Spectophotometric determination of paracetamole via oxidative coupling with phenylephrine ydrochloride in pharmaceutical preparations

Abstract EN

A new, simple, rapid and sensitive spectrophotometric method was described in the present study for the indirect determination of paracetamol.

The method is based on the oxidative coupling reaction of paracetamol ( after acidic hydrolysis to form p-aminophenol) with phenylephrine hydrochloride using atmospheric oxygen as an oxidant in alkaline medium to form a water soluble, stable indophenol dye and has a maximum absorption at 640 nm.

Beer’s law is obeyed in a concentration range of 0.5-24 μg.

mL-1 of paracetamol with a molar absorptivity of 7664 L.mol-1.cm-1, the accuracy is 98.86% and the relative standard deviation was less than 1.88% depending on the concentration levels.

The proposed method has been applied successfully for the determination of paracetamol in some pharmaceutical preparations.