Quantitative determination of cefepime in plasma and vitreous fluid by high-performance liquid chromatography

An isocratic reversed-phase HPLC method was developed to determine cefepime levels in plasma and vitreous fluid. Cefepime and the internal standard ce fadroxil were separated on a Shandon Hypersil BDS C18 column by using a mob ile phase of 25 mM sodium dihydrogen phosphate monohydrate (pH 3) and metha nol (87:13, v/v). Ultraviolet detection was carried out at 270 nm. The rete ntion times were 4.80 min for cefepime and 7.70 min for cefadroxil. This fa st procedure which involves an efficient protein precipitation step (additi on of HClO4), allows a quantification limit of 2.52 mu g ml(-1) and a detec tion limit of 0.83 mu g ml(-1). Recoveries and absolute recoveries of cefep ime from plasma were 96.13-99.44% and 94-102.5% respectively. The intra-day and inter-day reproducibilities were less than 2% for cefepime at 10, 30, 50 mu g ml(-1) (n=10). The method was proved to be suitable for determining cefepime levels in human plasma and was modified to measure vitreous fluid samples. (C) 1999 Elsevier Science B.V. All rights reserved.