Indirect Spectrophotometric Assay of Hydroxyurea with its Pharmaceutical Application as Capsules

The oxidationreduction reaction between hydroxyurea and ferric ions has been utilised for spectrophotometric assay of hydroxyurea. The ferrous ions that are produced from the redox reaction were complexed with 2,2-bipyridyl reagent to form a pink-red tris-chelate which has an absorption maxima at 522 nm. Beer's law agreed with the range of 5-150 g of hydroxyurea per 20 ml, i.e., 0.25-7.5 ppm, with a corresponding average molar absorptivity of 1.65x104 l.mol-1. cm-1, Sandell sensitivity index is 0.0044 g.cm-2, limit of detection 0.01g.ml-1 and limit of quantitation of 0.03 g.ml-1. The present method has been applied successfully to the determination of hydroxyurea in its pharmaceutical preparation as capsule.