Preparation Of Polylactic Acid - Loaded Sinomenine Microcapsule By Reverse Transfer Method And Its Properties

Sinomenine is an alkaloid monomers which is extracted from acutum of rhizomes. It has high medicinal value.But its half-life is very short. Still, It is light and thermal instability,easy to decompose and has irritating to human gastric mucosa. These defects have been greatly restricted its application in clinical medicine. In order to expand its range of application,we need to make it as core substance of microcapsules to overcome these shortcomings. Polylactic acid becomes the preferred drug microcapsule wall material substance because of its non-toxic and easily biodegradable and biocompatible as a polymer material.Polylactic acid contained Sinomenine microcapsules were prepared by phase inversion method using polylactic acid as the wall material, Sinomenine as core material,Methylene chloride as solvent,Gelatin as stabilizers,Tween80 and Span80 as emulsifier. The result showed that microcapsules had smooth surface and there were none damaging and holes and fold phenomenon on the surface.This provided better protection of the sinomenine as core material and improved its stability.Microcapsules had relatively uniform particle size distribution and no blocking phenomenon was occurred.Its drug loading and encapsulation efficiency is relatively high.The drug loading was up to 8.9% and the encapsulation efficiency was up to 89.2%. This showed that the drug utilization was higher. Microcapsules had obviously sustained release effect and the release rate was significantly different between in simulated gastric juice and simulated intestinal fluid. It was more easier to release in simulated intestinal fluid than that in mulated gastric juice. This illustrated that the polylactic acid contained sinomenine microcapsules were sensitive to pH and had the effect of intestinal targeting absorption which showed good prospects in terms of oral formulations. The polylactic acid contained sinomenine microcapsules had no cytotoxicity through cytotoxicity test by using mouse fibroblasts(L929 cells).But they had a certain inhibition to tumor cells through antitumor performance testing by using breast cancer cells.They controlled the proliferation rate of tumor cells through inhibit tumor cell from adherent growth. The polylactic acid contained sinomenine microcapsules had a certain significance in the research of anticancer drugs.