左旋多巴微囊胃内漂浮片犬体内药物动力学研究

Pharmacokinetic study of Levodopa Microcapsules Intragastric Floating Tablets in Beagle dogs

目的：建立左旋多巴微囊胃内漂浮片在比格犬体内的血药质量浓度的测定方法，并对其体内药动学行为进行研究。方法建立HPLC法测定血样中左旋多巴的质量浓度，流动相为水-甲醇（95∶5），其中水相含EDTA 0．08 mmol · L^ -1、磷酸二氢钾70 mmol · L^ -1、庚烷磺酸钠2．08 mmol · L^-1，流速为0．5 mL · min^-1，荧光检测，激发波长278 nm ，发射波长325 nm。6只Bea-g le犬分别给予复方左旋多巴微囊胃内漂浮片，并在给药后多点前肢静脉采血。用该方法检测血浆中左旋多巴的质量浓度，用3P97计算药动学参数。结果该方法的线性范围为0．078～20μg · mL^ -1，最低定量限为0．078μg · mL^ -1，日内RSD＜8.10％，日间RSD＜13．52％，回收率为105．1％～113．9％。左旋多巴微囊胃内漂浮片在犬体内的药时曲线符合单室模型，主要药物动力学参数分别为 t1/2（1.09±0．46）h，tmax（1．32±0．54）h，Cmax（1．33±0．31）μg· mL^-1；AUC为（3．31±1．26）μg·h·mL^ -1。结论该方法简单、快速，可用于比格犬的左旋多巴血药质量浓度的测定和药动学研究。

Objective To explore the plasma concentration measurement method and to study the pharmacokinetic profiles of Levo-dopa Microcapsules Intragastric Floating Tablets in Beagle dogs .Methods An HPLC method was developed to determine the con-tent of levodopa in the blood samples from Beagle dogs .The mobile phase was consisted of water and methanol（95∶5） ,containing EDTA 0 .08 mmol · L^ -1 ,potassium dihydrogen phosphate 70 mmol · L^ -1 ,and heptane sulfonate 2 .08 mmol · L^ -1 .The flow rate of mobile phase was 0 .5 mL · min^-1 .The excitation wavelength of fluorescence detection was 278 nm ,and the emission wave-length of fluorescence detection was 325 nm .Six Beagle dogs were given Levodopa Microcapsules Intragastric Floating Tablets ,and the blood from the forelimb vein were collected at different time after administration .According to the result of concentration of levodopa in plasma ,pharmacokinetic parameters were calculated with 3P97 software .Results The linear range was 0 .078-20μg · mL -1 .The minimum detection limit was 0 .078 μg · mL -1 .The RSD of within-day was below 8 .10% ,and the RSD of be-tween-days was below 13 .52% .The recovery was between 105 .1%-113 .9% .The concentration-time curve of Levodopa Microcap-sules Intragastric Floating Tablets fitted to one-compartment model .The main pharmacokinetic parameters of Levodopa Microcap-sules Intragastric Floating Tablets was t1/2 （1 .09 ± 0 .46） h ,tmax （1 .32 ± 0 .54） h ,Cmax （1 .33 ± 0 .31）μg · mL^ -1 ,and AUC （3 .31 ± 1.26）μg · h · mL ^-1 .Conclusion The method was simple and rapid ,which can be used to determine the levodopa plasma con-centration and study the pharmacokinetic profiles .