Abstract: AIM: To assess the bioequivalence of pramipexole hydrochloride tablets with reference(Sifrol).  METHODS: A randomized, open-label, 2-period crossover study was conducted in 48 healthy Chinese volunteers under fasted or fed conditions (24 volunteers for each condition). In each session, the subjects received a single oral dose of 0.25 mg test (T) or reference (R) formulation. Pramipexole concentrations in plasma were determined by a validated HPLC-MS/MS. Pharmacokinetic parameters were calculated using a non-compartmental model through Phoenix WinNonlin version 6.4. Other statistic analysis were analyzed by using software of SAS 9.3. RESULTS: The pharmacokinetic parameters of test drug and reference drug under fasted condition(n=20) were: Cmax (481.15±102.21) and (497.25±133.31)  pg/mL, Tmax 1.77 (0.5, 5) and 1.50 (0.5, 5) h, AUC0-t (6.18±1.49) and (6.20±1.28) pg·mL-1·h, AUC0-∞ (6.41±1.55) and (6.42±1.31) pg·mL-1·h, T1/2 (9.18±1.29) and (9.02±1.14) h, respectively. The 90%CIs of T/R for Cmax, AUC0-t and AUC0-∞ were 92.20%-103.10%, 94.06%-104.35%, 94.17%-104.07%, all were within the range of 80.00%-125.00%; the two formulations tested were considered bioequivalent when administered under fasted condition to healthy adult subjects. The pharmacokinetic parameters of test drug and reference drug under fedcondition (n=22) were: Cmax (515.36±83.28) and (500.05±64.12) pg/mL, Tmax 2.00 (1.00, 4.00) and 1.75 (1.00, 4.00) h, AUC0-t (5.94±1.36) and (5.67±1.05) pg·mL-1·h, AUC0-∞ (6.16±1.43) and (5.88±1.11) pg·mL-1·h, T1/2 (8.92±2.00) and (8.85±1.98) h, respectively. The 90%CIs of T/R for Cmax, AUC0-t and AUC0-∞ were 97.84%-107.41%, 99.03%-108.79%, 99.12%-108.68%, all were within the range of 80.00%-125.00%. All results meet the cretiria of bioequivance. CONCLUSION: This study suggests that the test formulation of pramipexole hydrochloride tablets are bioequivalent with the reference formulation of Sifrol in Chinese healthy subjects. 

Key words: pramipexole, bioequivalence, pharmacokinetics