The octanol-water partition coefficient is a laboratory-measured property of a substance. It provides a thermodynamic measure of the tendency of the substance to prefer a non-aqueous or oily milieu rather than water (i.e. its hydrophilic/lipophilic balance). Partition coefficients are used extensively in medicinal chemistry, drug design, ecotoxicology and environmental chemistry. The partition coefficient is recognized by governmental and international agencies (U.S. Environmental Protection Agency, OECD) as a physical property of organic pollutants equal in importance to vapour pressure,...