Raju B, Ramesh M, Borkar Roshan M, Padiya Raju, Banerjee Sanjay K, Srinivas R
National Centre for Mass Spectrometry, Indian Institute of Chemical Technology, Hyderabad, 500 007, India.
Biomed Chromatogr. 2012 Nov;26(11):1341-7. doi: 10.1002/bmc.2701. Epub 2012 Feb 15.
A highly sensitive, selective and rapid liquid chromatography-electrospray ionization mass spectrometry (LC-MS) method has been developed and validated for simultaneous determination of moxifloxacin (MFX) and ketorolac (KTC) in rat plasma. Gemifloxacin (GFX) was used as an internal standard (IS). A simple protein precipitation method was used for the extraction of analytes from rat plasma. Effective chromatographic separation of MFX, KTC and GFX was achieved on a Kromasil C(18) column (100 × 4.6 mm, 5 µm) using a mobile phase consisting of acetonitrile-10 mm ammonium acetate (pH 2.5)-0.1% formic acid (50:25:25) in an isocratic elution, followed by detection with positive ion electrospray ionization mass spectrometry using target ions of M + H at m/z 402 for MFX, m/z 256 for KTC and m/z 390 for GFX in selective ion recording mode. The method was validated over the calibration range of 5-100 ng/mL for MFX and 10-6000 ng/mL for KTC. The method demonstrated good performances in terms of intra- and inter-day precision (0.97-5.33%) and accuracy (93.91-101.58%) for both MFX and KTC, including lower and upper limits of quantification. The recoveries from spiked control samples were >75% for MFX and >79% for KTC. The matrix effect was found to be negligible and the stability data were within acceptable limits. Further, the method was also successfully applied to a single-dose pharmacokinetic study in rats. This method can be extended to measure plasma concentrations of both drugs in human to understand drug interaction and adverse effects.
已开发并验证了一种高灵敏度、高选择性且快速的液相色谱 - 电喷雾电离质谱（LC-MS）方法，用于同时测定大鼠血浆中的莫西沙星（MFX）和酮咯酸（KTC）。吉米沙星（GFX）用作内标（IS）。采用简单的蛋白沉淀法从大鼠血浆中提取分析物。在Kromasil C(18)柱（100×4.6 mm，5 µm）上，使用由乙腈 - 10 mM醋酸铵（pH 2.5） - 0.1%甲酸（50:25:25）组成的流动相进行等度洗脱，实现了MFX、KTC和GFX的有效色谱分离，随后在选择性离子记录模式下，采用正离子电喷雾电离质谱，以m/z 402处的M + H作为MFX的目标离子、m/z 256处的M + H作为KTC的目标离子、m/z 390处的M + H作为GFX的目标离子进行检测。该方法在MFX的校准范围为5 - 100 ng/mL和KTC的校准范围为10 - 6000 ng/mL内进行了验证。该方法在MFX和KTC的日内和日间精密度（0.97 - 5.33%）和准确度（93.91 - 101.58%）方面均表现良好，包括定量下限和上限。加标对照样品中MFX的回收率>75%，KTC的回收率>79%。发现基质效应可忽略不计，稳定性数据在可接受范围内。此外，该方法还成功应用于大鼠单剂量药代动力学研究。此方法可扩展用于测定人体中两种药物的血浆浓度，以了解药物相互作用和不良反应。
