Tests within the validation of the instructions for sterilization of medical devices
(as per DIN EN ISO 17664)

In the same way as with processing of medical devices (cleaning and disinfection) the manufacturer or the distributor must describe and provide a suitable sterilization method if the medical device is designated for sterilization.

To achieve the required sterility safety level the medical device manufacturer must indicate at least one validated sterilization method which meets the requirements of an international standard wherever possible, e.g. damp heat (ISO 17665).

To verify the suitability of the sterilization method indicated in the product-related instructions the sterile product is ino­culated with the spores of very heat-resistant bacteria Geobacillus stearothermophilus. The inoculated product is packaged in accordance with the specifications (primary and, if applicable, secondary packaging) and then sterilized with steam with the speci­fied parameters.

The steam sterilization is performed in a half-cycle process (e.g. 134°C, 2.5 minutes). The success of sterilization is then tested by inserting the product in a liquid culture medium for 7 days. The culture medium must not show any signs of bacteria growth, i.e. it must not be clouded.

Test procedure

Contamination Inoculation of the product with spores of Geobacillus stea-rothermophilus, areas of the product which are difficult to access by the steam must be afforded particular attention
Sterilization Steam sterilization of the product as per specifications of the manufacturer (in half-cycle process)
Assessment of sterilization Examination of the sterility using incubation of the product in a liquid culture medium for 7 days -> there must be no visible growth of microorganism