Purpose: A fixed-dose combination (FDC) tablet of melitracen/flupentixol has been widely used for depression. The purpose of this study was to assess the safety profile and the relative bioavailability of two FDC products containing 10 mg melitracen and 0.5 mg flupentixol from two different manufacturers, in order to acquire adequate pharmacokinetic evidence for registration approval of the test formulation.
Methods: The study was designed as a single-dose, randomized, open-label, 2-period crossover study under fasted or fed conditions in healthy Chinese subjects. Twenty-four subjects (16 men and 8 women) were selected for fasted study, and another 24 cases (16 men and 8 women) were in fed study. Each subject was randomized at the beginning to receive either a single dose of the reference FDC or the test FDC tablet during the first period. Following two-week washout period, all subjects received the alternate formulation during the second period. Blood samples were collected up to 144 hrs after administration. Pharmacokinetic parameters, including C_max, T_max, AUC_0-t, AUC_0-∞, t½, CL/F, and V_d/F were acquired based on the time versus concentration profiles. Then, the geometric mean ratios (GMR) and corresponding 90% CIs were calculated for the determination of bioequivalence analysis. Safety assessment included changes in vital signs and laboratory tests, physical examination findings, and incidence or reports of adverse events (AEs).
Results: The present study has clearly indicated the test and the reference FDC products are bioequivalent in terms of rate and extent of drug absorption. GMR of C_max, AUC_0–t, and AUC_0-∞ for both flupentixol and melitracen between the two formulation FDC products, and corresponding 90% CIs, were all within the range of 80% to 125% under fasted or fed conditions. Both the test and the reference FDC products indicated good tolerance in all volunteers. Chinese Clinical Trials Registry identifier: CTR20171256.
Keywords: bioequivalence, melitracen, flupentixol, pharmacokinetics, fixed-dose combination tablet