固相萃取-反相高效液相色谱测定法评价氧化苦参碱的生物等效性

Determination of oxymatrine concentrations in plasma by RP-HPLC with solid phase extraction method and study on its bioequivalent

目的：建立一种测定人体血浆中氧化苦参碱浓度的反相高效液相色谱法，并对氧化苦参碱分散片与氧化苦参碱胶囊进行生物等效性评价。方法：待测的人体血样经固相萃取后，将其洗脱液于60℃氮气挥干并用流动相溶解残渣，取20μl进样。色谱条件：色谱柱为C18柱（150mm×4．6mm，5μm）；流动相为0．005mol·L^-1庚烷磺酸钠溶液（用磷酸调pH为3．5）-乙腈=80：20；流速为1．0ml·min^-1；紫外检测波长为220nm。人体药动学试验采用双周期交叉设计方案，将18名男性健康志愿者随机分为2组，分别单剂量口服氧化苦参碱分散片和氧化苦参碱胶囊600mg。结果：本方法线性范围为0．025～1．600mg·L^-1，r=0．9999，最低检测浓度为0．025mg·L^-1，方法回收率为96．5％-110．2％。日内、日间RSD均小于10％；两种制剂的主要药动学参数经统计学分析无统计学差异。结论：本方法灵敏度高、特异性强、重现性好，两种制剂具有生物等效性。

AIM： To develop a reversed RP-HPLC method for the study of pharmacokinetics and bioavailability of oxymatrine in male volunteers. METHODS： 1.0 ml plasma sample was applied to C18 cartridges activated with methanol. After washing, the cartridge was eluted with 2 ml mixed liquor of methanol and chloroform. The elution was evaporated to dryness with nitrogen gas at 60℃. The residue was dissolved with 80 μl mobile phase solution, and 20 μl was injected onto a Diamonsil ODS C18 column （5μm, 4.6 mm × 150 mm）. The mobile phase was 0.005 mol· L^- 1 sodium heptanesulfonate （ pH = 3.5, adjusted with HaPO4）-acetonitrile （80：20）. The flow rate was 1.0 ml· min^-1. An ultraviolet detector was set at 220 nm wavelength to monitor eluted components. A single oral dose of 600 mg of oxymatrine dispersible tablet and oxymatrine capsule was given to each of 18 healthy volunteers in an open randomized two-way crossover design. RESULTS： The linear range was 0.025 - 1.600 mg· L^- 1, r =0.9999. The limit of determination was 0.025mg· L^-1. The method recovery was 96.5 % - 110.2%. Within-day precision （RSD） and between-day precision （RSD） were less than 10%. The main pharmacokinetic parameters obtained showed no statistically significant difference between two preparations. CONCLUSION： The method is sensitive, specific and reproducible for the determination of oxynmtrine concentration in human plasma. Two products are bioequivalent.