology is commonly adopted to provide the highest levels of sterility assurance. Inside an isolator or cleanroom, containers are conveyed between the operations using methods that allow and rely on systematic contact between containers. These conveyance methods may include but are more not limited to mass container conveyors, in line conveyors, star-wheel singulators, and the like. Moreover, although filling line designs vary, conveyance methods during handling can be classified into either bulk (wide belts or tables that are commonly used during loading, depyrogenation and accumulation) or singulated (single-file processing which is typically used for washing, filling and inspection). The container interactions may vary based on the conveyance method.

For bulk handling, containers are conveyed by motion of a belt or table underneath the containers. Forces or pressure is applied to the mass of containers as they are constrained by stationary barriers that guide vials relative to the movement of the conveyor drive system (e.g., belt, wheels, chains, etc). Lateral loads on the containers are generally proportional to the number of containers between a stationary guide. For these operations, the interaction speed between adjacent containers is generally low; however, forces generated can be relatively large due to the large collective mass of containers or pinch points along the conveyor system. As shown in FIG. 57, frictive sliding between vials may occur during bulk handling, which results in surface stress at the location of contact. When the surface stress exceeds the local material strength, the glass may partially fracture and generate particles. As shown in the rotary accumulator table 700 depicted in FIG. 57, vials move 100 in the direction illustrated by the arrow; however, many of the vials 100 are constrained by inner guide 705 of the rotary accumulator table 700. As moving vials slide past constrained vials adjacent the inner guide, frictive contact between vials results.

Containers in singulated conveyance are also transported by underneath conveyers. Although containers are more constrained than in bulk, containers (e.g., vials) can also slide and tilt resulting in frictive contact between containers. Starwheels or screw feeders are often used to transition between bulk and singulated conveyance modes. Referring to FIG. 58, these operations accelerate containers upon exit, often into or onto stationary containers or a mass of containers in bulk. Specifically, as shown in FIG. 58, the screw feeder 750 accelerates vials 100 into vials located in a stationary plate 760 receiving location. Alternatively, equipment misalignment can also result in unintended container impact events. In these situations, container glass to glass contact is the primary impact event.

To quantify typical and maximum loads applied on containers, forces between containers on multiple filling lines were probed using a piezo sensor-based device (Tekscan® Flexiforce Load/Force Sensor) that records forces using a thin sensor. The sensor was inserted between containers during typical operation on the accumulator table and other accessible regions where impacts occur. Peak forces as high as 30 N were observed between containers, and typical frequent loads on these filling lines ranged from approximately 2 to 10 N.

Bulk or high speed filling line handling methods for loading, conveyance and singulation require part to part contact by design. The glass contact between uncoated containers results in damage and airborne particle generation. This is due in part to the high coefficient of friction of approximately 0.9 or more and the fact that glass is a brittle material that fractures under strain.

The coated glass containers described herein address this particle generation concern when the coated glass containers are processed. Specifically, because the present coated glass containers comprise a chemically-strengthened glass container with a thermally stable, low-COF exterior coating, the described coated containers are able to withstand higher stress on the filling line and are resistant to damage. The strengthening of the coated glass container also reduces the probability of catastrophic failure or breakage events from high stress loading, a secondary source of particles in both visible and sub-visible categories.

In one or more embodiments, the pharmaceutical container is provided as a glass body comprising glass and a coating bonded to at least a portion of the first surface of the glass body. In one embodiment, the glass is chemically strengthened by ion exchange. In further embodiments, the coating comprises a polymer chemical composition and optionally a coupling agent as described above. In specific embodiments, the coating has sufficient thermal stability and coefficient of friction to withstand processing, for example, the processing steps conducting in the pharmaceutical filling lines.

In other embodiments, the coated glass container demonstrates at least a 50% reduction in average particle count for generated sub-visible glass particles compared to an average particle count of generated sub-visible glass particles by the processing of an uncoated glass container, which has the same shape and dimensions as the coated glass container. In one embodiment, coated glass container is an uncoated borosilicate glass container. In many of the embodiments herein, the particle amount may refer to the average particle count computed across multiple article samples. While various counting methods are contemplated, the average particle count is performed herein using the light obscuration technique described in United States Pharmacopoeia Reference Standard 788. In one or more additional embodiments, the coated glass article may demonstrate a reduction in average particle count of at least 75% compared to the average particle count for the uncoated glass article, or a reduction in average particle count of at least 90% compared to the average particle count for the uncoated glass article, or a reduction in average particle count of at least 99% compared to the average particle count for the uncoated glass article.

In one or more embodiments, the coated glass containers reduce formation of visible glass particles when subjected to the conditions associated with pharmaceutical filling lines or other types of processing. These conditions may include horizontal compression forces ranging from 0.1 N to 30 N and glass to glass contact scratch velocities ranging from at least 6 to 120 mm/min. Moreover, the coated glass containers results in the amount of sub-visible glass particles at levels significantly below the maximum allowable levels defined by USP <788> i.e., the coated glass container may produce a significant reduction in particles above and beyond what is required by USP standards.

In further embodiments which demonstrate the improved particle reduction, the average particle count for sub-visible glass particles with a size of 25 to 50 μm is from 0.1 to 1.0 when a coated glass article having a container volume of 3 mL undergoes processing, for example, filling and the other steps defined above. In further embodiments, the average particle count for sub-visible glass particles with a size of 25 to 50 μm may be from 0.1 to 1.5, or 0.1 to 2.5 when the coated glass article having a container volume of 3 mL undergoes filling. In yet another coated glass article embodiment, the average particle count for sub-visible glass particles with a size of 10 to 25 μm is from 1 to 20 when a coated glass article having a container volume of 3 mL undergoes processing. Furthermore, the average particle count for sub-visible glass particles with a size of 10 to 25 μm may be from 1 to 15 when the coated glass article having a container volume of 3 mL undergoes processing.

While this present description focuses on vial filling lines, particle generation due to glass contact is also relevant to other containers and delivery vehicles, such as cartridges, barrels, and syringes. Moreover, while many of the example vials described are 3 mL containers, the coated glass containers of the present disclosure also encompass additional vial sizes, ranging from 0.1 mL to 100 mL sizes.

As further illustrated in the Examples which follow, the coated glass articles provide substantial reductions in particles in both the filling environment (via real time particle monitors and collection) and in liquid drug product (via light obscuration) in two separate filling line studies. Additionally, while many of the Examples demonstrate the improved results of the coated glass vials of the present disclosure in contrast to uncoated glass containers, Example 25 below demonstrates the improved results of the present coated glass containers relative to other conventional coated containers, such as silicone coated borosilicate glass containers (See FIGS. 54 and 55).

EXAMPLES

The various embodiments of glass containers with low-friction coatings will be further clarified by the following examples. The examples are illustrative in nature, and should not be understood to limit the subject matter of the present disclosure.

