Simulated drug guidelines

Finally, yet importantly, cosmetic sunscreen substances can be looked at as materials being exposed to solar radiation. Their photostability can then be evaluated as change of protective potential based on a transmission measurement or loss (or survival rate) of individual UV filters upon exposure to simulated solar radiation. It is in this sense that the term "photostability" is normally used in the context of cosmetic sunscreens. It is also in this sense that the "Photostability of Cosmetic Sunscreens" will be discussed in this chapter (and not in the meaning of drug/lCH guidelines). 

In the past, various publications on photostability testing of drugs under simulated conditions were based on a wide range of quite different artificial light sources. Much of this work remains questionable because the real stress conditions were partially unknown. In 1996, publication of ICH guideline Qlb — Photostability Testing of New Drug Substances and Products — improved this situation. This ICH... 

As recommended in the ICH Q1A(R2) guideline, data from primary stability studies are to be collected for at least three batches of the drug product. The primary batches should be of the same formulation and packaged in the marketed container-closure system. The manufacturing process used for the primary batches should simulate that of the production batches and should provide product of the same quality and meet the specifications proposed for marketing. Two of the three batches should be at least pilot scale batches and the third one can be smaller, if justified. Where possible, batches of the drug product should be manufactured using different batches of API. 

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