An approach to determine crystalline content of Granisetron in transdermal patches using X-ray diffraction technique

Granisetron is a drug used to treat nausea and vomiting after chemotherapy. Crystallization of drug is always a major concern in the transdermal drug delivery system. In view of consistent biopharmaceutical performance, monitoring and controlling the crystallization during product development and shelf life is very important. The need was felt to have an accurate method for determination of crystallinity in transdermal patches.The present study is about development and validation of a quantitative X-ray diffraction method for the determination of the extent of crystallization of the drug in transdermal formulation of Granisetron. Specimens of different physically spiked concentrations were carefully prepared accurately by weighing and distributing crystalline active pharmaceutical ingredient (API) onto placebo liner patches, pasted on Silicon low background sample holder (diameter of 24.5 mm, made up of Si crystal). All the specimens thus prepared were scanned using optimized instrumental parameters while enabling specimen rotation during the diffraction analysis to ensure homogeneous exposure to the incident X-rays. Using this novel approach, limit of detection o