Solid-Liquid Equilibrium Behavior and Data Correlation of Furosemide in 12 Pure Solvents from 283.15 to 323.15 K

In this paper, the solubility of furosemide in 12 monosolvents including methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, 1-pentanol, acetone, 2-butanone, methyl acetate, ethyl acetate, and water was measured by using a static gravimetric method within the temperature range of 283.15 to 323.15 K under atmospheric pressure. The solubility magnitudes show an increasing tendency with the increase of temperature in all solvents. Within the entire temperature range, the solubility is the lowest in water (0.0053 × 10–3 at 283.15 K) and the highest in 1-pentanol (72.736 × 10–3 at 323.15 K). The rough subsequence of solubility is 1-pentanol > methanol > n-propanol > ethanol > isopropanol > sec-butanol > n-butanol in alcoholic solvents and acetone >2-butanone > methyl acetate > ethyl acetate > water in nonalcohol solvents. The solubility behavior of furosemide is a result of the combined effects of solvent polarity, solvent–solvent intermolecular interactions (characterized by cohesive energy density), and summation of hydrogen bond acceptor propensities. Moreover, the experimental solubility data were fitted by the models of Apelblat and Yaws. The results indicate that the two models could both correlate the experimental values satisfactorily, and the Yaws model is more appropriate to fit the solubility data of furosemide compared with the Apelblat model.