碱水解转化-紫外分光光度法测定聚乙二醇负载葛根素前药的载药量研究

目的: 建立聚乙二醇负载葛根素前药的载药量测定方法。方法: 将葛根素溶于不同浓度的氢氧化钠溶液中在60 ℃水浴中进行水解,HPLC跟踪筛选出较适宜的水解方法,并将水解产物用NMR进行表征。将葛根素前药通过相应方法水解后,紫外分光光度法测定其水解产物吸光度从而确定葛根素前药载药量。结果: 实验发现,葛根素在1 mol·L^-1 氢氧化钠溶液60 ℃水浴孵育30 min后水解完全,水解后葛根素转化形成的产物经结构鉴定为二氢葛根素,该物质在碱性溶液中在336 nm处有稳定吸收峰,并且在1.378~28.947 μg·mL^-1范围内浓度与吸光度呈良好的线性关系,回归方程为:Y=0.0432X+0.077,r=0.9996;平均回收率为99.1%。结论: 本方法简便、快速、准确且成本低,可用于葛根素前药的质量控制。

Objective: To develop a method for determine the drug loading of the puerarin prodrug.Methods: The puerarin was dissolved in NaOH solution with different concentrations and was hydrolyzed in 60 ℃ bath, HPLC was used to trace detection and select the opportunely method for hydrolysis. And the product was characterized by NMR. The prodrug was hydrolyze by the corresponding method and the absorbance of the product of hydrolysis was determined by UV-spectrophotometry, and then the drug loading was caculated.Results: It was found that the puerarin was completely hydrolyzed and conversion after 30 min incubation in 1 mol·L^-1 NaOH solution and 60 ℃ bath. The product is dihydro puerarin after structure identification, which has a stable absorption peak at 336 nm in alkaline solution, and it showed good linearity in the range of 1.378－28.947 μg·mL^-1. The regression equation was Y=0.0432X+0.077,r=0.9996; the average recovery was 99.1%.Conclusion:We established a simple, rapid, accurate and low cost method, which was fit for the quality control of puerarin prodrug.