Formulation and stability testing of photolabile drugs

Exposure of a drug to irradiation can influence the stability of the formul ation, leading to changes in the physicochemical properties of the product. The influence of excipients of frequently used stabilizers is often diffic ult to predict and, therefore, stability testing of the final preparation i s important. The selection of a protective packaging must be based on knowl edge about the wavelength causing the instability. Details on drug photorea ctivity will also be helpful in order to minimize side-effects and/or optim ize drug targeting by developing photoresponsive drug delivery systems. Thi s review focuses on practical problems related to formulation and stability testing of photolabile drugs. (C) 2001 Elsevier Science B.V. All rights re served.