A Systematic Review of the Stability of Finished Pharmaceutical Products and Drug Substances Beyond Their Labeled Expiry Dates

In recent years, there has been a very active debate about the stability of drug products especially after exceeding the expiry dates. The regulatory authorities require comprehensive stability data for market approval. The shelf-life obtained determines the expiry date, which is typically between 1 and 5 years and commonly set in a conservative manner. Conducting stability studies is a resource- and time-consuming matter for the pharmaceutical manufacturer. Short shelf-lives of drug products are also a challenge for managers of hospitals, nursing homes, and strategic national stockpile agencies which have to dispose of large quantities of outdated medicines every year. This conflict raises the question whether shelf-lives are often longer than the labeled one. In the past years, the FDA has launched several programs for shelf-life extension in order to defer replacement costs and to prevent drug shortages due to supply disruption. The aim of this review was to bring together the available literature of expired drug products as well as historical pharmaceutical relicts with an age of more than 80 years and to discuss the actual shelf-life with regard to the respective dosage form and the affiliation of the drug class. It seems to be reasonable for a large portion of drugs to extend the expiry dates far beyond five years.