Use of charge-transfer complexation in the spectrophotometric assay of antazoline and naphazoline in combination

Abstract

A simple and accurate spectrophotometric method is described for the assay of antazoline and naphazoline, combined in eye-nose drops in a ratio of 20 : 1. The major component, antazoline, is determined, without interference from naphazoline, by charge-transfer complexation with σ-acceptor iodine. After precipitation of antazoline with sodium carbonate, the minor component, naphazoline, can be determined using the π-acceptor chloranil. The accuracy of the method is assessed by the assay of a standard mixture of the two components containing the same proportions as the commercial preparation.