Critical Parameters affecting Stability of APIs and Drug Products: A Review

Stability is a cornerstone of pharmaceutical product development, ensuring the safety, efficacy and longevity of drug formulations. This review explores the importance of critical and physical parameters influencing the stability of both Active Pharmaceutical Ingridients (APIs) and finished drug products. Critical factors such as temperature, humidity, light exposure, pH and their effects on chemical degradation, physical changes and overall product integrity are discussed in detail. Temperature accelerates degradation processes like hydrolysis and oxidation, while humidity can lead to hydrolysis, microbial contamination and changes in the physical form of solid dosage forms. Light exposure can cause photo-degradation, altering drug potency and pH variations affect solubility and stability. Physical parameters, including particle size, viscosity, color and clarity, also play vital roles in determining stability by influencing dissolution rates, bioavailability and uniformity. Methods for evaluating these parameters through accelerated and real-time stability testing are examined, highlighting their significance in predicting shelf life and storage conditions. Furthermore, the role of packaging in protecting against environmental factors and ensuring stability is addressed. The review also discusses regulatory guidelines for stability testing and their role in ensuring product quality. Understanding and controlling these stability factors is essential for ensuring the safety and therapeutic effectiveness of pharmaceutical products throughout their shelf life.