ICH Q7 - Good Manufacturing Practice Guide for Active Pharmaceutical Ingredients 14.3: Investigate non-conformance before reworking, then show reworked batches are of equivalent quality by evaluation, testing, stability where warranted and impurity profile comparison

What does 14.3 require?

Before reworking batches that do not meet standards or specifications, the reason for the non-conformance should be investigated. Reworked batches should be evaluated, tested, stability-tested if warranted and documented to show equivalent quality to the original process, concurrent validation often being suitable (a protocol defining the procedure, its conduct and expected results), or for a single batch a report with release once acceptable. Procedures should compare each reworked batch's impurity profile with batches from the established process, adding methods where routine ones cannot characterise the reworked batch.