Spectrophotometric determination of acetaminophen, salicylamide and codeine phosphate in tablets

Abstract

An accurate and simple method is proposed for the analysis of a three-component mixture composed of acetaminophen, salicylamide and codeine phosphate, without the necessity for the previous separation of any component. The first two components are determined directly by independent spectrophotometric measurements, based on the pH-induced spectral changes. Codeine phosphate is assayed by the formation of an ion pair with methyl orange. The procedure has been applied successfully to the analysis of known mixtures and commercial tablets.