Pharmacokinetics of the cinnarizine floating sustained-release tablet in dogs

LIU Li-ping; TANG Xing; ZHANG Xi-hui; ZANG Yu-lan

Abstract：Objective:To establish the HPLC method for detecting cinnarizine concentration in dog plasma, and evaluate the pharmacokinetics and the sustained-release performance of the cinnarizine floating sustainedrelease tablet by this method. Methods: Plasma was extracted by n-hexane-chloroform (3:2). The analyzing method included an HPLC column of spherisorb ODS (150 mm × 4.6 mm, 5 μm) ; a mobile phase of 0.04% triethylamine NH_4H_2PO_4(0.01 mol·L_(-1), pH 4.7) in aqueous solution-acetonitrile (40: 60), and a flow rate of 0.8 mL·min~(-1) (injection volume 20.0 μL). Results: The linear range of cinnarizine was 15 ～ 1 500 ng·mL~(-1); the relative recoveries were 86.7% ～ 101.2% ; the absolute recoveries were 78.5% ～ 88.9% ; the intraday RSD was less than 3.26% ; the interday RSD was less than 6.38%. The main pharmaeokinetic parameter T_(max) was 3.48,2.98 or 0.83 h, and the corresponding AUC value was 5 460.67, 4 019.5 or 2 524.4 ng·h·mL~(-1) by using the trapezoidal method, after taking floating sustained-release tablets, gel-matrix sustained-release tablets or conventional tablets. The bioavailability of the cinnarizine floating sustained-release tablet or the gel-matrix sustained-release tablet was 237.72% or 155.89%, respectively, as compared with the conventional tablet. Conclusion: The method is sensitive, accurate and reliable in the measurements of dog pharmacokinetic study. The floating sustained-release tablet has a reliable sustained-release effect, resulting in a statistically higher bioavailability than those of the gel-matrix sustained-release tablet and the conventional tablet.