CS249080B1 - Material for therapeutical aids production - Google Patents

Abstract

Material for therapeutic production aids intended mainly for single use use, characterized in that it is formed copolymer containing 40 to 99% by weight of weight of repeating units of ethylene in combination with acrylic acid units and / or methacrylic and / or their derivatives selected from the group consisting of sodium, magnesium and aluminum salts, esters derived from ethylene glycol and amides

Description

The present invention relates to the use of copolymers of ethylene with polar acrylic monomers for the manufacture of medical devices, devices, implants, long-term contact elements with blood or physiological fluids and disposable devices.

The hitherto known materials used in health care are subject to increased demands on health safety, specific physico-mechanical properties corresponding to the conditions of use. In particular, emphasis is placed on strength, toughness, elasticity, transparency, degradation resistance and the like. production of disposable aids and devices are used for example polyvinyl chloride PVC, polyethylene PE, polypropylene PP, polymethylmethacrylate PMMA, polycarbonate PC, styrene-acrylonitrole copolymers SAN, acrylonitrole-butadiene-styrene ABS and others. For some demanding long-term implants, silicones and teflon are used. The polymers and copolymers of styrene can only be applied in places of medical devices where the residual content of monomeric styrene, which is usually about 0.1 to 0.2% for acrylonitrole-butadiene-styrene and styrene-acrylonitrole, does not matter. However, it has been shown that polymers and copolymers derived from highly toxic monomers, such as acrylonitrole and cyanoacrylic acid esters, can also be applied without difficulty to aids and apparatus that come into contact with living tissues and blood as long as the low molecular weight content of the polymeric material is sufficiently reduced. .

A disadvantage of vinyl chloride-based polymers is that they require a significant addition of plasticizers for processing. For example, the soft polyvinyl chloride blend used for making hoses and plastic bags for blood storage, transfusion service and other uses contains 25 to 50 weight percent dioctyl phthalate (DOP) as plasticizers. Some DOP has been shown to elute into the cellular components of the blood. Furthermore, the residual content of vinyl chloride monomer should be monitored very carefully for these mixtures, as concentrations of more than about 10 ppm vinyl chloride have been shown to be dangerous by the formation of cancer.

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It is also known to use polyvinyl alcohol and hydroxyethyl methacrylate gels for the manufacture of mammary prostheses. However, this application had to be withdrawn due to gradual calcification and subsequent changes in the mechanical properties of the implant *

Polyethylene and its vinyl acetate copolymers have been used for the construction of intrauterine bodies or as long-term drug dispensers, but only suitable for the narrow selection of drugs miscible with the polymeric materials.

It has now been found that the above-mentioned deficiencies are overcome by material for the manufacture of medical devices and apparatus, especially for disposable use, consisting of a copolymer containing 40 to 99.8% by weight of ethylene repeating units in combination with acrylic acid units (a) or methacrylic units (a) or derivatives thereof selected from the group consisting of sodium, magnesium and aluminum salts, esters derived from ethylene glycol and amides *

The copolymers of the present invention may consist of a pair of monomers - (A) _x - (9- _y -), a triple - (Α) _χ - (B) _y - (C) _w - or more components - (Α) _χ - (B) _y - (C), _w.. <> - gloom but it is essential that one of the components of the ethylene copolymers (e.g. monomers a) and its proportion in the polymer product is in the disclosed range of 40 to 99.8 weight percent * polar components (e.g. The monomers B, C to I) are present in the copolymers in the sum of 0.2 to 60% by weight, said ethylene copolymers may be used singly or as mixtures and composites for medical applications, the average content of copolymer components being as described above. *

The main advantage of using copolymers of ethylene with polar monomers as defined herein is that, depending on the polar monomer content, the ductility and elasticity of the products can be varied over a wide range, and at the same time surface characteristics that affect blood coagulation or nonaggregation or sorption of specific proteins physiological fluids at the interfacial interface of the polymeric article, and thus optimally control the conditions of application of the article.

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In the selection of comonomer content and composition with higher content of - OH and - COOH groups (up to 10% by weight) the products have good surface wettability and improved blood compatibility (antithrombogenic behavior) · Copolymers contain more amide groups and salts of more toxic metals, then can be applied in situations where polymerization of fibrinogen to fibrin is desirable ·

Injection molding, extrusion, rolling or molding technology enables the formation of ethylene copolymers in the form of hoses, films and complex moldings that can be further bonded by gluing or by high-frequency or ultrasonic welding. It is of the utmost importance that the monomer residues, possibly contained in trace amounts, in commercially available semi-finished products (granules and the like) are non-toxic and can only rarely and to a small extent cause a pyrogenic reaction of the organism,

The following are examples of embodiments of the invention:

Example 1

Rabbit implantation specimens were made from a polymer blend of the following composition: ethylene methacrylic acid-magnesium acrylate copolymer (95: 3.0: 2.0 molar ratios) with lubricant and antioxidant additives up to 0.1 weight percent *

The specimens were located in the subcutaneous tissue of the abdominal and thoracic part of the animal body * All test results had a positive evaluation of the hietological image of the ligament surrounding the Implanted specimens after 1 month * Material suitable for construction of moving blood pump parts and cardiac replacement applications

Example 2

Ethylene copolymer containing 4.0% by weight sodium acrylate is mixed with about 0.1% by weight, percentage of antioxidants (stabilizer against thermo-oxidative destruction, chemical composition di-tert-butyl-p-cresol) and 0.1% by weight non-toxic lubricants (eg * paraffin oil or silicone oil) *

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By processing the granulate on an injection molding machine at temperatures up to 250 ° C, the body parts of the plate hemodialyser were produced. Connecting the mouthpieces, blood supply and dialysis solution, as well as the ultimate connection of the components to each other was performed by ultrasonic welding »The same material was used to make the micro-dispenser of the insulin type, piston type for pancreas (replacing the pancreas function). medical applications where health safety and long-term mechanical strength are required »

Example 3

A load-bearing, mechanically stressed loop in the shape of U.S. Pat. No. 3,250,271 or CS Pat, 125,729 of an intrauterine contraceptive device (IUD) was made from a combination of a high mechanical stress bearing material by injection molding a copolymer of 99.3 weight percent ethylene and 0, 2% by weight of aluminum (or sodium) acrylate, e.g., Surlyn A, a product of company E, Dupont (USA),

Example 4

The cylindrical hollow body, for use as a long-term reservoir of hormonal contraceptive drug (IUD), was made of a copolymer of the composition ethylene + glycol methacrylate + glycol methacrylate + acrylamide (in a molar ratio of 166 s 8 s: 1: 7).

This body was immersed in an aqueous solution of 2% progesterol and an antibiotic and then sterilized »In combination with the IUD loop of Example 3, it is then applied to the uterus»

Claims (1)

Material for the manufacture of therapeutic devices and apparatus, in particular for single use, characterized in that it consists of copolymers containing 40 to 99.6% by weight of ethylene repeating units in combination with acrylic and / or methacrylic acid units and / or their derivatives selected from the group consisting of sodium, magnesium and aluminum salts, esters derived from ethylene glycol, and amides.