Abstract: Objective: To evaluate the bioequivalence of loratadine orally disintegrating tablets and loratadine tablets in healthy volunteers.Methods: A single oral dose of 20 mg test or reference formulations were given to 20 male healthy volunteers in a randomized crossover design.The serum concentration of loratadine was determined by liquid chromatography-tandem mass spectrometry(LC-MS/MS) method.Pharmacokinetic parameters and relative bioavailability were calculated with DAS program to evaluate the bioequivalence of the two formulations.Results: Pharmacokinetic parameters of loratadine reference formulation were obtained as follows:T_max was(1.33±1.02) h,C_max was(41.0±17.1) μg/L,AUC_0-15hwas(89.4±43.2) μg·L^-1·h^-1,AUC_0-∞ was(101.7±39.2) μg·L^-1·h^-1.For test formulation:T_max was(1.14±0.43) h,C_max was(37.0±16.0) μg/L,AUC_0-15hwas(99.6±49.5) μg·L^-1·h^-1,AUC_0-∞ was(108.0±50.7) μg·L^-1·h^-1.Calculated with AUC_0-15h,the bioavailability of two formulations was(115.1±32.0)%.Conclusions: The loratadine orally disintegrating tablets and loratadine tablets were bioequivalent.