Investigation and resolution of incurred sample reanalysis failures: two case studies

The reanalysis of incurred bioanalytical samples (incurred sample reanalysis) provides additional data that help us to ensure that a 'validated bioanalytical method' is reproducible. While the guidelines for the conduct of incurred sample reanalysis evaluations have been well described, published information pertaining to the occurrence of failures and the manner in which they are resolved has not received the same amount of attention. The purpose of this manuscript is to describe two case studies where incurred sample reanalysis failures were encountered for small molecules, the approaches that were taken to elucidate the root cause of the failures, and the remedial actions that were implemented to prevent such failures from recurring.