LC-MS法分析拉米夫定的有关物质

目的建立检测拉米夫定中有关物质的液质联用分析方法,分析鉴定拉米夫定原料药、加速破坏样品和制剂产品中的有关物质,并推测其可能的降解途径。方法色谱柱为Syncronjs C_(18)柱,以5 mmol·L^(-1)乙酸铵-甲醇为流动相,线性梯度洗脱,对拉米夫定有关物质进行分离。分别在正负离子模式下采用一级全扫描和自动二级全扫描方式对样品进行质谱检测。结果拉米夫定及其各有关物质分离良好,共检测到13种有关物质。结果表明,拉米夫定的主要降解反应为氧化、差向异构化、脱氨和水解。在酸性和高温条件下,药物的稳定性良好,但在碱性和氧化条件下,药物稳定性较差。制剂产品中有关物质的种类较原料药有显著增加。结论该方法适用于拉米夫定有关物质和降解途径的研究,试验中检测到的有关物质,推测的降解途径及该类物质的质谱行为规律为该产品的质量控制及稳定性研究提供了重要的依据。

Identification of the related substances in lamivudine by LC-MS

Objective To develop the LC-MS method for the identification of the related substance of lamivudine in the raw material, accelerated degradation products and the formulation product of lamivudine, and illustrate the proposed degradation pathways of the drug. Methods The chromatographic separation was achieved on a Syncronis C₁₈ column by gradient elution with a mobile phase consisting of 5 mmol·L^-1 ammonium acetate solution (A) and methanol (B).The detection was operated by the ion trap mass spectrometer with the ESI source in the MS and MS/MS full scan mode. Results Good resolution for lamivudine and the related substances was obtained. Total 13 compounds were detected and their structures were elucidated. The drug showed instability in alkaline and peroxide while it remained stable to the thermal and acid stress. The results showed that the major degradation pathways of lamivudine were oxidation, epimerization, deamination and hydrolysis. Compared with the raw material, the number of the impurities of the formulation product was increased significantly. Conclusion The method is qualified for the identification of related substance in the lamivudine samples and the research of the degradation pathway of the drug with high sensitivity and efficiency. The results are useful to do research in the quality control of lamivudine products.