Abstract: In this study,indirubin self-microemulsion was used as core material,chitosan and sodium alginate were used as wall materials to prepare chitosanalginate indirubin self-emulsifying microcapsules by complex coacervation method.The preparation process was optimized by single factor and orthogonal experiments.Then the quality evaluation was carried out with the drug loading and encapsulation efficiency.At the same time,the drug release property was evaluated with the drug release in vitro. The optimal preparation process was determined as follows:The concentration of sodium alginate was 1.5%,the proportion of indirubin self-microemulsion volume,sodium alginate volume and chitosan mass was 1:1:0.5,the optimal concentration of calcium chloride was 2%.The drug loading rate and encapsulation rate of microcapsules prepared by the optimized process was 0.0416% and 79.2%,respectively.The cumulative release rate of 24 h in vitro was (97.1±2.68)%.The release of the microcapsules conformed to the Higuchi equation and one-order kinetics,hence it had a better sustained release effect.

Key words: indirubin self-microemulsion, microcapsules, sodium alginate, chitosan