Abstract: AIM: To establish a HPLC method to determine the concentration of clarithromycin in human plasma, and to study clarithromycin bioequivalence by this method.METHODS: A HPLC assay was developed.Chromatographic assay was performed on a column of diamonsil C18 (4.6 mm×150 mm).The mobile phase was a mixture of acetonitrile and water (32∶68), the flow rate 1.0 ml·min^-1, and the detection wavelength 210 nm.RESULTS: The calibration curve was linear in the range of 0.05 -3.2 mg·L^-1.The minimum detection concentration was 0.05 mg·L^-1.The values of AUC, C_max, T_maxand t_12β of two preparations did not show significant difference (P>0.05).The relative bioavailability was (101.10 ±19.40) %.CONCLUSION: The proposed method can be applied to the assay of clarithromycin in reverse phase conditions easily and rapidly, and the two preparations of clarithromycin hydrochloride are bioequivalent.

Key words: solid-phase extraction, HPLC, clarithromycin, pharmacokinetics, bioavailibility, bioequivalent