Distinguishing Anhydrous and Hydrous Forms of an Active Pharmaceutical Ingredient in a Tablet Formulation Using Solid‐State NMR Spectroscopy

With or without water? In under two hours, an NMR spectroscopy experiment can determine whether the anhydrous form of an active pharmaceutical ingredient is present in a tablet formulation. Such a high-resolution spectrum constitutes a new analytical tool that should be routinely adopted in the characterization of pharmaceuticals.