(en)The invention relates to a triple emulsion comprising:
(A) a continuous gelled outer aqueous phase, containing, as gelling agent, at least one acrylic or methacrylic acid polymer or copolymer, combined with a polyglyceryl methacrylate;
(B) a fatty phase dispersed in the outer aqueous phase, and an aqueous phase (C) dispersed in the fatty phase. Process for preparing a triple emulsion conforming to the invention.
Application in cosmetics and dermatology.

1.ApplicationNumber: US-86271692-A
1.PublishNumber: US-5306498-A
2.Date Publish: 19940426
3.Inventor: VESPERINI; LAURENCE
FODOR; PIERRE
BOUGET; FRANCOISE

4.Inventor Harmonized: VESPERINI LAURENCE(FR)
FODOR PIERRE(FR)
BOUGET FRANCOISE(FR)

5.Country: US
6.Claims:
(en)The invention relates to a triple emulsion comprising:
(A) a continuous gelled outer aqueous phase, containing, as gelling agent, at least one acrylic or methacrylic acid polymer or copolymer, combined with a polyglyceryl methacrylate;
(B) a fatty phase dispersed in the outer aqueous phase, and an aqueous phase (C) dispersed in the fatty phase. Process for preparing a triple emulsion conforming to the invention.
Application in cosmetics and dermatology.

7.Description:
(en)The present invention relates to cosmetic compositions provided in the form of a triple emulsion, to the process for producing these and to their applications in the cosmetology field.
Emulsions have for many years been used in cosmetics, especially in products for the cosmetic treatment of the skin. These emulsions are generally oil-in-water or water-in-oil emulsions (O/W) or (W/O).
Triple emulsions W/O/W or O/W/O have already been described in the state of the art. However, such emulsions have many problems both with respect to their production and with respect to their stability over time especially when these incorporate active substances which tend to destabilize them.
The Applicants have discovered, and this constitutes the subject of the invention, a triple emulsion exhibiting characteristics of stability and cosmetic feel which are particularly remarkable, and comprising a continuous gelled outer aqueous phase, a fatty phase dispersed in the outer aqueous phase and an inner aqueous phase dispersed in the said fatty phase. This triple emulsion in particular enables cosmetic or dermatological active substances to be incorporated in greater quantities compared with those which could possibly be introduced in emulsions of the state of the art without destabilizing the emulsion as a result.
The subject of the invention is therefore a triple emulsion exhibiting the characteristics defined below.
Another subject of the invention is the process for producing such an emulsion.
The subject of the invention is also the cosmetic application of such emulsions.
Other subjects of the invention will emerge on reading the following description and examples.
The triple emulsion conforming to the invention is essentially characterized in that it comprises (A) a continuous gelled outer aqueous phase, containing, as gelling agent, at least one acrylic or methacrylic acid polymer or copolymer, combined with a polyglyceryl methacrylate; (B) a fatty phase dispersed in the outer aqueous phase and an aqueous phase (C) dispersed in the fatty phase.
In accordance with a preferred embodiment of the invention, the gelled outer aqueous phase represents 40 to 60% by weight of the total emulsion, the fatty phase representing 10 to 25% of the total emulsion.
According to a preferred embodiment of the invention, a combination of two gelling agents are used in the outer aqueous phase consisting, on the one hand, of an alkali metal salt of an acrylic copolymer sold under the name HOSTACERINE PN 73 by HOECHST and, on the other hand, of a polyglyceryl methacrylate produced under the name LUBRAGEL MS by UNITED GUARDIAN INC.
The fatty phase comprises, in particular, vegetable oils, mineral or synthetic oils. Waxes and/or silicone oils may also be introduced into this fatty phase.
A preferred embodiment consists in the use, in the fatty phase, of a perfluorinated oil, in particular a perfluoropolyether of the formula: ##STR1## in which n and m are integers such that the molecular weight is between 100 and 10,000, the n/m ratio being between 20 and 40.
The products which can be used in particular within the framework of the invention consist of the products sold under the name FOMBLIN HC, sold and produced by MONTEFLUOS, Milan, Italy, and in particular the products FOMBLIN HC/04, FOMBLIN HC/25, and FOMBLIN HC/R.
The triple emulsion conforming to the invention contains one or more active substances in proportions which may be as high as 20% by weight relative to the weight of the total emulsion. These active substances may consist in particular of UV-A, UV-B or broad band sunscreen agents, of natural protein extracts such as collagen-based products, preferably of marine origin.
The triple emulsions contain, in addition, emulsifiers used in the preparation of water-in-oil (W/O) and oil-in-water (O/W) emulsions.
According to a preferred embodiment of the process of the invention, in a first stage, a W/O emulsion is prepared by adding an aqueous phase to the fatty phase so as to obtain a W/O emulsion followed, in a second stage, by the preparation of the triple emulsion by adding the W/O emulsion thus obtained to a second gelled aqueous phase which constitutes the outer aqueous phase of the emulsion.
The emulsifier used for preparing the W/O emulsion preferably comprises a sorbitan oleate, lecithin mixture and, as co-emulsifier, a dodecyl glycol and ethylene oxide copolymer, such as more particularly the product sold under the name ELFACOS ST37 by AKZO.
The second gelled aqueous phase comprises an emulsifier chosen preferably from sucrose esters.
The addition of the active substances and the usual adjuvants such as perfumes, preservatives, may be carried out after preparation of the triple emulsion.
The gelling agents used in the outer aqueous phase generally represent 0.1 to 4.0% by weight relative to the total weight of the triple emulsion, and preferably 0.2 to 2.5% by weight.
Lecithin/oleate weight ratios of between about 4/2 and 8/2, and preferably equal to about 5/2 and copolymer/oleate co-emulsifier weight ratios of between 0.2/2 and 1/2 and preferably equal to 0.375/2, may be envisaged in the compositions in the form of an emulsion according to the invention.
As already indicated above, the compositions in the form of triple emulsions conforming to the invention exhibit particularly remarkable cosmetic properties, in particular with respect to the feel, which makes it possible to use them as foundations for applying active cosmetic substances to the skin.
These emulsions exhibit, in addition, stability characteristics which are perfectly acceptable under the usual conditions for storing cosmetic products.
These emulsions may in particular be used in protective creams, in so-called "barrier" creams, or alternatively in compositions for preventing skin irritations. They may be used in products for the cosmetic treatment of keratinous materials, such as various creams for anti-sun products, foundations, day creams, and the like.
These emulsions may also be used in dermatological applications as carriers for active agents used in dermatology.


