Abstract
Derivative Spectrophotometric And Graphical Absorbance Ratio Method For Simultaneous Estimation Of Norfloxacin And Tinidazole In Two-Component Tablet Formulations
Norfloxacin (NF) has an absorbance maxima at 275 nm and tinidazole (TZ) has an absorbance maxima at 317.8 nm in 10% v/v N,N-dimethylformamide. In derivative spectrophotometry, absorbance of norfloxacin was measured at 264.2 nm which is the zero crossing point on the first derivative spectra of tinidazole. Similarly, the absorbance of tinidazole was measured at 306.2 nm which is the zero crossing point of norfloxacin. The Beer's law is obeyed in the concentration range of 0-24 mg/ml for norfloxacin and 0-36 mg/ml for tinidazole. In the graphical absorbance ratio method the concentration of norfloxacin and tinidazole was determined using the ratio of absorbances at 275 nm and 300.4 nm for each drug. The calibration curves were linear in the concentration range of 0-20 mg/ml for both drugs. The methods have been validated statistically and by recovery studies.
