WO2013072200A2

WO2013072200A2 - Cosmetic composition

Info

Publication number: WO2013072200A2
Application number: PCT/EP2012/071704
Authority: WO
Inventors: Zhaoting Liu; Xiaoyi Pang; Xiuxia Wang
Original assignee: Unilever N.V.; Unilever Plc; Hindustan Unilever Limited; Conopco, Inc., D/B/A Unilever
Priority date: 2011-11-14
Filing date: 2012-11-02
Publication date: 2013-05-23
Also published as: WO2013072200A3

Abstract

Disclosed is a cosmetic composition comprising: (a) 0.1 % to 6% by weight of the composition of single-crystal platy particles having a refractive index of from 1.7 to 2.3; (b) 0.5 to 4% by weight of the composition of particles comprising titanium dioxide and having a particle size of from 1 to 100 nm; and (c) a cosmetically acceptable vehicle. The composition is useful for topical application to skin, in particular for providing benefits such as providing improved skin radiance and/or opacity.

Description

COSMETIC COMPOSITION

FIELD OF THE INVENTION

The present invention relates to a composition for improving the appearance of skin. In particular the present invention relates to compositions comprising platy particles and which is useful for topical application to skin, especially for providing benefits such as providing soft focus and/or opacity.

BACKGROUND OF THE INVENTION

Ageing brings with it many changes to the appearance of skin. Of particular concern to individuals wishing to maintain a youthful appearance is the reduction or elimination of skin imperfections such as wrinkles, age spots or general unevenness of skin tone.

Thus there has been considerable effort by the cosmetics industry to provide compositions which can mask or at least attenuate skin imperfections. Often this is achieved by creation of a matte effect using materials such as talc, silica, kaolin and other inorganic particulates. These inorganic particulates achieve a matte effect by their optical properties.

Imperfect skin can be hidden in two ways through manipulation of light transmission. In the first, components of the cosmetic may simply reflect light back toward the source. An alternative approach is referred to as achieving a soft focus effect. Here the incoming light is distorted by scattering (lensing). Components of the cosmetic in this mechanism operate as lenses to bend and twist light in a variety of directions. While it is desirable to hide imperfect skin through a matte effect, there is also a desire to achieve healthy skin radiance. A cosmetic covering that simply provides opacity gives the skin an artificial "paint-like" appearance. Imperfections are hidden but there is no radiance. Some refer to this as whitening. Where light transmission is insufficiently hindered, the opposite occurs. Here glow may be healthy but skin imperfections may still be apparent. Cosmetic compositions, such as anti-aging or moisturising creams or lotions which have been traditionally formulated to hide skin imperfections often suffer a further drawback in that their effect is temporary. As the composition spreads, dries and/or absorbs on the skin its optical properties change and opacity decreases thus allowing skin imperfections to reappear.

US patent application published as US 2005/0079190 A (Polonka) discloses a cosmetic skin care composition that can provide the consumer-desired properties of appearance of natural skin radiance, containing solid single-crystal flat platy particles having an Index of Refraction of about 1.8 to about 2.2, the composition having less than 20% Opacity, preferably less than 10% Opacity. The platy particles preferably include bismuth oxy- chloride, aluminium oxide, zirconium oxide, boron nitride, solid solutions and mixtures thereof. A method of imparting radiant skin appearance, especially in the facial area, by applying to the skin the inventive composition is also disclosed.

US patent application published as US 2008/0152682 A (Polonka etal.) discloses a cosmetic composition which includes from 0.01 to 10% of single-crystal platy barium sulfate, from 0.5 to 10% of a water insoluble powdered acrylic polymer in porous particle form and a carrier. The composition has soft focus optics imparting radiance to the applied skin area without excessive shininess or opacity and has excellent skinfeel properties.

Despite the impressive optical properties provided by previous compositions comprising platy particles such as those described above, we have recognised that there remains a need to provide cosmetic compositions which are capable of providing opacity to skin while maintaining radiance. In particular we have recognised a need to provide such composition and which has a long-lasting effect. DEFINITIONS

Refractive Index

Refractive index values referred to herein are those determined at a temperature of 25 °C and a wavelength of 589 nm unless otherwise stated.

