Simultaneous Quantitation of Caffeine, Ethoxybenzamide and Propyphenazone in Oral Analgesic Tablets by High-Pressure Liquid Chromatography

AN-RONG LEE, KUANG-SEN SUNG AND WEN-HSIN HUANG

School of Pharmacy and Analytical Center of Medical Supply, National Defense Medical Center Taipei, Taiwan, R.O.C.

ABSTRACT

   A method for simultaneous quantitation of caffeine, ethoxybenzamide and propyphenazone is described. The method was based on reversed-phase high-pressure liquid chromatography with a mobile phase of methanol-acetonitrile-3% aqueous acetic acid solution (24 : 16 : 60, v/v). The compounds were well separated from each other by the procedure, using salicylamide as internal standard. The method gave excellent results and provided a simple, rapid and accurate method for separation and quantitation of synthetic mixtures and commercial products.

Key words : High-pressure liquid chromatography, Caffeine, Ethoxybenzamide, Propyphenazone.