Example 1

Glass vials were formed from Schott Type 1B glass and the glass composition identified as “Example E” of Table 1 of U.S. Pat. No. 8,551,898 and entitled “Glass Compositions with Improved Chemical and Mechanical Durability” assigned to Corning, Incorporated (hereinafter “the Reference Glass Composition”). The vials were washed with deionized water, blown dry with nitrogen, and dip coated with a 0.1% solution of APS (aminopropylsilsesquioxane). The APS coating was dried at 100° C. in a convection oven for 15 minutes. The vials were then dipped into a 0.1% solution of NOVASTRAT® 800 polyamic acid in a 15/85 toluene/DMF solution or in a 0.1% to 1% poly(pyromellitic dianhydride-co-4,4′-oxydianiline) amic acid solution (Kapton precursor) in N-Methyl-2-pyrrolidone (NMP). The coated vials were heated to 150° C. and held for 20 minutes to evaporate the solvents. Thereafter, the coatings were cured by placing the coated vials into a preheated furnace at 300° C. for 30 minutes. After curing, the vials coated with the 0.1% solution of NOVASTRAT® 800 had no visible color. However, the vials coated with the solution of poly(pyromellitic dianhydride-co-4,4′oxydianiline) were visibly yellow in color. Both coatings exhibited a low coefficient of friction in vial-to-vial contact tests.

Example 2

Glass vials formed from Schott Type 1B glass vials (as received/uncoated) and vials coated with a low-friction coating were compared to assess the loss of mechanical strength due to abrasion. The coated vials were produced by first ion exchange strengthening glass vials produced from the Reference Glass Composition. The ion exchange strengthening was performed in a 100% KNO₃bath at 450° C. for 8 hours. Thereafter, the vials were washed with deionized water, blown dry with nitrogen, and dip coated with a 0.1% solution of APS (aminopropylsilsesquioxane). The APS coating was dried at 100° C. in a convection oven for 15 minutes. The vials were then dipped into a 0.1% solution of NOVASTRAT® 800 polyamic acid in a 15/85 toluene/DMF solution. The coated vials were heated to 150° C. and held for 20 minutes to evaporate the solvents. Thereafter, the coatings were cured by placing the coated vials into a preheated furnace at 300° C. for 30 minutes. The coated vials were then soaked in 70° C. de-ionized water for 1 hour and heated in air at 320° C. for 2 hours to simulate actual processing conditions.

Unabraded vials formed from the Schott Type 1B glass and unabraded vials formed from the ion-exchange strengthened and coated Reference Glass Composition were tested to failure in a horizontal compression test (i.e., a plate was placed over the top of the vial and a plate was placed under the bottom of the vial and the plates were pressed together and the applied load at failure was determined with a load cell). FIG. 12 graphically depicts the failure probability as a function of applied load in a horizontal compression test for vials formed from a Reference Glass Composition, vials formed from a Reference Glass Composition in a coated and abraded condition, vials formed from Schott Type 1B glass, and vials formed from Schott Type 1B glass in an abraded condition. The failure loads of the unabraded vials are graphically depicted in the Weibull plots. Sample vials formed from the Schott Type 1B glass and unabraded vials formed from the ion-exchange strengthened and coated glass were then placed in the vial-on-vial jig of FIG. 9 to abrade the vials and determine the coefficient of friction between the vials as they were rubbed together over a contact area having a 0.3 mm diameter. The load on the vials during the test was applied with a UMT machine and was varied between 24 N and 44 N. The applied loads and the corresponding maximum coefficient of friction are reported in the Table contained in FIG. 13. For the uncoated vials, the maximum coefficient of friction varied from 0.54 to 0.71 (shown in FIG. 13 as vial samples “3&4” and “7&8”, respectively) and while for the coated vials the maximum coefficient of friction varied from 0.19 to 0.41 (shown in FIG. 13 as vial samples “15&16” and “12&14”, respectively). Thereafter, the scratched vials were tested in the horizontal compression test to assess the loss of mechanical strength relative to the unabraded vials. The failure loads applied to the unabraded vials are graphically depicted in the Weibull plots of FIG. 12.

As shown in FIG. 12, the uncoated vials had a significant decrease in strength after abrasion whereas the coated vials had a relatively minor decrease in strength after abrasion. Based on these results, it is believed that the coefficient of friction between the vials should be less than 0.7 or 0.5, or even less than 0.45 in order to mitigate the loss of strength following vial-on-vial abrasion.

Example 3

In this example, multiple sets of glass tubes were tested in four point bending to assess their respective strengths. A first set of tubes formed from the Reference Glass Composition was tested in four point bending in as received condition (un-coated, non-ion exchange strengthened). A second set of tubes formed from the Reference Glass Composition was tested in four point bending after being ion exchange strengthened in a 100% KNO₃bath at 450° C. for 8 hours. A third set of tubes formed from the Reference Glass Composition was tested in four point bending after being ion exchange strengthened in a 100% KNO₃bath at 450° C. for 8 hours and coated with 0.1% APS/0.1% NOVASTRAT® 800 as described in Example 2. The coated tubes were also soaked in 70° C. de-ionized water for 1 hour and heated in air at 320° C. for 2 hours to simulate actual processing conditions. These coated tubes were also abraded in the vial-on-vial jig shown in FIG. 9 under a 30 N load prior to bend testing. A fourth set of tubes formed from the Reference Glass Composition was tested in four point bending after being ion exchange strengthened in a 100% KNO₃bath at 450° C. for 1 hour. These uncoated, ion exchange strengthened tubes were also abraded in the vial-on-vial jig shown in FIG. 9 under a 30 N load prior to bend testing. A fifth set of tubes formed from Schott Type 1B glass was tested in four point bending in as received condition (uncoated, non-ion exchange strengthened). A sixth set of tubes formed from Schott Type 1B glass was tested in four point bending after being ion exchange strengthened in a 100% KNO₃bath at 450° C. for 1 hour. The results of testing are graphically depicted in the Weibull plots displayed in FIG. 14.

Referring to FIG. 14, the second set of tubes which were non-abraded and formed from the Reference Glass Composition and ion exchange strengthened withstood the highest stress before breaking. The third set of tubes which were coated with the 0.1% APS/0.1% NOVASTRAT® 800 prior to abrading showed a slight reduction in strength relative to their uncoated, non-abraded equivalents (i.e., the second set of tubes). However, the reduction in strength was relatively minor despite being subjected to abrading after coating.

Example 4

Two sets of vials were prepared and run through a pharmaceutical filling line. A pressure sensitive tape (commercially available from FujiFilm) was inserted in between the vials to measure contact/impact forces between the vials and between the vials and the equipment. The first set of vials was formed from the Reference Glass Composition and was not coated. The second set of vials was formed from the Reference Glass Composition and was coated with a low-friction polyimide based coating having a coefficient of friction of about 0.25, as described above. The pressure sensitive tapes were analyzed after the vials were run through the pharmaceutical filling line and demonstrated that the coated vials of the second set exhibited a 2-3 times reduction in stress compared to the un-coated vials of the first set.

