The Jouyban-Acree model’s usefulness for estimating ibuprofen and naproxen solubility in some cosolvent mixtures

Estimating drug solubility in cosolvent mixtures has been an important pharmaceutical science research field at theoretical and practical levels for several decades. The validity of an adapted version of the Jouyban-Acree (J-A) model for predicting ibuprofen (IBP) and naproxen (NAP) solubility in propylene glycol + water cosolvent mixtures was thus evaluated. The usefulness of Yalkowsky and Roseman’s solubility log-linear equation was also evaluated for the same drugs in such cosolvent system. The solubility estimation was studied as a function of temperature and cosolvent composition. The J-A and Y-R models only require experimental equilibrium solubility values in pure solvents at all temperatures evaluated. Estimated solubility values obtained by using both semi-empiric models were similar but presented notable deviations regarding experimental values presented in the literature, especially for IBP. These results show that currently available theoretical strategies for estimating this property must be improved; they also demonstrate the importance of experimental determination of drug solubility according to temperature in all cosolvent mixtures which could be useful when designing homogeneous liquid dosage at industrial level.