Validated spectrophotometric methods for estimation of Cefixime and Ornidazole in combined dosage form

Objective: Solubility enhancing agents, like hydrotropic agents, co solvents acids or alkali. Major drawbacks of organic solvents include high cost, volatility and toxicity. On the other hand use of alkali or acids may reduce the stability of compounds under investigation throughout the process of estimation. In the present investigation, co-solvency technique has been employed to solubilize the poorly water-soluble drugs.Methods: Four perspicacious spectrophotometric methods employed in the study including the application of simultaneous equation method and multicomponent mode of analysis at 288 nm and 319 nm, absorbance maxima of Cefixime and Ornidazole respectively and the absorbance Ratio (Q-analysis) method at 302.8 (iso-absorptive point) and 319 nm (absorbance maxima of Cefixime and Ofloxacin) and the First Order Derivative Spectroscopy method at 312 nm for Cefixime (zero cross for Ornidazole) and 290.7 nm for Ornidazole (zero cross for Cefixime). All these methods utilized Methanol: Water (1:1) as a solvent.Results: The methods discussed in the present work provide a convenient and accurate way for simultaneous analysis of CEF and ORN. Percent label claim for CEF and ORN in tablet, by all four methods, was found in the range of 99.99% to 100.02%. Standard deviation and coefficient of variance for six determinations of tablet sample, by all the methods, was found to be less than ±2.0 indicating the precision of all the methods. Accuracy of proposed methods was ascertained by recovery studies and the results are expressed as % recovery. Percent recovery for CEF and ORN, by all four methods, was found in the range of 99.95% to 100.087%, values of standard deviation and coefficient of variation were in the range of ±0.115 to ±0.519 and 0.083 to 0.226, respectively indicating the accuracy of proposed methods.Conclusions: The procedures were successfully applied for the simultaneous determination of both drugs in laboratory prepared mixtures and in commercial tablet formulation. The accuracy of the methods was assessed by recovery studies.