ABSTRACT
Purification processes for biopharmaceuticals are designed to perform a variety of different functions (Table 1). The FDA and international regulatory agencies require that process validation studies be carried out before product licensure to ensure that these functions will be performed consistently and reliably. This chapter presents some of the strategic issues that arise in meeting these process validation requirements for removal of host cell protein, clearance of DNA and other process-related molecules, process and solution hold times, in-process controls, reprocessing strategies, and process changes.
