Process Validation
Documented evidence that a manufacturing process consistently produces a product meeting predetermined specifications and quality attributes. Process validation for peptide drugs covers synthesis, purification, formulation, fill-finish, and sterilisation steps. It is a regulatory requirement for GMP manufacturing.
Technical Context
FDA process validation guidance (2011) defines three stages: Stage 1 (Process Design — developing understanding of the process through DOE, scale-down studies, and defining critical process parameters and their acceptable ranges), Stage 2 (Process Qualification — confirming the process performs as expected at commercial scale, typically 3 consecutive successful validation batches meeting all specifications), Stage 3 (Continued Process Verification — ongoing monitoring ensuring the process remains in a validated state during routine production). For SPPS-based peptide production, critical process parameters include: coupling reagent concentrations, reaction times, temperatures, washing volumes, cleavage conditions (TFA concentration, time, temperature, scavenger ratios), and purification parameters (HPLC gradient, loading, flow rate). Process validation must demonstrate that: each batch meets the defined quality attributes, batch-to-batch variability is within acceptable limits, and the process is reproducible across operators, equipment, and raw material lots.