SEPARATION AND DETERMINATION OF PROPRANOLOL ENANTIOMERS IN PLASMA BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH FLUORESCENCE DETECTION

The separation and determination of (-)- and (+)- propranolols in plasma by high-performance liquid chromatography (HPLC) are described. The newly developed method is based on precolumn derivatization with a chiral axis reagent, (-)-2-methyl-1,1'-binaphthalene-2'-carbonyl cyanide (MBNCC), to form diastereomeric esters. The diastereomers were separated on a normal phase column by HPLC with fluorescence detection employing 0.3% methanol in hexane-ethyl acetate (15:1, v/v) as the mobile phase. The clean-up of propranolol in plasma was efficiently attained by the combined use of a Sep-pak C18 cartridge and an ion exchange gel, carboxymethyl Sephadex LH-20. The detection limit of each propranolol enantiomer was 100 pg.