Analytical Method Validation
The process of demonstrating that an analytical procedure is suitable for its intended purpose through assessment of accuracy, precision, specificity, linearity, range, and robustness. All quality control methods used in peptide drug testing must be validated according to ICH guidelines.
Technical Context
ICH Q2(R1) validation parameters: specificity (ability to measure the analyte in the presence of impurities, degradation products, and matrix components), linearity (proportional detector response across concentration range — r² >0.999 for quantitative methods), accuracy (closeness to true value — assessed by spiking studies, typically 98-102% recovery), precision (reproducibility: repeatability — same analyst, same day, RSD <1%; intermediate precision — different analysts/days/instruments, RSD <2%), range (validated concentration interval — typically 80-120% of target for assay methods, LOQ to 120% for impurity methods), detection limit (LOD — lowest detectable amount, typically signal-to-noise ≥3), quantitation limit (LOQ — lowest quantifiable amount with acceptable precision/accuracy, typically S/N ≥10), and robustness (deliberate variation of method parameters to assess sensitivity — e.g. ±2°C column temperature, ±0.1 pH buffer).