Abstract: AIM: To develop a high performance liquid chromatography-mass spectrometry method for the determination of α-Lipoic acid in plasma , to study the pharmacokinetics of α-Lipoic acid and evaluate the bioequivalence of two preparations in healthy subjects. METHODS: A single oral dose of 200 mg α-Lipoic ac-id capsules and tablets was given to 22 healthy male volunteers according to an open randomized 2 way crossover design.Plasma concentrationsof α-Lipoic ac-id were determined by HPLC-MS method. The pharma-cokinetic parameters and relative bioavailability were calculated to evaluate the bioequivalence of the two preparations. RESULTS: The pharmacokinetic parameters of the two products were as follows:t max were (16 ±4)and (20±20)min, ρ_max were (1490±359)and (1537±290)ng/mL , AUC_0-t were (59559±18456) and (58210 ±15080)ng°mL^-1 ·min, AUC_0-∞ were (60068 ± 18556) and (58634 ± 15126) ng°mL^-1 ·min , respectively .The relative bioavailabili-ty of AUC_0-t and AUC_0-∞ were (102.97 ±18.28)% and (103.09 ±18.26)%.CONCLUSION: The re-sult demonstrated that two formations are bioequivalent by statistical analysis of variant , two one-side t-test and 90%confidential interval .

Key words: α-Lipoic acid, HPLC-MS, pharma-cokinetics, bioequivalence