Determination of the cephalosporin antibiotic cephradine in human plasma by high-performance liquid chromatography with ultraviolet detection

A simple and sensitive high-performance liquid chromatographic method, for the determination of cephradine in human plasma samples has been developed and validated. Cephradine and cephaloridine (internal standard) were extrac ted from human plasma by perchloric acid protein precipitation followed by centrifugation. Aliquots of the extracts were analysed by reversed-phase hi gh-performance liquid chromatography (HPLC) utilising a polymeric reversed- phase PLRP-S column, followed by ultraviolet detection at 260 nm. The metho d has a working dynamic range from 0.2 to 30.0 mu g/ml from 200 mu l human plasma. The precision of the method at 0.2 mu g/ml was 4.9% (intra-assay) a nd negligible (inter-assay) as calculated by one-way analysis of variance a nd the accuracy of the method at 0.2 mu g/ml was -4.1% in terms of percenta ge bias. This method has been successfully applied to clinical studies incl uding an oral bioequivalence study comparing the pharmacokinetics of 500 mg tablets of Kefdrin with 500 mg tablets of Velosef in healthy human volunte ers. (C) 2000 Elsevier Science BN. All rights reserved.