CS241266B1 - Material for medical aids making - Google Patents

Abstract

Material for medical production aids and devices designed especially for one-off use, characterized in that contains terpolymers of ethylene with vinyl alcohol (I) and / or vinyl alcohol derivatives of formulas (II) and (III) wherein R 1 and R 6 are hydrogen or alkyl C 1 -C 12, and ethylene content it lies between 40 and 99.8 wt. percent, wherein the suitable comonomers are (I) especially vinylformal. vinyl butyrate, vinyl acetate and vinyl etherate.

Description

The present invention relates to the use of copolymers of ethylene with vinyl alcohol and its derivatives for the manufacture of medical devices and devices, implants, parts in long-term contact with blood or physiological fluids.

The hitherto known materials used in the health care sector are subject to increased demands on health safety and the speolithic physico-meohani properties correspond to the conditions of use. Particular emphasis is placed on strength, toughness, elasticity, transparency, degradation resistance and the like. Of the commercially available polymeric materials, polyvinyl alcohol chloride, polymers of ethylene PE, polypropylene PP, polymethylmethacrylate PMMA, polycarbonate PC, ethylene-acrylonitrole copolymers, acrylonitrile-butadiene-styrene ABS and the like have been used to produce disposable devices and devices. For some demanding long-term implants, silicones and teflon are used. Polymers and copolymers of styrene can only be applied at such locations in a media device where the residual content of monomeric styrene, which is typically about 0.1-0.2% for acrylonitrole-butadiene-styrene and styrene-acrylonitrile, does not matter. It has been shown that only low molecular weight polymers and copolymers derived from highly toxic monomers, such as acrylonitrile and ethoxy cyanoacrylic esters, have no harmful effects and can also be applied without difficulty to devices and devices that bring in contact with living tissues and blood, provided reducing the low molecular weight content of the polymeric material.

A disadvantage of vinyl chloride based polymers is that they require a significant addition of plasticizers for processing. For example, the soft polyvinyl chloride chloride blend used to make hadio and plastic blood storage bags for transfusion service and other uses contains 25 to 50 weight percent prooent of dioctyl phthalate (DOP) as plasticizer. Some PPE has been shown to elute into the cellular components of the blood. Furthermore, these mixtures need to be very carefully

- 2 241 266 to monitor the residual content of vinyl chloride monomer, since it has been shown that a conoentra of branches of more than about 10 ppm vinyl chloride is dangerous by the formation of caroinoma. It is also known to use polyvinyl alcohol and hydrayethyl methacrylate gels for the manufacture of mammary prostheses. However, this application had to be withdrawn due to the gradual kaloificae in the consequent changes in the meohaniocyte properties of the implants. Polyethylene and its copolymers with vinyl acetate were used for the construction of intrauterine bodies or as long-term drug dispensers. Also disclosed are US Patent Nos. 4,016,251 and 4,052,505, wherein polyethylene and ethylene-vinyl acetate copolymers are used by the cell to construct intrauterine bodies, or as long-term hormone or drug dispensers. These applications are limited by the relatively low regions of vinyl acetate acetate in the copolymex, which have satisfactory properties and allow diffusive transport of said drugs through a layer of polymeric material. For example, according to U.S. Pat. No. 4,016,251, an EVA copolymer containing 22 weight percent VAC was used as a carrier of diethylstilbesterol hormones.

Further, according to U.S. Pat. No. 4,052,505, the progesterone hormone is placed in a tube having a diameter of about 4 hours and a further 1.5 µm, which is made of an EVA copolymer containing 28 weight percent proacent VAC.

It has now been found that the above-mentioned drawbacks are remedied by a material for the manufacture of medical devices and devices intended, in particular, for single-use applications, characterized in that it is a copolymer of ethylene with vinyl alcohol (s) and / or vinyl alcohol derivatives. II and III

I - ... ^CH 2 - CH 1 OH * · · · II - CH ₂ - CH ~ · · · m - ... - CH ₂ - CH ... 0 OH “ ^R 1 O-CO-R ^ 0 of where R ^ and R ^ are hydrogen, or alkyl and 1 up to 12 carbon atoms.

