Phillips Oludotun A, Abdel-Hamid Mohammed E
Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kuwait University, Kuwait.
J Pharm Pharm Sci. 2008 May 22;11(2):22s-31s. doi: 10.18433/j3101n.
Triazolylmethyl oxazolidinones are novel potent antibacterial agents recently synthesized in our laboratory.
Development of a rapid and specific LC-MS method for evaluating the stability of three potentially active antibacterial triazolylmethyl oxazolidinone compounds, namely PH-27, PH-38 and PH-41, in human plasma.
Ion-trap mass spectrometry using +APCI-MS at m/z 348.1 (PH-27), 389.1 (PH-38) and 451.1 (PH-41) combined with liquid chromatographic analysis using C18 reversed-phase column and a mobile phase consisting of 20 mM ammonium acetate solution and acetonitrile (50:50 v/v) was used. Plasma samples were pre-treated with acetonitrile to precipitate proteins prior to LC-MS analysis. Linezolid was used as an internal standard whose predominant ion at m/z 338.1 was monitored and used to construct the calibration curves. An accelerated stability study under controlled experimental conditions was conducted at -20 oC for a 5-weeks period.
Calibration curves of the examined oxazolidinones in human plasma were established (r: 0.99) up to the concentration of 20.0 microg ml-1 with LLQ of 0.1 (PH-27), 0.5 (PH-38) and 1.0 microg ml-1 (PH-41). Validation data showed appropriate intra- and inter-day precision and accuracy as indicated from RSD% 1.3 - 8.6 and % DEVs -12.7 to +11.3, respectively. Stability studies gave the kinetic degradation parameters of kdeg 0.0191- 0.0857 week-1, t1/2 8.1-36.3 weeks and t90 1.2 -5.5 weeks.
The developed +APCI-LC-MS assay is simple, fast and specific method that could be applied for the routine analysis of the selected oxazolidinones during stability and pharmacokinetic studies. The examined compound PH-27 was proved to be relatively more stable and resistant to degradation in human plasma compared to PH-38 and PH-41, as indicated from the kinetics and recovery studies at -20 oC.
三唑基甲基恶唑烷酮是我们实验室最近合成的新型强效抗菌剂。
开发一种快速、特异的液相色谱 - 质谱法，用于评估三种具有潜在活性的抗菌三唑基甲基恶唑烷酮化合物，即PH - 27、PH - 38和PH - 41在人血浆中的稳定性。
采用离子阱质谱，在m/z 348.1（PH - 27）、389.1（PH - 38）和451.1（PH - 41）处进行正离子大气压化学电离质谱（+APCI - MS），结合液相色谱分析，使用C18反相柱和由20 mM醋酸铵溶液与乙腈（50:50 v/v）组成的流动相。在进行液相色谱 - 质谱分析之前，血浆样品用乙腈预处理以沉淀蛋白质。利奈唑胺用作内标，监测其在m/z 338.1处的主要离子并用于构建校准曲线。在 - 20℃下进行为期5周的控制实验条件下的加速稳定性研究。
建立了所检测的恶唑烷酮在人血浆中的校准曲线（r：0.99），浓度范围高达20.0 μg/ml，PH - 27的定量下限为0.1 μg/ml，PH - 38为0.5 μg/ml，PH - 41为1.0 μg/ml。验证数据显示日内和日间精密度及准确度合适，相对标准偏差（RSD%）分别为1.3 - 8.6和偏差百分比（% DEVs）为 - 12.7至 + 11.3。稳定性研究给出了降解动力学参数，降解速率常数kdeg为0.0191 - 0.0857周 - 1，半衰期t1/2为8.1 - 36.3周，有效期t90为1.2 - 5.5周。
所开发的 +APCI - LC - MS测定法是一种简单、快速且特异的方法，可应用于稳定性和药代动力学研究中所选恶唑烷酮的常规分析。如在 - 20℃下的动力学和回收率研究所示，所检测的化合物PH - 27在人血浆中被证明比PH - 38和PH - 41相对更稳定且更耐降解。
