High-performance liquid chromatographic method for the determination of a novel leukotriene D4 antagonist (MK-0571) in biological specimens

A rapid, sensitive and selective liquid chromatographic procedure was developed to quantitate the levels of a novel leukotriene D₄ antagonist, MK-0571 (I), in biological samples. The method involves the addition of an internal standard, an analogue of I, and methanol to the biological matrix. Following centrifugation the supernatant is chromatographed isocratically on a C₁₈ reversed-phase column and the acids are detected with an ultraviolet detector. The sensitivity of the method is such that 50 ng of drug can be quantitated per aliquot of sample. Assays were linear over a 0.06–40.0 μg range and exhibited a recovery of 100.5 ± 7.0% (mean ± S.D.) over this range. This procedure was utilized to monitor plasma, liver and urinary levels of I in chronic and acute toxicity studies in several animal species.