Surfactant, and emulsion cosmetic and liposome each containing the same

Abstract

The invention provides a surfactant comprising at least one trehalose-6-fatty acid ester selected from those represented by the following formula: wherein R represents a saturated or unsaturated acyl group having 8-22 carbon atoms, and may have a hydroxyl group or other substituents, and an emulsion-type cosmetic composition comprising said surfactant and a water-soluble polymer. The surfactant of the invention has excellent surface activity and safety. Also, the emulsion-type cosmetic composition has excellent long-term storage stability and sensory properties, has no irritation to skin, and gives beautiful appearance with fine surface texture. Further, the invention is a liposome having a membrane wall composed of trehalose fatty acid ester. Said liposome has excellent chemical and physical stabilities such as long-term storage stability.

1 . A method of preparing an emulsion cosmetic composition, comprising emulsifying a mixture of:
 0.1 to 10% by weight of at least one trehalose-6-fatty acid monoester, the at least one trehalose-6-fatty acid monoester represented by the following formula:   
     
       
         
         
             
             
         
       
       
         wherein R is selected from a group consisting of saturated acyl groups having 10-18 carbon atoms, unsaturated acyl groups having 10-18 carbon atoms, saturated acyl groups having 10-18 carbon atoms and a hydroxyl group substituent; 
       
       0.01 to 20% by weight of at least one water-soluble polymer selected from a group consisting of carageenan, xanthan gum, methyl cellulose, carboxyvinyl polymers, polyvinylalcohol, and polyvinylpyrrolidone; 
       an aqueous component; and 
       an oil component; 
       wherein the emulsion cosmetic composition exhibits stability during storage. 
     
   
   
       2 . A method of preparing an emulsion cosmetic composition as claimed in  claim 1 , wherein said trehalose-6-fatty acid monoester is one or more trehalose-6-fatty acid monoester selected from the group consisting of 6-(10-undecylenyl)-trehalose, 6-lauroyl-trehalose, 6-stearoyl-trehalose, trehalose monoisostearate, trehalose monodocosanate, trehalose monolinolenate, trehalose monocaprate, and trehalose monomyristate. 
   
   
       3 . (canceled) 
   
   
       4 . A method of preparing an emulsion cosmetic composition as claimed in  claim 1 , wherein said trehalose-6-fatty acid monoester is present in an amount of 0.1 to 5 wt % and said water-soluble polymer is present in an amount of 0.01 to 18 wt %. 
   
   
       5 . A method of preparing an emulsion cosmetic composition as claimed in  claim 1 , wherein said emulsion cosmetic composition is a massage cream, a cleansing cream, a skin cream, a foundation cream, a makeup base, a hair cream, a massage jelly or a medicinal jelly.