Spectrophotometric determination of amidopyrine and antipyrine by charge-transfer complex formation

Abstract

The charge-transfer complex formed by the interaction between the electron acceptor dichlorobenzoquinone and an electron donor amidopyrine (aminophenazone) or antipyrine (phenazone) was adopted for the assay of these drugs in tablets. The conditions suitable for the complex formation were determined. The determination of the molar ratio of the reactants and of the association constant are also described. The method can be conveniently applied to assay individual dose units of amidopyrine and antipyrine with good accuracy and precision.