Determination of phenazopyridine in human plasma by high performance liquid chromatography

A simple, low-cost, sensitive and selective HPLC method was developed for t he determination of phenazopyridine in human plasma. The method employs UV detection of phenazopyridine and of the Internal Standard at 2 different wa velengths. Calibration curves were linear over a large dynamic range, i.e., within 0.05-10.0 mu g mL(-1) with limit of quantification of 0.05 mu g mL( -1),and a limit of detection of 0.01 mu g mL(-1).