Simultaneous analysis of piperacillin and tazobactam in rabbits: application to pharmacokinetic study

Abstract

A simple and rapid assay is developed for the simultaneous analysis of piperacillin and tazobactam in rabbit serum and tissue cage fluid (TCF). To eliminate endogenous interferences, a wavelength switch technique was applied, in which the programmable UV detector changed the monitoring wavelength from 218 to 254 nm at 10 min. After liquid–liquid extraction, sample analyses were performed on a C₁₈ column by gradient elution; the mobile phase consisted of acetonitrile and phosphate buffer (0.014 m, pH 2.4). Owing to the limited amount of rabbit TCF available, a cross‐validation of a proxy matrix was evaluated. The relative standard deviation of the between‐ and within‐batch precision of both compounds was less than 5.1%; the relative error of the between‐ and within‐batch accuracy was less than 7.3%. The recoveries of both compounds in serum and TCF were larger than 80%. This assay was successfully applied to simultaneously analyze piperacillin and tazobactam in rabbit serum and TCF samples. Copyright © 2004 John Wiley & Sons, Ltd.