Simultaneous spectrophotometric determination of metronidazole and diiodohydroxyquine

Four sensitive and precise spectrophotometric methods were developed and validated for the simultaneous determination of metronidazole (MTR) and diiodohydroxyquinoline (DIQ) in theirmixture and in their pharmaceutical formulations. Among the methods adopted were, second-derivative (2D), third-derivative (3D), derivative ratio spectroscopy (1DD) and isosbestic point technique. The selectivity of the proposed methods was checked using laboratory prepared mixtures. The proposed methods were simple, not expensive and applicable thatmake themsuitable for the analysis ofMTR and DIQ in theirmixture and in pharmaceutical formulations for routine unknown analysis in quality control labs.