Simultaneous determination of mesalazine and rifaximin in synthetic mixture using spectrophotometric technique (simultaneous equation method)

Objective: A simple, accurate and precise spectroscopic method was developed for simultaneous estimation of Mesalazine and Rifaximin in synthetic mixture using Simultaneous Equation Method. Objective of the study was to deliver information related to Mesalazine and Rifaximin combination’s analytical method.Methods: The absorbance was measured at 328 nm for Mesalazine and 292 nm for Rifaximin and calibration curves were plotted as absorbance versus concentration, respectively. The method was found to be linear (r2> 0.999) in the range of 10-50 μg/ml for Mesalazine at 328 nm. The linear correlation was obtained (r2> 0.999) in the range of 10-50 μg/ml for Rifaximin at 292 nm.Results: The limit of determination (LOD) was 0.215 μg/ml and 0.214μg/ml for Mesalazine and Rifaximin respectively. The limit of quantification (LOQ) was 0.652 μg/ml and 0.648 μg/ml for Mesalazine and Rifaximin respectively. The accuracy of this method was evaluated by recovery studies and good recovery results were obtained greater than 99%. The method was successfully applied for simultaneous determination of Mesalazine and Rifaximin in binary mixture.Conclusions: The method was successfully applied to pharmaceutical synthetic mixture which is considered in approved patent which show no interference. The result of analysis has been validated statistically and by recovery studies. So this method accurate, precise, robust, rugged and economic in nature.