Patent Application
20190038508
The invention relates to a container consisting of plastic material, which is produced using the blow, fill and seal method, and the filling of which, enclosed by a container wall, can be autoclaved. The invention further relates to a method for producing a container of this type.
A high packing density is required when packaging bulky drugs and medicinal products such as infusion or flushing solutions, as unnecessarily large and heavy packages lead to high costs in terms of material use, transport, and storage. For this reason, the glass bottles frequently used in the past for infusion solutions have largely been replaced with plastic containers. In a particularly rational manner, containers of this type are produced by the known blow, fill and seal (BFS) method, which is also known in the professional world under the designation (DE 103 47 908 A1, DE 10 2013 012 809 A1) “bottelpack®-system”. A substantial advantage of such containers for medical and/or pharmaceutical applications is that the contents only come in contact with the polymer forming the container material, hence containers produced and filled using this BFS method ensure that the contents remain germ-free/sterile for prolonged periods.
In order to permit easy and safe handling of such containers, users prefer relatively rigid and stable bottles. For example, medications are injected into infusion solutions or emulsions or suspensions for infusion such as isotonic saline solution, mannitol or glucose solutions, for example. For cannulas, this can be accomplished much more easily using more rigid containers than using mechanically highly unstable, thin pouches.
However, as a consequence of this user requirement, rigid containers cannot be emptied completely without allowing a pressure equalization (aeration). In the case of glass containers, this is typically accomplished using suitable aerated infusion devices (see FIG. 1 in DIN EN ISO 8536-4:2011- 01). However, for medical reasons aeration is not desired because of the associated risk of microbial contamination; hence preference is given to non-aerated infusion devices (see FIG. 2 in DIN EN ISO 8536-4:2011-01). On the other hand, for medical reasons it is necessary for infusion solutions in the sealed container to be terminally sterilized, which according to European specifications is achieved by autoclaving at temperatures of 121° C. for a period of at least 20 minutes. This means that polymers having a suitably high heat distortion temperature must be used for the container production. This precludes the use of soft polyethylene (LDPE) because of the excessively low heat distortion temperature and necessitates the use of substantially more rigid polypropylene. However, the autoclaving in a high temperature range and the convenient handling of relatively rigid polypropylene containers thus made possible negatively impact the discharge behavior of polypropylene containers during infusion processes without aeration if said containers are nearly completely filled and therefore contain only a small relative air volume. Whereas soft bottles and pouches collapse at small pressure differences, the rigidity of the container prevents such a pressure equalization.
In emergencies, infusions are frequently administered as pneumatic pressure infusions using pressure infusion apparatuses (ISO 8536-8). To this end, the infusion container is placed in an inflatable cuff, which exerts an increased pressure on the bottle from the outside and the contents of the bottle. Here again, a low restoring force of the container is a key criterion for ensuring that the infusion is as administered as quickly and as uniformly as possible.
To address these problems, the invention is based on the object of providing an autoclavable plastic container produced using the BFS method that, when almost completely filled, empties completely during the infusion process even without aeration.
In accordance with the invention, this object is achieved by a container having the features of claim 1 in its entirety.
In accordance with the characterizing part of claim 1, an essential feature of the invention is that at least one shaping means is provided in the container wall, which ensures, in spite of a high filling ratio, that the container wall collapses at least partially reducing the volume when the filler material is administered by infusion, without the container being aerated. The design resulting in the collapsing of the container wall and hence in the volume reduction of the inner volume of the container during the infusion process provides the advantageous opportunity of producing containers using the BFS method that, in spite of the use of more rigid materials, ensure a reliable discharge during infusion processes without aeration.
Plastic materials having high heat distortion temperatures such as polypropylene, which are sufficiently heat resistant to autoclaving, can thus be used with particular advantage as container materials well-suited for the BFS method.
In advantageous exemplary embodiments, the container wall is integrally formed with a hermetically sealed head part, which is arranged on one of its end faces and serves as an opening for extracting the container filler material. The containers can be easily produced in this form by means of molding tools of simple design.
In advantageous exemplary embodiments, the container is rectangularly shaped in terms of its basic design and has projecting wall parts on two opposite container wall sides as a shaping means, which are conically inclined, in pairs, toward one another and mutually form a cone angle (ifa) of 110° or less.
With particular advantage, the projecting wall part as the one shaping means can in each case form a shoulder surface in the form of a virtually isosceles triangle.
For a largely rectangular shape of the container, if one of its end faces is viewed from above, the width (Q) of a given container wall side in proportion (irsv) to the width (B) of an adjacent container wall side is preferably in the range of 0.7 to 1.2, wherein particular preference is given to the range of 0.8 to 1.1.
In a particularly advantageous manner, the arrangement can be such that starting from its two end faces and the allocatable container wall side, the shoulder surface slopes down, as a further shaping means in the form of a wall triangle, toward the projecting wall parts delimiting the cone angle (ifa), preferably at an angle of 30° to 60°, particularly preferably of 45°.
For facilitating the demolding process when blow molding and as a further shaping means, a gradually sloping recess can be formed on the opposite container wall sides, which recess extends in a center line along the longitudinal axis, ends at a distance from the bottom, and splits from there toward the adjacent front face into two end lines, which mutually form a 90° angle at the point of the transition to the center line.
