NO840110L - STERILIZABLE FILM MATERIALS FOR PRIMARY PACKAGING OF Aqueous MEDICAL SOLUTIONS - Google Patents

Description

The present invention relates to sterilizable foil materials

and their use for primary packaging of aqueous solutions in the medical field.

Infusion and transfer solutions are usually provided in glass bottles, plastic containers or pouch containers. Due to the shortcomings that come with the device material (energy-related high manufacturing costs, relatively high container weight, lack of fall resistance and problematic disposal of empty glass bottles), people have increasingly switched to using plastic containers for the storage or transfer of aqueous solutions in the medical field the area. Thereby to-

bag systems of plasticizer-containing polyvinyl chloride foils offer quite decisive advantages that make their use on the market so far without competition: the production of plasticizer-containing PVC bags can take place with a high frequency without problems arising when welding in supply and outlet pipe systems that are also made of PVC , such as e.g. filler pipes, insertion nozzles with membrane and injection channels with rubber membranes. The bags thus obtained show a high degree of flexibility, are largely transparent and do not tear open even when they fall to the ground in a filled state.

However, the application is precisely in the medical field

of with softener softened polyvinyl chloride for foil materials or the aforementioned bag systems are not entirely uncontroversial. However, it must be expected that the contents of the bag, especially solutions containing fat and blood serum, dissolve the plasticizer, usually di-2-ethylhexyl phthalate, from the foil material and foreign compounds are thus mixed in. Furthermore, the active substances in special solutions interact with soft-

PVC, e.g. by adsorption.

Usually bags made of soft PVC are steam sterilized at 110°C i

40 minutes or at 121°C for 20 minutes. Immediately after the steam sterilisation, the bag material is milky so that the content can only be assessed to an insufficient extent. Only after

the longer the storage, the better the transparency.

One of the objections due to the growing environmental concerns is that the empty soft PVC bags emit toxic hydrogen chloride vapors when disposed of in waste incineration plants and that their use must be restricted for these reasons.

The purpose of the present invention is to find an alternative material to the market-standard polyvinyl chloride softened with plasticizers for infusion solution bags. There must therefore be a material which no longer exhibits the described shortcomings of soft PVC and which at the same time brings the advantages of soft PVC<1>S into a new concept.

Accordingly, the present invention relates to sterilizable foil materials for primary packaging of aqueous solutions in the medical field which consist of a thermoplastic block copolymer, namely a polyether-ester-amide block copolymer of the general formula (i)

where A is a linear saturated aliphatic polyamide sequence, formed from a lactan or an animo acid with a hydrocarbon chain length of 4 to 14 carbon atoms or from an aliphatic CS to C12 dicarboxylic acid and a C6 to C9 diamine in the presence of a C4 to C20 aliphatic dicarboxylic acid as chain length limiter, wherein the polyamide has an average molecular weight between 300 and 15,000;

B means a polyoxyalkylene sequence formed from linear or branched aliphatic polyoxyalkylene glycols, mixtures thereof or cyclopolyether derivatives thereof, whereby the polyoxyalkylene glycol has an average molecular weight of 6000; and n is the number of repeating polymer units, which is such that the polyether-ester-amide block copolymer has an intrinsic viscosity of 0.8 to 2.05.

The mentioned polyether-ester-amide block copolymers are subject

for US-PS 4,331,786.

The material of the indicated general formula (I) exhibits i

its chemical structure a linear regular chain of rigid polyamide and flexible polyether segments.

The foils according to the invention contain no plasticizer in the sense that soft PVC contains a normal external plasticizer.

The foils of polyether blockamide can be produced as flat foils or as blown foils. This happens by filling polyetherblockamide granules in an extruder and feeding them out in a known manner through suitable nozzles. Immediately after the die, the foil material in its still plastic state is blown up using air to several times the outlet diameter and then pressed flat using a pair of rollers or turned flat. For the production of flat foils, the folding edges running along the side are then cut off, for the production of blown foils, the hose band thus produced can be further processed directly.

For hygienic reasons and because of the contamination-free further processing, blown films are preferable for use in the medical field.

The inflation process makes it possible to obtain very large hoses with small wall thicknesses without the nozzle needing to be as large and having to have a particularly narrow and thus delicate gap as with the later foil hose. With the blow extrusion method, a mono-tube foil can thus be produced with a wall thickness of 100 to 300 ym and preferably 150 to 200 ym.

Foils of the aforementioned materials and with the aforementioned wall thicknesses can be welded into bags in a very simple way using heat contact or heat impulse, preferably using the high-frequency method. A bag of this foil with an aqueous infusion solution as content can be sterilized without problems in a back pressure autoclave at 121°C and a loading time of 20 minutes without aids and without thermal deformation. The transparency of the foil material does not thereby deteriorate.

The sterilized bag exhibits excellent mechanical properties. In a drop resistance test according to DIN 58 363, part 15, point 4.1.4, a very high drop resistance was found.

