In this study we used coherent Raman microscopy to study the co-crystallization of indomethacin and nicotinamide during solvent-assisted milling. Stimulated Raman scattering (SRS) microscopy with fast spectral focusing and multivariate analysis efficiently resolved all components and was well-suited to quantitative image analysis. SRS microscopy efficiently revealed otherwise trace components undetected with conventional solid-state analysis methods. The dramatic sensitivity of co-crystallization to solvent content during milling, including reversal of partial co-crystallization, was revealed.
Authors: Alba M. Arbiol Enguita, Elina Harju, Lea Wurr, Teemu Tomberg, Oona Auvinen, Leena Peltonen, Clare Strachan and Jukka Saarinen.