Quantification of the cephalosporin antibiotic cefditoren in human plasma by high-performance liquid chromatography

A simple, sensitive and selective high-performance liquid chromatography (HPLC) method with ultraviolet detection (305 nm) was developed and validated for quantification of cefditoren (CAS 104145-95-1), a broad-spectrum orally administered cephalosporin in human plasma. Following solid-phase extraction using Waters Oasis SPE cartridges, the analyte and internal standard (hydrochlorothiazide, CAS 58-93-5) were separated using an isocratic mobile phase of 0.03 % trifluoro acetic acid buffer / acetonitrile (81/19, v/ v) on reverse phase Waters symmetry C18 column. The lower limit of quantification was 50 ng/mL, with a relative standard deviation of less than 4%. A linear range of 50 to 5000 ng/mL was established. This HPLC method was validated with between-batch and within-batch precision of 0.5 to 3.7 % and 0.5 to 2.5%, respectively. The between-batch and within-batch accuracy was 96.9 to 103.8% and 97.5 to 102.3%, respectively. Stability of cefditoren in plasma was excellent, with no evidence of degradation during sample processing (autosampler) and 30 days storage in a freezer. This validated method is sensitive, simple and repeatable enough to be used in pharmacokinetic studies.