PEG化脂质纳米粒进积雪草酸口服吸收研究.docVIP

PEG化脂质纳米粒促进积雪草酸口服吸收研究 　　[摘要]采用溶剂扩散法制备聚乙二醇修饰的积雪草酸（asiatic acid，AA）纳米结构脂质载体（pegylated asiatic acid loaded nanostructured lipid carriers，pAANLC），以结扎肠循环模型考察其在小肠的吸收分布情况，HPLC检测健康SD大鼠灌胃给予pAANLC后的胆汁药物浓度，间接评价PEG化脂质纳米粒的促口服吸收作用。结果显示，经PEG亲水性修饰的NLC在小肠黏膜的穿透能力大大提高，小肠内的转运量显著增加，大鼠体内药物排泄峰值Cmax较普通纳米粒（asiatic acid loaded nanostructured lipid carriers，AANLC）提高了76%，达峰时间tmax减慢，消除半衰期t1/2延长1倍，AUC0→t为AANLC组的15倍，提示AANLC经PEG亲水性修饰后，口服生物利用度显著提高。 中国论文网 /1/viewhtm　　[关键词]积雪草酸； 纳米结构脂质载体； 聚乙二醇； 口服吸收 　　[Abstract]A solvent diffusion method was used to prepare pegylated asiatic acid （AA） loaded nanostructured lipid carriers （pAANLC）， and the ligated intestinal circulation model was established to observe the absorption and distribution in small intestine The concentration of AA in bile after oral administration of pAANLC was detected by HPLC in healthy SD rats to indirectly evaluate the oral absorption promoting effect of PEGmodified namoparticles The results showed that the penetration of pAANLC was enhanced significantly and the transport capacity was increased greatly in small intestinal after PEG modification As compared with the normal nanoparticles （AANLC）， the Cmax of the drug excretion was increased by 76%， the time to reach the peak （tmax ） was decreased and the elimination halflife t1/2 was doubled in the rats after oral administration of pAANLC， and the AUC0→t was 15 times of the AANLC group， indicating that the oral bioavailability of AANLC was significantly improved by hydrophilic modification of PEG 　　[Key words]asiatic acid； nanostructured lipid carrier； PEG； oral absorption 　　?e雪草酸（asiatic acid，AA）为伞形科积雪草属植物积雪草Centella asiatica L Urban的有效成分之一，属于五环三萜酸，具有治疗皮肤创伤、护肝、抗炎、抗肿瘤等多种药理作用[14]，其代谢产物主要经胆汁排泄。AA水中溶解度极小，胃肠道吸收差，体内消除较快，口服生物利用度低[5]。本实验室早期制备了积雪草酸纳米结构脂质载体（asiatic acid loaded nanostructured lipid carriers，AANLC），但生物利用度改善不显著[6]，这可能与粒子易被高度黏弹性、附着性的肠道黏膜阻挡而无法进入体循环有关[78]。 　　聚乙二醇（PEG）是一种无毒、无免疫原性及抗原性化合物，被FDA批准可用于注射液、口服制剂。纳米脂质载体经低分子量的PEG（如2 kDa）修饰后，可提高粒子的亲水性，降低静电作用与网状内皮系统的清除速率，提高某些药物的相对生物利用度[