Managing the microbiological quality of pharmaceutical excipients

The microbiological quality of the pharmaceutical excipients used to manufacture pharmaceutical and over-the-counter drug products may significantly affect the outcome of individual processing steps and the microbiological attributes of the final drug products. Unlike active pharmaceutical ingredients, excipients are purchased from multiple suppliers and in many cases are produced for the food, cosmetics, consumer products, photographic, and paint industries and not specifically for the pharmaceutical industry, so the management of their microbiological quality is less straight- forward. This article discusses the qualification of suppliers, excipient production methods, compendial standards, regulatory controls, and microbial limits testing of excipients. Emphasis is given to risk assessment associated with pharmaceutical excipients.