Optimization and Validation of a Rapid Spectrophotometric Method for the Determination of Paracetamol in Pure and Human Dosage Forms

Abstract

Simple and reliable spectrophotometric method was developed for the determination of paracetamol in pure form and pharmaceutical formulations. The method is based on the oxidation of sodium nitroprusside by potassium ferrocyanide, followed by coupling with paracetamol to produce a stable green dye in a basic aqueous medium showing maximum absorbance at 675 nm. Several coupling reagents were examined to evaluate their reactivity toward paracetamol, and sodium nitroprusside was found to be the most effective, yielding a distinct and stable green aqueous product with superior analytical performance. The method obeys Beer`s law in the concentration range of 1-20 µg/mL, with a molar absorptivity of 4716.504 L/mol.cm and Sandall’s sensitivity of 0.0320 µg/mL. This reaction produces green dye in a basic aqueous medium at a wavelength of 675 nm. The detection and quantification limits were 0.0665 µg/mL and 0.2217 µg/mL, respectively. This proposed method was successfully applied to solid and liquid pharmaceutical preparations, simplicity, sensitivity, and cost - effectiveness suitable for routine quality control analysis.