抄録
In order to obtain emulsions highly safe for human skin, a new O/W emulsion system stabilized with insoluble materials was developed. Emulsification methods utilizing Na-montmorillonite (Na-Mont) and various organic polar substances were investigated. Stable O/W emulsions were obtained by combining Na-Mont and particular compounds such as glycerol monopalmitate. The results of DSC and X-ray diffraction measurements showed that Na-Mont formed insoluble complexes with the compounds in this emulsion system. From the results of microelectrophoresis, scanning electron microscopy, and X-ray microanalysis it was found that the complexes surrounded oil droplets and that the droplets were fixed by network structures formed by the interaction of Na-Mont platelets in aqueous phase. These configurations appears to stabilize the emulsions. The authors named this new O/W emulsion system “The Insoluble Complex Emulsion System”. Cosmetic emulsions such as milky lotions, skin creams, cleansing creams and foundation creams can be prepared using this emulsion system. Two of the major advantages of the emulsions are good waterproofing ability and relatively small change in their viscosity or hardness with temperature. Various safety evaluation tests with experimental animals show that the products using this emulsion system are highly safe.
