LIPOPHILICITY DETERMINATION OF SOME MONOAMINE-OXIDASE INHIBITORS BY REVERSED-PHASE THIN-LAYER CHROMATOGRAPHY - THE EFFECT OF PH

The lipophilicity (R(M) value) of 17 monoamine oxidase inhibitory drugs was determined by reversed_phase thin-layer chromatography and the effect of various eluent additives such as acetic acid, sodiumacetate and sodium chloride on the retention was studied. Each drug exhibited regular retention behavior, their R(M) value linearly decreased with the increasing concentration of methanol in the eluent. Acetic acid decreased the retention, the effect was higher at lower acid concentrations which indicates that the phenomena is of saturation character. The effect of sodiumchloride and sodiumacetate was negligible. The lipophilicity and specific hydrophobic surface area values of the drugs were intercorrelated, however, their information content is different, therefore their simultaneous application in quantitative structure-activity relationship studies is recommended.