Platy Particles

As used herein "platy particles" refers to solid particles having a flat, plate-like appearance. Specifically, the particles will comprise flat single crystals with a platy habit. Such appearance can be confirmed, for example, by electron microscopy.

Particle Size

Where the size of platy particles is mentioned this means the apparent volume median diameter (D50, also known as x50 or sometimes d(0.5)) of the particles in an non- aggregated state, measurable for example, by laser diffraction using a system (such as a Mastersizer™ 2000 available from Malvern Instruments Ltd) meeting the requirements set out in ISO 13320.

Where the size of particles comprising titanium dioxide is mentioned this means the primary particle size (diameter) measurable by transmission electron microscopy (TEM) using a method such as that described by S. Gu et al in Journal of Colloid and Interface Science, 289 (2005) pp. 419-426. In the event that a particle comprising titanium dioxide is not spherical then "diameter" means the largest distance measurable across the particle.

Consisting Essentially

By specifying that particles "consist essentially of a certain material is meant that the specified particles comprise the material in an amount of at least 90% by total weight of the specified particles, more preferably at least 95%, more preferably still at least 99% and most preferably from 99.9 to 100%. Leave-on and Wash-off

The term "leave-on" as used with reference to compositions herein means a composition that is applied to or rubbed on the skin, and left thereon. The term "wash-off' as used with reference to compositions herein means a skin cleanser that is applied to or rubbed on the skin and rinsed off substantially immediately subsequent to application.

Skin

The term "skin" as used herein includes the skin on the face (except eye lids and lips), neck, chest, abdomen, back, arms, hands, and legs. Preferably "skin" means skin on the face.

Miscellaneous

Except in the examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use may optionally be understood as modified by the word "about" .

All amounts are by weight of the final composition, unless otherwise specified.

The term "solid" as used herein means that the material is not fluid at 25 degrees C.

It should be noted that in specifying any range of values, any particular upper value can be associated with any particular lower value.

For the avoidance of doubt, the word "comprising" is intended to mean "including" but not necessarily "consisting of or "composed of. In other words, the listed steps or options need not be exhaustive. The disclosure of the invention as found herein is to be considered to cover all embodiments as found in the claims as being multiply dependent upon each other irrespective of the fact that claims may be found without multiple dependency or redundancy.

Where a feature is disclosed with respect to a particular aspect of the invention (for example a composition of the invention), such disclosure is also to be considered to apply to any other aspect of the invention (for example a method of the invention) mutatis mutandis.

SUMMARY OF THE INVENTION

In a first aspect, the present invention is directed to a cosmetic composition comprising:

(a) 0.1 % to 6% by weight of the composition of single-crystal platy particles having a refractive index of from 1.7 to 2.3;

(b) 0.5 to 4% by weight of the composition of particles comprising titanium dioxide and having a particle size of from 1 to 100 nm; and

(c) cosmetically acceptable vehicle.

In a second aspect, the invention is directed to a method for improving skin characteristics comprising the step of topically applying to skin the composition of the first aspect.

In a third aspect, the present invention is directed to use of the composition of the first aspect for improving soft focus, radiance and/or opacity of the skin of an individual. All other aspects of the present invention will more readily become apparent upon considering the detailed description and examples which follow. DETAILED DESCRIPTION

The present inventors have found that titanium dioxide having a specific particle size and when used in certain amounts, can synergistically enhance soft focus and/or opacity provided to skin by cosmetic compositions comprising certain types of platy particles.

The only limitations with respect to the platy particles for use in the present invention are that they are single-crystal and have a refractive index in the range of from 1.7 to 2.3.

By virtue of being flat single crystals, the platy particles deliver high reflectance. Flat platy crystals can generate natural radiant appearance via optical reflectance.

