DETERMINATION OF METOCLOPRAMIDE IN SERUM BY HPLC ASSAY AND ITS APPLICATION TO PHARMACOKINETIC STUDY IN RAT

A simple, sensitive, and reproducible HPLC method has been developed f or the determination of metoclopramide employing reversed phase high p erformance liquid chromatography with UV detection at 270 nn. The sepa ration was performed on a Novapak C-18, 4 mu m (3.9 x 150 mm) column. Acetonitrile (18%) in 0.02 M ammonium acetate containing 0.1% triethyl amine was used as the mobile phase and the run time was 7 min. Tramado l was used as the internal standard. The mean retention times of metoc lopramide and tramadol were 3.4 and 4.6 min, respectively. Linear resp onse (r > 0.997) was observed over the range of 0.025 - 5 mu g/ml of m etoclopramide. There was no significant difference (p < 0.05) between inter- and intra-day studies for metoclopramide. The mean relative sta ndard deviations (RSD%) of the results of within-day precision and acc uracy of the drug were < 10%. The applicability of the assay was demon strated in measuring metoclopramide pharmacokinetics in rats. The elim ination half-life was 2.09 +/- 0.39 h with an apparent clearance of 2. 45 +/- 0.70 (L/h)/kg in rat.