Development and Validation of Norfloxacin and Metronidazole in Combined Dosage form by vierordts’s Method

A simple, rapid, precise and highly selective spectrophotometric method was developed for simultaneous estimation of Norfloxacin and metronidazole in tablet dosage form. This method involves the measurement of absorbances of Norfloxacin and Metronidazole at the wavelength of 272nm (λmax of Norfloxacin) and 334nm (λmax Metronidazole) .0.1 N NaOH was used as solvent. Linearity was observed in the concentration range of 1-10 µg/ml for Norfloxacin and 1- 19µg/ml for Metronidazole. The accuracy of the method was confirmed by recovery studies of tablet dosage forms and was found to be 101 and 102% for Norfloxacin and metronidazole respectively. The method showed good reproducibility and recovery with % RSD less than 2. The LOD of Norfloxacin and metronidazole and LOQ of Norfloxacin and metronidazole   was found to be 0.3μg/ml and 1.16μg/ml and 0.79μg/ml and 2.4μg/ml respectively. The developed method was free from interferences due to excipients present in tablets .Thus the proposed method was found to be rapid, specific, precise, accurate and cost effective quality control tool for the routine analysis of Norfloxacin and metronidazole in bulk and combined dosage form.