A sensitive assay for the aminoimidazole-containing drug GP531 in plasma using liquid chromatography with amperometric electrochemical detection: a new class of electroactive compounds.

Aminoimidazole-containing compounds have been found to be electroactive and can be detected by amperometric electrochemical detection (ECD) with a high degree of sensitivity. A liquid chromatography (LC) method using ECD was developed for measuring plasma concentrations of the aminoimidazole-containing drug GP531, a potent adenosine-regulating agent. Plasma samples were extracted with 2-propanol and analyzed by LC under isocratic conditions using a mobile phase of methanol-sodium phosphate (pH 6.3; 3.3 mM) (32:68, v/v). The potential of the glassy carbon working electrode was set at +800 mV. The limit of quantitation was 12.5 ng ml-1 of GP531 using 100 microliters of plasma. The method was used to define the pharmacokinetics of GP531 in monkey following i.v. administration.