Estimation of the aqueous solubility of complex organic compounds

Abstract

The aqueous solubility of organic compounds depends on two contributing parameters: the ideal solubility and the activity coefficient. The methods available for the prediction of aqueous solubility have the ideal solubility term in common. They differ in the way they account for the activity coefficient. Various empirical and theoretical methods for predicting activity coefficients are compared in this report. The methods were first used with a Training Set of solutes. The same methods were then applied to a Test Set of solutes, which consisted of a series of compounds of pharmaceutical and environmental relevance. The Test Set encompassed a wide variety of chemical structures and high degree of structural complexity. Only those methods with a sound theoretical rationale are useful for both the Training and Test sets. A comparative evaluation of the methods tested was made through the quantification of the accuracy of their predictions and their range of applicability.