积雪草总苷脂质体的肠吸收特征研究

Absorption characteristics of liposome encapsulated Centella asiatica total glucosides

目的研究积雪草总苷脂质体在离体小肠中的肠吸收特征。方法采用透析法考察积雪草总苷脂质体在磷酸盐和台氏液中的稳定性,应用RP-HPLC法检测积雪草总苷的色谱轮廓,采用离体外翻肠囊模型研究积雪草总苷和积雪草总苷脂质体的肠吸收性质,以积雪草总苷中指标成分积雪草苷计算两者在不同肠段的累积吸收百分率,绘制回肠中累积吸收曲线,比较积雪草总苷及其脂质体的肠吸收效果。结果积雪草总苷脂质体在磷酸盐和台氏液中均能稳定存在。积雪草总苷和积雪草总苷脂质体在大鼠小肠内无明显的特定吸收部位,回肠中积雪草苷的吸收量随时间增加,120 min未见饱和现象。积雪草总苷脂质体在回肠吸收中具有更高的累积吸收量和累积吸收百分率,其表观渗透系数显著高于积雪草总苷的表观渗透系数。结论积雪草总苷制成脂质体后,可促进其在大鼠肠内的吸收,为积雪草总苷口服剂型的开发提供实验依据。

Objective To study the intestinal absorption characteristics of the liposome encapsulated Centella asiatica total glucosides in vitro. Methods Dialysis method was adopted to study the stability of the liposome encapsulated C. asiatica total glucosides in both PBS and Tyrode solution. RP-HPLC was adopted to detect the chromatographic profile of the sample solutions. To research the in vitro intestinal absorption properties of C. asiatica total glucosides and its liposome in isolated everted intestine model, the cumulative absorptive percentages of them in the different intestines are calculated and the cumulative absorption curve of them are drawn, in which the cumulative absorptive percentages of them are calculated by the amount of asiaticoside, and the intestinal absorption effects of them are compared. Results The results show that the lipsome encapsulated C. asiatica total glucosides could exist stably in the PBS and Tyrode solution. C. asiatica total glucosides and its liposome could be absorbed in the small intestine and have no significant absorption site. The uptake of asiaticoside in ileum increased with time prolonging, and there was no absorptive saturation within 120 min. During the ileum absorption, the liposome encapsulated C. asiatica total glucosides have a higher percentage and a higher quantity of cumulative absorption than the drug of C. asiatica total glucosides, which showed that apparent permeation coefficient was higher significantly. Conclusion The encapsulated C. asiatica total glucosides could promote the absorbtion of C. asiatica total glucosides in the ileum of rats, which provides the experimental evidence for the development of the oral dosage forms of C. asiatica total glucosides.