Preparation, Characterization and Property Research of Epalrestat Co-crystal

OBJECTIVE  To prepare the eutectic of epalrestat and improve its water solubility.

METHODS Using epalrestat as starting material and 4,4'-bipyridine as eutectic precursor, the epalrestat co-crystal was obtained by solvent volatilization. The structure of prepared co-crystal was characterized by ¹H-NMR, X-ray single-crystal diffraction, power X-ray diffraction, differential scanning calorimetry and thermal gravimetric analysis respectively. The solubility and hygroscopicity of the co-crystal were also studied.

RESULTS  The solubility of epalrestat co-crystal in water was increased to nearly 40 times as compared with epalrestat raw materials.

CONCLUSION  The solubility of epalrestat co-crystal increased significantly.