ABSTRACT
Numerous compounds degrade when exposed to light. The most obvious result of drug photodecomposition is a loss of potency of the product. Consequently, this can result in a drug preparation that is therapeutically inactive This entry presents various aspects of drug photoreactivity and common photochemical reactions by which drugs have been found to decompose, and discusses the influence of formulation factors, such as excipients, on product stability and the variables considered in photostability studies.
