微乳液相色谱法测定大鼠血浆中罗布麻甲素的浓度及其药动学研究

目的：建立测定大鼠血浆中罗布麻甲素的微乳液相色谱方法，并将其用于大鼠体内药动学的研究。方法：用微乳液相色谱法分别测定给药后不同时间点大鼠的血药浓度，并对其药动学参数进行研究。色谱条件为：色谱柱为Zorbax SB-C₁₈（150 mm×4.6 mm，5 μm）柱；流速0.8 mL·min^-1；检测波长360 nm；柱温30℃。采用经过优化后的微乳体系为流动相，其组成为：2.0% Genapol X-080-2.8%正丁醇-1.8%乙酸乙酯-0.4%三乙胺-93.0%水溶液（pH调至5.0）。结果：大鼠静脉注射罗布麻甲素后，其药动学模型符合二室模型。分布和消除相半衰期分别为7.3 min和28.7 min。药时曲线下面积AUC（μg·min^-1·mL^-1）为804.37。表观分布容积V_d（μg·mL^-1）为0.325。平均驻留时间MRT（min）为25.8。大鼠血浆中罗布麻甲素在0.1~10 μg·mL^-1内线性均良好（r=0.998 6），最低定量浓度（S/N=10）为0.1 μg·mL^-1，日内和日间RSD均小于4.9%，平均加样回收率在96.3%~98.8%之间，RSD均小于5.1%。结论：本法快速、简便、准确、重现性好，可用于罗布麻甲素血药浓度测定及药动学研究。

Determination of isoquercitrin in rat plasma sample by microemulsion liquid chromatography and the pharmacokinetic study

OBJECTIVE To establish a microemulsion liquid chromatography method for determination of isoquercitrin in plasma and to study the pharmacokinetics of isoquercitrin in rats. METHODS After intravenous injection of isoquercitrin, the plasma concentration was determined by microemulsion liquid chromatography. Separations were performed on the Zorbax Extend-C₁₈ column with UV detection at 360 nm. The flow rate was 0.8 mL·min^-1. The optimized microemulsion mobile phase consisted of 2.0% (V/V) Genapol X-080, 2.8% (V/V) n-butanol, 1.8% (V/V) ethyl acetate, 0.4% (V/V) triethylamine and 93.0% (W/V) water, with pH adjusted to 5.0. RESULTS The pharmacokinetic course of isoquercitrin was fitted with two-compartment model in rats, t_1/2α=7.3 min and t_1/2β=28.7 min, AUC (μg·min^-1·mL^-1)=804.37, V_d (μg·mL^-1)=0.325,MRT (min)=25.8. The calibration curve for isoquercitrin was linear in the range of 0.1-10 μg·mL^-1(r=0.998 6). The intra-day and inter-day precision values (RSD) were lower than 4.9% and the limit of detection (LOD) was 0.1 μg·mL^-1(S/N=10). The average recovery was between 96.3% and 98.8% and RSD was less than 5.1%. CONCLUSION The microemulsion liquid chromatography (MELC) method is successfully applied to determine isoquercitrin in rat plasma and to study the pharmacokinetics in rats.