Chemistry Department, School of Sciences, Gujarat University, Navrangpura, Ahmedabad 380009, India.
J Chromatogr B Analyt Technol Biomed Life Sci. 2010 Aug 15;878(24):2217-25. doi: 10.1016/j.jchromb.2010.06.028. Epub 2010 Jul 1.
A sensitive, selective and high throughput liquid chromatography tandem mass spectrometry (LC-ESI-MS/MS) method has been developed for the determination of teriflunomide, an active metabolite of leflunomide in human plasma. Plasma samples were prepared by liquid-liquid extraction of teriflunomide and valsartan as internal standard (IS) in ethyl acetate from 200microL human plasma. The chromatographic separation was achieved on an Inertsil ODS-3 C18 (50mmx4.6mm, 3microm) analytical column using isocratic mobile phase, consisting of 20mM ammonium acetate-methanol (25:75, v/v), at a flow-rate of 0.8mL/min. The precursor-->product ion transition for teriflunomide (m/z 269.0-->82.0) and IS (m/z 434.1-->350.3) were monitored on a triple quadrupole mass spectrometer, operating in the multiple reaction monitoring (MRM) and negative ion mode. The method was validated over a wide dynamic concentration range of 10.1-4001ng/mL. Matrix effect was assessed by post-column infusion experiment and the mean process efficiency were 91.7% and 88.2% for teriflunomide and IS respectively. The method was rugged and rapid with a total run time of 2.0min and is applied to a bioequivalence study of 20mg leflunomide (test and reference) tablet formulation in 12 healthy Indian male subjects under fasting condition.
已开发出一种灵敏、选择性和高通量的液质联用（LC-ESI-MS/MS）方法，用于测定人血浆中活性代谢物来氟米特的浓度。采用液液萃取法，以缬沙坦为内标（IS），从 200μL 人血浆中提取乙酸乙酯中的来氟米特。采用 Inertsil ODS-3 C18（50mmx4.6mm，3μm）分析柱，以 20mM 乙酸铵-甲醇（25:75，v/v）为等度流动相，流速为 0.8mL/min，实现色谱分离。来氟米特（m/z 269.0-->82.0）和 IS（m/z 434.1-->350.3）的前体-产物离子跃迁在三重四极杆质谱仪上进行监测，采用多反应监测（MRM）和负离子模式。该方法在 10.1-4001ng/mL 的宽动态浓度范围内得到验证。采用柱后注入实验评估基质效应，来氟米特和 IS 的平均过程效率分别为 91.7%和 88.2%。该方法快速、稳健，总运行时间为 2.0min，适用于在禁食条件下进行的 12 名健康印度男性中 20mg 来氟米特（受试和参比）片剂制剂的生物等效性研究。
