Simultaneous Determination of Mesalazine and Rifaximin in Synthetic Mixture Using Spectrophotometric Technique (Simultaneous Equation Method)

A simple, accurate and precise spectroscopic method was developed for simultaneous estimation of Mesalazine and Rifaximin in synthetic mixture using Simultaneous Equation Method. The absorbance was measured at 328 nm for Mesalazine and 292nm 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 of10-50 μg/ml for Mesalazine at 328nm. The linear correlation was obtained (r²> 0.999) in the range of 10-50 μg/ml for Rifaximin at 292nm. The limit of determination (LOD) was 0.215μg/ml and 0.214μg/ml for Mesalazine and Rifaximin respectively. The limit of quantification (LOQ) was 0.652μg/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.