High-performance liquid chromatographic determination and pharmacokinetic study of cefepime in goat plasma and milk after pre-column derivatization with Hg(I)

A highly sensitive and selective H PLC method with UV detection was developed for the determination of cefepime in goat plasma and milk. The proposed method was based on the complexation of cefepime with Hg(I) ions that imparts the high selectivity of the proposed method with enhancement of the sensitivity which enabled the analysis of cefepime in complex matrices such as plasma and milk. Detection was performed at 263 nm, using cefuroxime sodium as an internal standard. Chromatographic separation of cefepime and the internal standard was achieved with Aqua RP-C-18 column using methanol/triethylamine-acetate buffer, pH 3.5 (18:82, v/v) as mobile phase at a flow rate of 1 mL/min. Linear detector responses were observed spanning the range of 1.3-20 mu g/mL. The LOD for standard cefepime was 0.43 mu g/mL, whereas the LOD for cefepime in goat plasma was 0.84 mu g/mL and the corresponding value in goat milk was 1.1 mu g/mL. No interference from endogenous substances in plasma and milk was observed. The developed HPLC method has been successfully applied for the pharmacokinetic study of cefepime in goat plasma and milk, for the first time, after a single intramuscular injection of 50 mg cefepime/kg body weight.