Solubility determination and thermodynamic modelling of gliclazide in five binary solvent mixtures

Abstract

The solubility of gliclazide in five different binary solvent mixtures, (i.e. acetone-water, tetrahydrofuran-water, N, N-dimethylformamide-water, acetone-ethanol, and chloroform-ethanol) was measured in the temperature rang 278.15–318.15 K and at atmospheric pressure by a gravimetric method. The results show that the solubility of gliclazide increases with an increase in temperature and an increase in the mole fraction of nonpolar aprotic solvent. The combined nearly ideal solvent / Redlish-Kister (CNIBS/R-K) model, modified Jouyban-Acree model, non-random two-liquid (NRTL) model, and the Wilson model were selected to correct the solubility data. It was found that, solvent polarity has a critical effect on the solubility of gliclazide. The CNIBS/R-K model, with maximum RAD and RMSD values of 0.0540 and 0.000131, respectively, was found to be the best-fitting model for solubility data correction in the selected binary solvent mixtures. RAD values of all the selected thermodynamic models were <0.0806, that is, these equations produced well fitted results for the solubility data of gliclazide. These experimental data are of great significance for investigation of the crystallization process of gliclazide.