Example 5

Three sets of four vials each were prepared. All the vials were formed from the Reference Glass Composition. The first set of vials was coated with the APS/NOVASTRAT® 800 coating as described in Example 2. The second set of vials was dip coated with 0.1% DC806A in toluene. The solvent was evaporated at 50° C. and the coating was cured at 300° C. for 30 min. Each set of vials was placed in a tube and heated to 320° C. for 2.5 hours under an air purge to remove trace contaminants adsorbed into the vials in the lab environment. Each set of samples was then heated in the tube for another 30 minutes and the outgassed volatiles were captured on an activated carbon sorbent trap. The trap was heated to 350° C. over 30 minutes to desorb any captured material which was fed into a gas chromatograph-mass spectrometer. FIG. 15 depicts gas chromatograph-mass spectrometer output data for the APS/NOVASTRAT® 800 coating. FIG. 16 depicts gas chromatography-mass spectrometer output data for the DC806A coating. No outgassing was detected from the 0.1% APS/0.1% NOVASTRAT® 800 coating or the DC806A coating.

A set of four vials was coated with a tie-layer using 0.5%/0.5% GAPS/APhTMS solution in methanol/water mixture. Each vial had a coated surface area of about 18.3 cm². Solvent was allowed to evaporate at 120° C. for 15 min from the coated vials. Then a 0.5% NOVASTRAT® 800 solutions in dimethylacetamide was applied onto the samples. The solvent was evaporated at 150° C. for 20 min. These uncured vials were subjected to an outgassing test described above. The vials were heated to 320° C. in a stream of air (100 mL/min) and upon reaching 320° C. the outgassed volatiles were captured on an activated carbon sorbent traps every 15 min. The traps then were heated to 350° C. over 30 minutes to desorb any captured material which was fed into a gas chromatograph-mass spectrometer. Table 1 shows the amount of captured materials over the segments of time that the samples were held at 320° C. Time zero corresponds with the time that the sample first reached a temperature of 320° C. As seen in Table 1, after 30 min of heating the amount of volatiles decreases below the instrument detection limit of 100 ng. Table 1 also reports the volatiles lost per square cm of coated surface.

TABLE 1

Table 1. Volatiles per vial and per area.

Amount,
Amount

Time Period at 320° C.
ng/vial
ng/cm²

25° C. to 320° C. ramp (t = 0)
60404
3301

t = 0 to 15 min
9371
512

t = 15 to 30 min
321
18

t = 30 to 45 min
<100
<5

t = 45 to 60 min
<100
<5

t = 60 to 90 min
<100
<5

Example 6

A plurality of vials was prepared with various coatings based on silicon resin or polyimides with and without coupling agents. When coupling agents were used, the coupling agents included APS and GAPS (3-aminopropyltrialkoxysilane), which is a precursor for APS. The outer coating layer was prepared from NOVASTRAT® 800, the poly(pyromellitic dianhydride-co-4,4′oxydianiline) described above, or silicone resins such as DC806A and DC255. The APS/Kapton coatings were prepared using a 0.1% solution of APS (aminopropylsilsesquioxane) and 0.1% solution, 0.5% solution or 1.0% solutions of poly(pyromellitic dianhydride-co-4,4′-oxydianiline) amic acid (Kapton precursor) in N-methyl-2-pyrrolidone (NMP). Kapton coatings were also applied without a coupling agent using a 1.0% solution of the poly(pyromellitic dianhydride-co-4,4′oxydianiline) in NMP. The APS/NOVASTRAT® 800 coatings were prepared using a 0.1% solution of APS (aminopropylsilsesquioxane) and a 0.1% solution of NOVASTRAT® 800 polyamic acid in a 15/85 toluene/DMF solution. The DC255 coatings were applied directly to the glass without a coupling agent using a 1.0% solution of DC255 in Toluene. The APS/DC806A coatings were prepared by first applying a 0.1% solution of APS in water and then a 0.1% solution or a 0.5% solution of DC806A in toluene. The GAPS/DC806A coatings were applied using a 1.0% solution of GAPS in 95 wt. % ethanol in water as a coupling agent and then a 1.0% solution of DC806A in toluene. The coupling agents and coatings were applied using dip coating methods as described herein with the coupling agents being heat treated after application and the silicon resin and polyimide coatings being dried and cured after application. The coating thicknesses were estimated based on the concentrations of the solutions used. The Table contained in FIG. 17 lists the various coating compositions, estimated coating thicknesses and testing conditions.

Thereafter, some of the vials were tumbled to simulate coating damage and others were subjected to abrasion under 30 N and 50 N loads in the vial-on-vial jig depicted in FIG. 9. Thereafter, all the vials were subjected to a lyophilization (freeze drying process) in which the vials were filled with 0.5 mL of sodium chloride solution and then frozen at −100° C. Lyophilization was then performed for 20 hours at −15° C. under vacuum. The vials were inspected with optical quality assurance equipment and under microscope. No damage to the coatings was observed due to lyophilization.

Example 7

Three sets of six vials were prepared to assess the effect of increasing load on the coefficient of friction for uncoated vials and vials coated with Dow Corning DC 255 silicone resin. A first set of vials was formed from Type 1B glass and left uncoated. The second set of vials was formed from the Reference Glass Composition and coated with a 1% solution of DC255 in Toluene and cured at 300° C. for 30 min. The third set of vials was formed from Schott Type 1B glass and coated with a 1% solution of DC255 in Toluene. The vials of each set were placed in the vial-on-vial jig depicted in FIG. 9 and the coefficient of friction relative to a similarly coated vial was measured during abrasion under static loads of 10 N, 30 N, and 50 N. The results are graphically reported in FIG. 18. As shown in FIG. 18, coated vials showed appreciably lower coefficients of friction compared to uncoated vials when abraded under the same conditions irrespective of the glass composition.

Example 8

Three sets of two glass vials were prepared with an APS/Kapton coating. First, each of the vials was dip coated in a 0.1% solution of APS (aminopropylsilsesquioxane). The APS coating was dried at 100° C. in a convection oven for 15 minutes. The vials were then dipped into a 0.1% poly(pyromellitic dianhydride-co-4,4′-oxydianiline) amic acid solution (Kapton precursor) in N-methyl-2-pyrrolidone (NMP). Thereafter, the coatings were cured by placing the coated vials into a preheated furnace at 300° C. for 30 minutes.

Two vials were placed in the vial-on-vial jig depicted in FIG. 9 and abraded under a 10 N loaded. The abrasion procedure was repeated 4 more times over the same area and the coefficient of friction was determined for each abrasion. The vials were wiped between abrasions and the starting point of each abrasion was positioned on a previously non-abraded area. However, each abrasion traveled over the same “track”. The same procedure was repeated for loads of 30 N and 50 N. The coefficients of friction of each abrasion (i.e., A1-A5) are graphically depicted in FIG. 19 for each load. As shown in FIG. 19, the coefficient of friction of the APS/Kapton coated vials was generally less than 0.30 for all abrasions at all loads. The examples demonstrate improved resistance to abrasion for polyimide coating when applied over a glass surface treated with a coupling agent.

