HPLC法测定人胸腔积液中左氧氟沙星的浓度及其药动学研究

目的:建立测定人胸腔积液中左氧氟沙星浓度的方法,研究其药动学特征。方法:6名感染性胸腔积液患者静脉滴注左氧氟沙星0.4gqd后,收集给药后0.5、1、2、4、8、12、24h的胸腔积液,甲醇沉淀蛋白处理后,采用高效液相色谱法测定其中左氧氟沙星的浓度,色谱柱为Agilent ZORBAX SB-C18,流动相为甲醇-0.02mmol/L磷酸二氢钾缓冲液(含0.3%三乙胺,70∶30,V/V),流速为1.0mL/min,检测波长为294nm,柱温为35℃,进样量为20μL,运用WinNonlin 5.2软件计算药动学参数。结果:该色谱条件下,左氧氟沙星的保留时间为4.9min左右,峰形良好,基线平稳,胸腔积液中内源性物质对其测定无干扰,检测质量浓度的线性范围为0.625~20 μg/mL(R^2=0.998 9),低、中、高质量浓度质控样品的相对回收率为(83.75±1.66)%^87.73±2.43%(n=3),日内RSD为2.23%~4.96%(n=5)、日间RSD为4.10%~4.78%(n=5),准确度为(97.76±4.85)%^100.87±2.25%(n=5),稳定性试验中测得浓度的RSD均小于5%(n=3)。左氧氟沙星在患者体内的药动学参数:cmax为(2.21±0.87)μg/mL、AUC0-24h为(37.31±11.94)μg h/mL、t1/2为(4.50±0.21)h(n=6)。结论:本方法简便、可靠、灵敏度高,可用于人胸腔积液中左氧氟沙星的浓度测定及其药动学研究。

Determination of Levofloxacin Concentration in Human Pleural Effusion by HPLC and Its Pharmacokinetic Study

OBJECTIVE:To establish a method for the determination of levofloxacin concentration in human pleural effusion, to study its pharmaceutical characteristics. METHODS:Totally 6 patients with infectious pleural effusion received levofloxacin 0.4 g qd intravenous drip. Pleural effusion was collected at 0.5,1,2,4,8,12 and 24 hours after administration. After treated with methanol precipitation protein,HPLC was used to determine the concentration of levofloxacin. The determination was performed on Agilent ZORBAX SB-C18 column with mobile phase consisted of methanol-0.02 mmol/L KH2PO4 buffer (containing 0.3% triethylamine,70 ∶ 30,V/V at the flow rate of 1.0 mL/min. The detection wavelength was set at 294 nm,and the column temperature was 35 ℃. The sample size was 20 μL. The pharmacokinetic parameters were calculated with WinNonlin 5.2 software. RESULTS:Under this chromatogram condition,retention time of levofloxacin was about 4.9 min,the peak shape was good,the baseline was stable,and the determination of endogenous substances in pleural effusion had no interference. The linear range of levofloxacin were 0.625-20 μg/mL(R^2=0.998 9). The relative recovery rates were(83.75±1.66)%-(87.73±2.43)% for low, medium and high concentration samples(n=3);RSDs of intra-day were 2.23%-4.96%(n=5);RSDs of inter-day were 4.10%-4.78%(n=5);the accuracy ranged(97.76±4.85)%-(100.87±2.25)%(n=5);RSD of concentration was no more than 5% in stability test(n=3)for low,medium and high quality control sample. The pharmacokinetic parameters of levofloxacin included cmax were(2.21±0.87)μg/mL;AUC0-24 h were(37.31±11.94)μg h/mL;t 1/2 were(4.50±0.21)h. CONCLUSIONS: Established method is simple,reliable and sensitive,and can be used for the determination of levofloxacin concentration in human pleural effusion and its pharmacokinetic study.