Xu Wen, Sun Jin, Zhang Ting-ting, Ma Bo, Cui Sheng-miao, Chen Da-wei, He Zhong-gui
Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China.
Acta Pharmacol Sin. 2006 Dec;27(12):1642-6. doi: 10.1111/j.1745-7254.2006.00440.x.
To study the intravenous and oral pharmacokinetic behavior of oridonin and its extent of absolute oral bioavailability in rats.
Oridonin was administered to rats via iv (5, 10 and 15 mg/kg), po (20, 40 and 80 mg/kg) or ip administration (10 mg/kg). The concentrations of oridonin in rat plasma were determined by a high performance liquid chromatography with electrospray ionization mass spectrometric detection (HPLC/ESI-MS) method and the pharmacokinetic parameters were determined by non-compartmental analysis.
The plasma concentration of oridonin after intravenous administration decreased polyexponentially, and the pharmacokinetic parameters of oridonin were dose-independent within the examined range. Oridonin was absorbed rapidly after oral gavage with a t(max) of less than 15 min; the extent of absolute bioavailability of oridonin following oral administration was 4.32%, 4.58% and 10.8%. The extent of absolute bioavailability of oridonin following intraperitoneal administration was 12.6%.
First order rate pharmacokinetics were observed for oridonin within the range of iv doses, while the extent of absolute oral bioavailability was rather low and dose- dependent. The low and dose-dependent extent of oral bioavailability may be due to the saturation of first-pass effects.
研究冬凌草甲素在大鼠体内的静脉注射和口服药代动力学行为及其绝对口服生物利用度。
将冬凌草甲素以静脉注射（5、10和15mg/kg）、口服（20、40和80mg/kg）或腹腔注射（10mg/kg）的方式给予大鼠。采用高效液相色谱-电喷雾电离质谱检测法（HPLC/ESI-MS）测定大鼠血浆中冬凌草甲素的浓度，并通过非房室分析确定药代动力学参数。
静脉注射后冬凌草甲素的血浆浓度呈多指数下降，在所考察范围内其药代动力学参数与剂量无关。口服灌胃后冬凌草甲素吸收迅速，达峰时间（t(max)）小于15分钟；口服给药后冬凌草甲素的绝对生物利用度分别为4.32%、4.58%和10.8%。腹腔注射后冬凌草甲素的绝对生物利用度为12.6%。
在静脉注射剂量范围内，冬凌草甲素呈现一级速率药代动力学特征，但其绝对口服生物利用度较低且与剂量有关。口服生物利用度低且与剂量有关可能是由于首过效应饱和所致。
