A Simultaneous Assay of Theophylline, Ephedrine Hydrochloride, and Phenobarbital in Suspensions and Tablets Formulations by High Performance Liquid Chromatography

Abstract

A simple reversed phase high-performance liquid chromatographic (HPLC) procedure is described for simultaneous determination of Theophylline, Ephedrine Hydrochloride and Phenobarbital in suspensions and tablets matrices. The separation was performed on a radial pak cartridge packed with octadecylsilane (C18) material using methanol and 0.01M monobasic potassium phosphate (33:67) as the mobile phase. Measurement was made by a uv-spectrophotometer at 215 nm and quantitation was based on the sample-internal standard peak area ratio. The respective precision and relative standard deviations from suspensions and tablets were: theophylline 95.27%, 0.06% and 101.35%, 0.16%, ephedrine hydrochloride 101.49%, 0.34% and 101.69%, 0.47% and phenobarbital 93.03%, 0.30% and 94.91%, 0.14%.