Design, synthesis, characterization, and improvement of water solubility of coumarin pharmaceutical cocrystal

Three coumarin cocrystals composed of coumarin and appropriate conformers of hydroquinone, 3,5-dihydroxybenzoic acid and trimesic acid were successfully obtained by the solution crystallization, and then characterized by single crystal X-ray diffraction analysis, powder X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermogravimetric, the experimental results show that the three cocrystals synthesized and belong to the Pī space group triclinic system. Subsequent solubility experimental results show that the water solubility of coumarin in the three cocrystals is in turn increased by 1.63, 1.68, and 2.18 times. Thus, pharmaceutical cocrystal is an alternative approach to increase the water solubility of drugs with poor solubility.