Ion transfer voltammetry with the polarized 1,2-dichloroethane (DCE)vertical bar water (W) interface was carried out to determine the standard ion-transfer potential (Delta(W)(O)phi(.)) and the distribution coefficient (logK(D)) for amine drugs, including desipramine, imipramine, labetalol, etc. The values of Delta(W)(O)phi(.) and logK(D) are the hydrophobicity scales for the ionized and neutral forms of a drug, respectively, and were found to show a good mutual correlation. However, these hydrophobicity scales did not show a good correlation to the 1-octanol-water partition coefficient (logP(oct)) being conventionally used. In contrast, the permeability coefficient (logP(pampa)) in the parallel artificial membrane permeation assay showed a clear and characteristic dependence on Delta(W)(O)phi(.) (or logK(D)). These results suggested that the solvation environment in DCE should be more similar to that in the hydrocarbon region of lipid bilayers than in 1-octanol. Thus, it was shown that Delta(W)(O)phi(.), which can be easily determined by ion-transfer voltammetry, is a promising scale for predicting drug permeability through lipid membranes. (C) 2016 Elsevier B.V. All rights reserved.