Population pharmacokinetic study of imipramine in Taiwan people healthy volunteers

Imipramine is an antidepressant drug (ADs) that shows therapeutic efficacy in a maximum of 60–80% of patients who have experienced a major depressive episode (unipolar or bipolar). The purpose of the study was to investigate the pharmacokinetics of a multi-oral dose of Imipramine 25 mg tablet in a Taiwan healthy population. The study was a standard two-way, crossover, randomized, and single dose daily for 5 days study with a two-week washout period in 30 healthy volunteers who received 25 mg imipramine tablets (test and reference formulation). After drug administration, blood samples were taken according to the planned times over a period of 24 hours. The plasma concentrations of Imipramine were determined using the validated high-performance liquid chromatography method with ultraviolet detection. All the pharmacokinetic parameters for Imipramine in healthy volunteers were calculated using nonlinear mixed-effect modeling and standard non-compartmental methods. Values (relative standard error (RSE) %) for first-order absorption rate constant (Ka), oral clearance (Cl/F), and apparent volume of distribution (Vd/F) were 1.05 (7.11) 1/h, 6.99(0.27) L/h, and 71.7.9(4.80) L. The median for the time to peak plasma Imipramine concentration (Tmax) for the test and reference drug was 2(1.1-4) hours and 4(1.9-5) hours respectively. In conclusion, the imipramine pharmacokinetic model in the Taiwan healthy population was similar to other studied populations.