High performance liquid chromatographic determination of fluvoxamine and paroxetine in plasma

A rapid, simple and accurate method for the determination of paroxetine and fluvoxamine in human plasma is presented. Solid-phase extraction of these substances was carried out using a LiChrolut RP-18 column. A methanol-tetra hydrofuran-phosphate buffer at pH 2.65 (0.0657 mol 1(-1)) (53:5:42, v/v) wa s used as the mobile phase. Determination was performed using isocratic rev ersed-phase high-performance liquid chromatography (HPLC) with a Nova-Pak C -18 column and UV detection at 293 nm and 253 nm. The lower limit of quanti tation for paroxetine and fluvoxamine was 10 ng ml(-1), when 1 ml plasma wa s extracted. Accuracies calculated at three concentrations in each of three separate runs were between 93.6 and 104.7% for paroxetine and 91.8 and 102 .2% for fluvoxamine, and precision data were from 5.8 to 7.9 for paroxetine and from 2.2 to 8.8 for fluvoxamine.