The present invention is directed to crystalline polymorphs of benfotiamine, its methods of preparation and its use thereof. Five crystalline polymorphs of benfotiamine are designated as crystalline forms A, B, C, D and E, and may be distinguished by their respective patterns of X-ray powder diffraction (XRPD), differential scanning calorimetry (DSC), infrared spectroscopy (IR), raman spectroscopy, moreover by their diverse preparing process. The crystalline polymorphs of the present invention are useful as they act in treating Vitamin B1 deficiency, metabolic disorders, mental illness and disorders, diabetes complications, neurodegerative diseases. Further the present invention is a process for preparing and transforming diverse crystalline form of benfotiamine through different synthesis routes and varied solvents and combinations. The crystalline polymorphs of the present invention are basically pure. The present invention not only provides new crystalline forms of benfotiamine, but also provides its new solvates, especially hydrates.
