Stability Testing
Experiments determining how a peptide drug's quality changes over time under defined storage conditions. Following ICH guidelines, products are tested at long-term, accelerated, and stress conditions to establish shelf life, expiry date, and storage requirements.
Technical Context
ICH Q1A(R2) stability conditions: long-term (25°C±2/60%RH±5% — primary shelf-life data), intermediate (30°C±2/65%RH±5% — if significant change at long-term), accelerated (40°C±2/75%RH±5% — stress testing, 6 months; if significant change at 3 months, long-term data required), and photostability (ICH Q1B — confirming light sensitivity and justifying light-protection measures). Testing intervals: long-term — 0, 3, 6, 9, 12, 18, 24, 36 months (annually thereafter until expiry); accelerated — 0, 3, 6 months. Parameters tested: appearance, purity/impurities (HPLC), potency, pH, water content, sterility (at initial and end), endotoxin, and product-specific tests. For lyophilised peptides, reconstituted stability (stability after dissolving in solvent) must also be established — this determines the in-use shelf-life after preparation. Peptide-specific degradation pathways monitored: oxidation (Met, Trp, Cys), deamidation (Asn, Gln), aggregation, and hydrolysis.