Zhou Zhi-Ling, Yang Min, Yu Xi-Yong, Peng Huai-Yan, Shan Zhi-Xin, Chen Shu-Zhen, Lin Qiu-Xiong, Liu Xiao-Ying, Chen Tie-Feng, Zhou Shu-Feng, Lin Shu-Guang
Research Center of Medical Sciences, Guangdong Provincial People's Hospital, Guangzhou 510080, People's Republic of China.
Biomed Chromatogr. 2007 Oct;21(10):1045-51. doi: 10.1002/bmc.851.
A high-performance liquid chromatography method with fluorescence detection (HPLC-FLD) for the determination of levofloxacin in human plasma is described. Neutralized with phosphate buffer (pH 7.0), the sample (0.1 mL) was extracted with dichlormethane (1 mL). After voltex-mixing and centrifuged at 3000g for 6 min at 4 degrees C, the upper aqueous layer was aspirated using a micro vacuum pump and the organic layer was directly transferred to a clean test tube without pipetting. The organic solvent was evaporated and the residues were reconstituted with the mobile phase. Levofloxacin and terazosin (internal standard, IS) were chromatographically separated on a C(18) column with a mobile phase containing phosphate buffer (pH 3.0, 10 mm), acetonitrile and triethylamine (76:24:0.076, v/v/v) at a flow rate of 1 mL/min. The analytes were detected using fluorescence detection at an excitation and emission wavelength of 295 and 440 nm, respectively. The linear range of the calibration curves was 0.0521-5.213 microg/mL for levofloxacin with a lower limit of quantitation (0.0521 microg/mL). The retention times of levofloxacin and terazosin were 2.5 and 3.1 min, respectively. Within- and between-run precision was less than 12 and 11%, respectively. Accuracy ranged from -6.3 to 4.5%. The recovery ranged from 86 to 89% at the concentrations of 0.0521, 0.5213 and 5.213 microg/mL. The present HPLC-FLD method is sensitive, efficient and reliable. The method described herein has been successfully used for the pharmacokinetic and bioequivalence studies of a levofloxacin formulation product after oral administration to healthy Chinese volunteers.
描述了一种采用荧光检测的高效液相色谱法（HPLC-FLD）测定人血浆中左氧氟沙星的方法。用磷酸盐缓冲液（pH 7.0）中和后，取0.1 mL样品，用1 mL二氯甲烷萃取。经涡旋混合并在4℃下以3000g离心6分钟后，用微型真空泵吸出上层水相，有机层直接转移至干净的试管中，无需移液。蒸发挥发性有机溶剂，残留物用流动相复溶。左氧氟沙星和特拉唑嗪（内标，IS）在C(18)柱上进行色谱分离，流动相包含磷酸盐缓冲液（pH 3.0，10 mM）、乙腈和三乙胺（76:24:0.076，v/v/v），流速为1 mL/min。分别在激发波长295 nm和发射波长440 nm下使用荧光检测法检测分析物。校准曲线的线性范围为左氧氟沙星0.0521 - 5.213 μg/mL，定量下限为0.0521 μg/mL。左氧氟沙星和特拉唑嗪的保留时间分别为2.5分钟和3.1分钟。批内和批间精密度分别小于12%和11%。准确度范围为-6.3%至4.5%。在0.0521、0.5213和5.213 μg/mL浓度下回收率范围为86%至89%。本HPLC-FLD方法灵敏、高效且可靠。本文所述方法已成功用于健康中国志愿者口服给药后左氧氟沙星制剂产品的药代动力学和生物等效性研究。