Example 9

Three sets of two glass vials were prepared with an APS coating. Each of the vials were dip coated in a 0.1% solution of APS (aminopropylsilsesquioxane) and heated at 100° C. in a convection oven for 15 minutes. Two vials were placed in the vial-on-vial jig depicted in FIG. 9 and abraded under a 10 N load. The abrasion procedure was repeated 4 more times over the same area and the coefficient of friction was determined for each abrasion. The vials were wiped between abrasions and the starting point of each abrasion was positioned on a previously non-abraded area. However, each abrasion traveled over the same “track”. The same procedure was repeated for loads of 30 N and 50 N. The coefficients of friction of each abrasion (i.e., A1-A5) are graphically depicted in FIG. 20 for each load. As shown in FIG. 20, the coefficient of friction of the APS only coated vials is generally higher than 0.3 and often reached 0.6 or even higher.

Example 10

Three sets of two glass vials were prepared with an APS/Kapton coating. Each of the vials was dip coated in a 0.1% solution of APS (aminopropylsilsesquioxane). The APS coating was heated at 100° C. in a convection oven for 15 minutes. The vials were then dipped into a 0.1% poly(pyromellitic dianhydride-co-4,4′-oxydianiline) amic acid solution (Kapton precursor) in N-methyl-2-pyrrolidone (NMP). Thereafter, the coatings were cured by placing the coated vials in into a preheated furnace at 300° C. for 30 minutes. The coated vials were then depyrogenated (heated) at 300° C. for 12 hours.

Two vials were placed in the vial-on-vial jig depicted in FIG. 9 and abraded under a 10 N load. The abrasion procedure was repeated 4 more times over the same area and the coefficient of friction was determined for each abrasion. The vials were wiped between abrasions and the starting point of each abrasion was positioned on a previously abraded area and each abrasion was performed over the same “track”. The same procedure was repeated for loads of 30 N and 50 N. The coefficients of friction of each abrasion (i.e., A1-A5) are graphically depicted in FIG. 21 for each load. As shown in FIG. 21, the coefficients of friction of the APS/Kapton coated vials were generally uniform and approximately 0.20 or less for the abrasions introduced at loads of 10 N and 30 N. However, when the applied load was increased to 50 N, the coefficient of friction increased for each successive abrasion, with the fifth abrasion having a coefficient of friction slightly less than 0.40.

Example 11

Three sets of two glass vials were prepared with an APS (aminopropylsilsesquioxane) coating. Each of the vials was dip coated in a 0.1% solution of APS and heated at 100° C. in a convection oven for 15 minutes. The coated vials were then depyrogenated (heated) at 300° C. for 12 hours. Two vials were placed in the vial-on-vial jig depicted in FIG. 9 and abraded under a 10 N loaded. The abrasion procedure was repeated 4 more times over the same area and the coefficient of friction was determined for each abrasion. The vials were wiped between abrasions and the starting point of each abrasion was positioned on a previously abraded area and each abrasion traveled over the same “track”. The same procedure was repeated for loads of 30 N and 50 N. The coefficients of friction of each abrasion (i.e., A1-A5) are graphically depicted in FIG. 22 for each load. As shown in FIG. 22, the coefficients of friction of the APS coated vials depyrogenated for 12 hours were significantly higher than the APS coated vials shown in FIG. 20 and were similar to coefficients of friction exhibited by uncoated glass vials, indicating that the vials may have experienced a significant loss of mechanical strength due to the abrasions.

Example 12

Three sets of two glass vials formed from Schott Type 1B glass were prepared with a Kapton coating. The vials were dipped into a 0.1% poly(pyromellitic dianhydride-co-4,4′-oxydianiline) amic acid solution (Kapton precursor) in N-Methyl-2-pyrrolidone (NMP). Thereafter, the coatings were dried at 150° C. for 20 min and then cured by placing the coated vials in into a preheated furnace at 300° C. for 30 minutes.

Two vials were placed in the vial-on-vial jig depicted in FIG. 9 and abraded under a 10 N loaded. The abrasion procedure was repeated 4 more times over the same area and the coefficient of friction was determined for each abrasion. The vials were wiped between abrasions and the starting point of each abrasion was positioned on a previously non-abraded area. However, each abrasion traveled over the same “track”. The same procedure was repeated for loads of 30 N and 50 N. The coefficients of friction of each abrasion (i.e., A1-A5) are graphically depicted in FIG. 23 for each load. As shown in FIG. 23, the coefficients of friction of the Kapton coated vials generally increased after the first abrasion demonstrating poor abrasion resistance of a polyimide coating applied onto a glass without a coupling agent.

Example 13

The APS/NOVASTRAT® 800 coated vials of Example 6 were tested for their coefficient of friction after lyophilization using a vial-on-vial jig shown in FIG. 9 with a 30 N load. No increase in coefficient of friction was detected after lyophilization. FIG. 24 contains Tables showing the coefficient of friction for the APS/NOVASTRAT® 800 coated vials before and after lyophilization.

Example 14

The Reference Glass Composition vials were ion exchanged and coated as described in Example 2. The coated vials were autoclaved using the following protocol: 10 minute steam purge at 100° C., followed by a 20 minute dwelling period wherein the coated glass container 100 is exposed to a 121° C. environment, followed by 30 minutes of treatment at 121° C. The coefficient of friction for autoclaved and non-autoclaved vials was measured using a vial-on-vial jig shown in FIG. 9 with 30 N load. FIG. 26 shows the coefficient of friction for APS/NOVASTRAT® 800 coated vials before and after autoclaving. No increase in coefficient of friction was detected after autoclaving.

Example 15

Three sets of vials were prepared to assess the efficacy of coatings on mitigating damage to the vials. A first set of vials was coated with a polyimide outer coating later with an intermediate coupling agent layer. The outer layer consisted of the NOVASTRAT® 800 polyimide, which was applied as a solution of polyamic acid in dimethylacetamide and imidized by heating to 300° C. The coupling agent layer consisted of the APS and aminophenyltrimethoxysilane (APhTMS) in a 1:8 ratio. These vials were depyrogenated for 12 hours at 320° C. As with the first set of vials, the second set of vials was coated with a polyimide outer coating layer with an intermediate coupling agent layer. The second set of vials was depyrogenated for 12 hours at 320° C. and then autoclaved for 1 hour at 121° C. A third set of vials was left uncoated. Each set of vials was then subjected to a vial-on-vial frictive test under a 30 N load. The coefficient of friction for each set of vials is reported in FIG. 27. Photographs of the vial surface showing damage (or the lack of damage) experienced by each vial is also depicted in FIG. 27. As shown in FIG. 27, the uncoated vials generally had a coefficient of friction greater than about 0.7. The uncoated vials also incurred visually perceptible damage as a result of the testing. However, the coated vials had a coefficient of friction of less than 0.45 without any visually perceptible surface damage.

The coated vials were also subjected to depyrogenation, as described above, autoclave conditions, or both. FIG. 25 graphically depicts the failure probability as a function of applied load in a horizontal compression test for the vials. There was no statistical difference between depyrogenated vials and depyrogenated and autoclaved vials.

