Solubility parameter and solution thermodynamic properties of Form I Trimebutine maleate in six mono-solvents and three binary mixed solvents at different temperatures

• The solubility of Form I Trimebutine maleate in mono-solvents and binary mixed solvents was determined. • Solubility data was correlated by five models. • Thermodynamic parameters were estimated using the van’t Hoff equation. The solubility information of drugs in solution is of great significance in the fields of chemistry and pharmacy. Trimebutine maleate is a commonly used drug for treating gastrointestinal disorders, and its solid-liquid balance data are critical for a preliminary study of industrial application. This study investigated the solubility of medicinal crystal form (Form Ⅰ) of Trimebutine maleate at T=283.15-328.15 K. The molar fraction solubility of Form Ⅰ in six mono-solvents and three binary mixtures were studied. The modified Apelblat equation, the general Buchowski-Ksiazaczak λh model and the new correlative model were used for correlation analysis of the solubility of Form Ⅰ in mono-solvents. The general cosolvency model and Jouyban-Acree-van't Hoff model were used for correlation analysis of the solubility of Form Ⅰ in binary mixed solvents. By comparing the models, the modified Apelblat equation and the general cosolvency model provided more accurate experimental data for predicting the solubility of Form Ⅰ in mono-solvents and binary mixed solvents, respectively. Finally, the apparent thermodynamic properties were calculated by the van't Hoff analysis.