Measurement and Correlation of the Solubility of Dimetridazole in Three Binary Solvent Systems

The solubilities of dimetridazole (DMZ) in different binary solvent mixtures─methanol + water, ethanol + water, and isopropanol + water─were measured by using the gravimetric method under atmospheric pressure, within the temperature range of 297.95–323.15 K. The experimental data indicate that the solubilities of DMZ in all three solvent systems increased with rising temperature. At a constant temperature, the solubilities of dimetridazole in the ethanol + water and isopropanol + water systems initially increased and then decreased with the increasing mole fraction of ethanol or isopropanol, reaching maximum values at mole fractions of 0.6003 for ethanol and 0.4999 for isopropanol. However, in the methanol + water system, the solubility increased continuously with an increased mole fraction of methanol, albeit at a gradually diminishing rate. The solubility data for DMZ in the three binary solvent mixtures were successfully correlated using the modified Apelblat, the general cosolvency model, the Apelblat–Jouyban–Acree, the van’t Hoff–Jouyban–Acree, and the NRTL models, all models provided good fitting results and can be used for solubility prediction. Furthermore, solvent–solvent and solvent–solute interactions were evaluated using the KAT-LSER analysis. The results indicate that the hydrogen bond basicity and acidity of the solvent are the main factors influencing solubility.