Solid-liquid equilibrium, thermodynamic modelling and the solvent effect of glimepiride in mono-solvents and binary mixed solvents

The solubility of glimepiride (GLM) in eight mono-solvents (including acetonitrile, methyl acetate, acetone, 2-butanone, 1,4-dioxane, cyclohexanone, tetrahydrofuran, and dimethyl sulfoxide) and two binary mixed solvents (N, N-dimethylformamide (DMF) + water, and N, N-Dimethylacetamide (DMA) + water) at 278.15 K to 323.15 K (1,4-dioxane at 288.15 K to 323.15 K; DMSO at 293.15 K to 323.15 K) was determined via the high-performance liquid chromatography (HPLC) method. Solubility increases with the increase of temperature and good-solvent content. The solubility order (T > 293.15 K) of GLM in mono-solvents is DMSO > THF > cyclohexanone > 1,4-dioxane > 2-butanone > acetone > methyl acetate > acetonitrile. The solubility order of GLM in binary mixed solvents is (DMA + water) > (DMF + water) at a given temperature and solvent composition. KAT-LSER model was selected to study the solvent effect of GLM in the tested solvents. In mono-solvents, the experimental solubility data of GLM were correlated by the Yaws model, the modified Apelblat model, the λh model, and the Jouyban model. In binary mixed solvents, the GSM model, the modified Apelblat model, and the Jouyban-Acree-Apelblat model were employed to fit the experimental data. According to RAD and RMSD values, the experimental solubility data of GLM are well corrected. Finally, the thermodynamic properties (i.e., Δ_solH^o, Δ_solS^o, Δ_solG^o, %ζ_H, and %ζ_TS) of the dissolution process of GLM were calculated based on the van't Hoff equation.