High-Performance Liquid Chromatographic and Derivative Difference Spectrophotometric Methods for the Determination of Acetaminophen and Its Degradation Product in Aged Pharmaceutical Formulations

Abstract

Abstract Two stability-indicating methods, HPLC and derivative difference spectrophotometry, have been described for the determination of acetaminophen as well as its degradation product, 4-aminophenol. The former method is based on the selection of two chromatographic systems using an octadecylsilane (C18) stationary phase. The latter involves the use of derivative (first and second) difference spectrophotometric technique. Interference from the coformulated excipients (colorant, flavour, preservative) of liquid formulations is completely eliminated. Accuracy, precision and the limit of detection of 4-aminophenol are discussed. The proposed methods are applied for determination of acetaminophen and 4-aminophenol in pharmaceutical formulations.