Objective: To study the preparation method of PNS enteric microcapsules and to investigate the release properties in vitro. Method : The solvent-non-solvent extraction was used to prepare enteric microcapsule of PNS with the polyacrylic acid resin II as the pouch material. The encapsulation efficacy and loading efficiency as well as the properties in vitro release of PNS enteric microcapsules were investigated. Result : Encapsulation efficiency was 90.85%

90.15%

and 89.06%

loading efficiency was 26.05%

25.04%

and 25.16% respectively. The release of R1

Rg1 and Rb1 was less than 10% in the artificial gastric juices

and up to 86.08%

88.76%

and 84.98% in the artificial intestinal juices after 45 min. Conclusion : The microcapsules meet the requirements of pharmacopoeia in vitro release.