Solubility, thermodynamic properties and molecular simulation of tinidazole in fourteen mono-solvents at different temperatures

The solubility properties of tinidazole (TNZ) in investigated fourteen mono-solvents were further studied at several temperature points (278.15 K similar to 323.15 K) under 101.2 kPa using the laser monitoring technique. The selected solvents were acetone, methanol, ethanol, 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-butoxyethanol, methyl acetate, ethyl acetate, n-propyl acetate, n-butyl acetate, NMP, DMF, DMAC, respectively. The order of solubility of tinidazole in fourteen mono-solvents at 298.15 K is: NMP > DMAC > DMF > acetone > 2-methoxyethanol > methylacetate > 2-ethoxyethanol > ethyl acetate > 2-propoxyethanol > n-propyl acetate > 2-butoxyethanol > n-butyl acetate > methanol > ethanol. As shown by the solubility data of TNZ in chosen fourteen mono-solvents in this work, TNZ is more soluble in higher temperature. The KAT-LSER model and molecular dynamics simulation were adopted to probe the influence of solvent effects and solute-solvent interaction on TNZ solubility. The obtained solubility data of TNZ was fitted by (lambda h equation, NRTL model, NRTL-SAC model, two-Suffix Margules model, and UNIQUAC model). The results indicate that five models can fit the experimental values well, in which the NRTL-SAC model gives the best regression effect. Moreover, the apparent thermodynamic properties (Delta(sol)G degrees, Delta H-sol degrees and Delta S-sol degrees) of TNZ in various solvents were calculated by Van't Hoff equation. In accordance with the analysis and calculation of dissolution, the dissolution process is is entropy-motivated and endothermal.