OBJECTIVETo study the feasibility of digalactosyl diglyceride (DGDG) , which was used as a new type of emulsifier to prepare submicro-emulsion of bay oil.

METHODBay oil was employed as the model drug, emulsifer in oil method was used to prepare foremilk. Through single factor investigation and central composite design-response surface methodology (CCD-RSM) , we optimized the preparation technology and formula respectively. The stability of sub-microemulsion was studied.

RESULTThe optima technology was following: emulsifer in oil method was used to prepare foremilk, temp was 60 degrees C, the micro emulsion was prepared by two-step high pressure homogen method with that the pressure was 80 Pa, 10 times, micropore film was used to sterilize, filling and sealing at the preservation of nitrogen. The best formula was following: soybean oil was 1.1%, DGDG was 1.6%, and sodium oleate was 0. 16%. The particle size of three batch submicro-emulsions were from 168.0 to 169.3 nm; Zeta potential were from-25.53 to 24.90 mV, pH value were from 8.48 to 8.52. The deviation between measured value and predictive value was 1.8%. It was stable in high temperature and illumination.

CONCLUSIONDGDG can be used as the emulsifier of bay oil sub-microemulsion.