A method for improving the properties of famotidine

According to crystal engineering, the pharmaceutical intermediate m-nitrobenzoic acid (MNBA), which contains a carboxylic acid group, was selected as a coformer (CCF) for drug cocrystallization with famotidine (FMT), and a new stable FMT salt cocrystal was synthesized. The salt cocrystals were characterized by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, infrared spectroscopy, powder X-ray diffraction and X-ray single crystal diffraction. A single crystal structure of FMT–MNBA (1:1) was successfully obtained, and then the solubility and permeability of the newly synthesized salt cocrystal were studied. The results showed that, compared with free FMT, the FMT from the FMT–MNBA cocrystal showed improved permeability. This study provides a synthetic method to improve the permeability of BCS III drugs, which will contribute to the development of low-permeability drugs.