RP-HPLC测定大鼠N,N-双乙酰胱氨酸的血药浓度

Determination of N,N-Diacetylcystine in Rats Plasma by RP-HPLC

目的:建立一种RP-HPLC测定大鼠血浆中N,N-双乙酰胱氨酸的浓度。方法:血浆样品经10%高氯酸沉淀蛋白后,上清液直接进样分析。色谱柱为LichrospherC18柱(5μm,150mm×4.5mm,ID),流动相为0.025mol/L磷酸二氢钾(磷酸调节pH至3.0)甲醇(90∶10,v/v),流速1.0mL/min,柱温25℃,检测波长205nm。对乙酰氨基酚为内标。测定了大鼠静脉注射N,N双乙酰胱氨酸40mg/kg后的血药浓度时间过程。结果:标准曲线线性范围为1.0～600.0μg/mL(r=0.9988),最低检测限为0.2μg/mL,回收率均大于90%,日内、日间精密度RSD均小于15%。结论:此方法快速、可靠,可用于N,N-双乙酰胱氨酸血药浓度分析及药代动力学研究。

AIM:To develope a RP-HPLC method for the determination of N,N-diacetylcystine in the plasma of rats.METHODS:Samples, to which paracetamol was added as internal standard,were mixed with 10% perchloric acid to precipitate the plasma protein,and the supernatant was injected into the HPLC system with an analytical column of Lichrospher C_(18)(5 μm,150 mm×4.5 mm,ID) with the column temperature set at 25 ℃.The mobile phase consisted of a mixture of 0.025 mol/L KH_2PO_4-methanol(90∶10,v/v)(H_3PO_4 adjusted to pH 3.0) with a flow rate of 1.0 mL/min.The N,N-diacetylcystine was detected by UV absorption at 205 nm.The plasma concentrations of N,N-diacetylcystine were determined after i.v. dose of 40 mg/kg in rats.RESULTS:The assay was linear in the range of 1.0～600.0 μg/mL(r=0.998 8)with the limite of quantification of 0.2 μg/mL in plasma.The recoveries of N,N-diacetylcystine in plasma were more than 90%.Within-day and between-day assays variations (expressed as RSD) were all less than 15%.CONCLUSION:This method is rapid and reliable for assay of N,N-diacetylcystine concentrations in rat plasma and relevant pharmacokinetics studies.