HPLC法测定人血浆中左旋多巴和卡比多巴浓度及其药代动力学研究

Simultaneous Determination of L-dopa and Carbidopa in Plasma by HPLC and Its Pharmacokinetics in Men

目的 :建立人血浆中左旋多巴和卡比多巴同时测定的HPLC ECD方法 ,研究左旋多巴卡比多巴在人体中的药代动力学。方法 :样品提取采用偏重亚硫酸钠抗氧化 ,高氯酸沉淀蛋白 ,氧化铝在碱性条件下吸附样品 ,酸性条件下解吸附的方法。流动相 :储备液 (2 3%柠檬酸 ,1 6 6 %NaOH) 甲醇 冰醋酸 水 (2 5 0∶4 0∶14∶6 96 ,v/v/v/v) ,庚烷磺酸钠为 4mmol/L。流速 1 0ml/min。色谱柱为C18,5 μm ,2 5 0mm× 4 6mmI D。电化学检测器(ECD)极化电压为 0 8V。用上述方法研究了 2 0名健康志愿者单剂量和多剂量口服息宁控释片后血药浓度 时间过程。结果 :血浆中杂质不干扰样品峰 ,最低检测浓度 :左旋多巴 5 0ng/ml,卡比多巴 12 5ng/ml,线性范围 :左旋多巴 5 0～ 32 0 0ng/ml,卡比多巴 12 5～ 80 0ng/ml。回收率大于 70 % ,日间和日内的变异系数小于 15 %。受试者单剂量口服 2 5 0mg(2 0 0 / 5 0 )息宁控释片后估算的左旋多巴末端相半衰期为 2 0 2± 0 4 1h ,峰时间为 2 0± 0 9h ,峰浓度为 15 5 3 5± 35 0 6ng/ml;卡比多巴的末端相半衰期为 1 77± 0 6 8h ,峰时间为 3 8± 0 7h ,峰浓度为 2 36 98±6 2 0 3ng/ml。多剂量口服息宁控释片达稳态时的左旋多巴药代动力学参数为tmax1 8± 0 6h ,cmax12 0 3

AIM:To establish an HPLC method for simultaneous determination of L -dopa and carbidopa in human plasma and to study pharmacokinetics of L -dopa and carbidopa in men. METHOD:The protein in plasma was precipitated with the mixture of HClO_ 4 and sodium metabisulfite was used as antioxidant.The drug was absorbed by Al_ 2 O_ 3 on the condition of alkalescence and separated on the condition of acidity.Mobile phase was consisted of stock solution (2.3% citric acid,1.66% NaOH):methol:acetic acid:H_ 2 O (250∶40∶14∶696, v/v/v/v ) containing 4 mmol/L sodium heptanesulfonate.The column is C_ 18 ,5μm,250 mm×4.6 mm I.D.The polar potential was 0.8 V.The plasma concentration of L -dopa and carbidopa was determined in 20 healthy subjects after oral administration of single-dose and multi-dose. RESULT: The assay exhibited a linear range of 50～3200 ng/ml.The absolute recoveries of L -dopa and carbidopa are both larger than 70% and RSD within and between days were smaller than 15%. After oral administration of a single dose,the pharmacokinetic parameters of L -dopa were: t _ 1/2 2.02±0.41 h, t _ max 2.0±0.9 h, c _ max 1553.5±350.6 ng/ml;the parameters of carbidopa were: t _ 1/2 1.77±0.68 h, t _ max 3.8±0.7 h, c _ max 236.98±62.03 ng/ml.And after muti-dose,the parameters were: L -dopa: t _ max 1.8±0.6 h, c _ max 1203.0±319.5 ng/ml, c _ av 322.9±62.5 ng/ml,AUC_ ss 3874.9±749.5 ng·h/ml,DF3.75±0.84;carbidopa: t _ max 2.8±0.7h, c _ max 225.94±89.94 ng/ml, c _ av 60.53±20.66 ng/ml,AUCss 726.41±247.88 ng·h/ml,DF3.68±0.52. CONCLUSION:The method of HPLC-ECD we established can be used for clinical study of the co-administration of L -dopa and carbidopa.