ABSTRACT
The information gained from stability programs informs us about the important ways a molecule changes over time, including the overall degradation profile, degradation products formed under certain conditions, and how combinations of different conditions may affect overall product quality. Practical application of stability analysis can drive objective decisions about shelf life and product handling, and can inform decisions about container, formulation, or production changes.
A comprehensive program includes compulsory studies required by regulatory agencies to establish retest or expiry periods. It also includes studies that examine conditions of real-world use, such as storage or handling instructions communicated to prescribers and patients. Stability studies can also be used to evaluate product comparability by comparing degradation rates of different configurations or manufacturing processes.
This chapter focuses on addressing most of the research questions that one may ask of a stability program. Topics covered include determining if an attribute is stability-indicating, setting and extending retest or expiry periods, trending stability results and annual trend analyses, using stability data to evaluate specification limits, and analysis of special stability studies including photostability, temperature cycling, and comparability studies.
