Studies on preparation of diclofenac sodium silk fibroin-chitosan sustained-release microspheres and its characteristics

Objective:To investigate preparation and releasing property of diclofenac sodium loaded silk fibroin-chitosan microspheres in vitro.Methods:Diclofenac sodium loaded fibroin-chitosan microspheres were prepared with an emulsion cross-linking technique.The orthogonal design was used to optimize the technology of preparation of drug-loaded microspheres.X-ray diffraction and DSC were used to analyze their structural characteristics.Drug release from microspheres was determined by a dynamic dialysis system.Results:The microspheres were spherical and well distributed in shape.The average diameter was about(26.54±1.39)μm.The loading drug content and encapsulated efficiency of the microspheres were(9.88±0.49)% and(50.35±0.92)% respectively.The release of diclofenac sodium followed Higuchi's equation in vitro and was sustained for 200 h.The slow-release property of silk fibroin-chitosan microspheres was better than that of the chitosan microspheres.Conclusion:The optimized technology presented high encapsulated efficiency,good stability and excellent repeatability.