Tips on sourcing polymers for implantable medical devices

I don’t think that there is any challenge more confusing to product development teams than selecting materials that can be used for long-term implantable medical devices, writes Len Czuba in an article published recently by sister brand MD+DI. He brought some clarification to the challenges of the material selection process, as well as pathways to achieving a satisfactory outcome, at a conference session during the co-located MD&M West and PLASTEC West event in Anaheim, CA, in February. Czuba is President of Chicago-based medical device product development consultancy Czuba Enterprises.

It’s important to have a thorough understanding of how the device will be made and used prior to beginning the material selection process, said Czuba. Product function dictates material selection, he stressed. “The implantable material designation is specific to that product and its intended use,” he told attendees. “Bear in mind that each time the manufacturing process changes, including sterilization, the material will need to be requalified.” That’s a tall, and expensive, order that you want to avoid.

Testing requirements for materials used in an implantable device include physical and functional, chemical, and biological testing. The precise tests that will need to be performed will depend on the end use of the device, added Czuba, but keep in mind that “you want to establish testing requirements that show safety and efficacy.”

Establishing a solid supplier relationship

The pool of suppliers able to provide the material that has been specified for the implantable device is likely to be small, said Czuba. To find the ideal candidate, Czuba recommends taking into account the supplier’s experience with implantable devices and FDA; its history of providing safe and effective polymers; and the willingness to share master files with FDA.

A robust agreement that spells out material specifications, acceptable variations in the application, and so forth will be required to shield the materials company from litigation as long as it conforms with the agreed-upon specification. The Biomaterial Access Assurance Act of 1998 in the United States also protects suppliers from litigation in the event a product is found defective or deficient after it is introduced in the marketplace, noted Czuba in the MD+DI article.

These safeguards help to ensure the availability of implantable materials, which is not a given in a litigious society—remember the dark ages of the 1990s, Czuba reminded conference attendees, when litigation involving breast implants spooked a number of materials suppliers. 

Device manufacturers also should make a good-faith effort to get buy-in from their materials suppliers by sharing information about the methods of fabrication, assembly and use. Open communication and a partnership approach will go a long way to allaying any lingering uncertainties, but don’t expect to use it as a bargaining chip when it comes to negotiating price. Given the relatively small quantities of material that are in play in this highly regulated, niche market, medical device manufacturers should expect to pay a premium for materials used in implantable devices, Czuba told the audience.