Spectrophotometric Determination of Nicorandil in Bulk andPharmaceutical Formulation Using Phospho-Molybdenum Blue Complex

A new spectrophotometric method is described for the determination of nicorandil in bulk and pharmaceutical dosage form. It is based on the reduction of nitrate in nicorandil to nitrite ion by using vanadium chloride, and reduction of phosphomolybdic acid to phospho-molybdenum blue complex by sodium sulfide, phospho-molybdenum blue complex is then oxidized by nitrite ion leading to a decrease in blue color intensity which found to be directly proportional to the concentration of nicorandil. Maximum absorbance was measured at 827 nm. Effect of acidity, volume of Sodium Sulfide, stability of complex, volume of vanadium chloride, time and temperature of the reaction were completely studied. The proposed method was satisfactorily applied for the determination of the drug in both bulk and pharmaceutical forms, the calibration curve was linear over the range (60–200 μg/ml) and the results were compared statistically with reference methods.