Development and Validation of Q-Absorbance Ratio Spectrophotometric Method for the Simultaneous Estimation of Ciprofloxacin and Ornidazole; in Combined Pharmaceutical Dosage Form

Abstract

The present research work demonstrates an analytical method development for simultaneous estimation of Ciprofloxacin and Ornidazole in combined dosage form using Q-absorbance ratio concept. While method development, two different wavelengths one representing iso-absorptive point (290 nm) and other representing the λmax of Ornidazole (311 nm) were used. Optimum response was obtained in solvent system that comprises water and methanol in ratio of 80:20 v/v. Proposed UV method was found to be linear over the concentration range of 1-12 µg/ml for Ciprofloxacin and that of 1-20 µg/ml for Ornidazole. Based on recovery studies after standard addition, accuracy of proposed method was found to be in between 99.54 to 100.24 and 99.53 to 100.04% for Ciprofloxacin and Ornidazole respectively. Intra-day precision of the method in terms of % relative standard deviation was found to be in between 0.15 to 0.83 and 0.10 to 1.34 for Ciprofloxacin and Ornidazole respectively. Inter-day precision range of the method for Ciprofloxacin and Ornidazole was found to be in between 0.12 to 0.83 and 0.10 to 1.34 respectively. LOD and LOQ of proposed UV method were 0.01037µg/ml and 0.03142µg/ml for Ciprofloxacin and 0.01929µg/ml and 0.05848µg/ml for Ornidazole. Proposed UV method was robust and rugged in nature. Proposed method was successfully used for the estimation of Ciprofloxacin and Ornidazole contents of marketed formulation consisting of APIs and the common excipients.