Spectrophotometric Estimation of Ibuprofen and Chlorzoxazone in Synthetic Mixture by Q-Absorbance Ratio method

The present manuscript describes simple, sensitive, rapid, accurate, precise and economical Q-absorbance ratio method for the simultaneous determination of ibuprofen and chlorzoxazone in bulk and synthetic mixture. Absorbance ratio method uses the ratio of absorbances at two selected wavelengths, one which is an isoabsorptive point and other being the λ-max of one of the two components. Ibuprofen and Chlorzoxazone show an isoabsorptive point at 227 nm in methanol. The second wavelength used is 221 nm, which is the λ-max of Ibuprofen in methanol. The linearity was obtained in the concentration range of 2-20 μg/ml for both Ibuprofen and Chlorzoxazone. The concentrations of the drugs were determined by using ratio of absorbances at isoabsorptive point and at the λ-max of Ibuprofen. The method was successfully applied for the determination of these two drugs in synthetic mixture. No interference was observed from excipients present in the synthetic mixture. The suitability of this method for the quantitative determination of Ibuprofen and Chlorzoxazone was proved by validation. The proposed method was found to be simple and sensitive for the routine analysis of these two drugs in synthetic mixture. The results of analysis have been validated statistically and by recovery studies.