In addition to the production of mono foils as described above, it is also possible to produce multi-layer foils. Numerous other thermoplastic materials suitable for foil production are suitable for this, such as polypropylene, high-density polyethylene, polyvinyl alcohol, polyethylene terephthalate, polybutylene terephthalate, linear low-density polyethylene ionomers, polyamide, elastomeric copolymers of ethylene and vinyl acetate, cellulose acetate or polyvinylidene chloride. . The purpose of such multi-layer foils which consist of a laminate of polyether-blockamide with the aforementioned thermoplastic materials is the production of foil bags with gas and water vapor barriers.

Thus, in order to reduce the oxygen or water vapor permeability, a foil could be produced by the coextrusion-blowing method with three layers of polyetherblockamide/polyvinylidene dichloride/polyetherblockamide.

The invention shall be explained in more detail with reference to relevant examples.

Example 1.

In a foil blowing plant, a mono-tube foil was blown with the help of the described copolyetheresteramide.

The extruder had a screw with a diameter of 60 mm and a length of

25 d. Connected to it was a ring nozzle with a diameter of 200 mm.

Extrusion conditions:

The foil was then processed by high-frequency welding to

500 ml bag containers. At the same time, postil inlet and outlet systems were welded in. These systems, like the foil, were produced from copolyether-ester-amide and were produced by injection molding and by tube extrusion.

The bag thus obtained was filled with an aqueous infusion solution (0.9% physiological saline solution) and steam-distilled at 120°C for 20 minutes without aids in a counter-pressure autoclave. Finally, the sterilized bag was judged against a non-sterilized bag.

The transparency was as good as before the sterilization. Deformation phenomena due to temperature stress could not be determined on the container material.

In accordance with DIN 58 363, part 15, point 4.1.4, a drop test with bags was carried out. All five bags passed this test.

Admittedly, the barrier properties against water vapor and oxygen were not yet satisfactory. Additional bags were then sealed into a steam-sterilizable transparent overwrap bag. Commercially available foils such as e.g. polyamide-polyethylene (50 ym/75 ym) and polyamide-polypropylene (70 pm/75 pm). Thereby, the polyamide layer provided a sufficient oxygen barrier and the polyolefin layer a sufficient water vapor barrier. Care was taken in the experiments that the re-shuffling bag lay as close as possible to the dissolution bag. With the help of a vacuum, this could be achieved.

Example 2.

A further embodiment for improving the water vapor and oxygen barrier properties of the foil according to the invention is the direct combination with one or more barrier layers. In co-extrusion, a three-layer hose foil was blown. The plan was a film with the following structure: copolyether-ester-amide/polyvinylidene chloride/copolyether-ester-amide.

The machine conditions for the extrusion were chosen as in the example

1, however, the following changes were made:

3 substances were brought together in a ring nozzle by means of 3 extruders

Extruders 1 and 2 fed copolyether ester amide and the 3rd extruder fed polyvinylidene chloride to the ring die.

A transparent hose foil was obtained with the following layer thicknesses:

From this foil, bags with closure systems were produced by high-frequency welding and these were judged by the same tests as in example 1.

The filled bags showed the same good results after steam sterilization at 121°C for 20 minutes. In contrast to the mono hose foil, good gas and water vapor barrier properties were also measured.

Claims (6)

1. Sterilizable foil materials for primary packaging of aqueous solutions in the medical field, characterized in that they consist of a thermoplastic block copolymer with the general formula (I) where A is a linear, saturated aliphatic polyamide sequence, consisting of a lactan or an amino acid with a hydrocarbon chain of 4 to 14 carbon atoms or of an aliphatic, 6 to 12 carbon atom containing dicarboxylic acid and a 6 to 9 carbon atom containing diamine in the presence of a chain length-limiting, aliphatic dicarboxylic acid of 4 to 20 carbon atoms, whereby the polyamide exhibits an average molecular weight between 300 and 15,000; B means a polyoxyalkylene sequence, consisting of linear or branched, aliphatic polyoxyalkylene glycols, their mixtures or copolyether derivatives, whereby the polyoxyalkylene glycols have an average molecular weight of 6000; and n means the number of repeating polymer units such that the polyether-ester-amide block copolymer exhibits an intrinsic viscosity of 0.8 to 2.05. 2. Foil material according to claim 1, characterized in that it has a thickness of 100 to 300 ym and preferably 150 to 200 ym. 3. Foil material according to claims 1 and 2, characterized in that it can be sterilized without thermal deformation and without loss of transparency at 121°C for 20 minutes without additional wrapping. 4. Sterilizable foil material, characterized in that it is formed as a composite foil of several layers whereby one layer of the foil material according to claims 1-3 encloses a layer of another thermoplastic material on both sides. 5. Foil material according to claim 4, characterized in that polypropylene, high-density polyethylene, polyvinyl alcohol, polyethylene terephthalate, polybutylene terephthalate, linear low-density polyethylene, ionomers, polyamide, elastomeric copolymers of ethylene and vinyl acetate, cellulose acetate or polyvinyl chloride are used as thermoplastic materials. 6. Use of foil materials according to claims 1-5 for the production of primary packaging for aqueous solutions in the medical field.