By definition, semi finished products are not medical or pharmaceutical products, but pre-products used for their production. As there is consequently no standardized requirement to evaluate the biological suitability of semi finished products and biocompatibility of polymers, Ensinger has made its own selection from the wide spectrum of different biocompatibility tests contained in ISO 10993 and USP Class VI. This is intended to provide our customers with the greatest possible assistance with the risk evaluation and approval process for their medical or pharmaceutical end products using biocompatible polymers.
Ensinger generally subjects its medical materials (MT semi finished plastics) intended for use in medical products, which are suitable for a contact period of 24 h with skin and tissue, and, where applicable, indirect contact with blood, to the followingcombined tests on biocompatibility:
- Cytotoxicity/growth inhibition (ISO 10993-5)
- Haemolysis (ISO 10993-4)
- Chemical analysis/"fingerprinting" (ISO 10993-18)
- Biological-toxicological evaluation (ISO 10993-1)
With this approach, Ensinger is following the recommendations of ISO 10993-1 with respect to step by step biological qualification.
By means of in vitro tests for cytotoxicity (ISO 10993-5) and haemolysis (ISO 10993-4), steps are taken to ensure that the products demonstrate sufficiently inert properties in contact with blood and tissue, and have a defined toxicological profile. In this process, the cytotoxicity/growth inhibition test, which is regarded as the standard test and basic biological test for all medical products, represents the basis for toxicological evaluation of the material.
USP Plastic Class VI (Pharmacopoeia of the United States of America) also describes a biological evaluation of plastics with regards to their suitability for various applications. It comprises individual monographs and is a compilation of tests on active substances or dosage forms, as well as specifications and standards relating to the quality, purity and identity of substances. The biological evaluation of plastics is described in chapter <87> and <88> of the USP Class VI tests, which originally resulted from the evaluation of packaging for pharmaceutical products. USP chapter <87> describes the cytotoxicity test, which varies in details from ISO 10993-5.