Material Changes for FDA Regulated Medical Devices

Changes in formulations of materials used for manufacturing patient-contacting medical devices or device components often require submission of a new 510(k) by the device manufacturer.  This is because formulation changes can affect the biocompatibility, material properties and performance of a device.

The FDA defines material formulation changes to include the following:

– Changes to the chemical composition of the material (including constituent ratios, ingredients, and interactions) and related physical chemistry.

– Changes in processing aids, catalysts and residual contamination that are not part of the formulation but may be introduced during manufacturing process can indirectly affect materials formulations.

– Changes to a device coating or surface modification technique, including chemical formulation, method of application, or surface preparation (e.g., acid-etching, blasting) that significantly affect safety or effectiveness of the device.

The FDA defines patient-contact to include both direct and indirect contact, and for temporary or permanent duration. Direct contact is when a material touches any tissue or bodily substance of a patient while it is still in or on a patient. Indirect contact is when a material has the potential to come into contact with any patient tissue or bodily substance by first coming in contact with some intervening material (e.g., liquid, gas) which subsequently contacts patient tissue or bodily substance. For example, a hub is a component of a catheter which is external to the patient. Fluids and drugs are infused through the hub and directly into the patient.  Therefore, the hub material contacts the patient indirectly and must demonstrate biocompatibility.

While most implants contact patients directly, there are some exceptions.  For example, the internal contents of a spinal cord stimulator are hermetically sealed within the device and not patient-contacting.   When there is no material transfer, fluid transfer, or leeching out of any material internal to the device the internal components do not need to demonstrate biocompatibility.

In general, material modifications to device components that do not have direct or indirect contact with the patient do not significantly affect safety or effectiveness of the device.  These material changes often do not require submission of a new 510(k), unless they affect the fundamental device technology or performance.  For most formulation changes of non-patient-contacting materials, it is often appropriate for the device manufacturer to simply document the change with the FDA.

*This information is based content provided by FDA document: Guidance for Industry and FDA Staff, ‘510(k) Device Mofications: Deciding When to Submit a 510(k) for a Change to an Existing Device – DRAFT GUIDANCE. July 27, 2011.

**The information is made available for informational and educational purposes only.  This content is not intended to be a substitute for professional advice or guidance regarding medical device regulations, submissions, development or any other considerations associated with the content.  Foster Corporation does not make any representation or warranties with respect to the accuracy, applicability, fitness, or completeness of the content.