Per current ISO 10993-1 governing the biological evaluation of medical devices, more or less biological endpoints have initially to be considered to demonstrate the biocompatibility of devices. These endpoints can be addressed in a number of different ways including chemical/biological testing and/or written justification, through a Biological Risk Assessment. This document is intended to leveraging on all existing data to reduce as much as possible the number of tests to perform and to conduct the most appropriate ones, based on a relevant and robust approach considering that biological risks arising from the use of medical devices are related to three main parameters:
type and duration of contact with the body;
raw materials that may leach, generate degradation products etc.;
manufacturing processes (machining, assembly, cleaning, packaging and sterilization) that may also generate residues bioavailable as soon as the device is in contact with the body.
That’s why much more emphasis has been placed on the chemical characterization prior to conducting biological tests, to initially identify and quantify most all chemicals susceptible to migrate and/or leach from the device. However, while helpful in providing information and reducing the risks by design as required by the current EN ISO 14971, the chemical characterization is not capable of replacing all biocompatibility testing: both approaches are complementary, even so, when used properly, chemical characterization may help to reduce or even eliminate some expensive and time consuming biological tests. Nonetheless, both chemical characterization and biological programs depend on the nature and duration of the exposure to the body, the raw materials composition of the device and the manufacturing processes used. Accordingly, writing a structured Biological Risk Assessment on a case-by-case basis will help avoiding pitfalls and efficiently demonstrate the biocompatibility of medical devices within a risk management process.