Development of an HPLC Method for the Determination of Ceftolozane/Tazobactam in Biological and Aqueous Matrixes

Herein, we report the development and validation of an HPLC method to analyze ceftolozane and tazobactam simultaneously in human plasma, human serum, swine serum and saline matrixes. A reversed-phase column was used with a UV detector set at 260 nm and switched to 218 nm. The mobile phase consisted of methanol and sodium phosphate buffer at a flow rate of 1.1 mL/min. Cefepime was used as the internal standard. The standard curves were linear over a range of 0.4-50 μg/mL. This methodology represents a simple, reproducible approach to the determination of drug concentrations with sufficient accuracy and precision for pharmacokinetic studies undertaken with this recently FDA-approved antimicrobial therapy.