Microstructure of Crystals in a Topical Drug Product

Topical drug products are locally acting therapies typically used to treat skin conditions. Some formulations have solid drug particles suspended in a gel or cream for application onto the skin. Characterizing the microstructure of these solid particles can help to rationalize the formulation design and be used to support in vitro bioequivalence in lieu of expensive clinical end-point studies. This application note outlines the use of morphology-directed Raman spectroscopy (MDRS) to analyze two active pharmaceutical ingredients in a topical gel.