USP CLASS PLASTICS (USP CLASS VI)
To test medical device biocompatibility, manufacturers often use USP procedures such as the USP In Vivo Biological Reactivity Tests (Class I-VI Plastics Tests). The Class Plastics tests consist of various combinations of the USP Intracutaneous Test and the USP Systemic Injection Test, using one or more combinations of four extracting media. The Class IV and Class VI tests also include the USP Implantation Test.
Is Class VI Testing Necessary?
For medical device manufacturers, Class Plastics tests have some value in a biocompatibility testing program, but a full Class VI test is rarely needed for a medical device. As a general rule, the Blue Book Memo and ISO documents take a broader and more thorough view of biocompatibility than does the U.S. Pharmacopoeia, and they supersede the USP for evaluating which studies to submit to FDA in support of product registrations.
For plastic resin manufacturers and non-medical device manufacturers, USP Class VI certification is often an important level of assurance to give customers looking for device component materials. Additionally, many products not regulated by the FDA as "medical devices" may still be used in a laboratory setting. The extra assurance given by USP Class VI certification may be important.