Dong Xin, Ding Li, Cao Xiaomei, Jiang Liyuan, Zhong Shuisheng
Department of Pharmaceutical Analysis, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing, China.
Biomed Chromatogr. 2013 Apr;27(4):520-6. doi: 10.1002/bmc.2824. Epub 2012 Oct 2.
Amoxicillin (AMO) degrades in plasma at room temperature and readily undergoes hydrolysis by the plasma amidase. In this paper, a novel, rapid and sensitive LC-MS/MS method operated in segmental and multiple reaction monitoring has been developed for the simultaneous determination of amoxicillin and ambroxol in human plasma. The degradation of amoxicillin in plasma was well prevented by immediate addition of 20 μL glacial acetic acid to 200 μL aliquot of freshly collected plasma samples before storage at -80°C. The sensitivity of the method was improved with segmental monitoring of the analytes, and lower limits of quantitation of 0.5 ng/mL for ambroxol and 5 ng/mL for amoxicillin were obtained. The sensitivity of our method was five times better than those of the existing methods. Furthermore, the mass response saturation problem with amoxicillin was avoided by diluting the deproteinized plasma samples with water before injection into the LC-MS/MS system. The method was successfully employed in a pharmacokinetic study of the compound amoxicillin and ambroxol hydrochloride tablets.
阿莫西林（AMO）在室温下于血浆中降解，并容易被血浆酰胺酶水解。本文开发了一种新颖、快速且灵敏的液相色谱-串联质谱法，采用分段和多反应监测模式，用于同时测定人血浆中的阿莫西林和氨溴索。通过在将200μL新鲜采集的血浆样品等分试样储存于-80°C之前立即加入20μL冰醋酸，可有效防止血浆中阿莫西林的降解。通过对分析物进行分段监测提高了该方法的灵敏度，氨溴索的定量下限为0.5 ng/mL，阿莫西林的定量下限为5 ng/mL。我们方法的灵敏度比现有方法高五倍。此外，通过在注入液相色谱-串联质谱系统之前用水稀释去蛋白血浆样品，避免了阿莫西林的质量响应饱和问题。该方法成功应用于复方阿莫西林和盐酸氨溴索片的药代动力学研究。
