Abstract：Objective To prepare curcuma zedoaria oil-loaded submicron emulsion and investigate the effect of HLB on its physicochemical properties. Methods The high pressure homogenization method was employed to prepare curcuma zedoaria oil-loaded submicron emulsion. The particle distribution and zeta-potential were determined by using zetasizer. The stability was investigated by centrifugalization. The solubilities of zedoaria oil in aqueous phase with various HLB value were determined. The dialysis method was established for determination of entrapment efficiency and drug release behavior of curcuma zedoaria oil in the submicron emulsion. Results Curcuma zedoaria oil-loaded submicron emulsion was charge negative and with the mean particle size between 123 nm and 154 nm. Solubilizations were observated obviously with emulsifiers of various HLB value, and solubilization multiples were between 5.5 and 8.2. The drug encapsulation efficiencies of curcuma zedoaria oil-loaded submicron emulsion were between 73% and 83%. In vitro drug release experiments indicated the drug release from submicron emulsion was lasted to 48 hours, and the release behavior was consistent with Higuchi equation. Conclusion The curcuma zedoaria oil-loaded submicron emulsions with various HLB value of emulsifier were prepared. Their physicochemical properties such as particle distribution and stability were different accompany with various HLB value of emulsifiers. And as HLB value of emulsifiers increased, more solubilizations were observated, thus entrapment efficiencies were decreased slightly But no significant deviations were observated when released in vitro, and was represented a sustained release.
Key words：HLB value; submicron emulsion; curcuma zedoaria oil; stability; entrapment efficiency; drug release
