Solubility Prediction of Pharmaceutical Compounds in Pure Solvent by Different Correlations and Thermodynamic Models

Abstract

The solubility of active pharmaceutical compounds and chemical intermediate used in pharmaceutical industry is a vital information for synthesis and purification process. The selection of solvent directly influences the yield and purity of a product. The experimental determination of solubility by static-equilibrium method is discussed here. The experimental data were correlated with different correlations and thermodynamics models to predict the solubility at different temperature. In this work, correlations and thermodynamics models such as modified Apelblat equation, λh equation, non-random two-liquid (NRTL) and the Wilson equation used to predict the solubility are presented. The method to determine the accuracy of these models is discussed. The algorithm to estimate the adjustable parameters of semi-empirical correlations and thermodynamics models is explained.

Keywords: solubility, modelling, NRTL, Wilson, UNIQUAC