The Question posed on LinkedIn:

“Dear Experts, What are the guidelines that clarify the frequency and number of cycles required for re-Validation of equipment? For example, during re-qualification of the autoclave should each cycle be repeated 3 times (empty, minimum and maximum loads)? Or is it based on risk assessment by choosing the maximum loads only? (On initial qualification each cycle was performed 3 times consecutively). Also for depyrogenation tunnels, should the runs be repeated 3 times? Thank you“

My reply was this:

“Hi Salma.

When I re-validated our microbiology equipment autoclave loading patterns each pattern was revalidated three times using both biological indicators and temperature probes. One successful run might have been chance.  Three successful runs showed reproducibility.  You need to determine your risk aversion here. The same applies to depyrogenation tunnels.

You can revalidate each of your patterns with a full load.  Productions runs can be performed on reduced equipment loads.

More information can be found in documents such as these:

Steam Sterilization and the 2007 Revision of PDA Technical Report 1 – https://www.pda.org/docs/default-source/website-document-library/chapters/presentations/new-england/steam-sterilization-and-the-2007-revision-of-pda-technical-report-1.pdf?sfvrsn=6

PDA Technical Report 48 Moist Heat Sterilizer Systems – https://www.pda.org/docs/default-source/website-document-library/chapters/presentations/new-england/pda-technical-report-48-moist-heat-sterilizer-systems.pdf?sfvrsn=6

Top 10 considerations when validating an autoclave – PharmOut – https://www.pharmout.net/downloads/white-paper-autoclave-validation.pdf

Kind Regards

Paul”