Conventional single-use bags, such as drip bags, often comprise polyethylene and are often sterilized using a gamma radiation treatment. Recently, preference has shifted away from gamma radiation treatment in favor of dry heat sterilization. However, polyethylene often cannot withstand the heat required to achieve the necessary sterilization.
A single-use bag that can withstand the temperatures of dry heat sterilization while not compromising flow control would be welcomed.
Various embodiments of the present disclosure provide a single-use bag composed of materials that can withstand the temperatures required for dry heat sterilization and further includes specialized clamps that accommodate the materials and construction techniques necessary for constructing the single-use bag for restriction and isolation of flow from the single-use bag. Single-use bags of the present invention are constructed to be capable of holding large volumes of liquid and frozen media while the bag is being suspended. Single-use bags are intended to be used once and then disposed.
A storage and dispensing system capable of storing a liquid or frozen medium and dispensing the medium is provided. The system includes a single-use bag, the bag including an inner film defining a bag interior and an outer film overlying the inner film. The inner film and the outer film are heat bonded together. The inner film is composed of perfluoroalkoxy alkane (PFA), and the outer film is composed of polytetrafluoroethylene (PTFE). The single-use bag defines at least one exit port on a bottom edge thereof. The storage and dispensing system also includes at least one closeable exit passage depending from the bottom edge of the single-use bag. The exit passage(s) are coupled to respective exit port(s) and are in fluid communication with the bag interior. The exit passage(s) can be unitary with the single-use bag. The inner film and the outer film can be laminated together.
The system can include a clamp having opposed jaws, each of the opposed jaws including a compliant member disposed on a rigid sub structure. The compliant members of the opposed jaws are capable of engaging each other along a line of contact when the opposed jaws are in a closed position. The clamp is configured to engage one of the exit passage(s) for restricting flow through the exit passage. The opposed jaws can be pivotally connected. The clamp can include a ratchet and pawl for locking the opposed jaws in a fixed relationship when the clamp is occupied by the exit passage. The compliant members can have a hardness in a range of Shore A 10 to Shore A 60, inclusive, and can have a thickness in a direction of closing the opposed jaws in a range of about 1 mm to about 5 mm inclusive. The compliant members can each include a partial sleeve configured to fit over a respective one of the rigid sub structures. The compliant members can be overmolded onto the rigid sub structures.
The foregoing will be apparent from the following more particular description of example embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating embodiments of the present invention.
While this invention will be particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
While various compositions and methods are described, it is to be understood that this invention is not limited to the particular molecules, compositions, designs, methodologies or protocols described, as these may vary. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or versions only, and is not intended to limit the scope of the present invention which will be limited only by the appended claims.
It must also be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural reference unless the context clearly dictates otherwise. Thus, for example, reference to a “film” is a reference to one or more films and equivalents thereof known to those skilled in the art, and so forth. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art. Methods and materials similar or equivalent to those described herein can be used in the practice or testing of versions of the present invention. All publications mentioned herein are incorporated by reference in their entirety. Nothing herein is to be construed as an admission that the invention is not entitled to antedate such disclosure by virtue of prior invention. “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not. All numeric values herein can be modified by the term “about,” whether or not explicitly indicated. The term “about” generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In some versions the term “about” refers to ±10% of the stated value, in other versions the term “about” refers to ±2% of the stated value. While compositions and methods are described in terms of “comprising” various components or steps (interpreted as meaning “including, but not limited to”), the compositions and methods can also “consist essentially of” or “consist of” the various components and steps, such terminology should be interpreted as defining essentially closed-member groups.
Referring to
In various embodiments, the single-use bag 32 includes an inner film defining a bag interior 52 and an outer film overlying said inner film, the inner film and the outer film being heat bonded (e.g., fused or welded) together along a seam 54 proximate an outer perimeter 56 of the single-use bag 32. The inner film and the outer film of the single-use bag 32 can remain distinct sheets of material, that is, they are bonded together only along seam 54. A cross-section view of single-use bag 32 with distinct inner and outer films is shown in
Alternatively, an inner film and an outer film can be laminated together (for example, bonded or fixed together over the entire contact area of the films) such that they form a single sheet of material having two layers, as shown in
The single-use bag 32 defines at least one exit port 62 formed at the bottom edge 48—a corresponding or respective exit port 62 for each of the at least one exit passage 34. In the embodiment depicted in
In assembly, the sheets are arranged so that the inner layers are facing toward each other and cut to the shape outlined in
Optionally, instead of two sheets, the single-use bag 32 can be assembled from a single sheet of material folded onto itself (for example, along the upper edge 42) so that an inner layer of the material faces itself. The single sheet of material can then be cut and sealed along the remaining edges (for example, along edges 44, 46, and 48).
