兔眼结膜中阿奇霉素的浓度测定及其药动学

目的建立兔眼结膜中阿奇霉素的LC-MS/MS检测方法,研究阿奇霉素滴眼液在兔眼结膜中的药动学特征。方法 184只新西兰白兔进行单次以及多次给阿奇霉素滴眼液后,于不同时间点取眼结膜样本匀浆处理后以沉淀法去除匀浆液中蛋白基质,采用LC-MS/MS法测定兔眼结膜中的阿奇霉素。以克拉霉素为内标,采用Ultimate XB-Phenyl(100 mm×3.0 mm,3μm)色谱柱,流动相为乙腈-0.01 mol.L-1乙酸铵水溶液(含0.1%乙酸)(75∶25,V/V),电喷雾离子源,正离子SRM扫描分析,内标和阿奇霉素离子对分别为:m/z 748→m/z 590和m/z 749→m/z 591。结果阿奇霉素结膜浓度在10.128～8 102.4μg.L-1范围内线性关系良好(r=0.998 7);最低定量限为10.128μg.L-1;批内和批间RSD均小于10%;方法准确度在85%～115%之间。单次给药后参比制剂和受试制剂的药动学参数tmax分别为2 h和2 h,ρmax分别为22.29μg.g-1和21.80μg.g-1,AUC1-192分别为528.0μg.h.g-1和536.5μg.h.g-1,t1/2分别为25.5 h和24.1 h。多次给药后参比制剂和受试制剂的药动学参数tmax分别为8 h和8 h,ρmax分别为53.10μg.g-1和51.62μg.g-1,AUC1-192分别为1 584.9μg.h.g-1和1 379.4μg.h.g-1,t1/2分别为28.8 h和23.7 h。受试制剂和参比制剂药动学行为基本一致。结论建立的检测方法简便、灵敏。多次给药后在兔眼结膜内存在蓄积现象。

Determination and pharmacokinetics of azithromycin in rabbit conjunctiva

AIM To establish a LC-MS/MS method for the determination of azithromycin in rabbit conjunctiva and to study the pharmacokinetics of azithromycin eye drops after single and multiple dose administration.METHODS Following a deproteinization procedure,the azithromycin concentrations in conjun-ctiva were determined by HPLC-MS/MS and the pharmacokinetics were evaluated in 184 New Zealand albino rabbits after single and multiple dose of azithromycin eye drops,respectively.Clarithromycin was taken as internal standard and the samples were eluted utilizing a mobile phase containing of 0.01 mol·L-1 ammonium(containing 0.1% acetic acid)-acetate(25 ∶ 75,V/V)and an Ultimate XB-Phenyl column(100 mm × 3.0 mm,3 μm).ESI and SRM were used with positive ion scans and the mass transition pairs of m/z 748→m/z 590 and m/z 749→m/z 591 were used to detect internal standard and azithromycin.RESULTS The method demonstrated that good linearity ranged from 10.128 to 8 102.4 μg·L-1 with r = 0.998 7;the lower limit of quantification for azithromycin in conjunctiva tissues was 10.128 μg·L-1;the intra-and inter-batch precision(RSD)values were below 10% and the accuracy ranged from 85% to 115%.The main pharmacokinetics of standard formula-tion and test formulation after single administration were as follows:tmax 2 h versus 2 h;ρmax 22.29 μg·g-1 versus 21.80 μg·g-1;AUC1-192 528.0 μg·h·g-1 versus 536.5 μg·h·g-1,t1/2 25.5 h versus 24.1 h,respectively.The parameters after multiple administration were as follows:tmax 8 h versus 8 h;ρmax 53.10 μg·g-1 versus 51.62 μg·g-1;AUC1-192 1 584.9 μg·h·g-1 versus 1 379.4 μg·h·g-1,t1/2 28.8 h versus 23.7 h,respectively.There was no significant difference of the pharmacokinetics characteristics between two formulations.CONCLUSION The method is convenient and sensitive.There is a gentle accumulation of azithromycin after multiple administrations.