High-performance liquid chromatographic analysis of nitroxoline in plasma and urine

A high-performance liquid chromatographic method has been developed for the determination of nitroxoline in 50-microliter plasma and urine samples. A structural analogue of nitroxoline, 8-hydroxyquinoline, was added to the eluent in order to suppress peak asymmetry. Several parameters of the eluent were studied for the optimisation of the chromatographic system. Plasma concentration-time curves were constructed for three volunteers after they had received an oral dose of 100 mg of nitroxoline. Plasma half-life was about 1 h. Within 12 h, about 1% of the dose was excreted in the urine as free nitroxoline and about 30% as conjugated metabolite of the parent compound.