A TECHNO-ECONOMIC NEWS MAGAZINE FOR MEDICAL PLASTICS AND PHARMACEUTICAL INDUSTRY
Our 17th Year of Publication
Page  1 of 4

Cover Story

Performance Polymers For Development Of Medical Devices With High Performance

The use of plastic materials in the medical field is constantly increasing and is estimated to reach 4 billion dollar in two years (only in the US).

The need to reduce healthcare cost and use of a disposable medical supplies are important factors generating a higher demand of medical plastics.

New materials, with improved properties are developed in order to satisfy the requirements of infection control standards.

New studies and tests are conducted to determine the biological reactivity of polymeric materials.

Currently, plastics are graded on a scale of Class I to Class VI, which is done by injecting extracts of the test material intracutaneously into rabbits and mice.

Plastics not requiring implantation testing are graded Class I, II, III, or V and those plastics requiring implantation testing are graded Class IV or VI.

Guidance for the use of plastics in the manufacture of medical devices not being provided in the past, the medical device industry has primarily used Class VI plastics. The overuse of Class VI plastics is due to the assumption that its advanced level of testing the legal and biological risks are reduced. This leads to
manufacturers avoiding the use of a number of appropriate and preferable plastics or polymers.

Packaging of medical products, tubes and pharmaceutical closures are also applications for plastic materials. The high impact and chemical resistance as well as excellent resistance to steam exposure of some materials (like polyphenylsulfone) is making them a strong choice for products that need to be sterilized.

Performance Polymers

Innovations in medical procedure are giving rise to new medical devices with high performance. Neurology is a key area for research to tackle brain and spinal cord injuries and restore patient functions. Cardiology is a key area for device use from catheters and stents to pacemakers and even artificial heart tissue. Joint replacements in orthopedics and tissue matrices are other examples of medical implants.

Many medical devices incorporate polymers , either as key components or as coatings to improve the biocompatibility of other materials. Polymers are relatively easy and cheap to manufacture, and in medicine they must also withstand sterilization procedures. Many devices require different properties such as stability of a tent combined with slow drug release to combat infections. Antimicrobials can also be added to the plastic to limit bacterial growth and silver ions have a key role here. All components of a device must pass extensive testing to minimize risk to the patient.

The plastics and polymers industry in India can be suitably segmented into three sectors : Commodity plastics, engineering thermoplastics and high
performance engineering plastic.

While 80% of polymers used in the medical industry is represented by PVC, polypropylene and polystyrene, the the new challenges in Medical Technology, require new developments specially by Performance Polymers to satisfy the quality requirements of Global country- specific regulations such as the European Community‘s Directive 93/42/EEC and the regulations of the United States Pharmacopeia (USP). Some of such requirements include :

High quality and low processing tolerances in the extrusion process. This is required for materials for the manufacture of catheters. Their mechanical properties, the combination of elasticity, flexibility, hardness and toughness and their high bursting pressure provide for the reliability that, for example, dilation catheters do not buckle and never burst.

  • A glass-clear, UV resistant compound with excellent resistance to chemicals and stress cracking, good creep behavior, and also low tendency to warp manufactured under USP, Class VI, the highest class in the United States Pharmacopeia that even allows exposure to blood. It is suitable for manufacture of structural components that come into direct contact with drugs or bodily fluids. These include infusion and transfusion components such as connectors, adapters, and multiple stopcocks and the
    housings of devices.

  • Special polybutylene terephthalate compounds are manufactured for direct contact with active ingredients. These compounds are easy to process and the moldings made of them are dimensionally stable. They feature low sliding friction. Thus, on the one hand, dimensionally stable housings like pipette housings and functional components of inhalers can be made with them. These materials are also suitable for processing with the melt-blow process, where the structure of the non-wovens produced can be adjusted. They are used as blood filters, for example.

  • Sterilizable coatings for metal parts such as orthopedic instruments and knee-joint supports offer a low sliding friction and a high mechanical strength. Thanks to the smooth non-porous surface, bacterial growth is prevented, and components are easy to clean. Therefore it is not only used to coat components in medical technology, but also hospital furniture and permanent installations.

Few Guidelines For Use of Polymeric Materials For Medical Application of

 

All "medical-grade" resins, films, etc. should meet the requirements of the FDA-Modified ISO 10993, Part 1 "Biological Evaluation of Medical Devices" tests with human tissue contact time of 30 days or less.

  • Regrind resins must not be used in the medical applications requiring biocompatibility.

 

Back | Back to Top | Previous | Next