Abstract: Aim Therelative bio avalability of hydrochloride eperisone granule in 10 healthy volunteers was studied.Methods The time-p lasma concentrations of hydrochloride eperisone granule, as test drug, and my onal, as reference drug, weredetermined by GC-MS, with tolperisone senuingas internal standard.The pharmacokinetic parameters of both reference and test drug werecalculated and analyzed with two-one side test and confidential intervaltest.Results Theresults showed that the AUC^0-8, AUC^0-∞, C_max, T^peak, t^1/2 (α)and t^1/2(β) were(17.9±1.3)ng·h·ml^-1 and(18.6±1.6)ng·h·ml^-1, (19.1±1.2)ng·h·ml^-1 and (20.2±1.6)ng·h·ml^-1, (5.2±0.5)ng·ml^-1 and (5.4±0.5)ng·ml^-1, (1.05±0.18)h and (1.08±0.23)h, (0.78±0.13)h and (0.82±0.14)h, (1.8±0.3)h and (1.8±0.3)h, respectively.Therelative bioavalability of test drug was (105±5)%.Conclusion I t can be concluded that the test and reference arebioequivalented be tween individuals, preparations and periods.

Key words: eperisone hydrochloride, myonal, bioavalability, bioequivalence, GC-MS, tolperisong