HPLC法测定大鼠血、脑组织和脑脊液中尼莫地平的浓度

HPLC method for the determination of nimodipme in rat plasma, brain tissues and cerebrospinal fluid

目的:建立大鼠血、脑组织和脑脊液(CSF)中尼莫地平(NM)浓度测定的HPLC法。方法:血和脑组织样品采用正己烷-乙醚(1:1)萃取后行HPLC法测定,CSF样品直接测定。色谱柱:DiamonsilTM C18(200 mm×4.6 mm,5 μm),流动相:乙腈-0.05 mol·L-1乙酸铵(60:40或65:35,V/V),流速1.0 mL·min-1;检测波长358 nm;柱温25℃。大鼠静注NM溶液2 mg·kg-1,用所建RP-HPLC法测定3种生物样品的浓度。结果:血、脑组织和CSF样品分别在20-1000μg·L-1,25-3500 ng·g-1和10-150μg·L-1浓度范围内线性良好,最低检测浓度分别为15μg·L-1,15 ng·g-1和8μg·L-1,方法回收率为98.71％-103.86％,日内及日间PSD<6％,血和脑组织中NM的萃取回收率均>80％。大鼠静注NM后,血药数据符合二室开放模型,各脑组织药物浓度相近,均于2 min达峰值。CSF中NM浓度很低。结论:该方法适于大鼠体内药动学研究。

AIM: To develop a reversed phase HPLC method for the determination of nimodipine (NM) in rat plasma, brain tissues and cerebrospinal fluid (CSF) . METHODS: NM in plasma and brain tissue was extracted with n-hexane/diethylether (1 : 1) and NM in CSF was measured directly. Chromatographic separation was achieved at ambient temperature on a DiamonsilTM C18(200 mm×4.6 mm, 5 μm) analytical column. The mobile phase consisted of acetoni trile-0.05 mol·L-1 ammonium acetate in a ratio of 60:40 (V/V) for the plasma and brain tissue samples, and 65:35 for CSF analysis. The flow rate was 1 mL·min-1. UV detection was set at 358nm. NM was administered intravenously (iv) to rats at a dose of 2 mg·kg-1, and the concentrations of NM in three kinds of biological samples were analyzed by the analytical procedures currently established. RESULTS: The linear range of NM was 20-1000μg·L-1, 25-3 500 ng· g-1 and 10-150 μg·L-1 and the detection limits were 15 μg·L-1, 15 ng·g-1 and 8 μg·L-1 for plasma, brain tissue and CSF samples, respectively. Method recovery was 98.71%-103.86%, inter-and intra-day variations were less than 6%. The extraction recoveries of NM from plasma and tissue homogenates were more than 80% . Plasma concentration data after iv administration was fitted to a two-compartment model. Brain NM concentrations reached peak level at 2 min post dose and similar NM concentrations were found in different brain tissues. However, the uptake of NM into CSF was low. CONCLUSION: The method can be used to study the pharmacokinetics of NM in rats.