The retention mechanism in reversed-phase liquid chromatography was quantitatively
described using log P (octanol-water partition coefficient). The hydrophobic (lipophilic) interaction
liquid chromatography was then used to measure the hydrophobicity of a variety of compounds.
Furthermore, the technique has been used as an analytical method to determine molecular
properties during the drug discovery process. However, log P values cannot be applied to other
chromatographic techniques. Therefore, the direct calculation of molecular interactions was proposed
to describe the general retention mechanisms in chromatography. The retention mechanisms
in reversed-phase liquid chromatography were quantitatively described in silico by using simple
model compounds and phases. The competitive interactions between a bonded-phase and a solvent
phase clearly demonstrated the retention mechanisms in reversed-phase liquid chromatography.
Chromatographic behavior of acidic drugs on a pentyl-, an octyl-, and a hexenyl-phase was quantitatively
described in the in silico analysis. Their retention was based on their hydrophobicity, and
hydrogen bonding and electrostatic interaction were selectivity of the hexenyl-phase. This review
focuses on the quantitative explanation of the retention mechanisms in reversed-phase liquid
chromatography and the practical applications in drug discovery.