Emulsifying composition for cosmetic use for producing an o/w pickering emulsion and process for producing this emulsion

Abstract

The application relates to an emulsifying composition, in particular for cosmetic use, allowing an oil-in-water emulsion (O/W) to be obtained, the emulsion comprising at least one cyclodextrin and at least one O/W emulsifier of natural origin with a hydrophilic-lipophilic balance value (HLB) of more than 8. The O/W emulsifier of natural origin can be selected from alkyl polyglucosides, mixtures of at least one alkyl polyglucoside and at least one fatty alcohol, and non-ethoxylated polyol fatty esters. The application also relates to a composition of the Pickering emulsion type, in particular for cosmetic use, containing the emulsifying composition according to the invention, and to the process for preparing such a composition of the O/W Pickering emulsion type, in particular at low temperatures.

1 . An emulsifying composition, in particular for cosmetic use, allowing an oil-in-water (O/W) emulsion to be obtained, the emulsion comprising:
 a. at least one cyclodextrin, and   b. and at least one O/W emulsifier of natural origin, wherein the O/W emulsifier is selected from fatty eaters of dextrins or of hydrolyzed starches. in the form of sodium octeoylsuccinate ester.   the O/W emulsifier having a hydrophilic-lipophilic balance (HLB) greater than 8, preferentially greater than or equal to 9.   
     
     
         2 . The emulsifying composition as claimed in  claim 1 , characterized in that the O/W emulsifier is present in the emulsifying composition in a ratio of between 0.01 and 1 part, preferably between 0.05 and 0.5 part, more preferentially between 0.10 and 0.35 part, and even better still between 0.15 and 0.30 part, per 1 part by weight of cyclodextrin. 
     
     
         3 . The emulsifying composition as claimed in  claim 1 , wherein said at least one cyclodextrin is selected from alpha-, beta-, and gamma-cyclodextrins, preferably from native beta-cyclodextrin. 
     
     
         4 . The emulsifying composition as claimed in  claim 1 , wherein the cyclodextrin is present in the form of a crystalline, pseudo-crystalline or amorphous powder. 
     
     
         5 . The emulsifying composition as claimed in  claim 1 , wherein the O/W emulsifier is also selected from products which are naturally biodegradable in a hydrated natural medium with a hydrophilic-lipophilic balance (HLB) of between 8 and 20, preferably between 9 and 16 and even better still between 11 and 14. 
     
     
         6 . (canceled) 
     
     
         7 . The emulsifying composition as claimed in  claim 1  , also comprising at least one polyol, which is preferably selected from maltitol, mannitol, xylitol, erythritol, sorbitol and glycerol. 
     
     
         8 . The emulsifying composition as claimed in  claim 1 , wherein the composition contains, in % by weight:
 a. 40% to 95% of at least one cyclodextrin,   b. 5% to 40% of at least one O/W emulsifier of natural origin, wherin the O/W emulsifier is selected from fatty esters of dextrins or of hydrolyzed starches in the form of sodium octenylauccinate esters, having a hydrophilic-lipophilic balance (HLB) greater than 8, preferentially greater than or equal to 9, and   c. and 0% to 40% of at least one polyol.   
     
     
         9 . A composition of the O/W Pickering emulsion type, in particular for cosmetic use, characterized in that it contains, per 1 part by weight of at least one cyclodextrin, between 0.01 and 1 part, preferably between 0.15 and 0.30 part of at least one O/W emulsifier of natural origin, wherin the O/W emulsifer is selected from fatty esters of dextrins or of hydrolyzed starches, in the form of sodium octenylsuccinate esters having a hydrophilic-lipophilic balance (HLB) greater than 8, preferentially greater than or equal to 9. 
     
     
         10 . The composition as claimed in  claim 9 , containing one or more oils which are liquid at ambient temperature (25° C.), preferably at least one nonvolatile liquid oil. 
     
     
         11 . The composition as claimed in  claim 10 , wherein the oil content of the final O/W emulsion is between 10 and 65% by weight, and preferably between 20 and 55% by weight. 
     
     
         12 . The composition as claimed in  claim 9 , further comprising a rheological agent, preferably a thickener for the aqueous phase, a gelling agent or a suspension agent. 
     
     
         13 . The composition as claimed in  claim 9 , having a droplet size of less than or equal to 30 µm, preferentially less than or equal to 10 µm. 
     
     
         14 . (canceled) 
     
     
         15 . A process for producing a composition of the O/W Pickering emulsion type, in particular for cosmetic use, comprising the following steps:
 a) the dispersion in an aqueous phase of an emulsifying composition comprising at least one cyclodextrin and at least one O/W emulsifier of natural origin, wherein the O/W emulsifier is selected from fatty esters of dextrins or of hydrolyzed starches in the form of sodium octenylsuccinate esters the latter being present in a ratio of between 0.01 and 1 part, preferably between 0.15 and 0.30 part, per 1 part by weight of at least this cyclodextrin; and having a hydrophilic-lipophilic balance (HLB) greater than 8, preferentially greater than or equal to 9, and   b) the addition, to the mixture obtained in step a), of a fatty phase, in an amount of between 10 and 65% by weight, with mechanical stirring sufficient to allow the fatty phase to be dispersed as fine droplets in the aqueous phase and for an O/W emulsion which has a droplet size of less than or equal to 30 µm, preferentially less than or equal to 10 µm, to be obtained.