DETERMINATION OF TICLOPIDINE IN HUMAN PLASMA BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY AND ULTRAVIOLET ABSORBENCY DETECTION

A simple HPLC method has been developed for the determination of ticlo pidine in human plasma. Plasma samples were buffered at pH 9 and extra cted with n-heptane-isoamyl alcohol (98.5:1.5, v/v). Imipramine was us ed as internal standard. Chromatography was performed isocratically wi th acetonitrile-methanol-0.05 M KH2PO4 (20:25:55, v/v) at pH 3.0 conta ining 3% triethylamine at a flow-rate of 1 ml/min. A reversed-phase co lumn Supelcosil LC-8-DB, 15 cm x 4.6 mm I.D., 5 mu m particle size, wa s used. The effluent was monitored by UV absorbance detection at 235 n m. The method showed good accuracy, precision and linearity in the con centration range 5-1200 ng/ml. The limit of quantitation was 5 ng/ml, with a precision (C.V.) of 8.91%, which is the same as that achieved b y other authors with a previously published GC-MS method. The procedur e described in this paper is simple and allows the routine assessment of ticlopidine plasma concentration in pharmacokinetic studies followi ng therapeutic doses in human subjects.