Spectrophotometric Estimation of Eperisone Hydrochloride and Diclofenac Sodium 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 diclofenac sodium and eperisone hydrochloride 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. Eperisone hydrochloride and diclofenac sodium show an isoabsorptive point at 270 nm in methanol. The second wavelength used is 255 nm, which is the λ-max of eperisone hydrochloride in methanol. The linearity was obtained in the concentration range of 2-20 μg/ml for both eperisone hydrochloride and diclofenac sodium. The concentrations of the drugs were determined by using ratio of absorbances at isoabsorptive point and at the λ-max of eperisone hydrochloride. The method was successfully applied to pharmaceutical dosage form because no interference from the synthetic mixture excipients was found. The suitability of this method for the quantitative determination of eperisone hydrochloride and diclofenac sodium was proved by validation. The proposed method was found to be simple and sensitive for the routine quality control application of eperisone hydrochloride and diclofenac sodium in synthetic mixture or pharmaceutical dosage form. The results of analysis have been validated statistically and by recovery studies.