Quantitative Evaluation of the Crystallinity of Indomethacin Using 1H T2 Relaxation Behaviors Measured by Time Domain NMR

We sought to demonstrate the usefulness of the T2 relaxation behaviors measured by time domain NMR (TD-NMR) for the quantitative evaluation of the crystallinity of an active pharmaceutical ingredient (API). This study used indomethacin as a model API. After blending amorphous and crystalline indomethacin powders at a designated ratio, T2 relaxation curves were measured by TD-NMR. Subsequently, we acquired a calibration curve to quantify...