The parylene coating is inert and is approved by the FDA
Its virtuosic capability of penetration, covering, electrical insulation, and insulation against the environment, against liquids and gases, having optical transparency, etc., and its capability of reaching every point on the coated infrastructure (whatever material the infrastructure is made from, and of any complex architecture) awards it the tremendous advantage of providing the protection required for medical and bio-medical products and components.
Parylene is a bio-stable and bio-compatible polymeric coating. Its stability and inertness against acids and gases, together with low friction coefficient and the fact that we are speaking of a polymeric coating that is not toxic, have led the medical authorities in the US and in Europe to register it as a coating approved for swallowing in invasive and non-invasive medical devices. This includes for coating components and infrastructures that are not friendly to the human body and that which, using parylene, receive approvals for implants, touch, and swallowing.
Many medical applications use parylene, including invasive and non-invasive applications, including: catheters, stents, pills containing cameras, brain electrodes, etc.