Determination of Cefoselis in Human Plasma by HPLC

OBJECTIVE To establish an HPLC method for the determination of cefoselis in human plasma. METHODS With metronidazole as the internal standard, the separation of sample was carried out on a ZORBAX Extend C₁₈ column (4.6 mm×250 mm, 5 μm) with the mobile phase consisted of phosphate buffer (pH 6.5)-acetonitrile (94.5∶5.5) at a flow rate of 1.0 mL·min^-1. The detection wavelength was 254 nm, injected sample volume was 20 μL, and the column temperature was set at 25 ℃. RESULTS The linear range of cefoselis was 1-200 mg·L^-1 (r=0.999 9) with the lower limit of quantization of 1 mg·L^-1. The average methodological recovery was 99.8%(RSD=1.53%). The inter-day RSD and intra-day RSD were all less than 3%. CONCLUSION The method is simple, sensitive, rapid, and accurate, and can be used for clinical pharmacokinetic and bioavailability study of cefoselis.