ABSTRACT
The international conference on harmonization Harmonised Tripartite Guideline covering the Stability Testing of New Drug Substances and Products notes that light testing should be an integral part of stress testing. The guideline primarily addresses the generation of photostability information for submission in Registration Applications for new molecular entities and associated drug products. The confirmatory studies should identify precautionary measures needed in manufacturing or in formulation of the drug product, and whether light-resistant packaging is needed. Normally, the studies on drug products should be carried out in a sequential manner, starting with testing the fully exposed product, then progressing as necessary to the product in the immediate pack, and then in the marketing pack. Depending on the extent of change, special labeling or packaging may be needed to mitigate exposure to light. The samples should be positioned to provide the maximum area of exposure to the light source.
