Salt solvates of quinolones and oxicams: Theoretical computation, structural characterization and dissolution studies

Abstract

In general, theoretical computation was performed to improve the efficacy of regular experiments by predicting possible interaction sites. At present work, density functional theory (DFT) was employed to study the interactions between active pharmaceutical ingredients (API) and cocrystal formers (CCF) to screen appropriate molecules for the rational design of cocrystals salts. On the basis of theoretical calculations, four salt solvates of piroxicam(PX), tenoxicam(TNX), lornoxicam(LNX) and meloxicam(MLX) were synthesized with norfloxacin(NF) and ciprofloxacin(CIP), namely, PX·NF·2MeO (1:1:2), TNX·CIP·2MeOH (1:1:2), MLX·CIP·ACN (1:1:1), and LNX·NF·H2O·0.3MeOH (1:1:1:0.3). The structures were characterized by single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA). The results showed that the solubility of oxicams salts were improved remarkably compared with original components and it can be a useful method to improve the bioavailability of oxicams followed by the removal of solvents in further research.