Abstract: AIM: To study the pharmacokinetics and bioavailability of ribavirin in 18 young healthy volunteers.METHODS: The ribavirin concentrations in plasma were determined by HPLC after a single oral dose of the stan-dard formulation and the tested formulation which were re-spectively given to 18 volunteers in randomized cross-over test. RESULTS: The concentration-time curves of three formulations fitted to one-compartment open model. The C max were 0.76 ±0.37, 0.72 ±0.22 and 0.76 ±0.40 mg°L^-1;T_max were 2.07±0.89, 1.67±0.49 and 1.86 ±0.41 h;T_1/2ke was 22 ±3, 24 ±4 and 22 ±4 h; $AUC^{t}_{0}$ were 12±4, 14 ±4 and 12 ±4 mg°h°L^-1;and $AUC^{∞}_{0}$ were 16±5, 18±5 and 15±5 mg°h°L^-1 in a standard formulation and two tested formulations, respec-tively. The pharmacokinetic parameters showed no signifi-cant difference among three formulations (P>0.05). The relative bioavailability of two tested formulations was (112 ±21) % and (100 ±18) %.CONCLUSION: The two tested formulations are bioequivalent with refer-enced formulation.

Key words: RP-HPLC, pharmacokinetics, rib-avirin, bioequivalence, bioavailability