A sensitive method for the determination of gemfibrozil in human plasma samples by RP-LC

A sensitive high-performance liquid chromatographic assay for the quantitat ive determination of gemfibrozil is described in this work. Ibuprofen was u sed as internal standard, The assay involved a single cyclohexane extractio n and LC analysis with fluorescence detection. Chromatography was performed at 40 degreesC on a Hypersil ODS column. The mobile phase was a mixture of a solution of phosphoric acid 0.4% and acetonitrile (45:55). The method wa s validated. The detection limit of this method was 0.025 mug ml(-1); only 0.5 ml of the plasma sample was required for the determination. The calibra tion graph was linear from 0.05 to 0.5 mug ml(-1) and required a cubic equa tion from 0.5 to 30 mug ml(-1). Intra and inter-day precision (C.V.) did no exceed 15%. Mean recoveries were of 90.15 +/- 6.9% (C.V.'s < 8%) for gemfi brozil and 93.10% for ibuprofen Applicability of the method was demonstrate d by a pharmacokinetic study in normal volunteers who received gemfibrozil by oral route. (C) 2001 Elsevier Science B.V. All rights reserved.