NEW COSMETIC USE OF POROUS SPHERES OF METAL OXIDE

Abstract

The present invention relates to the cosmetic use of porous spheres comprising a metal oxide for improving the appearance and/or comfort of the skin, skin integuments, notably the hair, and/or mucous membranes. The invention also relates to a cosmetic or pharmaceutical composition comprising said spheres.

Claims

1.-18. (canceled)

19. A cosmetic method comprising applying porous spheres comprising a metal oxide to akin, skin integuments, and/or mucous membranes, thereby improving the appearance or comfort of the skin, skin integuments, or mucous membranes.

20. The cosmetic method according to claim 19, in which the spheres have at least one of a mean diameter ranging from 0.5 μm to 100 μm and a mean porosity ranging from 0.10 to 0.90, and a mean pore diameter ranging from 50 nm to 999 nm.

21. The cosmetic method according to claim 19, in which the spheres have a mean diameter ranging from 0.5 μm to 100 μm and a mean porosity ranging from 0.10 to 0.80 and a mean pore diameter ranging from 50 nm to 999 nm.

22. The cosmetic method according to claim 19, in which the spheres have a mean diameter ranging from 1 μm to 100 μm.

23. The cosmetic method according to claim 19, in which the spheres have a mean pore diameter ranging from 220 nm to 300 nm.

24. The cosmetic method according to claim 19, in which the metal oxide is the oxide silica, titania, alumina or zirconia, cerium oxide, iron oxide, zinc oxide, indium oxide, tin oxide, chromium oxide, mixed metal oxide and combinations thereof.

25. The cosmetic method according to claim 24, in which the metal oxide is a silica or titanium oxide or a combination thereof.

26. The cosmetic method according to claim 19, in which the porous spheres comprise from 60% by weight to 99.9% by weight of metal oxide and from 0.1% by weight to 40% by weight of light-absorbing agents, relative to the total weight of the spheres.

27. The cosmetic method according to claim 19, in which the spheres have a mean diameter ranging from 1 μm to 75 μm and a mean porosity ranging from 0.45 to 0.65.

28. The cosmetic method according to claim 19, in which the spheres have a mean diameter ranging from 4.5 μm to 9.9 μm, a mean porosity ranging from 0.45 to 0.65 and a mean pore diameter ranging from 220 nm to 300 nm.

29. The cosmetic method according to claim 19, for reducing the visibility of the unaesthetic manifestations of the skin, skin integuments or mucous membranes, skin relief or texture irregularities, and skin colour irregularities.

30. The cosmetic method according to claim 19, in which the spheres are in a cosmetic composition, in a concentration ranging from 1×10.sup.−3 to 100% by weight relative to the total weight of the composition.

31. The cosmetic method according to claim 30, for improving the organoleptic properties of the cosmetic composition.

32. A cosmetic composition, characterized in that it contains porous spheres as described in claim 19.

33. The cosmetic composition according to claim 32, characterized in that it is in the form of a serum, a lotion, a cream, a shampoo, a hair conditioner, an oil, a milk, an ointment, a paste, a foam, an emulsion, a hydrogel, a shower gel, a mask, a lacquer, a spray, a wax, a powder, a makeup powder, or a stick.

34. The cosmetic composition according to claim 32, characterized in that it is in the form of a slightly gelled composition or comprises an oily phase, and is of oily composition type or oil-in-water or water-in-oil emulsion or lotion type.

35. A dermatological composition, characterized in that it contains porous spheres as described in claim 19.

36. A dermatological composition, according to claim 35, for improving the comfort of skins, skin integuments or mucous membranes presenting a pathology.

37. The cosmetic method according to claim 19, in which the spheres have a mean diameter ranging from 4.5 μm to 9.9 μm.

38. The cosmetic method according to claim 19, in which the spheres are in a cosmetic composition, in a concentration ranging from 0.5% to 5% by weight, relative to the total weight of the composition.

