Moving Beyond "Blue Plastic"
Last month in this column I expressed concern about materials testinghow even though the medical device industry has reached a certain level of maturity in this area, material behaviors still surprise us, and sometimes in harmful ways. My urging device companies to accept the responsibility of thoroughly understanding the materials they use drew some impassioned E-mails.
For the most part, readers assured me that the industry has made significant advances in the area of materials science and has learned from past mistakes. However, others stated that this is an area that needs more focused attention. Biocompatibility and regulatory consultant William Wustenberg, DVM, of AlterNet Medical (Farmington, MN), recalled being asked to test a sample submitted as "blue plastic" without any accompanying lot number. Obviously, this is not the norm, he said, but he has observed many cases in which manufacturers did not know the specific chemical characteristics of the materials used in their devices.
However, he said, much work is being done to raise industry awareness about the needs and benefits of understanding biomaterials to a greater degree than what is required by regulation. One activity in this area is the development of two ISO documents, one addressing characterization of materials and the other focusing on identification of leachable materials. Another project in this area is CDRH's Office of Science and Technology's work to develop a biological evaluation paradigm, which would apply the sciences of analytical chemistry and toxicology, rather than the current general screening that is promulgated in the ISO 10993 series.
"In many cases, the development of a better understanding of the materials used in devices can prevent problems like those noted in your editor's page and also can save time and money in obtaining adequate data to demonstrate safety to regulatory agencies," Wustenberg said.
In defense of companies that submit vaguely labeled samples for testing, one reader cited confidentiality as the rationale. Oftentimes, the materials used provide a technological advantage over competing products, he explained. His firm had been advised to not identify the materials submitted for biocompatibility tests because the results are filed with the 510(k), making the material composition public information.