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 drug s was determined by reversed_phase thin-layer chromatography and the e ffect of various eluent additives such as acetic acid, sodiumacetate a nd sodium chloride on the retention was studied. Each drug exhibited r egular retention behavior, their R(M) value linearly decreased with th e increasing concentration of methanol in the eluent. Acetic acid decr eased the retention, the effect was higher at lower acid concentration s which indicates that the phenomena is of saturation character. The e ffect of sodiumchloride and sodiumacetate was negligible. The lipophil icity and specific hydrophobic surface area values of the drugs were i ntercorrelated, however, their information content is different, there fore their simultaneous application in quantitative structure-activity relationship studies is recommended.