SEPARATION AND DETERMINATION OF β-LACTAMASE INHIBITORS IN HUMAN SERUM BY HPLC WITH A β-CYCLODEXTRIN STATIONARY PHASE

ABSTRACT A high performance liquid chromatography (HPLC) method has been developed for the separation and quantitation of clavulanic acid (CA), sulbactam (SUL), and tazobactam (TAZ) in human sera. The optimum mobile phase used in conjunction with a β-cyclodextrin (β-CyD) column contained methanol-5 mM tetraethylammonium acetate (TEAA) (35 : 65, v/v, pH 4.5) and 1.0 mL/min flow rate for chromatographic separation. The mean recoveries of CA, SUL, and TAZ range from 84.4 to 87.8%, 88.4 to 90.6%, and 89.0 to 90.8% respectively, from human serum samples spiked with the inhibitors, are routinely obtained. The lower limit of quantitation ( < 0.156 µg/mL) and the low coefficient of variation ( < 3.92%) assure that this method is sensitive and reproducible.