A portable fiber-optic Raman analyzer for fast real-time screening and identifying cocrystal formation of drug-coformer via grinding process

A portable Raman analyzer with a fiber-optic probe was first used to rapidly screen and identify the cocrystal formation between drug and coformer. Indomethacin (IMC) and anhydrous theophylline (TP) were selected as model drugs, but saccharin (SAC) and anhydrous citric acid (CA) were chosen as model coformers. The cocrystal formation that occurred in the solid-state IMC-SAC or TP-CA system via mechanical grinding process was investigated. Differential scanning calorimetry (DSC) was also used to investigate the possible cocrystal formation. The present study indicates that this new portable fiber-opticRaman spectroscopic technique was an easy and fast “real-time” method to screen and identify the progressive cocrystal formation in solid-state IMC-SAC or TP-CA system in the process of mechanical grinding by inserting the probe directly into the ground mixtures.