Simultaneous Determination of Paracetamol and Caffeine in tablets by Mean Centering and Derivative Transforms of UV Ratio Spectra

Mean centering and first derivative transforms of UV ratio spectra were developed to resolve strongly overlapping spectra of paracetamol and caffeine in binary mixtures. Paracetamol 25 mg/L and caffeine 3.25 mg/L were identified as suitable divisors to obtain highest spectral recovery. The calibration graphs were recorded in phosphate buffer pH 7.2 for paracetamol (10–35 mg/L) and caffeine (2.4–4.4 mg/L). These spectrophotometric methods were successfully applied to the simultaneous determination of paracetamol and caffeine in commercially available tablets. They were also more sensitive than previously reported spectrophotometric method. No significant difference in accuracy and precision was observed for the proposed methods and official USP-HPLC.