The following example is intended to illustrate the invention without being limiting as a result.
EXAMPLE

______________________________________FATTY PHASE (B)Octyl palmitate 7.00%Karite butter 1.50Block copolymer containing 0.2022 ethylene oxide units and9 dodecyl glycol units(ELFACOS ST 37)Dimethicone (polydimethylsiloxane) 3.00Perfluoropolymethylisopropylether 1.00(FOMBLIN HC/25)Sorbitan oleate (SPAN 80 sold by ICI) 2.00Natural hydrogenated lecithin 5.00Tocopherol 0.202-ethylhexyl Para-methoxycinnamate 0.50(PARSOL MCX sold by GIVAUDAN)Propyl para-hydroxybenzoate 0.10AQUEOUS PHASE I (C)Potassium sorbate 0.10Water 20.00Hydrolyzed animal protein 10.00AQUEOUS PHASE II (A)Sodium acrylate/acrylamide copolymer 0.25(HOSTACERINE PN 73)Polyglyceryl methacrylate (LUBRAGEL MS) 2.00Methyl gluceth-20 sesquistearate 1.50Glycerin 4.00Methyl para-hydroxybenzoate 0.25Water 36.80______________________________________ *CTFA Dictionary names.

The above triple emulsion is prepared in the following manner:
a) a W/O emulsion is prepared by adding, around 60° C., the aqueous phase C. to the fatty phase B under turbo stirring;
b) the W/O emulsion thus obtained is added to the second gelled aqueous phase A.
The following active substances and adjuvants are then added:

______________________________________Collagen 2.00Perfume 0.30Imidazolidinyl urea 0.30Water 2.00______________________________________