Background: The combination of Ciprofloxacin and Ornidazole is used for the effective treatment of intra-abdominal infections. Many branded and generic combined dosage formulations of Ciprofloxacin and Ornidazole are available in market. Objective: To develop and validate rapid, sensitive, simple and accurate reverse phase ultra-fast liquid chromatographic method for the determination of Ciprofloxacin and Ornidazole in combined dosage forms. Methods: The separation was carried out by using Phenomenex Luna C18 (250×4.6 mm, 5 μm) column as stationary phase and acetonitrile: methanol: 0.1% formic acid as a mobile phase in ratio of 35:35:30 % v/v/v. The analysis was performed at flow rate of 0.8 ml/min using PDA detector at 300 nm. The column temperature was maintained at 20oC for better separation and resolution. Results: The retention time for Ciprofloxacin HCl and Ornidazole was found to be 2.1 min and 4.2 min respectively. The developed method was validated with respect to specificity, linearity and range, precision, robustness and accuracy according to ICH guidelines. The method was found to be linear between the concentration ranges of 2-10 μg/ml with correlation coefficient of 0.999. The % relative standard deviation of precision and robustness was found to be less than 2%. The percent accuracy was found to be 98-103% and 99-102% for Ciprofloxacin HCl and Ornidazole respectively. Conclusion: The method is applicable for the routine analysis and quality control of Ciprofloxacin HCl and Ornidazole in combination.
Key words: Ciprofloxacin HCl, Ornidazole, Intra-abdominal infections, Ultra-fast, PDA detector.