Determination and Correlation of the Solubility of Monosodium Fumarate in Different Neat and Binary Solvent Systems

Monosodium fumarate solubility in 12 monosolvents (water, methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 2-propanol, 2-methyl-1-propanol, ethyl acetate, 1,4-dioxane, acetonitrile, and acetone) and four binary solvents (water + methanol, water + ethanol, water + 2-propanol, and water + acetone) was determined by the gravimetric method from 283.15 to 323.15 K. The solubility order in pure solvents was water > methanol > ethyl acetate > 1,4-dioxane > ethanol > 1-propanol > 1-butanol > acetonitrile > 1-pentanol > 2-propanol > acetone > 2-methyl-1-propanol. Also, it was positively related to experimental temperature and solvent composition for all solvent systems. According to the solubility results, the dissolution behavior of monosodium fumarate in pure solvents was mainly affected by the solvent properties including polarity, hydrogen bond acidity (α), hydrogen bond basicity (β), bipolar/polarizability (π*) and Hildebrand solubility parameter (δ_H). The modified Apelblat, Jouyban–Acree, and Apelblat–Jouyban–Acree models were used to correlate the solubility data, and the values calculated by the three thermodynamic models were found to agree well with the experimental data.