Example 16

Referring now to FIG. 28, vials were prepared with three different coating compositions to assess the effect of different ratios of silanes on the coefficient of friction of the applied coating. The first coating composition included a coupling agent layer having a 1:1 ratio of GAPS to aminophenyltrimethyloxysilane and an outer coating layer which consisted of 1.0% NOVASTRAT® 800 polyimide. The second coating composition included a coupling agent layer having a 1:0.5 ratio of GAPS to aminophenyltrimethyloxysilane and an outer coating layer which consisted of 1.0% Novastrat® 800 polyimide. The third coating composition included a coupling agent layer having a 1:0.2 ratio of GAPS to aminophenyltrimethyloxysilane and an outer coating layer which consisted of 1.0% NOVASTRAT® 800 polyimide. All the vials were depyrogenated for 12 hours at 320° C. Thereafter, the vials were subjected to a vial-on-vial frictive test under loads of 20 N and 30 N. The average applied normal force, coefficient of friction, and maximum frictive force (Fx) for each vial is reported in FIG. 28. As shown in FIG. 28, decreasing the amount of aromatic silane (i.e., the aminophenytrimethyloxysilane) increases the coefficient of friction between the vials as well as the frictive force experienced by the vials.

Example 17

Vials formed from type 1B ion-exchanged glass were prepared with low-friction coatings have varying ratios of silanes.

Samples were prepared with a composition which included a coupling agent layer formed from 0.125% APS and 1.0% aminophenyltrimethyloxysilane (APhTMS), having a ratio of 1:8, and an outer coating layer formed from 0.1% NOVASTRAT® 800 polyimide. The thermal stability of the applied coating was evaluated by determining the coefficient of friction and frictive force of vials before and after depyrogenation. Specifically, coated vials were subjected to a vial-on-vial frictive test under a load of 30 N. The coefficient of friction and frictive force were measured and are plotted in FIG. 29 as a function of time. A second set of vials were depyrogenated for 12 hours at 320° C. and subjected to the same vial-on-vial frictive test under a load of 30 N. The coefficient of friction remained the same both before and after depyrogenation indicating that the coatings were thermally stable. A photograph of the contacted area of the glass is also shown.

Samples were prepared with a composition which included a coupling agent layer formed from 0.0625% APS and 0.5% aminophenyltrimethyloxysilane (APhTMS), having a ratio of 1:8, and an outer coating layer formed from 0.05% NOVASTRAT® 800 polyimide. The thermal stability of the applied coating was evaluated by determining the coefficient of friction and frictive force of vials before and after depyrogenation. Specifically, coated vials were subjected to a vial-on-vial frictive test under a load of 30 N. The coefficient of friction and frictive force were measured and are plotted in FIG. 37 as a function of time. A second set of vials were depyrogenated for 12 hours at 320° C. and subjected to the same vial-on-vial frictive test under a load of 30 N. The coefficient of friction remained the same both before and after depyrogenation indicating that the coatings were thermally stable. A photograph of the contacted area of the glass is also shown.

FIG. 38 graphically depicts the failure probability as a function of applied load in a horizontal compression test for the vials with low-friction coatings formed from 0.125% APS and 1.0% aminophenyltrimethyloxysilane (APhTMS), having a ratio of 1:8, and an outer coating layer formed from 0.1% NOVASTRAT® 800 polyimide (Shown as “260” on FIG. 38), and formed from 0.0625% APS and 0.5% aminophenyltrimethyloxysilane (APhTMS), having a ratio of 1:8, and an outer coating layer formed from 0.05% Novastrat® 800 polyimide (Shown as “280” on FIG. 38). A photograph of the contacted area of the glass is also shown. The data shows that failure load remains unchanged from uncoated unscratched samples for coated, depyrogenated, and scratched samples demonstrating glass protection from damage by the coating.

Vials were prepared with low-friction coatings have varying ratios of silanes. Samples were prepared with a composition which included a coupling agent layer formed from 0.5% Dynasylan® Hydrosil 1151 and 0.5% aminophenyltrimethyloxysilane (APhTMS), having a ratio of 1:1, and an outer coating layer formed from 0.05% NOVASTRAT® 800 polyimide. The thermal stability of the applied coating was evaluated by determining the coefficient of friction and frictive force of vials before and after depyrogenation. Specifically, coated vials were subjected to a vial-on-vial frictive test under a load of 30 N. The coefficient of friction and frictive force were measured and are plotted in FIG. 39 as a function of time. A second set of vials were depyrogenated for 12 hours at 320° C. and subjected to the same vial-on-vial frictive test under a load of 30 N. The coefficient of friction remained the same both before and after depyrogenation indicating that the coatings were thermally stable. A photograph of the contacted area of the glass is also shown. This suggests that hydrolysates of aminosilanes, such as aminosilsesquioxanes, are useful in the coating formulations as well.

The thermal stability of the applied coating was also evaluated for a series of depyrogenation conditions. Specifically, type 1B ion-exchanged glass vials were prepared with a composition which included a coupling agent layer having a 1:1 ratio of GAPS (0.5%) to aminophenyltrimethyloxysilane (0.5%) and an outer coating layer which consisted of 0.5% NOVASTRAT® 800 polyimide. Sample vials were subjected to one of the following depyrogenation cycles: 12 hours at 320° C.; 24 hours at 320° C.; 12 hours at 360° C.; or 24 hours at 360° C. The coefficient of friction and frictive force were then measured using a vial-on-vial frictive test and plotted as a function of time for each depyrogenation condition, as shown in FIG. 30. As shown in FIG. 30, the coefficient of friction of the vials did not vary with the depyrogenation conditions indicating that the coating was thermally stable. FIG. 40 graphically depicts the coefficient of friction after varying heat treatment times at 360° C. and 320° C.

Example 18

Vials were coated as described in Example 2 with a APS/NOVASTRAT 800 coating. The light transmission of coated vials, as well as uncoated vials, was measured within a range of wavelengths between 400-700 nm using a spectrophotometer. The measurements are performed such that a light beam is directed normal to the container wall such that the beam passes through the low-friction coating twice, first when entering the container and then when exiting it. FIG. 11 graphically depicts the light transmittance data for coated and uncoated vials measured in the visible light spectrum from 400-700 nm. Line 440 shows an uncoated glass container and line 442 shows a coated glass container.

Example 19

Vials were coated with a 0.25% GAPS/0.25% APhTMS coupling agent and 1.0% NOVASTRAT® 800 polyimide and were tested for light transmission before and after depyrogenation at 320° C. for 12 hours. An uncoated vial was also tested. Results are shown in FIG. 46.

Example 20

To improve polyimide coating uniformity, the Novastrat® 800 polyamic acid was converted into polyamic acid salt and dissolved in methanol, significantly faster evaporating solvent compared to dimethylacetamide, by adding 4 g of triethylamine to 1L of methanol and then adding NOVASTRAT® 800 polyamic acid to form 0.1% solution.

Coating on 1B ion-exchanged vials formed from 1.0% GAPS/1.0% APhTMS in methanol/water mixture and 0.1% NOVASTRAT® 800 polyamic acid salt in methanol. The coated vials were depyrogenated for 12 h at 360° C. and undepyrogenated and depyrogenated samples were scratched in vial-on-vial jig at 10, 20 and 30 N normal loads. No glass damage was observed at normal forces of 10 N, 20 N and 30 N. FIG. 41 shows the coefficient of friction, applied force and frictive force for the samples after a heat treatment at 360° C. for 12 hours. FIG. 42 graphically depicts the failure probability as a function of applied load in a horizontal compression test for the samples. Statistically the sample series at 10 N, 20N, and 30 N were indistinguishable from each other. The low load failure samples broke from origins located away from the scratch.