In containers formed from rigid polypropylene material, the average thickness of the container wall is preferably 0.3 mm to 0.5 mm.
A hanging tab can advantageously be disposed on the front face forming a container bottom, which opposes and faces away from the front face with the head part. If the hanging tab is downfoldable, a recess can be formed on the container bottom, in which the downfolded hanging tab can be received in such a way that a level base remains on the container bottom.
In accordance with claim 11, a method for producing a container in accordance with any one of claims 1 through 10 is also the subject matter of the invention.
The invention is explained in detail in the following, with reference to the appended drawing, wherein:
The round head part 3 transitions via a radially projecting flat collar 10 and a neck 9 into the shoulder 11 forming the top end face of the container 1, which end face is rectangular in outline. In each case a container main wall 15 that extends to the bottom 17 adjoins the two opposing side edges 13 of the sides of the rectangular outline of the shoulder 11. At the other two side edges of the shoulder 11, in each case a recessed, optional shoulder notch 19 is formed, adjoined by the side shoulders 21, which, together with other wall parts, form container wall sides 20 projecting from the rectangular basic shape. These side shoulders 21 have, adjacent to the associated optional shoulder notch 19, a side shoulder surface 23 having an approximately triangular outline, which surfaces are delimited on the outside by shoulder folds 25. These folds 25 mutually form a cone angle ifa of 110°. As can be discerned in the figures and most clearly in
In
The shaping means in accordance with the invention, which effect the collapsing of the container 1 during infusion processes performed without aeration in spite of a more rigid container material such as polypropylene, make it possible to provide the container 1 in accordance with the invention with a very high filling ratio. In the production of the container 1 using the BFS method, in accordance with the invention it is thus also possible to proceed in a supporting manner such that after the filling and prior to the sealing of the container 1, a pre-collapsing is performed that results in a reduction of the air volume remaining in the container 1. In the form of a schematic diagram,
As known per se for plastic containers from document DE 103 47 908 A1, the container in accordance with the invention can also consist of several layers of different polymers. Instead of the shown single access with the membrane on the circular cylindrical head part 3, the container can also be equipped with several accesses, preferably on the bottom and in the head area. Furthermore, a pierceable elastomer element can be inserted prior to sealing the container 1, which can be a single- or multi-component element. In addition, the heat part 3 can be equipped with a welded-on infusion cap, as known per se from DE 10 2013 012 809 A1, for example.
As described in the following, discharge tests were performed in order to compare the discharge behavior of the container 1 in accordance with the invention to the discharge behavior of typical standard containers without the shaping means in accordance with the invention:
A bp 364 Bottel-Pack® system (rommelag, Waiblingen, Germany) was used to manufacture water-filled and sealed single-piece infusion containers in accordance with the invention and standard containers having three different rated volumes (100 ml, 250 ml, 500 ml) and with an average wall thickness of 0.35-0.52 mm from different polypropylene materials (LyondellBasell RP 270G; Borealis SB 815 MO, Flint Hills Rexene 23M2A) using the blow, fill and seal method. Before sealing, some of the containers were pre-collapsed by an 8 mm travel distance of the die (47) and an infusion cap in accordance with ISO 15759 was then welded on as described above. The containers were subsequently sterilized by autoclaving at 121° C. for 20 min, and then the discharge behavior was measured and the maximum filling ratio was determined.
For measuring the discharge behavior, the containers were pierced using a non-aerated infusion device in accordance with DIN EN ISO 8536-4:2011-01, and the mass of the outflowing fluid was monitored over time on an analytical balance. The discharge took place via an 0.6 mm×30 mm injection cannula in accordance with ISO 13097. The measurements were taken at an ambient temperature of 21° C. The height of the fluid column (discharge height) was 775 mm.
In order to compare bottles of different volume classes to each other, the maximum filling ratio of the container, in other words the ratio of the experimentally determined total volume to the maximum filling volume, at which the container still drains, was chosen as a quality criterion for the evaluation. Unavoidably remaining quantities of fluid, for example quantities located in the head space below the opening of the puncturing mandrel of the infusion device, were not considered.
An increase of the maximum filling ratio means that a considerably smaller volume of air is needed in comparison to the standard containers, which has very advantageous consequences in terms of reduced pack sizes, packaging and transport costs, storage and disposal costs, etc.
The three materials used, as well as their moduli of elasticity (tensile modulus at 50 mm/min in accordance with ISO 527 and optionally bending modulus at 50 mm/min in accordance with ISO 178) and their densities in accordance with ISO 1183 at 23° C., are listed in the following table.
The results for standard containers (tests 1 and 2) and for the containers in accordance with the invention (tests 3-14) are summarized in the following table.
As can be discerned from the table of test results, in comparison to the standard containers a substantially higher maximum filling ratio is achievable with the invention, wherein it can also be discerned that particularly high filling ratios of up to 91% are achievable if pre-collapsing is performed (see test no. 11).
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2016 002 467.4 | Feb 2016 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/000191 | 2/10/2017 | WO | 00 |
