Preparation,Characterization and Drug Release Property of Chitosan Microspheres Loaded with Arsenic Trioxide

Objective:To study the technique for preparing chitosan microspheres loaded with arsenic trioxide(As2O3),and its characterization and drug release property in vitro.Methods:Chitosan microspheres loaded with As2O3 were prepared through the electrostatic droplet generation technique using the mixture of sodium tripolyphosphate and acetone as coagulation bath. Drug-loaded chitosan microspheres were observed by optical microscope and scanning electron microscope.Particle diameter, Fourier transform infrared(FT-IR)spectra and X-ray diffraction result were analyzed.Then the microspheres were were placed in simulated body fluid.The arsenic dose of sample extracted at different time was detected by atomic fluorescence spectrometry so as to estimate drug release property.Results:The drug-loaded chitosan microspheres looked round and regular without adhesion between them,and had good uniformity and dispersion.The mean particle diameter was(239.5±11.2)μm and encapsulation efficiency was(87.3±6.5)%.FT-IR and X-ray diffraction analysis showed that sodium tripolyphosphate had a good effect on ionic crosslinking during microspheres formation.As reducing crystallinity of chitosan,sodium tripolyphosphate could also increase microspheres′water solubility.Release of As2O3 was rapid up to 4 h followed by a slow release status.Percentage of drug release was up to only(30.8±0.5)%in 24 h.Conclusions:The electrostatic droplet generation technique for preparing chitosan microspheres loaded with As2O3is simple and feasible.The resulting microspheres has good water solubility,satisfied characterization,high encapsulation efficiency and gentle drug release,which has potential advantages during the research of drug-loaded bone repair material consequently.