DETERMINATION OF DICENTRINE IN RAT PLASMA BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY AND ITS APPLICATION TO PHARMACOKINETICS

A simple high-performance liquid chromatographic method was developed to study the pharmacokinetics of dicentrine in rat plasma after 10 mg/ kg intravenous administration. After addition of an internal standard (coumarin), plasma was deproteinized by acetonitrile for sample clean- up. The drugs were separated on a reversed-phase Nucleosil C-18 column (250 x 4 mm I.D., particle size 5 mu m) and detected by photodiode-ar ray detection at a wavelength of 308 nm. Acetonitrile-water (35:65, v/ v, pH 2.5-2.8, adjusted with orthophosphoric acid) was used as the mob ile phase. A biphasic phenomenon with a rapid distribution followed by a slower elimination phase was observed from the plasma concentration -time curve.