Kallem Raja Reddy, Ramesh Mullangi, Seshagirirao J V L N
College of Pharmaceutical Sciences, Andhra University, Visakhapatnam, -530 003, India.
Biomed Chromatogr. 2013 Jun;27(6):784-91. doi: 10.1002/bmc.2861. Epub 2013 Jan 10.
A highly sensitive and specific LC-ESI-MS/MS method has been developed and validated for simultaneous quantification of felodipine (FDP) and metoprolol (MPL) in rat plasma (50 μL) using phenacetin as an internal standard (IS) as per the FDA guidelines. Liquid-liquid extraction method was used to extract the analytes and IS from rat plasma. The chromatographic resolution of FDP, MPL and IS was achieved with a mobile phase consisting of 0.2% formic acid in water-acetonitrile (25:75, v/v) with a time program flow gradient on a C18 column. The total chromatographic run time was 4.0 min and the elution of FDP, MPL and IS occurred at 1.05, 2.59 and 1.65 min, respectively. A linear response function was established for the range of concentrations 0.59-1148 and 0.53-991 ng/mL for FDP and MPL, respectively, in rat plasma. The intra- and inter-day accuracy and precision values for FDP and MPL met the acceptance as per FDA guidelines. FDP and MPL were stable in battery of stability studies viz., bench-top, auto-sampler and freeze-thaw cycles. The validated assay was applied to a pharmacokinetic study in rats.
根据美国食品药品监督管理局（FDA）的指导原则，已开发并验证了一种高灵敏度和特异性的液相色谱 - 电喷雾串联质谱（LC - ESI - MS/MS）方法，用于同时定量大鼠血浆（50 μL）中的非洛地平（FDP）和美托洛尔（MPL），使用非那西丁作为内标（IS）。采用液 - 液萃取法从大鼠血浆中提取分析物和内标。在C18柱上，流动相由水 - 乙腈（25:75，v/v）中含0.2%甲酸组成，并采用时间程序流动梯度，实现了FDP、MPL和内标的色谱分离。总色谱运行时间为4.0分钟，FDP、MPL和内标的洗脱时间分别为1.05、2.59和1.65分钟。在大鼠血浆中，分别针对FDP和MPL建立了浓度范围为0.59 - 1148和0.53 - 991 ng/mL的线性响应函数。FDP和MPL的日内和日间准确度及精密度值符合FDA指导原则的验收标准。FDP和MPL在一系列稳定性研究中，即台式、自动进样器和冻融循环条件下均稳定。该验证后的方法应用于大鼠的药代动力学研究。