In one embodiment, each sheet of material 66, 68 can have a thickness of about 2.5 mil (63.5 μm) to about 30 mil (762 μm), or of about 6 mil (152.4 μm) to about 15 mil (381 μm). As described above, each sheet of material can include at least two layers, including an inner layer (formed from a film of a first type) and an outer layer (formed from a film of a second type). The inner layer may alternatively be referred to as the wetted surface, and the outer layer may alternatively be referred to as the non-wetted surface.
Both the inner and outer layers can be composed of fluoropolymers. In a particular embodiment, the inner layer of each sheet is composed of perfluoroalkoxy alkane (PFA) and the outer layer of each sheet is composed of polytetrafluoroethylene (PTFE). The inner layer can have a thickness of about 0.5 mil (12.7 μm) to about 15 mil (381 μm), or of about 1 mil (25.4 μm) to about 5 mil (127 μm). The outer layer can have a thickness of about 2 mil (50.8 μm) to about 15 mil (381 μm), or of about 5 mil (127 μm) to about 10 mil (254
In further embodiments, the outer layer of each sheet can be composed of PTFE hybrid materials, including modified PTFE, such as PTFE modified with perfluoropropyl vinyl ether (PPVE). Modified PTFE provides improved fatigue resistance over standard PTFE and is described further in U.S. Pat. No. 7,407,708, the entire teachings of which are incorporated herein by reference. For example, modified PTFE can contain specific amounts of perfluoro alkyl residue on the main polymer chain that is useful in acting as a barrier against chemicals and can have reduced crystallinity, reducing the chance of fibrillation of the resin after several cycles of bending. The PTFE can be skived PTFE or extrudable PTFE (e.g., Moldflon™, ElringKlinger, Germany).
Functionally, the PFA and PTFE materials can withstand the temperatures of dry heat sanitation without adverse effects, which can range from 160° C. to 270° C. for some applications. Typically, 160° C. is the minimum temperature that is applied in dry heat sterilization, with a standard temperature range of about 160° C. to 170° C. However, it is often desirable to reach temperature ranges closer to depyrogenation, which may be up to 270° C. Higher temperatures can also reduce cycle time.
PFA is preferred for an inner layer as it is a flexible polymer with a low coefficient of friction and is inert to a large variety of chemicals and solvents. As such, an inner layer composed of PFA provides a wettable surface that will not react with solutions contained in the bag. Additionally, as films are cleaned prior to their assembly into single-use bags, PFA provides an easily cleanable material for use as an inner layer of single-use bags.
Skived PTFE is also inert to most chemicals and solvents; however, as compared to PFA, skived PTFE has a rough surface that lends itself to particulation and is more difficult to clean than PFA. Particulation is undesirable as it may contaminate the solution contained in the bag. PTFE is preferred for an outer layer as it provides strength and structure to the bag and has greater stress-cracking resistance than PFA. Stress-cracking, which can occur when the film materials are exposed to excessive tensile stress, can cause leaks in the single-use bag and is a concern during sterilization and dispensing processes, particularly for bags holding larger volumes of liquid. A bag formed from a sheet of material having an inner layer of PFA and an outer layer of PTFE is able to provide a secure, non-reactive vessel for a solution undergoing a dry heat sterilization process. An additional benefit of assembling a bag with an inner layer of PFA and an outer layer of PTFE is that PFA is capable of sealing at a lower temperature than PTFE. PFA has a melting point of about 305° C., and PTFE has a melting point of about 327° C. As such, during assembly of single-use bags, both materials need not be melted in order to seal sheets of material together (e.g., at seam 54).
In a further embodiment, an outer and/or inner layer of the bag is composed of extrudable PTFE, which has a smoother surface than skived PTFE. Extrudable PTFE can offer improved resistance to particulation due to its smoother surface and can serve as an inner layer of a bag.
To create a single sheet of material formed from PFA and PTFE, layers of PFA and PTFE undergo a lamination process. Due to the lower melting point of PFA, films of PFA can be heat bonded to films of PTFE over their entire surface area, forming a single composite material.
In a further embodiment, a skived PTFE film undergoes the lamination process described above and serves as both the inner and outer layers of a sheet of material from which a single-use bag may be assembled. After undergoing the lamination process, the surface texture of skived PTFE is transformed to a smoother surface, reducing the likelihood of particulation.
