The purpose of this work was to develop and validate a single sensitive, selective and rapid bioanalytical method to determine ceftolozane and tazobactam concentrations in human plasma and urine and to use this method to analyze samples from a human clinical study. Human plasma and urine samples were prepared by protein precipitation using a solution of acetonitrile, water and formic acid. Following protein precipitation, samples were analyzed by liquid chromatography tandem mass spectrometry. Chromatographic resolution was achieved on a Kinetex PFP column using a gradient elution, a flow rate of 0.4 mL/min, and a total run time of 5 min. Positive electrospray ionization was employed and analytes were quantitated using multi-reaction monitoring mode. Method validation was conducted in accordance with Unites States Food and Drug Administration’s regulatory guidelines for bioanalytical method validation. Calibration curves were determined to linear over the range of 0.1 to 40 µg/mL for ceftolozane and 0.05 to 20 µg/mL for tazobactam. The method was determined to be accurate (−6.24 to 12.53 percent relative error), precise (less than 13.28 percent standard deviation) and sensitive in both human plasma and urine. Ceftolozane and tazobactam were determined to be stable across a battery of stability studies including autosampler, benchtop, freeze/thaw and long-term stability. This validated method successfully applied to human clinical samples to determine the concentration versus time profiles of the intravenously administered combination of Zerbaxa (ceftolozane-tazobactam) in burn patients.

这项工作的目的是开发和验证一种单一，灵敏，选择性和快速的生物分析方法，用于测定人血浆和尿液中的头孢洛氮和他唑巴坦的浓度，并使用该方法分析来自人类临床研究的样品。通过使用乙腈，水和甲酸的溶液进行蛋白质沉淀来制备人血浆和尿液样品。蛋白质沉淀后，通过液相色谱串联质谱分析样品。使用梯度洗脱，0.4 mL / min的流速和5分钟的总运行时间在Kinetex PFP色谱柱上实现了色谱分离。采用正电喷雾电离，并使用多反应监测模式对分析物进行定量。方法验证是根据美国食品药品监督管理局的生物分析方法验证法规指南进行的。头孢唑烷的校准曲线在0.1至40 µg / mL范围内呈线性，而他唑巴坦的校准曲线在0.05至20 µg / mL之间。该方法被确定为准确的（相对误差为-6.24至12.53％），精确的（小于13.28％标准偏差）并且在人血浆和尿液中均敏感。在包括自动进样器，台式，冷冻/融化和长期稳定性在内的一系列稳定性研究中，确定头孢洛赞和他唑巴坦是稳定的。该经过验证的方法已成功应用于人的临床样品，以确定烧伤患者静脉注射的Zerbaxa（头孢洛氮烷-他唑巴坦）组合的浓度与时间的关系。