Preparation and preliminary characterization of lyophilized astragaloside IV-loaded nanostructured lipid carriers

OBJECTIVE To prepare and characterize the lyophilized Astragaloside IV-loaded nanostructured lipid carriers(AST-NLC).METHODS AST-NLC was prepared by film-ultrasound dispersion technique.The lyophilized AST-NLC were prepared using different supporting agent.The type and concentration of the supporting agents were optimized by the shape,color,redispersion,size and PDI of the lyophilized AST-NLC.The characteristics of AST-NLC,including shape,size,PDI,Zeta potential,entrapment efficiency(EE%) and drug loading(DL%),before and after freeze-drying were investigated.RESULTS Satisfied lyophilized AST-NLC could be prepared using 10% sucrose as the supporting agent.The freeze-drying process was as follow:pre-cooled at 40 ℃ for 4 h,freeze-drying for 24 h.AST-NLC presented a spherical shape under transmission elecctron microscopy(TEM).The characteristics before freeze-drying were as follows:average diameter was 104.3±1.25 nm,PDI was 0.118±0.033,Zeta potential was-7.00±0.35 mV,entrapment efficiency and drug loading were 94.37%±0.39% and 2.80%±0.02%,respectively.After freeze drying,the average diameter was 144.1±17.08 nm,PDI was 0.132±0.055,Zeta potential was-11.2±0.9 mV,the entrapment efficiency and drug loading were 96.60%±0.45% and 2.60%±0.05%,respectively.CONCLUSION The preparation of AST-NLC is convenient and the produced AST-NLC has a high entrapment efficiency.Satisfied lyophilized AST-NLC can be prepared using 10% sucrose as the supporting agent.