Single-use bags can have volumetric capacities of about 500 mL to about 20 L. For example, a single-use bag can have a capacity of 50 0 mL, 1 L, 2 L, 3 L, 5 L, 10 L, 15 L or 20 L. During dry-heat sterilization and/or dispensing, single-use bags 32 will typically be suspended. Seam 54 along edge 42 can include opening 14 through which a hook or other fixture can be threaded to suspend the bag 32 during the sterilization process. Single-use bags 32 are capable of withstanding the weight of volumes of liquid up to about 20 L while the bags are suspended and undergoing sterilization/dispensing processes.
Returning to
Referring to
The compliant members 106 are made of a soft material that complies with a contour of an object that is compressed between the opposed jaws 102 and 104. In various embodiments, the compliant members 106 have a hardness in a range of Shore A 10 to Shore A 60 inclusive. (Herein, a range that is said to be “inclusive” includes the endpoints of the stated range.) Each compliant member 106 can be further characterized as having a thickness 122 (
Referring to
Referring to
In operation, the clamp 160 is positioned so that, upon closure, the opposed jaws 102, 104 converge substantially at the plane 162. In this way, the sheets 66 and 68 are brought into planar alignment with the opposing edges 72 and 74. In various embodiments, the clamp 160 can pinch the sheets 66 and 68 together to provide a liquid-tight seal. In various embodiments, the seam 54 that defines the opposing edges 72 and 74 are thicker than the combined thicknesses of the two sheets 66 and 68. The compliant members 106 conform to the topography defined by the opposing edges 72 and 74 and the two sheets 66 and 68 to exert a pressure along the interface of the two sheets 66 and 68, thereby providing the seal. The clamp 160 can also be loosened to allow restricted flow through the exit passage 34. It is also contemplated that a single clamp (not depicted) could be utilized to restrict or isolate flow through more than one exit passage 34.
Referring to
In assembly, the fitment 216 is inserted between the sheets 66 and 68 along the bottom edge 204, and bonded to the bottom edge 204. The fitting(s) 202 are thus placed in fluid communication with the bag interior 52.
Referring to
The single-use bags 32 herein have been depicted with three exit passages 34, but can be made shorter and wider to accommodate more exit passages 34 along the bottom edge 48, 204. The configuration of a single-use bag having multiple exit passages will depend upon the volume of media intended to be stored and dispensed from the bag. A person having ordinary skill in the art can determine a suitable width of single-use bags 32 and a suitable number of exit passage(s) 34 based on the teachings in this application.
Each of the additional figures and methods disclosed herein can be used separately, or in conjunction with other features and methods, to provide improved devices and methods for making and using the same. Therefore, combinations of features and methods disclosed herein may not be necessary to practice the disclosure in its broadest sense and are instead disclosed merely to particularly describe representative and preferred embodiments.
Various modifications to the embodiments may be apparent to one of skill in the art upon reading this disclosure. For example, persons of ordinary skill in the relevant art will recognize that the various features described for the different embodiments can be suitably combined, un-combined, and re-combined with other features, alone, or in different combinations. Likewise, the various features described above should all be regarded as example embodiments, rather than limitations to the scope or spirit of the disclosure.
Persons of ordinary skill in the relevant arts will recognize that various embodiments can comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the claims can comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art.
Any incorporation by reference of documents above is limited such that no subject matter is incorporated that is contrary to the explicit disclosure herein. Any incorporation by reference of documents above is further limited such that no claims included in the documents are incorporated by reference herein. Any incorporation by reference of documents above is yet further limited such that any definitions provided in the documents are not incorporated by reference herein unless expressly included herein.
References to “embodiment(s)”, “disclosure”, “present disclosure”, “embodiment(s) of the disclosure”, “disclosed embodiment(s)”, and the like contained herein refer to the specification (text, including the claims, and figures) of this patent application that are not admitted prior art.
For purposes of interpreting the claims, it is expressly intended that the provisions of 35 U.S.C. 112(f) are not to be invoked unless the specific terms “means for” or “step for” are recited in the respective claim.
While this invention has been particularly shown and described with references to example embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention encompassed by the appended claims.
This application claims the benefit of U.S. Provisional Application No. 62/248,680, filed on Oct. 30, 2015, which is related to U.S. Provisional Application No. 62/145905, filed on Apr. 10, 2015, the contents of which are incorporated herein by reference in their entirety for all purposes.
Filing Document | Filing Date | Country | Kind |
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PCT/US2016/026658 | 4/8/2016 | WO | 00 |
Number | Date | Country | |
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62145905 | Apr 2015 | US | |
62248680 | Oct 2015 | US |