SIMPLE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC METHOD FOR DETERMINATION OF PENTOXIFYLLINE IN HUMAN PLASMA

A simple high-performance liquid chromatographic method using ultravio let detection was developed for the determination of pentoxifylline in human plasma. Prior to analysis, pentoxifylline and the internal stan dard (chloramphenicol) were extracted from plasma sample using dichlor omethane. The mobile phase comprised 0.02 M phosphoric acid adjusted t o pH 4, methanol and tetrahydrofuran (55:45:1, v/v). Analysis was ran at a flow-rate of 1.4 ml/min with the detector operated at a wavelengt h of 273 nm. The method was specific and sensitive with a detection li mit of approximately 3.0 ng/ml at a signal to noise ratio of 3:1, whil e the limit of quantification was 12.5 ng/ml. Mean recovery value of t he extraction procedure was about 99.9%, while the within-day and betw een-day coefficient of variation and percent error values of the assay method were all less than 10.0%. The calibration curve was linear ove r a concentration range of 12.5-400.0 ng/ml. (C) 1998 Elsevier Science B.V. All rights reserved.