Lipophilicity--methods of determination and its role in medicinal chemistry

Lipophilicity is a physicochemical property of crucial importance in medicinal chemistry. On the molecular level it encodes information on the network of inter- and intramolecular forces affecting drug transport through lipid structures as well as drug's interactions with the target protein. In result, on the organism level, lipophilicity is an important factor defining pharmacokinetics and pharmacodynamics of a drug substance. Thus, it is a meaningful parameter that found innumerable applications in drug development, Quantitative Structure-Activity Relationships (QSARs) and Quantitative Structure-Pharmacokinetic Relationships (QSPkRs) analyses. This report reviews the importance of lipophilicity on each step of the presence of a medicinal substance in the organism and describes progress in experimental methods of its determination. It has been documented that the retention of a compound in reversed-phase liquid chromatography is governed by its lipophilicity and shows significant correlation with n-octanol/water partition coefficient. Hence, reversed phase chromatography may provide relevant information about the compounds' property. Elaboration of biomimetic stationary phases provides better insight into biological partition processes. Nowadays, there is an urgent need for both precise and quick procedures for quantification of molecular lipophilicity.