Describe the process validation lifecycle approach for a biopharmaceutical.

Process validation follows ICH Q8/Q9/Q10 and FDA guidance lifecycle stages. Stage 1 (Process Design): process development, characterization studies establishing relationships between parameters and quality, defining design space and control strategy, developing scale-down models. Stage 2 (Process Qualification): equipment qualification (IQ/OQ/PQ), facility validation, PPQ (process performance qualification) batches demonstrating reproducibility within design space - typically 3+ consecutive batches meeting predefined acceptance criteria. Stage 3 (Continued Process Verification): ongoing monitoring post-approval using control charts, trending, and periodic reviews, detecting drift and enabling continuous improvement. Key elements: risk-based approach (ICH Q9), integration of QbD principles, scientifically justified specifications, and maintenance of validated state. Documentation includes validation master plan, protocols, reports, and change control procedures.