For every commercial drug product, it is essential to indicate the expiration date to provide the consumer with some assurance that the drug product will retain its identity, strength, quality, and purity throughout the expiry period. For the determination of an expiration dating period^ it is necessary to conduct stability studies to assess the intrinsic degradation of the drug product- In this paper5 we provide an overview of regulatory requirements for stability including stability guidelines issued by the United States Food and Drug Administration and those established by the International Conference on Harmonization. In addition^ we address current statistical design and analysis issues that often occur during the conduct of stability studies.