荆芥内酯大鼠血浆蛋白结合率的测定

目的:研究荆芥内酯与大鼠血浆蛋白的结合情况。方法:采用平衡透析法测定体外荆芥内酯对大鼠血浆蛋白的结合率,以HPLC法测定透析袋两侧溶液中荆芥内酯的质量浓度,计算其血浆蛋白结合率。结果:荆芥内酯与内标完全分离,血浆中其他成分无干扰,在0.05～50.3μg.mL-1浓度范围内线性关系良好。日内、日间精密度及提取回收率均符合方法学要求。低、中、高(0.08,0.63,6.30μg.mL-1)质量浓度下,荆芥内酯在大鼠血浆中的蛋白结合率分别为(62.23±1.25)%,(62.71±0.04)%和(63.99±0.79)%。结论:该方法操作简便、快速、准确,灵敏度高,能满足生物样品的分析要求。荆芥内酯具有中等强度的蛋白结合率,蛋白结合率与透析液的药物浓度无关。

Determination of plasma protein binding rate of schizonepetin in rats

Objective:To study the plasma protein binding rate of schizonepetin in rats.Methods:Equilibrium dialysis was used to determine the in vitro binding rate of schizonepetin to rat plasma.A HPLC method for the determination of schizonepetin was established and then the plasma protein binding rate in rats was calculated.Results:Schizonepetin and internal standard were separated completely with no interference from other ingredients.The calibration curve of schizonepetin was in good linearity over the range of 0.05~50.3 μg·mL-1.The intra-day and inter-day precision and recovery of schizonepetin met the requirements of methodology.The plasma protein binding rate of schizonepetin at low,middle and high concentrations(0.08,0.63,6.30 μg·mL-1) were(62.23±1.25)%,(62.71±0.04)% and(63.99±0.79)%,respectively.Conclusion:The method is simple,rapid,accurate,and sensitive,and it can meet the requirement for analysis method of biological samples.Schizonepetin has medium plasma protein binding rate in rats,with no significant relation to drug concentrations in dialyzate.