The thickness of the coating layers was estimated using ellipsometry and scanning electron microscopy (SEM), shown in FIGS. 43-45, respectively. The samples for coating thickness measurements were produced using silicon wafer (ellipsometry) and glass slides (SEM). The methods show thicknesses varying from 55 to 180 nm for silsesquioxane tie-layer and 35 nm for NOVASTRAT® 800 polyamic acid salt.

Example 21

Plasma cleaned Si wafer pieces were dip coated using 0.5% GAPS, 0.5% APhTMS solution in 75/25 methanol/water vol/vol mixture. The coating was exposed to 120° C. for 15 minutes. The coating thickness was determined using ellipsometry. Three samples were prepared, and had thicknesses of 92.1 nm, 151.7 nm, and 110.2 nm, respectively, with a standard deviation of 30.6 nm.

Glass slides were dip coated and examined with a scanning electron microscope. FIG. 43 shows an SEM image glass slide dipped in a coating solution of 1.0% GAPS, 1.0% APhTMS, and 0.3% NMP with an 8 mm/s pull out rate after a curing at 150° C. for 15 minutes. The coating appears to be about 93 nm thick. FIG. 44 shows an SEM image glass slide dipped in a coating solution of 1.0% GAPS, 1.0% APhTMS, and 0.3% NMP with a 4 mm/s pull out rate after a curing at 150° C. for 15 minutes. The coating appears to be about 55 nm thick. FIG. 45 shows an SEM image glass slide dipped in a coating solution of 0.5 NOVASTRAT® 800 solution with a 2 mm/s pull up rate after a curing at 150° C. for 15 min and heat treatment at 320° C. for 30 minutes. The coating appears to be about 35 nm thick.

Comparative Example A

Glass vials formed from a Type 1B glass were coated with a diluted coating of Bayer Silicone aqueous emulsion of Baysilone M with a solids content of about 1-2%. The vials were treated at 150° C. for 2 hours to drive away water from the surface leaving a polydimethylsiloxane coating on the exterior surface of the glass. The nominal thickness of the coating was about 200 nm. A first set of vials were maintained in untreated condition (i.e., the “as-coated vials”). A second set of vials were treated at 280° C. for 30 minutes (i.e., the “treated vials”). Some of the vials from each set were first mechanically tested by applying a scratch with a linearly increasing load from 0-48 N and a length of approximately 20 mm using a UMT-2 tribometer. The scratches were evaluated for coefficient of friction and morphology to determine if the scratching procedure damaged the glass or if the coating protected the glass from damage due to scratching.

FIG. 33 is a plot showing the coefficient of friction, scratch penetration, applied normal force, and frictional force (y-ordinates) as a function of the length of the applied scratch (x-ordinate) for the as-coated vials. As graphically depicted in FIG. 33, the as-coated vials exhibited a coefficient of friction of approximately 0.03 up to loads of about 30 N. The data shows that below approximately 30 N, the COF is always below 0.1. However, at normal forces greater than 30 N, the coating began to fail, as indicated by the presence of glass checking along the length of scratch. Glass checking is indicative of glass surface damage and an increased propensity of the glass to fail as a result of the damage.

FIG. 34 is a plot showing the coefficient of friction, scratch penetration, applied normal force, and frictional force (y-ordinates) as a function of the length of the applied scratch (x-ordinate) for the treated vials. For the treated vials, the coefficient of friction remained low until the applied load reached a value of approximately 5 N. At that point the coating began to fail and the glass surface was severely damaged as evident from the increased amount of glass checking which occurred with increasing load. The coefficient of friction of the treated vials increased to about 0.5. However, the coating failed to protect the surface of the glass at loads of 30 N following thermal exposure, indicating that the coating was not thermally stable.

The vials were then tested by applying 30 N static loads across the entire length of the 20 mm scratch. Ten samples of as-coated vials and ten samples of treated vials were tested in horizontal compression by applying a 30 N static load across the entire length of the 20 mm scratch. None of the as-coated samples failed at the scratch while 6 of the 10 treated vials failed at the scratch indicating that the treated vials had lower retained strength.

Comparative Example B

A solution of Wacker Silres MP50 (part #60078465 lot #EB21192) was diluted to 2% and was applied to vials formed from the Reference Glass Composition. The vials were first cleaned by applying plasma for 10 seconds prior to coating. The vials were dried at 315° C. for 15 minutes to drive off water from the coating. A first set of vials was maintained in “as-coated” condition. A second set of vials was treated for 30 minutes at temperatures ranging from 250° C. to 320° C. (i.e., “treated vials”). Some of the vials from each set were first mechanically tested by applying a scratch with a linearly increasing load from 0-48N and a length of approximately 20 mm using a UMT-2 tribometer. The scratches were evaluated for coefficient of friction and morphology to determine if the scratching procedure damaged the glass or if the coating protected the glass from damage due to scratching.

FIG. 35 is a plot showing the coefficient of friction, scratch penetration, applied normal force, and frictional force (y-ordinates) as a function of the length of the applied scratch (x-ordinate) for the as-coated vials. The as-coated vials exhibited damage to the coating, but no damage to the glass.

FIG. 36 is a plot showing the coefficient of friction, scratch penetration, applied normal force, and frictional force (y-ordinates) as a function of the length of the applied scratch (x-ordinate) for the treated vials treated at 280° C. The treated vials exhibited significant glass surface damage at applied loads greater than about 20 N. It was also determined that the load threshold to glass damage decreased with increasing thermal exposure temperatures, indicating that the coatings degraded with increasing temperature (i.e., the coating is not thermally stable). Samples treated at temperatures lower than 280° C. showed glass damage at loads above 30N.

Comparative Example C

Vials formed from the Reference Glass Composition were treated with Evonik Silikophen P 40/W diluted to 2% solids in water. The samples were then dried at 150° C. for 15 minutes and subsequently cured at 315° C. for 15 minutes. A first set of vials was maintained in “as-coated” condition. A second set of vials was treated for 30 minutes at a temperature of 260° C. (i.e., “the 260° C. treated vials”). A third set of vials was treated for 30 minutes at a temperature of 280° C. (i.e., “the 280° C. treated vials”). The vials were scratched with a static load of 30 N using the testing jig depicted in FIG. 9. The vials were then tested in horizontal compression. The 260° C. treated vials and the 280° C. treated vials failed in compression while 2 of 16 of the as-coated vials failed at the scratch. This indicates that the coating degraded upon exposure to elevated temperatures and, as a result, the coating did not adequately protect the surface from the 30 N load.

