A randomized, open-label, crossover study to compare the safety and pharmacokinetics of two tablet formulations of tenofovir (tenofovir disoproxil and tenofovir disoproxil fumarate) in healthy subjects.

ABSTRACT

PURPOSE: This study was performed to compare the pharmacokinetic properties and assess bioequivalence for the test formulation (HUG116 tablet; tenofovir disoproxil) and reference formulation (Viread tablet; tenofovir disoproxil fumarate). MATERIALS AND METHODS: A randomized, open-label, single-dosing, two-treatment, two-period, two-sequence cross-over study was conducted in 50 healthy subjects. All subjects were randomly assigned to one of the two sequences, and they received a single dose of test or reference formulation in the first period and the alternative formulation during the next period under fasting conditions. Serial blood samples for pharmacokinetic evaluation were collected up to 72 hours post dose, and the pharmacokinetic parameters were estimated by noncompartmental methods. Throughout the study, tolerability was assessed based on adverse events, vital signs, and clinical laboratory tests. RESULTS: The test formulation showed similar pharmacokinetic profiles to those of the reference formulation. The geometric mean ratio and 90% confidence interval (CI) of the test formulation to the reference formulation for maximum plasma concentration (Cmax) was 0.93 (0.87 - 0.99), and the corresponding value for the area under the concentration-time curve from time zero to time of last quantifiable concentration (AUCt) was 0.94 (0.89 - 0.99). Both CIs were within the conventional bioequivalence range of 0.8 - 1.25. The tolerability profile was not significantly different between the test and reference formulations. CONCLUSION: This study found that the PKs of the test formulation (HUG116 tablet; tenofovir disoproxil) and reference formulation (Viread tablet; tenofovir disoproxil fumarate) were similar, and the test formulation met the regulatory criteria for assuming bioequivalence with the reference formulation.