High-throughput log Po/w determination from UHPLC measurements: Revisiting the chromatographic hydrophobicity index

• A high-throughput log Po/w determination approach is proposed in the present work.
• It is based on fast UHPLC CHI measurements and molecular descriptors.
• Molecular descriptors were calculated from ACD/Labs (Abraham) and CODESSA.
• Accurate determination of log Po/w with standard errors in the range of 0.4 is achieved.

A fast and accurate lipophilicity determination is fundamental in the drug discovery process, as long as it is a relevant property in the absorption, distribution, metabolism, excretion and toxicity (ADMET) of a potential drug substance. In the present work, different models based on chromatographic retention values for a large set of compounds and some of their molecular descriptors (calculated by ACD/Labs or CODESSA programs) have been examined in order to establish reliable equations for log Po/w determination from fast chromatographic hydrophobicity index (CHI) measurements. This appears to be a very interesting high-throughput methodology for screening purposes, since CHI values can be measured by UHPLC in very short runs (<4 min) and molecular descriptors can be easily computed from the structure of any compound. The selected final descriptors were Abraham’s hydrogen-bond acidity (A) and excess molar refraction (E) from ACD/Labs, and hydrogen-bond acidity HDCA-1/TMSA and HOMO-LUMO polarizability descriptors from CODESSA software. The proposed equations allow an accurate determination of log Po/w with standard errors in the range of 0.4 units.