Simultaneous determination of tapentadol HCl and paracetamol by ratio-spectra derivative spectrophotometry

Abstract

A new simple and sensitive ratio-spectra first derivative spectrophotometric method was developed for the simultaneous determination of tapentadol hydrochloride (TPH) and paracetamol (PCM) in binary mixtures. The method depends on the use of the first derivative of the ratio-spectra obtained by dividing the absorption spectrum of binary mixture by a standard spectrum of one of the compounds. TPH was determined at 280.4 nm while PCM was determined at 300 nm. Calibration graphs are linear over the range of 20–100 µg.ml^-1 and       2–14 µg.ml^-1 for TPH and PCM, respectively. The developed method was validated and successfully applied for the determination of TPH and PCM in laboratory prepared mixture containing all possible excipients present in tablet dosage form. The mean percentage recovery ± S.D. were found to be 99.855 ± 0.203, and 101.250 ± 0.190 for TPH and PCM, respectively.