Are the actual shelf lives of many prescription drug products greater than their labeled expiration dates?
The FDA defines shelf life as “the time interval that a drug product is expected to remain within the approved shelf life specification provided that it is stored under conditions defined on the label in the proposed containers and closures.”1 Using this definition, it appears that the actual shelf lives of some drug products are greater than their labeled expiration dates on containers/packages. The best evidence to support this comes from the Shelf-Life Extension Program (SLEP).6 In 1985, the United States Air Force was faced with a large (war reserve) stockpile of drugs that were approaching their expiration dates. The Air Force asked the FDA if it could determine if the drugs were safe and potent beyond the expiration dates set by the manufacturers. Since 1986, the FDA has administered SLEP for the United States military. According to the FDA, this is an internal program for conducting real-time and accelerated stability tests for drug products based on the same procedures that are
