HPLC法测定口服5-氨基水杨酸制剂后血浆和尿中的药物及其代谢物

HPLC Determination of 5-Aminosalicylic Acid and its Metabolite in Plasma and Urine for Pharmacokinetics Study of its Oral Preparation

目的 建立测定血浆和尿样中 5 氨基水杨酸 (5 ASA)及代谢物乙酰 5 氨基水杨酸 (Ac 5 ASA)浓度的HPLC方法 ,并进行 5 ASA缓释片Pentasa的人体药动学研究。方法 使用荧光检测器 ,以丙酰 4 氨基水杨酸为内标 ,用衍生化法使样品中的 5 ASA丙酰化 ,甲醇沉淀蛋白后上清液直接进样。色谱柱为PhenomenexLunaTMC18,流动相为 0 .1mol/L乙酸溶液∶乙腈∶三乙胺 (46 0∶40∶0 .4,V/V/V)的混合液。测定 6位健康志愿者口服10 0 0mgPentasa后血药浓度和尿药浓度。结果 血浆中 5 ASA及代谢物的线性范围为 0 .0 1～ 10 μg/ml,尿样中为 0 .2～ 2 0 0 μg/ml,血浆和尿中药物与代谢物的回收率在 95 .3 %～ 10 6 .2 %之间 ,日内日间相对标准差均在0 .5 2 %～ 9.2 2 %范围内。Pentasa口服后 5 ASA和Ac 5 ASA的血药浓度在 3～ 4h内达到峰值 ,分别为 1.5 5和3 .11μg/ml,AUC分别为 6 .90和 2 6 .32 μg/(ml·h) ,6 0h内尿中排泄了口服剂量 37.1%的药物。结论 方法简便 ,灵敏度和准确度高 ,可用于 5 ASA制剂的药物动力学研究。

Purpose: To establish a HPLC method for determination of 5-aminosalicylic acid (5-ASA) and its metabolite (acetyl-5-ASA) in plasma and urine and to study the pharmacokinetics of Pentasa, a 5-ASA slow-release tablet. Methods: A fluorescence detector λEx = 315 nm, λEx = 430 nm) was adopted with a Phenomenex Luna™ C18 column, a mobile phase consisting of 0.1 mol/L acetic acid-acetonitrile-triethylamine (460: 40: 0.4, V/V/V), and with propionyl-4-ASA as an internal standard. After 5-ASA was derivatized to propionyl-5-ASA and the proteins were precipitated with methanol, the sample was directly injected. The concentrations of 5-ASA and acetyl-5-ASA in plasma and urine were determined after oral administration of 1 000 mg Pentasa in 6 healthy volunteers. Results: The method showed good linearity for 5-ASA and its metabolite in the range 0.01 - 10 μg/ml in plasma and 0.2 - 200 μg/ml in urine. The mean recoveries ranged from 95.3% to 106.2% and the within-day and between-day RSD ranged from 0.52% to 9.22 %. The mean plasma 5-ASA and acetyl-5-ASA concentrations peaked at 1.55 and 3.11 μg/ml from 3 to 4 hours following administering Pentasa, respectively. The mean AUC values for 5 -ASA and acetyl-5 -ASA were 6.90 and 26.32 μg/(ml&middoth) respectively. An average of 37.1% of the dose was excreted in the urine within 60-hour collection interval primarily as acetyl-5-ASA. Conclusions: A simple, sensitive and accurate HPLC method for simultaneous determination of 5-ASA and its metabolite in plasma and urine was developed and used in the study of pharmacokinetics of a 5-ASA preparation.