ABSTRACT
This chapter discusses new approaches developed in certain years for the prediction of solubility of organic compounds in solutions, both theoretical and empirical. It explores the methods for prediction of solubility and provides tools for the design and study of new molecules in pharmaceutical research and development. The Mobile Order Theory was developed partly on the basis of the perpetual moving nature of molecules. In the partition theory, solubility was explained by the change of solute activity coefficient in the aqueous solution. Solubility can be estimated by the quantitative structure– solubility relationship approach. The chapter presents the use of partial atomic charges for the prediction of the solubility of polar compounds in a polar solvent, isopropyl alcohol. Solubility of an organic nonelectrolyte is largely determined by molecular interactions in solution and by the crystalline energy of the solute if the solute is a solid compound. Characterization of molecular interactions is still the main challenge for the prediction of solubility.
