DIN EN ISO 10993-18
Biological evaluation of medical devices – Part 18: Chemical characterisation of materials
The German version DIN EN ISO 10993-18 was published this month and replaces the version from 2009.
It describes a procedure for identifying and, where appropriate, quantifying the constituent materials of a medical device. This procedure enables the identification of biological hazards and the assessment and control of biological risks posed by component materials. A broad stepwise approach to chemical characterisation is described, which may include one or more of the following steps:
- Identification of the manufacturing materials (specifications)
- Characterisation of the manufacturing materials by means of identification and quantification of their chemical constituents (material composition)
- Characterisation of the medical device with respect to chemical substances introduced during manufacture (e.g., mould releasing agents, manufacturing-related impurities, sterilisation residues);
- Estimation (under laboratory extraction conditions) of the potential of the medical device or its manufacturing materials to release chemical substances under clinical conditions of use (extractable substances);
- Measurement of the released chemical substances within the scope of the intended purpose (extractable substances).
The DIN EN ISO 10993-n series of standards applies when the medical device comes into direct or indirect physical contact. EN ISO 10993-1 can be used for the exact assignment of contact situations and verification.
What has been changed?
Compared to the August 2009 version, the following changes have been made:
- Better alignment with other parts of the DIN EN ISO 10993-n series of standards,
- a revised and extended flow chart on the chemical characterisation procedure has been added,
- an improved explanation of the circumstances under which analytical tests can be omitted,
- a number of definitions were added (e.g., configuration of the medical device, manufacturing materials, material composition);
- test approaches for material characterisation are explained in more detail,
- a discussion of considerations for analytical method qualification was added,
- informative appendices on general principles and considerations have been added.
In complex regulatory practice, chemical characterisation plays an increasingly important role, even in the low and medium risk range (Class I and II a). Manufacturers who in the past were satisfied with testing for cytotoxicity, for example, should urgently also deal with this part of the series of standards.
Of course, our team of experts with many years of experience is by your side here as well.