Application of high-performance liquid chromatography based measurements of lipophilicity to model biological distribution.

Octanol-water partition coefficients are the most widely used measure of lipophilicity in modelling biological partition/distribution. It has long been recognised that the retention of a compound in reversed-phase liquid chromatography is governed by its lipophilicity/hydrophobicity, and thus shows correlation with an octanol-water partition coefficient. A great number of publications have reported the efforts made to adjust HPLC conditions to measure surrogate octanol-water partition coefficients. However, there is no general consensus in this field. HPLC provides a platform to measure various types of lipophilicity that can provide relevant information about the compounds' property. In this way HPLC can be more valuable than just a surrogate for octanol-water partition. Chromatography using biomimetic stationary phases may provide better insight for biological partition/distribution processes. The research in this field is still ongoing and a large variety of HPLC conditions have been suggested. This review will outline approaches to overcoming the difficulties of standardisation and describe different theoretical approaches for comparison of HPLC lipophilicity data obtained under various conditions, along with the relation of these results to biological partition/distribution.