ABSTRACT
As defined in the 1987 FDA stability guideline, the expiration dating period, or shelflife, of a drug product is the time interval that the drug product is expected to remain within specifications after manufacture. The shelf-life of a drug product is usually established based on the primary stability data. The primary stability data are obtained from long-term stability studies conducted under approved stability protocols with ambient storage conditions. Drug products under ambient storage conditions in longterm stability studies, however, usually degrade very slowly over time. Therefore, for most drug products, it may take more than a year to observe significant degradation.