Example 22
Pharmaceutical Filling Line Trial 1

Within an isolator room, a filling line trial for approximately 8,000 conventional uncoated type 1B glass 3 mL vials (hereinafter “comparative uncoated vial samples”) and approximately 8,000 coated 3 mL glass vials having the composition and coating from Example 1 above (“coated glass vial samples”) was conducted. The filling line is a conventional isolator style filling line that fills up to 350 vials/min. The depyrogenation temperature is greater than 300° C. The estimated time on the line for each vial was about 30-40 minutes. The comparative uncoated vial samples and the coated glass vial samples were both filled with 1.25 mL of water. The line was cleaned using typical methods in between trials. For the conventional vials, Schott Fiolax 3 mL vials were used.

During this trial, there was an explicit focus to assess the particulate generation performance. Airborne and surface particles in the isolator and in-solution particles were all monitored. Supplemental airborne monitoring in the isolator was completed using four-inch silicon wafers that were placed at various locations. Surface particle monitoring was completed by wiping surfaces with adhesive carbon tape and performing SEM analysis prior to and following each trial. Manipulation of particle monitoring wafers and carbon tape were performed without opening the isolator. Particles in the liquid drug product were assessed by light obscuration according to USP <788> with samples from the beginning, middle and end of the trial. The isolator portion of the line was cleaned using standard protocols prior to the trial of each vial type.

Optical inspection revealed that both frictive surface damage and sub-surface fractures (glass checks) can be observed on these comparative uncoated vial samples (See FIG. 47) after the processing line trial, as will be explained. As shown in FIG. 47, the vial is covered with small checks, scratches and a ‘wear ring’ is present on the barrel near the shoulder indicating numerous impacts with adjacent glass vials during processing. The frictive surface damage results in particles of less than 50 μm to be generated. As shown in FIG. 47, evidence of large ‘holes’ in the surface suggest large particles of glass could also be ejected from the surface. Without being limited to any particular theory, larger particles are more likely to be created from a two-step process. In the first step, a glass check is formed from an initial impact, thereby creating a surface fracture when the surface is in tensile force. The second step occurs when the same damage location experiences another impact or frictive contact which thereby ejects the larger particle. Evidence of particles greater than 120 μm being ejected from uncoated vials was found on 8% of vials inspected. In contrast, FIG. 48 illustrates images of the coated glass vial samples that were processed similarly, yet only manifested what was determined to be minor coating scuffing. No glass damage was observed.

In addition to characterizing the improvements qualitatively, two methods were utilized to assess and quantify particle contamination during the actual trial. Specifically, surfaces within the isolator were wiped with adhesive carbon tape to inspect for surface particle contamination. Silicon wafers were also used as airborne gettering plates. The wafers were 4″ in diameter and placed in the isolator near the accumulator table at the same elevation as the vial mouth. Additionally, four silicon wafers were in the isolator and four silicon wafers were placed outside the isolator at the depyrogenation tunnel entrance and near the washing area.

The carbon tape was analyzed by scanning electron microscopy (SEM) for particle density and size analysis. For the uncoated vial samples, the particle composition was analyzed by energy dispersive x-ray spectroscopy (EDX) to determine if the particle is glass. Between 4 and 43% of particles analyzed were from borosilicate glass. EDX was also used to distinguish between particles from the comparative uncoated vial samples and particles from the coated vial samples. FIGS. 49A and 49B illustrate the difference in EDX spectra between the two compositions. Referring to FIG. 49B, which is the EDX spectra of the uncoated borosilicate vial sample, the presence of potassium and magnesium indicated the presence of glass particles on the carbon tape. In contrast as shown in FIG. 49A, the EDX spectra of the present coated vial samples indicates that none of the particles on the carbon tape were the glass composition of the coated vial samples.

Despite the standard isolator cleaning protocol, carbon tape indicated the presence of a substantial quantity of conventional glass particles prior to the line trial with the coated glass vial. This was also confirmed by compositional analysis. Without being bound by theory, some quantity of sub-visible particles detected during the coated vial trial is a result of the residual particle contamination left on the line after the control trial run with conventional vials. With this result in mind, even greater particle reduction would be achieved if the underlying conventional glass particle contamination was fully removed. FIG. 56 illustrates representative SEM images from the accumulator table following the trial. As shown, a significant quantity of glass particles were observed ranging in size from 1 to 15 μm.

Alternatively, clean silicon wafers of 100 mm size were placed in various regions near the processed containers in order to capture airborne particles during the trial. Wafers were placed at both container mouth elevation and near exhaust ports. A total of 156 particles were collected with 4 wafers in the isolator. Compared to the control run with conventional glass vials, the trial with the coated glass vial showed an 85% reduction in airborne particles in size from 20 to 120 μm near the accumulator table as indicated by the settling plates. The wafers were optically inspected and the nature of the particles was characterized.

Based on sampling, approximately half of the particles identified were obvious glass particles with a size range of 20 to 120 μm. Using qualitative visual inspection, the remainder of the particles were either fibrous or were unable to be determined. Over half of the particles were collected at the same elevation as the container mouth. It is worth noting that no container break events occurred in the isolator during this trial, thereby demonstrating that glass particles are still being generated despite a lack of broken containers.

The light obscuration technique according to USP <788> was used to measure particles in solution within vials filled during the trial. Particle reduction in the isolator environment correlates to particle reduction in containers (e.g., vials). Referring to Table 2 below, the analysis indicated at least a 50% reduction in particles in three size ranges.

TABLE 2

Glass
Filling line trial
2-10 μm
>10 μm
>25 μm

USP limit

None
6000
600

Coated Glass
Beginning
685.9
11.5
0.4

Vial Sample

Coated Glass
Middle
678.1
11.7
0.3

Vial Sample

Coated Glass
End
918.6
16.1
0.0

Vial Sample

Coated Glass

760.9
13.1
0.24

Vial Sample

(Average)

Comparative
Beginning
1261.7
19.7
0.1

Uncoated Glass

Vial Sample

Comparative
Middle
1393.4
31.4
1.2

Uncoated

Glass Vial

Sample

Comparative
End
1296.3
31.6
0.0

Uncoated

Glass Vial

Sample

Comparative

1317.2
27.6
0.42

Uncoated Glass

Vial Sample

(Average)

The above data confirms that glass-to-glass vial contact is a significant source of particles. It also suggests that environmental controls such as vertical laminar flow are not completely effective at preventing particles generated on the line from entering the vial. Even in well-designed isolator systems, horizontal surfaces of the equipment (e.g. conveyor surfaces) and even the bottom of the vial disrupt vertical laminar flow that is intended to sweep away contaminants.

The particle reduction results for this trial are summarized in Table 3.

TABLE 3

Control
Coated Vial
% reduction

Airborne particle count (wafer
156
23
85%

settling plate)

Solution particle counts (2-10 μm)*
1318
761
42%

Solution particle counts (>10 μm)*
28
14
50%

Solution particle counts (>25 μm)*
0.42
0.23
45%

*Measured using an average of 40 samples from beginning, middle and end of trial

Example 23
Laboratory Simulations
Scratch Test

Laboratory simulations were also used to replicate the interactions of the vials on pharmaceutical filling lines. Two types of simulations were evaluated in order to separate the effects of static loading and impact events. A vial scratching test was used to evaluate effect of static loading. Referring to the schematic of the test setup of FIG. 50, two containers are oriented orthogonally in a fixture with contact between barrels. A Nanovea CB500 mechanical tester applies a controlled, constant load and translates one of the vials linearly. As shown, the translation direction is 45 degrees relative to the barrel direction in order to produce a scratch in virgin surfaces on each container. Moving load forces are applied in order to create controlled scratch along the barrel. The test setup results in the scratches being produced in a virgin surface on both parts as the vials are moved. The load is controlled using a feedback loop. During the scratch generation, particles are ejected and are monitored in a nearby particle debris field. The debris field is microscopically inspected and the particles can be automatically counted using ImageJ vision software.

