Process Characterization

The overall goal of adequate process characterization for commercial manufacturing processes is to ensure efficient and successful process validation and assure consistent process performance. In this chapter, the authors present an outline and some examples for how to carry out thorough and consistent process characterization. The driver for the timing of process characterization is the start of conformance/validation lots. Process characterization should be completed in time such that the information gained from these studies can be used to support operating ranges and acceptance criteria for validation protocols. There are three key aspects to pre-characterization work: historical data review and risk assessment, scale-down model qualification, and analytical method qualification. Retrospective review of historical data and risk assessment analysis can be used to determine operating parameters that need to be examined experimentally as part of process characterization. Screening experiments are designed to eliminate the less critical parameters from further, more rigorous, process characterization work.