Journal of Chemical Thermodynamics, Vol.62, 118-129, 2013
Prediction of the solubility of selected pharmaceuticals in water and alcohols with a group contribution method
An improved group contribution approach using activity coefficients at infinite dilution, which has been proposed by our group, was used for the prediction of the solubility of selected pharmaceuticals in water and alcohols [B. Moller, Activity of complex multifunctional organic compounds in common solvents, PhD Thesis, Chemical Engineering, University of KwaZulu-Natal, 2009]. The solubility of 16 different pharmaceuticals in water, ethanol and octan-1-ol was predicted over a fairly wide range of temperature with this group contribution model. The predicted values, along with values computed with the Schroeder-van Laar equation, are compared to experimental results published by us previously for 42 binary mixtures. The predicted solubility values were lower than those from the experiments for most of the mixtures. In order to improve the prediction method, a semi-predictive calculation using one experimental solubility value was implemented. This one point prediction has given acceptable results when comparison is made to experimental values. (c) 2013 Elsevier Ltd. All rights reserved.
Keywords:Prediction of solubility in water and alcohols;Improved group contribution model;Pharmaceuticals