Contributing factors to variability in biological indicator performance data

In the past few years, there has been a change in emphasis by regulatory and compendial requirements to require that pharmaceutical manufacturers verify the accuracy of the thermal death time (D-value) and organism control counts for biological indicators used. Although the requirements were presented in draft form through compendial documents, only when the documents were officially issued, did many pharmaceutical manufacturers first initiate verification procedures. When implementing these procedures, numerous discrepancies were found between the labeled values and the verification values. This paper presents concepts on how these discrepancies may be resolved, as well as, how to prevent them in future verification studies.