SIMULTANEOUS DETERMINATION OF (R)-BREFANOLOL AND (S)-BREFANOLOL IN HUMAN PLASMA - HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC ASSAY ON A CHIRALSTATIONARY-PHASE

A new method for the quantitative enantiospecific determination of rac brefanolol, a vasodilating beta-adrenoceptor blocking agent, in human plasma is described. After an alkaline liquid-liquid extraction from b iological material and a preseparation on a silica gel column with fra ctional collection of the eluate, the separation of the underivatized enantiomers is performed by high-performance liquid chromatography on cellulose tris-4-methylbenzoic acid polymer coated on silica gel. The UV-absorbance of the eluate was monitored at 254 nm. Determination lim its are 10 ng enantiomer per mi plasma and allow the performance of ph armacokinetic studies after the aimed therapeutic dosages.