- FDA has outlined testing and labeling information it wants to see in companies' premarket submissions for products containing nitinol, an alloy of nickel and titanium commonly used to manufacture medical devices.
- The draft guidance released Thursday proposes premarket applications for devices containing the material should include testing to evaluate susceptibility to corrosion, overall biocompatibility and performance under various stress and temperature conditions.
- Further, FDA recommends companies include information on how the device is manufactured and other factors that could affect the breakdown of the material in the body. Labeling should include language about the risk of potential allergic reactions to the metal, the agency said.
Nitinol is widely used in biomedical engineering thanks to the material's flexibility. It can be found in devices like cardiovascular stents and guidewires and transcatheter heart valves, as well as in orthodontic archwires, orthopaedic fracture fixation devices, various surgical instruments and the permanent birth control implant Essure.
The metal is considered biocompatible and resistant to corrosion, and is credited with having enabled advancements in the design of smaller devices for minimally invasive surgical techniques, according to the Cleveland Clinic.
FDA's new guidance is part of a broader effort by the agency to examine how the body responds to component materials used in medical devices. In March, FDA said it would focus on the potential for certain materials to produce an immune or inflammatory reaction, identifying breast implants, metal-on-metal hips and devices containing nitinol as among the products requiring greater scrutiny. The agency teased a future advisory panel meeting on the subject, but has yet to announce a date for the meeting.
Although nitinol has been used in medical devices for more than three decades, its increasing application in devices for minimally invasive procedures warrants more scrutiny in assessing its safety and effectiveness, the agency said.
In a previous guidance document, FDA said it provided recommendations on corrosion and nickel-ion release testing for intravascular cardiac stents and delivery systems containing nitinol. Because the use of nitinol has expanded into other product areas, the new guidance is intended to apply the agency's advice more broadly to any device that contains nitinol.
"We need to be able to assess whether, among other things, there are any health risks when the material comes into contact with various parts of the body for extended periods of time," said Jeff Shuren, director of FDA's Center for Devices and Radiological Health. "To ensure that the benefits patients receive from these devices outweigh any risks resulting from their use, the FDA needs to receive the right information as part of the premarket review process."