Reversed phase parallel artificial membrane permeation assay for log P measurement

Abstract

A reversed phase parallel artificial membrane permeation assay (RP-PAMPA) was newly invented for log P measurement. An oil/water/oil sandwich was constructed using a conventional PAMPA instrument. 1 % agarose was used to improve the physical stability of the water phase. A linear correlation between log P and the apparent permeability was observed in the -0.24 < log P < 2.85 region (R² = 0.98). RP-PAMPA was also applied to pKa measurement.