Prediction of Solubility of Drugs and Other Compounds in Organic Solvents

We have set out a procedure for the prediction of solubilities of drugs and other compounds in a wide range of solvents, based on the Abraham solvation equations. The method requires a knowledge of solubilities of a given compound in a few solvents, as shown by our own experimental data on apocynin, diapocynin, dehydrodivanillin, and dehydrodi(methyl vanillate). The procedure is especially useful for very hydrophobic compounds such as cholesteryl acetate and cholesterol that we give as examples. Other examples include vanillin and 3,4-dichlorobenzoic acid. If the solubility in water is available, then this alone is sufficient to predict solubilities in organic solvents, provided that the Abraham descriptors are available for the compound. Predictions can be made for solubilities in some 85 solvents. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 99: 1500–1515, 2010