Single-crystal structure is important because the smoothness of the crystal surface minimizes opacity or diffuse scattering effects, which would lead to an artificial cosmetic effect. In particular we have found that materials which are not single-crystal (such as composite particles of platy material and titanium dioxide) do not provide the soft focus enhancement desired by compositions of the present invention. The platy particles of the present invention are thus preferably substantially free from titanium dioxide, more preferably the platy particles comprise less than 5% T1O2 by total weight of the platy particles, more preferably still less than 1%, even more preferably less than 0.1% and most preferably from 0 to 0.001 %.

"Single crystal" as used herein also encompasses crystals of solid phase solutions or mixed crystals and such may be employed for the purposes of the present invention, as long as they meet the platy particle and refractive index criteria. Solid solutions are crystals with impurities dissolved therein, thereby affecting the optical properties of the crystals. The amount of impurities relative to the amount of the crystalline material may be varied to increase or decrease the overall refractive index of the solid solution plate-like particles according to the present invention, as appropriate. The platy particles of the present invention are preferably not coated. In particular the particles are preferably not coated with organic compounds as this may impair their optical properties. Most preferably the particles consist essentially of inorganic material. Suitable materials for the particles include (but are not limited to) bismuth oxychloride and boron nitride. Thus the platy particles preferably comprise boron nitride, bismuth oxychloride or a mixture thereof. More preferably the platy particles consist essentially of boron nitride, bismuth oxychloride or a mixture thereof. Most preferably the particles comprise or consist essentially of boron nitride, especially hexagonal boron nitride.

The refractive index of the platy particles is in the range of from 1.7 to 2.3. The exemplary suitable materials: bismuth oxy-chloride and boron nitride fall within this range; while, in contrast, materials such as barium sulfate (1.5), mica (1.57), glass (1.5-1.6), titanium dioxide (2.5-2.7) and iron oxides (3.1 ) lie outside the suitable range of refractive index. Preferably the refractive index of the platy particles is in the range of from 1.8 to 2.2.

In some instances, in order to provide a synergistic enhancement of soft focus and/or opacity, it may be necessary to employ platy particles having a specific particle size. In particular it is preferred to use platy particles having a particle size of less than 20 microns, more preferably in the range 0.1 to 12 micron, more preferably still from 0.5 to 9 microns, even more preferably from 0.7 to 5 microns and most preferably from 1 to 4 microns. Most preferred are particles comprising boron nitride (especially hexagonal boron nitride) and having a particle size of from 1 to 5 microns, more preferably 2 to 4 microns and optimally about 3 microns.

The inventive compositions contain 0.1 % to 6% by weight of the platy particles. At higher concentrations any synergistic enhancement of soft focus and/or opacity disappears or is at least reduced. Thus more preferably the composition comprises the platy particles in an amount of less than 5% by weight of the composition, more preferably still less than 4% and most preferably less than 3%. If the amount of platy particles is too low, however, the overall soft focus and/or opacity effect may be too small. Thus it is preferred that the composition comprises the platy particles in an amount of at least 0.2%, more preferably at least 0.5%, more preferably still at least 1 % and most preferably at least 1.5% by weight. The particles comprising titanium dioxide have a particle size of from 1 to 100 nm. With titanium dioxide particles of larger size the synergistic enhancement of soft focus and/or opacity disappears or at least is reduced. Thus it is preferred that the particles comprising titanium dioxide have a particle size of less than 70 nm, more preferably a particle size of from 1 to 50 nm, more preferably still a particle size of from 5 to 40 nm and most preferably a size of from 7 to 30 nm. Additionally or alternatively, the composition is substantially free from particles comprising titanium dioxide and which have a particle size of greater than 100 nm. More preferably, the composition comprises less than 1 % by weight of the composition of particles comprising titanium dioxide having a particle size of greater than 100 nm, more preferably still less than 0.5%, even more preferably less than 0.1 % and most preferably from 0 to 0.01 %.

