LAUSR

Solubility of nicotinamide in a series of pure solvents, including ethanol, 1-propanol, isopropanol, ethyl acetate, methanol, 1-butanol, methyl acetate, isobutanol, acetone, and butyl acetate, was measured between 283.15 and 323.15 K. The solubility data increase with rising of temperature and mainly follow the order methanol > ethanol > 1-propanol > isopropanol >1-butanol > isobutanol > acetone > methyl acetate > ethyl acetate > butyl acetate. The experimental data in different solvents was well-correlated by nonrandon two-liquid, Wilson, and modified Apelblat equations. To further study the above dissolution behavior, the thermodynamic properties, including dissolution Gibbs energy, dissolution entropy, and dissolution enthalpy, were also calculated. Based on solubility data, ethanol was selected as the cocrystallization solvent for nicotinamide and benzoic acid, and one cocrystal product with stoichiometric ratio of 1:1 was first formed and characterized.