Pharmacokinetic comparisons of two different varenicline formulations in humans: Varenicline tartrate versus varenicline oxalate

BACKGROUND AND OBJECTIVE: Varenicline is an effective drug for smoking cessation. The aim of the present study was to compare the pharmacokinetics and safety profiles of two different varenicline formulations (varenicline tartrate (reference) and varenicline oxalate (test)), each containing 1 mg varenicline base in humans. MATERIALS AND METHODS: and AUC values, and the geometric mean ratios (GMRs) and their 90% confidence intervals (CIs) were assessed as well. The safety profiles were also assessed. RESULTS: were 1.0106 (0.9626 - 1.0610), 0.9904 (0.9540 - 1.0282), and 0.9885 (0.9517 - 1.0268), respectively. No clinically relevant changes were observed in the physical, biochemical, hematologic, electrocardiographic, or urinalysis findings during the study, and no serious adverse events were found. CONCLUSION: The results of the present study reveal that varenicline oxalate and varenicline tartrate have similar pharmacokinetic characteristics as varenicline, and that these two formulations exhibit pharmacokinetic equivalence to meet the regulatory criteria. Both varenicline formulations were generally well tolerated.