Solubility and apparent thermodynamic analysis of pomalidomide in (acetone + ethanol/isopropanol) and (ethyl acetate + ethanol/isopropanol) and its correlation with thermodynamic model

Highlights: • Study the solubility profile of pomalidomide in four binary mixtures. • The result was evaluated by Jouyban-Acree model. • The molecular interactions were analyzed by solvent properties. • Some of apparent thermodynamic properties were calculated. Co-solvency has been extensively utilized as a very helpful dissolving technique for the poorly soluble pharmaceutical compounds. The dissolution of pomalidomide racemic mixture in four mixtures including (acetone + ethanol), (acetone + isopropanol), (ethyl acetate + ethanol) and (ethyl acetate + isopropanol) over the temperature from 278.15 K to 318.15 K was studied and correlated using the Jouyban-Acree model. In the acetone mixture, the increases occurred monotonously with the increasing mass fraction of acetone, while it increases to a maximum value with the rising concentration of ethyl acetate, and then decreases in ethyl acetate systems. The correlation result was evaluated by relative average deviation (RAD), which indicates that the Jouyban-Acree model can provide a reasonable correlation. The different types of interaction on the solubility were analysed by a multiple linear regression analysis (MLRA). In addition, apparent thermodynamic analysis indicates that the dissolution process of pomalidomide in four mixtures selected is an endothermic and entropy driven process. More importantly, the co-solvency on the dissolution process for pomalidomide is an important aspect of its purification and recrystallization.