Pharmacokinetics and bioequivalence of epinastine hydrochloride,a histamine H1 receptor antagonist, in healthy Chinese volunteers / 中国临床药理学与治疗学

ABSTRACT

To determine the pharmacokinetics and bioequivalence of epinastine (EPN) hydrochloride, a promising histamine H1 receptor antagonist, in healthy Chinese volunteers under fasting conditions. METHODS: EPN hydrochloride test and reference tablets were administered as a single dose on two treatment days separated by a 1-week washout period. After dosing, serial blood samples were collected for a period of 36 h, and plasma EPN hydrochloride concentrations were determined by a validated reversed-phase HPLC method and pharmacokinetic parameters were calculated with DAS software. RESULTS: Plasma concentration-time profiles were adequately described by a two-compartment open model. The compound was rapidly absorbed and cleared slowly from plasma with a half-life of approximately 10 h. The main pharmacokinetic parameters of EPN hydrochloride test and reference tablets were as follow tmax were (2.2±0.5) and (2.0±0.4)h, Cmax were (66±16)and (68±13)μg/L, t1/2 were(10.1±1.3) and (10.4±2.4)h, AUC0-36 were (592±88) and (601±94)μg·h·L-1, respectively. The relative bioavailability of test tablets was (99±13)%. CONCLUSION: The results indicate that the two formulations of EPN hydrochloride tablets are bioequivalent in the rate and extent of absorption.