Investigation on factors affecting entrapment efficiency of oridonin-loaded liposome

Objective To prepare oridonin-loaded liposome and investigate the effects of different factors on the entrapment efficiency of oridonin-loaded liposome.Methods Liposomes were prepared by thin-film dispersion method.The entrapment efficiency was determined by centrifugation of mini-column.The formulation and manufacture parameters were optimized concerning the drug entrapment efficiency through the single factor investigation.Results The optimal conditions were as follows:the concentration of lipid was 20 g·L-1,the mass ratio of lipid to cholesterol was 4∶1,the mass ratio of drug to lipid was 1∶20,pH value was 7.4,the temperature of the hydration was 50 ℃,the time duration of hydration was 30 min.Entrapment efficiency reached(65.25±3.63)%(n=3)after optimization.Conclusions The major factors affecting the entrapment efficiency of oridonin-loaded liposome are the concentration of lecithin,weight ratio of lecithin to drug and concentration of Tween80.A oridonin-loaded liposome with a high entrapment efficiency is obtained through the optimization of formulation and preparative parameters.