Mechanochemical synthesis, characterization and thermal study of new cocrystals of ciprofloxacin with pyrazinoic acid and p-aminobenzoic acid

Novel cocrystals of ciprofloxacin with pyrazinoic acid and p -aminobenzoic acid in the 1:1 stoichiometric ratio were obtained by the mechanochemical method, under conditions of liquid-assisted grinding (LAG/ethanol) and neat grinding. They were characterized by powder X-ray diffractometry, infrared spectroscopy, simultaneous thermogravimetry, differential thermal analysis, differential scanning calorimetry (DSC) and DSC-Microscopy system. The results confirmed the successful synthesis of the cocrystals and indicated the functional groups responsible for the formation of the new supramolecular synthons. In addition, from the thermal analysis, it was possible to evaluate the thermal stability, composition, crystallization processes during heating, polymorphic transitions and construct the binary phase diagrams.