Stability of proton pump inhibitors in various dosage forms: A review

Proton pump inhibitors (PPIs) are among the most widely prescribed drugs for the management of acid-related gastrointestinal disorders. Despite their clinical efficacy, PPIs exhibit significant chemical instability, primarily due to their acid-labile nature and sensitivity to environmental factors such as moisture, heat, light, and pH. From a pharmaceutical chemistry perspective, the inherent molecular structure of PPIs governs their degradation pathways, posing major challenges in formulation development and dosage form design. This review critically examines the chemical stability of commonly used PPIs, including omeprazole, esomeprazole, lansoprazole, pantoprazole, and rabeprazole, across various dosage forms such as tablets, capsules, suspensions, injectables, and novel delivery systems. The degradation mechanisms, stabilization strategies, and analytical approaches used for stability assessment are discussed to provide a comprehensive understanding of PPI stability from a chemistry standpoint.