Determination of MK-0476 in human plasma by liquid chromatography.

A simple and accurate assay for quantitating MK-0476 [sodium 1-(((1(R)-(3-(2-(7-chloro-2-quinolinyl)-(E)-(ethenyl)phenyl)(3-(2-(1- hydroxy-1-methylethyl)phenyl)propyl)thio)-methyl)cyclopropane)acetate], which is a potent and selective leukotriene D4-receptor antagonist, in human plasma has been developed. The method involves precipitation of protein and reversed-phase liquid chromatography with fluorescence detection. The assay is linear in the range of 30-3000 ng ml-1 of MK-0476, and the limit of detection is 5 ng ml-1. The interday precision (% relative standard deviation) values of this method at 51 and 2040 ng ml-1 are 10 and 3%, respectively. The interday accuracy values at these concentrations are 94 and 104%, respectively. The absolute recovery of MK-0476 is 99%. The utility of this method to determine plasma concentrations of MK-0476 in humans receiving the drug orally was demonstrated.