AN IMPROVED COLORIMETRIC DETERMINATION OF ANTAZOLINE

Document Type : Original Article

Author

Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Assiut, Assiut, Egypt

Abstract

A simple, precise and accurate spectrophotometric determination of antazoline salts is developed by improvement of the previously reported ceric sulfate procedure. Replacement of glacial acetic acid for water in preparing all assay solutions enabled the reproducible measurement of the chromogen absorbing at 505 nm. An appreciable increase in color stability was attained by the controlled addition of perchloric acid to the cerie sulfate solution, prior to interaction with antazoline at room temperature. Evidence is provided to account for the oxidation of antazoline-aniline moiety on the expense of an anionic ceric species. No interference with the investigated color reaction was offered by other 2-imidazolines or phenylephrine. Added to the considerably high value of chromogen molar absorptivity, ideal adherence of color absorption to Beer's law permitted the accurate and reproducible estimation of antazoline over the1-10 mcg/ml concentration range. Application of the improved procedure to the satisfactory analysis of different antazoline dosage forms was also effected.