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Particularly suitable comonomers are vinyl alcohol, vinyl formal, vinyl butyral, vinyl acetate and vinyl ether. The ethylene content of the copolymer is between 40 and 99.8% by weight.

The copolymers of the present invention consist of a triple ( ^A ) x - ( ^B ) y - (c) _w - or more component - (a) _x (B) _y - (C) _w -.

However, it is essential that one of the components of the copolymer is ethylene (for example, monomer (a)) and its proportion in the polymer product is between 40 and 99.8% by weight. Polar components (for example monomers B, C to I) are present in the copolymer in a weight ratio of 0.2 to 60% by weight. The ethylene copolymers may be used singly or as mixtures and composites for medical applications, with an average content of components of the copolymer corresponds to the values described.

The main advantage of using copolymers of ethylene with polar vinyl 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 those surface characteristics that affect blood clotting or clotting and or sorpoi speo-protein proteins from physiological fluids at the interfacial interface of the polymeric article and thus control the application conditions of the article in an optimal manner.

When selecting the content and composition of the comonomer with a higher content of -OH and -O-CH 2 -O- groups (in the range of up to 10 weight percent prooent), the product has good surface wettability and improved blood compatibility (antithrombogenic bending).

Injection molding, extrusion, rolling or molding technology enables the formation of said ethylene copolymers in the form of hoses, foils, and the production of complex moldings which can be further joined by gluing or by high frequency or ultrasonic welding. in trace amounts in commercially available semi-finished products (granules and the like), they are non-toxic and can only rarely and to a limited extent cause a pyrogenic reaction of the organism,

The following are examples of embodiments of the invention:

- 4 Example 1:

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The terpolymer containing 70 weight percent ethyl acetate, 0.2 weight percent vinyl alcohol, and 29 weight percent vinyl acetate was processed by extrusion at temperatures of 150-220 ° C to form hoses and films having a thickness of 0.8 mm. Bags for continuous peritoneal dialysis of CAPD, for infusion solutions and the like were made by welding.

Example 2:

A copolymer containing about 40 weight percent vinyl alcohol, 5 weight percent vinyl acetate and 55 weight percent ethylene was obtained by saponification of a commercially available Lewapren material (which is an ethylene vinyl acetate copolymer containing ooa 45 prooent vinyl acetate meth product in BASF, NSR). methyl acetate under catalysis with potassium methanolate. Treatment of the granules containing about 0.2% nonox VDS stabilizer (tetraalkyl-methylene-bisphenol, manufactured by ICI, England) and about 0.1% paraffinic lubricant having a molecular weight of 350 daltons yields hadioe and films suitable especially for pumping, blood preservation and transfusion service.

Example 3:

The bodies were pressed from the mixture:

ethylene + methacrylic acid + magnesium acrylate copolymer (99.5: 3: 2 mole ratio 75 wt.

ethylene vinylbutyral + vinyl stearate copolymer (in molar ratio 142: 78: 1 25 wt.

paraffin oil 0.1 wt.

stabilizer 0.1 wt.

In implantation experiments, the samples were located in the subcutaneous tissue of the abdominal and thoracic part of rabbits and rats. All test results were positive for hiatologic images of the ligament surrounding the implanted bodies after 1 month.

The material for the construction of the movable parts of the blood pump and for the replacement of the heart activity was suitable for the same properties.

Claims (1)

SUBJECT OF THE INVENTION Material for the manufacture of disposable medical devices and devices, characterized in that it contains terpolymers of ethylene and wool alcohol (i) and / or wool wool alcohol derivatives of the general formula (II) and (U1) ...- CH ₂ - CH ₂ ... (I) ² t OH CH, - · · · CH - R _x (II) ...- ^CH 2 - CH (m) O - CO wherein R ^ and R ^ are hydrogen or alkyl of 1 to 12 carbon atoms and the ethylene content lies between 40 and 99-8% by weight, suitable comonomers in addition to (i) being in particular vinyl formal, vinyl butyral, vinyl acetate and vinyl stearate.