Preparation technology of tanshinone sustained-release microcapsules

Objective To study the preparation technology and suitable formula of tanshinone(Tan) sustained-release microcapsules(SRMs) and to observe their in vitro drug release.Methods The microcapsules were prepared by the dropping method.The effects of several factors,such as the contents of sodium alginate and calcium chloride as well as the weight ratio of sodium alginate-Tan,were investigated,respectively.Because Tan was hard to dissolve,β-cyclodextrin was chosen as absorption enhancer in the study on the in vitro release.Results The result showed that the optimal formulation was sodium alginate 2.0%,calcium chloride 3.0%,and β-cyclodextrin 0.10%,with the weight ratio of sodium alginate-Tan being 0.5.Conclusion The microcapsules are good round,suitable hard with the high drug-load and high encapsulation.The microcapsules also show good in vitro sustained-release properties.