Quantitation of Terfenadine, Pseudoephedrine Hydrochloride, and Ibuprofen in a Liquid Animal Dosing Formulation Using High Performance Liquid Chromatography

Abstract

Stability-indicating assay methods based on high performance liquid chromatography have been developed for the quantitation of terfenadine, pseudoephedrine hydrochloride, and ibuprofen when combined in an aqueous 0.5% w/v Tween 20 and 0.5% methylcellulose animal dosing formulation. Because of the diversity of this drug mixture two separate chromatographic systems were required for the assays. A reversed phase system using a 3-μm Spherisorb 0DS-2 column was used to assay for terfenadine and ibuprofen. An ion-exchange system using a 10-μm Partisil SCX column was used to assay for pseudoephedrine hydrochloride. The methods are accurate and precise with relative standard deviations over the concentration ranges of interest of 2% or less.