Medical technology

Biocompatibility tests

The biocompatibility of a medical device depends on the part of the body (skin, blood, fatty tissue, etc.) with which it is in contact and on the duration of such contact. The biological evaluation of a medical device therefore depends on the use for which it is intended. EN ISO 10993 collects together a number of international standards for biocompatibility testing and regulates the choice of tests relevant to the application in question.
Biocompatibility testing must always be performed on the finished medical device because the processing and combination of the raw materials could alter their biocompatibility.
Certain tests on the raw material are meaningful, however, because they provide important information on the suitability of the material for the finished product. In addition to EN ISO 10993, General Chapter <88> of the US Pharmacopeia (USP) describes tests on plastics for medical devices; depending on the application, plastics are assigned to Classes I to VI, those of Class VI having to satisfy the most stringent requirements. Here again, the principle applies of ensuring the biocompatibility of the finished product rather than the raw materials.

VESTAKEEP^® PEEK grades for medical technology

We offer the grades VESTAKEEP^® M2G, VESTAKEEP^® I2G, VESTAKEEP^® M4G, VESTAKEEP^® I4G, and the powder VESTAKEEP^® M4P for medical applications. These products have been formulated for high biocompatibility, and batch tests are conducted in vitro to test for cytotoxicity according to EN ISO 10993-5, which ensures a necessary margin of safety.

The following lists the biocompatibility tests that are conducted at the VESTAKEEP^® M and I grades by independent qualified laboratories:

United States Pharmacopeia Testing: <88> "Biological Reactivity Testing In Vivo" Class VI:

• Acute Systemic Toxicity Test: Four different extraction media (70°C/24h);
• Irritation Test – Intracutaneous Injection Test: Four different extraction media (70°C/24h);
• Implantation Test: In Vivo-Implantation Test: intramuscular, seven days

United States Pharmacopeia Testing <87> “Biological Reactivity Testing In Vitro”

• Cytotoxicity Test: L929 MEM elution, according to EN ISO 10993-5 (37°C/24h)

According to that the material is inert to body fluids and shows no adverse effects in the standardized biocompatibility tests: They are not toxic, do not cause erythema or edema, and they are not biological reactive. In the intramuscular implantation test no sign of discoloration or encapsulation, hemorrhage or necrosis could be determined.

In addition the following biocompatibility tests for VESTAKEEP^® I grades, especially developed for the long-term contact with body tissues, were carried out:

• Haemocompatibility acc. to EN ISO 10993-4
• Intracutaneous implantation acc. to EN ISO 10993-6, 12 weeks
• Genotoxicity (Ames test, chromosome aberration test, mouse lymphoma assay) acc. to EN ISO 10993
• Systemic toxicity acc. EN ISO 10993-11
• Investigation of the content and extractable organic substances acc. to ISO 10993-18

The VESTAKEEP^® I grades are especially processed in such a way that guarantees a still higher purity compared to the standard products. They are compliant with the specifications as specified in ASTM F2026 “Standard Specification for Polyetheretherketone (PEEK) Polymers for Surgical Implant Applications”. Documentation, specification and quality assurance are adapted to the requirements of medical technology.

All relevant information of the VESTAKEEP^® I polymers concerning manufacturing, consistency, and quality assurance has been registered in a Device Master File at the U.S. Food and Drug Administration (FDA). FDA registration makes it easier for our customers to obtain approval for new medical products that use VESTAKEEP^® I grades: When a producer of medical devices now applies for registration of a new product in the U.S., the FDA can use the appropriate documentation to directly research all the relevant information on the raw material used. 

Our staff can provide you with information about their experience with various approval processes. Please contact us.