Preparation and properties of chitosan‐based microspheres by spray drying

In this study, the chitosan‐based release microspheres were prepared by spray drying method. Chitosan was used as the carrier material, and Panax notoginseng extract, Codonopsis extract, and Atractylodes extract (the mass ratio was 2:7:5) were active substance. The spray drying preparation process of microsphere was optimized by single factor experiment and L(9) (3(4)) orthogonal design. Drug loading (DL), particle size, and sustained release performance of microspheres were investigated. The mass fraction of chitosan was 1.5%, the mass ratio of drug to chitosan was 1:3, the inlet air temperature was 130°C, and the injection rate was 400 ml/hr. The chitosan‐based microspheres prepared under the above conditions had a smooth surface, and the DL was 23.87 ± 0.93%; the average particle diameter was 10.27 ± 1.05 μm, and the encapsulation efficiency (EE) of the microspheres was 91.28 ± 1.04%. The preparation process of chitosan‐based drug microsphere prepared by spray drying method was simple and stable. The prepared microspheres in this paper showed a sustained release effect in vitro.