Part 1: Basic Requirements – Setting the Stage
Part 2: Forced Degradation Studies to Support Photostability
Part 3: The Protocol Generation - Execution and Reporting of a Photostability Study
In this third and final section of our photostability series, the protocol design, execution, and reporting of the confirmatory photostability for API and pharmaceutical products will be discussed. ICH guidance Q1B presents a straight-forward flowchart that initiates with the direct exposure of the dosage form. To initiate a study, a protocol should be written based on the steps outlined in the flowchart. However, not every step in the flowchart is needed.
At this point in product development, it is very likely that the photo-sensitivity of the API is known. If the API is photo-labile, a prudent step would be to write the protocol to direct exposure of product and exposure of the product in its immediate packaging would occur simultaneously. Not only would this save time, but would demonstrate the effect of the immediate pack has in protecting the product from photo-degradation. On the other hand, if the API is photo-inert, the direct exposure of the product may be the only exposure required. As stated in the guidance, each exposed foil-wrapped dark control sample should be exposed and tested.