QUANTITATIVE-DETERMINATION OF THE DOPAMINE AGONIST LISURIDE IN PLASMA USING HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH FLUORESCENCE DETECTION

An HPLC method for the determination of lisuride hydrogen maleate in plasma is described. After addition of ergotamine tartrate as internal standard, plasma is extracted with diethyl ether. Following evaporation of the solvent and redissolving in methanol the extract is injected on a silica HPLC column and lisuride is monitored by fluorescence detection using an excitation wavelength of 322 nm and an emission wavelength of 405 nm. The method is sufficiently accurate and precise with a detection limit of 20 pg/ml lisuride in plasma. The usefulness of the method is demonstrated by measurements of lisuride levels after oral intake of a 0.6 mg dose of the drug by a healthy male volunteer, showing a peak level of 1266 pg/ml, 45 min after intake.