Preparation, Characterization, and Transformation Relationship of Gimeracil Crystal Forms P and L

Abstract In this study, the crystal forms P and L of gimeracil are prepared and characterized by various solid‐state analysis methods (powder X‐ray diffraction (PXRD), Fourier transform infrared spectroscopy (FT‐IR), polarizing microscope (PLM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic vapor sorption (DVS)). The melting point, solubility, crystal habit, and hygroscopicity of the two crystal forms are better understood. By combining the competitive slurry experiment, hot stage microscopy (HSM) experiments, and dynamic method measurements of the solubility curves of two crystal forms in purified water, methanol, ethanol, isopropanol, and n‐butanol, the transformation relationship between the two crystal forms is studied. Crystal form L is a thermodynamically stable crystal form relative to crystal form P. At the same time, various methods for preparing crystal forms P and L are studied. Overall, this study provides a reference for crystal forms' transformation relationship and selective control of crystal forms.