Chen Jianzhong, Ohnmacht Corey M, Hage David S
Department of Chemistry, University of Nebraska, 608 Hamilton Hall, Lincoln, NE 68588-0304, USA.
J Chromatogr A. 2004 Apr 9;1033(1):115-26. doi: 10.1016/j.chroma.2004.01.032.
This study examined the use of an immobilized human serum albumin (HSA) column to study solution-phase reactions between drugs and beta-cyclodextrin (beta-CD). Chromatographic equations were developed to characterize the binding of chemicals to a soluble ligand (beta-CD) in the presence of an independent immobilized ligand (HSA). Situations considered included the presence of both a homogeneous and heterogeneous immobilized ligand, as well as complex interactions between the chemical of interest and soluble ligand. Three drugs (warfarin, tamoxifen, and phenytoin) were examined by this approach. This method involved injecting a small amount of each drug onto an HSA column in the presence of various concentrations of beta-CD in the mobile phase. By measuring the change in the drug's retention factor as the concentration of beta-CD was varied, it was possible to determine the stability constant between the injected drug and beta-CD. With this approach, warfarin and beta-CD were found to have 1:1 interactions with a stability constant of 5.2 x 10(2) M(-1) at 37 degrees C and pH 7.4, a result in close agreement with previous literature values. Tamoxifen and phenytoin were also found to have 1:1 interactions with beta-CD and had stability constants of 0.9-1.2 x 10(4) and 6-9 x 10(2) M(-1) respectively. With these latter solutes, the effects of secondary binding to the chromatographic support had to be considered. The theory and methods described in this report are not limited to these drugs and beta-CD but can be applied to other analytes and soluble ligands.
本研究考察了使用固定化人血清白蛋白（HSA）柱来研究药物与β-环糊精（β-CD）之间的溶液相反应。推导了色谱方程，以表征在独立的固定化配体（HSA）存在下化学物质与可溶性配体（β-CD）的结合。考虑的情况包括均相和异相固定化配体的存在，以及目标化学物质与可溶性配体之间的复杂相互作用。通过这种方法研究了三种药物（华法林、他莫昔芬和苯妥英）。该方法包括在流动相中存在不同浓度β-CD的情况下，将少量每种药物注入HSA柱。通过测量随着β-CD浓度变化药物保留因子的变化，能够确定注入药物与β-CD之间的稳定常数。通过这种方法，发现华法林和β-CD在37℃和pH 7.4下具有1:1的相互作用，稳定常数为5.2×10² M⁻¹，这一结果与先前的文献值密切一致。还发现他莫昔芬和苯妥英与β-CD也具有1:1的相互作用，其稳定常数分别为0.9 - 1.2×10⁴ 和6 - 9×10² M⁻¹。对于后两种溶质，必须考虑与色谱支持物的二次结合效应。本报告中描述的理论和方法不仅限于这些药物和β-CD，还可应用于其他分析物和可溶性配体。
