Influences of Emulsifying Parameters on the Stability and Insulin Encapsulation Efficiency of W/O/W Multiple Emulsions

Influences of emulsifying parameters of the second emulsifying procedure during the preparation of multiple emulsions(MEs) by two-step emulsifying method were investigated with respect to multiple emulsions stability and insulin encapsulation efficiency(IEE).Emulsion stabilities were characterized by centrifugal creaming ratio,IEE were determined by HPLC method.Droplet size distribution were investigated by laser scattering technics.The results shows that emulsifying parameters of the second emulsifying procedure remarkably affected the stability and IEE of MEs.Strong emulsifying parameters improve the stability of MEs by decreasing droplet size of oily drops,but decrease IEE by increasing diffusion area and decreasing diffusion length.The best emulsifying parameters of the second emulsifying step with respect to IEE were as follow: Vir Tishear emulsifying machine,stirring rate: 2000r/min,stirring time: 3min,with an encapsulation efficiency of insulin 55%.