人血清白蛋白与手性药物相巨作用的毛细管电泳研究Ⅰ.液相预柱毛细管电泳技术定量可靠性的考察

Albumin-Drug Binding Study by Capillary Electrophoresis I. Quantitative Applicability Examination of Liquid Pre-Column

以药物Verapamil（VER）与人血清白蛋白（HSA）相互作用体系中游离的药物对映体浓度定量测定为目标，建立了一项适用于相互作用研究的液相预柱毛细管电泳（LPC－CE）技术。通过对该技术的考察，确定了这项技术的定量可靠性。在生理pH值条件下（pH7.4，离子强度I=0．17），使药物与人血清白蛋白达到结合平衡。在毛细管电泳手性拆分[pH2.5缓冲浪；三甲基-β-环糊精（TM－β-CD）浓度为45mmol／L]柱（32cm×50μm）内预先注入一段生理pH缓冲液，形成一段液相预柱（2．8cm）。在顶柱中，利用蛋白和药物在生理pH下的电泳特性差异，使HSA不进入手性拆分区域，而药物以平衡浓度进入拆分系统。结合毛细管电泳前沿分析技术，药物对映体在相互作用体系中的游离浓度的测定通过手性拆分实现。对7个不同浓度比的药物一白蛋白样品体系进行考察，具有良好的重现性（相对标准偏差RSD=2．17％～5．02％，n=4）;定量分析的相对误差在1．4％～5．8％范围内。

To measure the free concentration of verapamil (a basic drug) enantiomers in the binding system of human serum albumin(HSA),a capillary electrophoretic method, liquid precolumn(LCP),was established,and the method was examined systematically. In physiological PH condition (pH 7. 4, ionic strength 0. 17),HSA migrates in the opposite direction of verapamil. This electrophoretic property basically supposed the probability of preventing HSA from entering the capillary whereas a positive electric field was used. Finally,the drug enantiomers were separated by the chiral selector (45 mmol/L trimethyl - β-cyclode xtrin, pH 2. 5 phosphate buffer) and the free concentration of each optical isomer in the binding system was measured.Seven samples were examined and their relative standard deviations(RSD) and the relative errors (RE) of unbound drug were 2. 1 %-5. 02 % and 1. 4 %-5. 8 %,respectively.