Most preferred are spherical particles (or at least substantially spherical particles) comprising titanium dioxide. The particles comprising titanium dioxide preferably comprise the titanium dioxide in an amount of at least 50% by weight of the particles, more preferably at least 70% and most preferably the particles consist essentially of titanium dioxide.

Additionally or alternatively, the particles comprising titanium dioxide preferably have a refractive index greater than 2.3, more preferably a refractive index in the range 2.4 to 2.8 and most preferably in the range 2.5 to 2.7.

The inventive compositions contain 0.5 to 4% by weight of the composition of the particles comprising titanium dioxide. At higher concentrations any synergistic enhancement of soft focus and/or opacity disappears or is at least reduced. Thus more preferably the composition comprises the particles in an amount of less than 3.5% by weight of the composition, more preferably still less than 3% and most preferably less than 2.5%. If the amount of titanium dioxide-containing particles is too low, however, the overall soft focus and/or opacity effect may be too small. Thus it is preferred that the composition comprises the particles in an amount of at least 0.7%, more preferably at least 1 % and most preferably at least 1.5% by weight.

A variety of materials may be present in the compositions of this invention to serve as cosmetically acceptable vehicles (also called "cosmetically acceptable carriers" herein). Such carriers may, for example, be water-in-oil or oil-in-water emulsions where the oil-in- water type is preferred. Foremost is water as a carrier. Amounts of water may range, for example, from 1 to 90%, more preferably from 30 to 80%, optimally from 50 to 70% by weight of the composition. Emollient materials may be included as carriers in compositions of this invention. These may be in the form of silicone oils, synthetic esters and/or hydrocarbons. Amounts of the emollients may range, for example, anywhere from 0.1 to 95%, more preferably between 1 and 50% by weight of the composition. Silicone oils may be divided into the volatile and nonvolatile variety. The term "volatile" as used herein refers to those materials which have a measurable vapor pressure at ambient temperature (25 °C). Volatile silicone oils are preferably chosen from cyclic

(cyclomethicone) or linear polydimethylsiloxanes containing from 3 to 9, preferably from 4 to 5, silicon atoms. In many liquid versions of compositions according to the present invention, the volatile silicone oils may form a relatively large component of the

compositions as carriers. Amounts may range, for example, from 5% to 80%, more preferably from 20% to 70% by weight of the composition.

Nonvolatile silicone oils useful as an emollient material include polyalkyl siloxanes, polyalkylaryl siloxanes and polyether siloxane copolymers. The essentially nonvolatile polyalkyl siloxanes useful herein include, for example, polydimethyl siloxanes with viscosities of from about 5 x 10^"6 to 0.1 m²/s at 25 °C. Among the preferred nonvolatile emollients useful in the present compositions are the polydimethyl siloxanes having viscosities from about 1 x 10^"s to about 4 x 10^ m²/s at 25 °C.

Organopolysiloxane crosspolymers can be usefully employed. Representative of these materials are dimethicone/vinyl dimethicone crosspolymers and dimethicone

crosspolymers available from a variety of suppliers including Dow Corning (9040, 9041 , 9045, 9506 and 9509), General Electric (SFE 839), Shin Etsu (KSG-15, 16 and 18

[dimethicone/phenyl vinyl dimethicone crosspolymer]), and Grant Industries (Gransil brand of materials), and lauryl dimethicone/vinyl dimethicone crosspolymers supplied by Shin Etsu (e.g. KSG-31 , KSG-32, KSG^H , KSG^2, KSG-43 and KSG-44). Amounts of the aforementioned silicone elastomers (when present) will usually be from 0.1 to 20% by weight dissolved usually in a volatile silicone oil such as cyclomethicone.

When silicones are present in large amounts as carrier and water is also present, the systems may be oil continuous. These normally will require emulsification with a water-in- oil emulsifier such as a dimethicone copolyol (e.g. Abil EM-90 which is cetyl dimethicone copolyol).