Description

EXAMPLES

Example 1: Porous Silica Spheres

[0153] A copolymer of styrene and of acrylic acid is prepared as follows: an amount of 230 mL of deionized water is added to a three-necked reaction flask equipped with a thermometer, a condenser and a magnetic stirrer, and under a nitrogen atmosphere. The water is heated to 80° C. and an amount of 10 g of styrene is added with stirring, followed by an amount of 100 mg of acrylic acid dissolved in an amount of 10 mL of deionized water, by syringe. An amount of 100 mg of ammonium persulfate is dissolved in 10 mL of deionized water and added by syringe to the mixture with stirring. The mixture is left stirring for 24 hours at 80° C. The colloidal polymer dispersion is cooled to room temperature and is purified by centrifugation, thus forming the polystyrene nanospheres having a mean particle size of 250 nm. The colloidal aqueous dispersion of polystyrene is diluted to 1% by weight in deionized water and 1% by weight of silica nanoparticles is added. The mixture is sonicated to prevent agglomeration of the particles.

[0154] The continuous oily phase contains 0.1% by weight of polyethylene glycol/perfluoropolyether surfactant in a fluorinated oil.

[0155] The aqueous colloidal dispersion and the oil are each injected into a microfluidic device having a junction for obtaining a droplet size of 50 μm, via syringes connected to pumps. The assembly is left at equilibrium until the monodisperse droplets are produced. These droplets are then collected. The collected droplets are then dried in an oven at 45° C. for 4 hours to give monodisperse sphere models. These polymer model spheres are then calcined by placing them on a silicone plate and heating them from room temperature to 500° C. over a period of 3 hours, and then maintaining the temperature of 500° C. for 2 hours. The spheres are cooled to room temperature for 3 hours. The monodisperse spheres thus obtained have a mean diameter of 15 microns.

[0156] According to an alternative embodiment, Example 1 may be repeated, performing the drying step by microwave irradiation, by drying under vacuum and/or in the presence of a dehydrating agent.

Example 2: Variation of the Colours of Spheres

[0157] An amount of 0.5 mg of porous spheres is placed in a 10 ml clear glass flask having a bottom area of 6 cm.sup.2. The colour is observed with the naked eye. Two samples of porous spheres are prepared according to Example 1, in which the polymer/silica weight ratio is 1/1 and 3/1. The sample prepared with the 1/1 ratio is white—the sample prepared with the 3/1 ratio has a blue colour.

[0158] Another sample of porous silica spheres was prepared according to Example 1, in which the polystyrene nanospheres have a mean particle size of 360 nm and a polymer/silica weight ratio of 3/1. The sample obtained has a green colour.

Example 3: Porous Silica-Titanium Spheres

[0159] A sample of porous spheres containing silica and titanium was prepared according to the process described in Example 1, in which the polymer/metal oxide weight ratio is 3/1. The silica/titanium weight ratio is 9/1.

Example 4: Evaluation of the Colour

[0160] An amount of 10 g of spheres obtained according to Example 1, on the one hand, and according to Example 3, on the other hand, was evaluated by microscope, spread in powder form between slide and cover slip and illuminated in various directions. It was observed that the spheres reflect the light, appear bright under the microscope and have tints of various colours according to the size of the sphere and of the pores.

[0161] The same experiment was performed on a composition of carbomer hydrogel type containing 1% by weight of spheres relative to the total weight of the composition.

[0162] Similarly, a composition of pure oil type containing 1% by weight of spheres relative to the total weight of the composition was prepared and observed. Moreover, an oil-in-water emulsion containing 1% by weight of spheres relative to the total weight of the composition was evaluated.

[0163] Besides having very good compatibility with the aqueous and oily media, the spheres had a soft feel on topical application, in particular in the compositions containing oil (oil or emulsion).

[0164] Finally, it was observed by microscope that the spheres in the evaluated compositions reflect light in all directions. They make it possible to improve the appearance of the skin, notably by hiding the unaesthetic manifestations. This was confirmed in vitro on a biopsy model.

Example 5: Evaluation of the Improvement of the Comfort by a Cosmetic Composition According to the Invention

[0165] The spheres obtained in Example 1 were incorporated into a simple hydrogel of carbomer type at 0.5% and 0.1% by weight relative to the total weight of the composition, with vigorous stirring. The spheres are inert, do not swell again, and are in suspension in the medium. Dispersion is better with vigorous stirring by preventing agglomerates.

