Solubilities of Betulinic Acid in Thirteen Organic Solvents at Different Temperatures

The solubilities of betulinic acid in methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 1-pentanol, 1-hexanol, ethyl formate, ethyl acetate, butyl acetate, acetone, and tetrahydrofuran were measured by an analytical method in the temperature range of (278.2 to 318.2) K. The experimental data were correlated with a three-parameter empirical equation and UNIQUAC model, respectively. The calculated solubilities showed good agreement with the experimental data over this temperature range. Furthermore, the relation of the solubilities and the crystal habit were discussed.