The comparative uncoated glass vial samples and the coated glass vial samples were tested under the vial scratch test with an applied load ranging between 1 to 30 N representing the range of forces measured on an actual filling line. The subsequent damage on the pair of vials was inspected using optical microscopy. The size of the damage site and the debris field increased in size with larger loads as result of increased Hertzian contact area. Furthermore, when a larger load was applied, particles were ejected further away resulting in a larger debris field. Fractographic analysis revealed that the morphology, size and severity of damage compares well with damage observed on vials processed through a filling line.

High resolution optical images of the debris fields were captured and analyzed by software to determine particle distributions. Depending on the load, hundreds to thousands of glass particles were generated from a single 1 mm scratch of the uncoated borosilicate glass vial samples as summarized in FIG. 51. All of the particles observed were in the sub-visible range (<50 μm) with the majority of particles being less than 5 μm. As shown, the particle distribution at each size range is similar regardless of load between 1 and 30 N.

Referring to FIG. 52, the effect of translational scratch speed on the uncoated borosilicate glass vial samples was also examined over the range of 6 to 120 mm/min to simulate the observed wide range of the speed of interactions observed on a filling line. A comparison of the distributions versus speed is shown in FIG. 52 for a 30 N applied load. Thus, the particle size distribution for each size range is independent over the range of applied loads and speeds evaluated using this method, thereby demonstrating that the mechanism of particle generation is consistent over the range of static interactions on the filling line.

In order to assess the efficiency of particle collection by the optical inspection of the debris field, damage sites were also imaged by scanning electron microscopy. The morphology of the scratch damage did not vary significantly by load over the range studied. The images indicated that the damage site contained a significant number of particles that were not ejected to the debris field; however, the size range of the particles was consistent with those counted in the debris field. Therefore, the debris field particles represent only a portion of the total particles generated. Even with the conservative view that excludes particles which are not ejected to the debris field, this study shows that a single glass to glass contact event can generate thousands of particles while the container is being processed in the filling line where it is open and vulnerable to particle contamination. Thus, the particle distribution generated is independent of the nature of the frictive contact event over the range of loads and speeds tested.

An SEM image of the debris field is illustrated in FIG. 53 confirming the particle sizes as measured optically. The morphology of the particles is jagged and irregular consistent with those particles identified in the damage site. Gentle manipulation of the scratched samples revealed that the particles are not well adhered to the glass surface. Lightly blown air or physical contact by a swab easily removed the particles from both the debris field and from the damaged area. As further evidence that particles are not well adhered to the glass surface, parts processed through a filling line lack an associated debris field near damaged areas. With the aid of air flow and physical contact in the filling area, it is anticipated that the majority of the particles are introduced into the filling line environment when the damage is originally created.

Similar scratch test results for coating coated glass vial samples did not produce any detectable glass particles. Although some coating scuffing is noted, well defined or systematically generated coating particles were also not observed. Thus the scratch test results demonstrated the same particle reduction benefit as demonstrated in the filling line trial.

Example 24
Pharmaceutical Filling Line Trial 2

An additional trial was undertaken to quantify the particle reduction benefit in the filling line environment. This trial included processing greater than 1 million 3 mL Schott IB vials on a conventional high-speed barrier-style filling line with downward laminar flow. The typical vial filling speed is 400-550 vials/min. The protocol was specifically focused on assessing particle response. In-line monitoring of airborne particles in the barrier was performed using conventional monitors used for monitoring filling lines (sensitive to particle sizes of 0.5 μm or greater). In addition, a detailed record for each operator intervention was also maintained. The results were then compared to a conventional glass vial run. A standard line cleaning was performed prior to each run.

While processing conventional glass vials on the fill line, frequent operator interventions as noted in Table 4 below were required to alleviate jammed, tipped or broken vials or to clean specific container guide surfaces. Interventions tend to further elevate the contamination risk of all airborne particles by disrupting the laminar flow and disturbing settled particles. Referring to Table 4 below, with the coated glass vial, the machinability improved remarkably versus the control as evidenced by a 61% reduction in interventions and a 36% increase in effective line throughput. This suggests an overall lower level of contamination than what is traditionally experienced during a filling campaign. Particle monitoring showed a 96% reduction in peak particle levels above the post-depyrogenation accumulator table, where the vials are open and at risk to environmental contamination. Additionally, there was a decrease in particle spikes, which are temporary increases in airborne particle counts due to the disturbance of air flow, the dislodging of settled particles, or another temporary cause. Particle spikes are measured by determining the number of particles over time and locating time intervals wherein there is a sharp increase or decrease of particle generation. Complete line trial results are summarized in Table 4.

TABLE 4

Control
Coated Glass Vial

Peak particle count (0.5 μm/CM)
8609
337

Total particle spikes
59
36

Particle spikes at in-feed
50
4

Interventions
247
95

Example 25
Comparison to Silicone Coated Borosilicate Cartridges

Referring to FIGS. 54 and 55, the scratch test performance of the present coated ion exchanged glass cartridges having the composition of Example 1 and the Schott FIOLAX® silicone coated borosilicate cartridges (Comparative Example A) is shown, respectively. Comparing FIG. 54, which is the Weibull plot of Example 1, to FIG. 55, which is the Weibull plot of Comparative Example A, it is readily apparent that the Example 1 cartridge demonstrates approximately a tenfold improvement in failure load. As used herein, “failure load” is the load at which the glass article breaks.

For Example 1, the Weibull plot of FIG. 54 shows that there is no statistically significant difference in the article performance (as demonstrated by failure load) whether the scratch is conducted at a 1 N load or a 30 N load. Said another way, the Example 1 cartridge shows good wear resistance whether a 1 N load or 30 N load is used. In contrast, the Comparative Example A silicone coated article depicted in FIG. 55 shows a substantial change in failure load due to increasing scratch loads of 1 to 30 N. This deviation in FIG. 55 shows that the silicone is not fully protecting the vial because of coating deterioration. The coating deterioration results in glass damage and particle generation for the vials of Comparative Example A.

It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus it is intended that the specification cover the modifications and variations of the various embodiments described herein provided such modification and variations come within the scope of the appended claims and their equivalents.

	Number	Date	Country
	61665682	Jun 2012	US
	61604220	Feb 2012	US

	Number	Date	Country
Parent	13780754	Feb 2013	US
Child	15153295		US

PHARMACEUTICAL GLASS COATING FOR ACHIEVING PARTICLE REDUCTION

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Date Filed

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CPC

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Abstract

Description

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CROSS-REFERENCE TO RELATED APPLICATIONS

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Continuation in Parts (1)