A Novel Approach to Evaluate Amorphous-to-Crystalline Transformation of Active Pharmaceutical Ingredients in Solid Dispersion Using Time-Domain NMR

The aim of this study was to demonstrate the usefulness of the time-domain NMR (TD-NMR) method to characterize the crystalline state of active pharmaceutical ingredients (APIs) containing a solid dispersion. In this study, indomethacin (IMC) was used as a model for poorly water-soluble API. Solid dispersions of IMC were prepared with polyvinylpyrrolidone (PVP) at different weight ratios. First, we measured the T1 relaxation behavior of solid...