Solubility measurement and thermodynamic properties of sulfamonomethoxine in pure solvents and sulfamonomethoxine hydrate in acetone + water binary solvent at different temperature

Mole fraction solubility x1 of SMM in different solvents. [Display omitted] The experimental solubility of sulfamonomethoxine in six different pure solvents (methanol, ethanol, 1-propanol, l-butanol, ethyl acetate and acetone) and sulfamonomethoxine hydrate in acetone + water mixture solvents were measured from 294.55 K to 362.15 K by a laser dynamic method under atmospheric pressure. Experimental results indicated that the solubility data of sulfamonomethoxine increased with temperature increasing in pure solvents and the solubility followed this order: acetone > methanol > ethanol > ethyl acetate > 1-propanol > 1-butanol, but solubility in ethyl acetate was not affected significantly by temperature. In acetone + water mixture solvent, the solubility of sulfamonomethoxine hydrate increased with temperature and the acetone concentration. Thermodynamic equations were applied to correlate solubility data of sulfamonomethoxine and sulfamonomethoxine hydrate including the modified Apelblat equation, λh equation, Wilson equation, NRTL equation, Van’t Hoff-Jouyban Acree equation and modified Apel-Jouyban-Acree equation. Furthermore, thermodynamic properties ΔGd, ΔHd and ΔSd of sulfamonomethoxine and sulfamonomethoxine hydrate in dissolution process were obtained and discussed with the modified Van’t Hoff equation and Gibbs equation.