School of Pharmaceutical Sciences, University of Geneva, University of Lausanne, 30, Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland.
J Pharm Biomed Anal. 2010 Dec 15;53(5):1288-97. doi: 10.1016/j.jpba.2010.07.024. Epub 2010 Aug 16.
Drug-plasma protein interactions have a significant impact on both pharmacokinetics (i.e., absorption, distribution, metabolism, and excretion) and pharmacodynamics (pharmacological effects). Therefore, it is of high interest to evaluate this binding during the drug development process. Capillary electrophoresis (CE) is an interesting analytical tool for drug-protein binding characterization because it consumes a relatively low amount of reagents and enables assays that can be carried out under near-physiological conditions. The most interesting mode of CE for the study of biomolecular interactions is CE/frontal analysis (CE/FA). However, some confusion in how to conduct CE/FA experiments has emerged in the literature. The present study examines, using research into drug-albumin interactions as an example, the most important steps to take into consideration when building up new CE/FA binding assays. These include the following: choosing the buffer and applied voltage; evaluating protein adsorption onto the capillary wall; choosing the injection volume; choosing the drug and protein concentrations; and, finally, verifying the co-migration of the protein and drug-protein complex. The experimental part of the present report can serve as a checklist for developing the key parameters that need to be addressed for successful and reliable interaction studies. In a second time, short-end injection was used to enhance throughput. The strengths of the binding constants (K(a)) for nine selected drugs (basic, neutral, and acidic substances) to albumin, which is the most important plasma protein, were from logK(a) 2.9 to 5.4. These values were compared to those obtained with validated methods and good agreement was achieved.
药物-血浆蛋白相互作用对药代动力学（即吸收、分布、代谢和排泄）和药效学（药理作用）都有重大影响。因此，在药物开发过程中评估这种结合是非常重要的。毛细管电泳（CE）是一种用于药物-蛋白结合特性研究的有趣分析工具，因为它消耗相对较少的试剂，并能在接近生理条件下进行检测。CE 用于研究生物分子相互作用最有趣的模式是 CE/前沿分析（CE/FA）。然而，文献中出现了如何进行 CE/FA 实验的一些混淆。本研究以研究药物-白蛋白相互作用为例，检查了在建立新的 CE/FA 结合测定时需要考虑的最重要步骤。这些步骤包括：选择缓冲液和施加电压；评估蛋白质在毛细管壁上的吸附；选择注入体积；选择药物和蛋白质浓度；最后，验证蛋白质和药物-蛋白质复合物的共迁移。本报告的实验部分可以作为开发成功和可靠相互作用研究所需关键参数的检查表。在第二部分，短端注入被用来提高通量。与白蛋白（最重要的血浆蛋白）结合的九种选定药物（碱性、中性和酸性物质）的结合常数（K(a)）的强度从 logK(a) 2.9 到 5.4。将这些值与经过验证的方法进行比较，结果吻合良好。
