ABSTRACT
INTRODUCTION Ultraviolet (UV) and visible (VIS) radiation-induced degradation may take place during manufacturing, storage, and/or adminis tration of medicinal products. The International Conference on Harmonization (ICH) Tripartite guideline ( 1 ), covering the Stability Testing of New Active Substances and Medicinal Products, notes that photostability testing should be an integral part of stress testing. The systematic approach to photostability testing includes tests on the active substance, the product outside of its immediate packaging and, if necessary, tests on the product in its immediate packaging and/or in its marketed package. The resulting stability information is an important element in the quality assurance of drug therapy, e.g., in determining the expiration date (shelf life), storage instructions, and use life (i.e. stability in an opened container).
