Abstract: AIM: To study the pharmacokinetics and relative bioavailability of citalopra hydrobromide in human plasma.METHODS: The citalopra hydrobromide concentrations in plasma were determined by HPLC-UV.The column was Lichrospher ODS (5 μm, 250 mm×4.6 mm).The mobile phase was acetonitrile-0.1 mol/L KH₂PO₄ buffer-triethylamine (35：65：0.3, v/v/v).The flow rate was 1 mL/min.The detection wavelength was 240 nm.The test and reference formulations of citalopra were given to 18 healthy male volunteers.RESULTS: The calibration curve was linear within the range of 2- 128 μg/L, r=0.9992.The minimum detection limit was 1 μg/L.The recovery was 80%-88%, the RSDs of inter- day and intra-day were not more than 15%.After a single oral dose of 20 mg citalopra hydrobromide was given, the main pharmacokinetic parameters tmax were (4.6±1.0), (4.4±1.4) and (4.0±1.4) h;C_max were (70±19), (71±17) and (66±21) μg/L;and t_1/2 were (37±9), (37±6) and (36±6) h respectively.CONCLUSION: No significant difference exists among the pharmacokinetic parameters of the three formulations. They are bioequivalent.

Key words: citalopra hydrobromide, HPLC-UV, pharmacokinetics, relative bioavailability