An HPLC Method for the Determination of Theophylline Concentrations in Plasma from Both Healthy Rats and in Rats with Carbon Tetrachloride Induced Cirrhosis

Abstract An accurate and reproducible high performance liquid chromatographic assay for theophylline in rat plasma has been developed. After addition of ammonium sulfate to the samples, theophylline is extracted from the plasma into chloroform. Beta-hydroxyethyl theophylline is used as the internal standard and separation is achieved using a Zorbax ODS (C18) column with a gradient mobile phase system, consisting of 0.05 M sodium acetate and acetonitrile. Samples are quantitated by UV detection of the column effluent at 275 nm. The assay can accurately and precisely measure theophyliine concentrations in rat plasma ranging from 0.25 to 7.5 μ/ml. This procedure has been successfully applied to the analysis of rat plasma samples obtained from both healthy rats and rats with carbon tetrachloride induced cirrhosis. Key Words: TheophyllineHPLCratplasmacirrhosis