Direct spectrophotometric method and analytical method validation of metronidazole and ornidazoleAuthor(s): Srinivasa Rao, N.Surya Mohana Rao, B.Sreerama Murthy, G.V.Sitarama Pavan Kumar
A direct spectrophotometric method was developed for the detection and quantitative determination ofMetronidazole and Ornidazole in pure form as well in pharmaceutical formulations in the formof tablets and capsules. The method was based on the formation of reddish-purple colour dye due to the diazotization reaction between the nitro group of the drug samples, sulphanilamide and NEDA. The drug samples dissolved in hot water followed by the addition of 2ml of each 0.5%Sulphanilamide and 0.3%NEDA. It exhibited a stable reddish purple colour. The colour compound showed a maximum absorbance at 540nm. BeerÂs law was obeyed in the range of 200-800 µgmL-1 forMetronidazole and 100-600 µgmL-1 forOrnidazolewith a limit of detection of 0.01 µgmL-1 and 0.02 µgmL-1 respectively.Themethod was found to be simple, accurate and rapid.