高效迎头分析法测定药物-人血清白蛋白混合液中游离药物浓度

 用高效迎头分析法 (HPFA)测定了药物 人血清白蛋白 (HSA)混合液中游离药物的浓度。样品溶液不经任何处理直接进样到装有内表面反相固定相的色谱柱中 ,用 67mmol/L磷酸盐缓冲液 ( pH 7 4 ,I =0 17mol/L)作流动相。当进样体积足够大时 ,游离药物以平顶峰的形式被洗脱出来 ,平顶峰区域洗脱液中的药物浓度等于样品溶液中游离药物的浓度。收集平顶峰区域的洗脱液 ,然后将一定体积的洗脱液注入到反相色谱柱中 ,测定游离药物的浓度。用该法测定酮基布洛芬 HSA和头孢哌酮 HSA两种混合液中游离药物的浓度。

Determination of Unbound Concentration of Drug in Drug-Human Serum Albumin Mixture by High Performance Frontal Analysis

A high performance frontal analysis(HPFA) method was developed to determine the unbound concentration of drugs in drug human serum albumin (HSA) mixture under binding equilibrium The sample was injected directly onto an internal surface reversed phase silica column (ISRP) The mobile phase was 67 mmol/L phosphate buffer (pH 7 4, I =0 17 mol/L) When a large volume of sample solution under drug HSA binding equilibrium was directly injected, the drug was eluted as a trapezoidal peak with a plateau, and the drug concentration in this region was the same as that of the unbound drug in the sample solution The eluate of plateau region was collected and a small volume was injected onto a reversed phase HPLC column This HPFA HPLC method was employed in the determination of unbound concentration in both ketoprofen (KP) HSA and cefoperazone (CP) HSA mixtures The unbound concentrations of drugs obtained by using HPFA HPLC were compared with those determined with ultrafiltration HPLC The effects of sample volume and flow rate of mobile phase on the plateau formation were investigated It was found that the minimum injection volume to achieve a trapezoidal peak varied with drugs The flow rate showed no effect on the trapezoidal peak formation The unbound concentrations of KP and CP obtained were about the same by using HPFA HPLC or ultrafiltration HPLC and precisions were similar for both methods