[0166] Similarly, the spheres were suspended at 0.05% by weight in water and at 0.05% by weight in a plant oil, are inert and do not swell again.

[0167] Similarly, the spheres were incorporated into an emulsion of facial care type at 1% by weight and evaluated by individuals trained in sensory analysis: they applied to their forearm the emulsion containing the spheres according to a defined procedure. It emerges from this evaluation that the trained individuals reported that the emulsion containing the spheres according to the invention affords a richer, more oily application sensation, longer penetration of the cream into the skin was observed, and a velvety finish was observed. Finally, a very soft sensation on the skin was described, with a slightly satiny effect of the skin. The spheres according to the invention thus improved the comfort of the skin.

Example 6: Cosmetic Compositions According to the Invention

[0168] The porous spheres used are those obtained in Example 1, 2 or 3 in powder form.

Example 6a): Fluid Facial Emulsion

[0169]

TABLE-US-00001 TABLE 1 Amount Phase Name (% by total weight) A Water 77.05 A Glycerol 2.00 A Preserving agent 1.00 B Carbomer (Rheocare ™) 0.20 C Lauryl glucoside, polyglyceryl-2, 2.00 dipolyhydroxystearate, glycerol, cetearyl alcohol (Eumulgin ™ VL 75) C Cetearyl alcohol 1.00 C Cocoyl glycerides 3.00 C Ethylhexyl stearate 3.00 C Dicaprylyl carbonate 4.00 D Sodium polyacrylate, dicaprylyl 1.00 carbonate, polyglyceryl-3 caprate (Cosmedia ™ Ace), E Colourant CI 17200 0.10 E Pigments: mica, titanium dioxide, 2.00 silica (Flamenco ™ summit magenta M80H) F Spheres according to the invention 3.00 F Fragrance 0.65

[0170] The emulsion is prepared by the usual methods in the field well known to a person skilled in the art, by introducing phase B into phase A with stirring until fully dispersed. The mixture is heated to 75-80° C., as is phase C, separately. Phase C is then added to the mixture with stirring. The mixture is left to cool with gentle stirring to room temperature and the compounds of phases E and F are added, one after the other. The whole is homogenized for 2 minutes. The pH is adjusted to 5.2.

Example 6b): Facial Cream

[0171]

TABLE-US-00002 TABLE 2 Amount Phase Name (% by total weight) A Sucrose polystearate, cetyl palmitate 3.00 A Pentaerythrityl distearate 1.00 A Caprylic/capric triglyceryl 3.00 A Cocoyl caprylate/caprate 3.00 A Dicaprylyl carbonate 3.00 A Sodium polyacrylate 0.70 B Water 80.90 B Glycerol 2.00 B Sodium stearoyl glutamate 0.50 B Preserving agent qs C Spheres according to the invention 0.5 C Water 1.75 D Fragrance qs E pH adjuster (citric acid) qs

[0172] The cream is prepared by the usual methods in the field well known to those skilled in the art, by mixing phases A and B preheated to 75° C., followed by adding phases C and D while mixing and while adjusting the composition with phase E to a pH of 6.2 and to a viscosity of 15 000 mPa.Math.s (measured with a Brookfield instrument (RVT; 23° C., spindle TC; 20 rpm)).

Example 6c): Shampoo

[0173]

TABLE-US-00003 TABLE 3 Amount Phase Name (% by total weight) A Water 60.3 A Xanthan gum 1.2 B Decyl glucoside 14 B Dicaprylyl ether, decyl 5 glucoside, glyceryl oleate B Sodium cocoyl glutamate 12 B Cocoyl glucoside, glyceryl 2 oleate B Glycerol 3 B Preserving agent qs C pH adjuster (citric acid) qs D Fragrance 0.5 D Spheres according to the 0.01-10 invention

[0174] The shampoo is prepared by the usual methods in the field well known to those skilled in the art, by mixing the four phases and by adjusting the composition to a pH of 5.2 and to a viscosity of 2200 mPa.Math.s (measured with a Brookfield instrument (RVT; 23° C., spindle 5; 50 rpm)).