Development of high-performance frontal analysis and its application to the study of the drug-protein binding sites.

NAKAGAWA Terumichi, SHIBUKAWA Akimasa

doi:10.2116/bunsekikagaku.40.5_203

High-performance frontal analysis (HPFA) is a novel chromatographic method originally developed for the determination of unbound drug concentration in protein binding equilibrium. The present paper deals with the rationale and features of the HPFA method. HPFA uses a "restricted-access "HPLC column which is designed to size-exclude macromolecules such as plasma proteins, but to retain drugs of small molecular size. When a certain excess volume of drug-protein mixed solution is continuously injected to the column with the mobile phase, the protein binding equilibrium, same as that in the sample solution is reproduced in a limited zone near the top of the column. Consequently, the unbound drug is eluted as a zonal peak, being separated from the protein peak. Therefore, the unbound drug concentration can be determined from the plateau height of the drug peak. When the drug peak is completely separated from the protein peak, the total drug concentration can be also determined from the peak area. This is the rationale of the HPFA method. The HPFA method has several features; (i) it does not suffer from the undesirable adsorption of drug to the filter membrane and the leakage of unbound drug from the membrane, which are often encountered in the widely used equilibrium dialysis method and the ultrafiltration method, (ii) it is easy to incorporate HPFA into on-line HPLC systems, (iii) the unbound drug solution of larger volume than the injected sample volume is obtained when the drug is highly bound to protein. HPFA are applied to the simultaneous determination of total and unbound carbamazepine concentrations in human plasma and stereoselective determinations of unbound warfarin and ketoprofen following direct sample injection.

Development of high-performance frontal analysis and its application to the study of the drug-protein binding sites.

Bibliographic Information

Search this article

Description

Journal

Citations (3)*help

Keywords

Details 詳細情報について

Export

Report a problem