Stability Testing of Pharmaceutical Products: Predictive Modeling, Accelerated Studies, and Applications in Novel Drug Delivery Systems

Stability assessment is a crucial prerequisite in pharmaceutical development, ensuring safety, efficacy, and desired control of product performance throughout its shelf life. Although conventional stability testing guided by International Council for Harmonization Q1A(R2)–Q1E and Q5C remains essential for regulatory compliance, it is often time-consuming and resource-intensive. Developments in analytical sciences and computational modeling have transformed stability programs from trial-driven processes to predictive and risk-based strategies. Novel predictive tools, such as accelerated predictive stability studies, enable rapid, accelerated, science-driven prediction of product behavior under real-world conditions. As the industry increasingly adopts biologics, biosimilars, and nano-enabled drug delivery systems, stability testing must evolve beyond conventional assays to incorporate multi-parametric, high-resolution, and functional performance-based evaluations. These tools can facilitate faster decision-making and more efficient regulatory submission, reducing delays in product availability. This review provides a comprehensive overview of advanced methodologies, novel stability-indicating methods, and the existing regulatory frameworks for novel drug delivery systems. Ultimately, the future of stability assessment lies in intelligent, predictive, and adaptive approaches that integrate advanced analytics, modeling, and robust quality frameworks.