ABSTRACT
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.
ABSTRACT
Objective: To optimize the enzymolysis process for Whitmania pigra. Methods: In order to select an appropriate index for study on the enzymolysis process, the activated partial thromboplastin time (APTT), prothrombin time (PT), and thrombin time (TT) of enzymatic products were determined before and after intestinal absorption, respectively, using an isolated everted intestine model. The emzymolysis of W. pigra was carried out by pepsin, trypsin, and the complex enzyme of pepsin and trypsin. According to the selected indexes, the enzymolysis process was optimized under different conditions, such as the kind of enzyme, ratio of enzymes to substrates, time of enzymolysis, and temperature of enzymolysis. Results: TT was an appropriate index. Enzymatic products with high activity could be obtained only using trypsin. After optimization, the best enzymolysis conditions were as follows: 10% trypsin was added in the solution of W. pigra, and the reaction was proceeded under 73℃ for 8 h. Conclusion: TT is a reliable and sensitive anticoagulation index for enzymolysis. The enzymolysis technology is simple and stable, which could supply the supports for reasonable extraction of W. pigra.