Solubility and dissolution thermodynamic properties of L-carnosine in binary solvent mixtures

Abstract

Thermodynamic data are the basis for design of crystallization process and control of crystal morphology and polymorph. In this work, solubility data of L-carnosine in different binary solvent mixtures, including water + (methanol, isopropanol or acetone), were determined in temperatures ranging from 288.05 K to 323.15 K by static method under atmospheric pressure. It was found that the solubility data of L-carnosine decrease apparently with the increasing of the mole fraction of organic solvent in binary solvent mixtures and increase with the rising of temperature. In addition, the experimental solubility data were correlated and analyzed by the modified Apelblat equation, the NRTL model and the Jouyban–Acree model to extend the applicability of the solubility data. Finally, the standard dissolution thermodynamic properties, including Gibbs energy, entropy and enthalpy were calculated and discussed based on the experimental solubility data and Van’t Hoff equation.