High-Performance Liquid Chromatographic Analysis of Theophylline in the Presence of Caffeine in Blood Serum and Pharmaceutical Formulations

Abstract

A reversed phase high-performance liquid chromatographic (HPLC) method has been established for the separation and quantitative determination of the alkaloid theophylline in the presence of caffeine -internal standard- in blood serum and in pharmaceutical preparations. The separation was performed on Spherisorb-5 RP-18 5μm reversed phase column using methanol: 0.038 M ammonium acetate: acetonitrile (38: 57:5) at a pH of about 7.20. The eluted alkaloids are detected at 272 nm. The retention time is 3.09 min for theophylline and 3.85 min for caffeine. The correlation of the integrated peak area with the concentration of theophylline showed a linear relationship between 0.05 to 5.0 theophylline in blood serum, tablets, sprinkels, syrups, suppositories and injectable solutions.