Among the ester emollients are: a) Alkenyl or alkyl esters of fatty acids having 10 to 20 carbon atoms. Examples thereof include isoarachidyl neopentanoate, isodecyl neopentanoate, isononyl isonanoate, cetyl ricinoleate, oleyl myristate, oleyl stearate, and oleyl oleate. b) Ether-esters such as fatty acid esters of ethoxylated fatty alcohols. c) Polyhydric alcohol esters. Butylene glycol, ethylene glycol mono and di-fatty acid esters, diethylene glycol mono- and di-fatty acid esters, polyethylene glycol (200- 6000) mono- and di-fatty acid esters, propylene glycol mono- and di-fatty acid esters, polypropylene glycol 2000 monooleate, polypropylene glycol 2000 monostearate, ethoxylated propylene glycol monostearate, glyceryl mono- and di-fatty acid esters, polyglycerol poly-fatty esters, ethoxylated glyceryl mono-stearate, 1 ,3-butylene glycol monostearate, 1 ,3-butylene glycol distearate, polyoxyethylene polyol fatty acid ester, sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters are satisfactory polyhydric alcohol esters. Particularly useful are pentaerythritol, trimethylolpropane and neopentyl glycol esters of C1-C30 alcohols. Exemplative is pentaerythrityl

tetraethylhexanoate. d) Wax esters such as beeswax, spermaceti wax and tribehenin wax. e) Sterols esters, of which cholesterol fatty acid esters are examples thereof. f) Sugar ester of fatty acids such as sucrose polybehenate and sucrose polycottonseedate.

Of particular use also are the C12-15 alkyl benzoate esters sold under the Finsolve brand. Hydrocarbons which are suitable cosmetically acceptable carriers include petrolatum, mineral oil, C11-C13 isoparaffins, polyalphaolefins, and especially isohexadecane, available commercially as Permethyl 101 A from Presperse Inc.

Humectants of the polyhydric alcohol-type can be employed as cosmetically acceptable carriers. Typical polyhydric alcohols include polyalkylene glycols and more preferably alkylene polyols and their derivatives, including propylene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol and derivatives thereof, sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1 ,3-butylene glycol, isoprene glycol, 1 ,2,6-hexanetriol, glycerol, ethoxylated glycerol, propoxylated glycerol and mixtures thereof. The amount of humectant may range, for example, anywhere from 0.5 to 50%, more preferably between 1 and 15% by weight of the composition. Most preferred is glycerol (also known as glycerin). Amounts of glycerin may range, for example, from 1 % to 50%, more preferably from 10 to 35%, optimally from 15 to 30% by weight of the composition. Besides cosmetically acceptable carriers, the compositions of this invention may include a variety of other functional ingredients. Sunscreen actives may be included in compositions of the present invention. These will be organic compounds having at least one

chromophoric group absorbing within the ultraviolet ranging from 290 to 400 nm.

Chromophoric organic sunscreen agents may be divided into the following categories (with specific examples) including: p-Aminobenzoic acid, its salts and its derivatives (ethyl, isobutyl, glyceryl esters; p-dimethylaminobenzoic acid); Anthranilates (o-aminobenzoates; methyl, menthyl, phenyl, benzyl, phenylethyl, linalyl, terpinyl, and cyclohexenyl esters); Salicylates (octyl, amyl, phenyl, benzyl, menthyl, glyceryl, and dipropyleneglycol esters); Cinnamic acid derivatives (menthyl and benzyl esters, alpha-phenyl cinnamonitrile; butyl cinnamoyl pyruvate); Dihydroxycinnamic acid derivatives (umbelliferone,

methylumbelliferone, methylaceto-umbelliferone); Trihydroxycinnamic acid derivatives (esculetin, methylesculetin, daphnetin, and the glucosides, esculin and daphnin);

Hydrocarbons (diphenylbutadiene, stilbene); Dibenzalacetone and benzalacetophenone; Naphtholsulfonates (sodium salts of 2-naphthol-3,6-disulfonic and of 2-naphthol-6,8- disulfonic acids); Dihydroxy-naphthoic acid and its salts; o- and p-

Hydroxybiphenyldisulfonates; Coumarin derivatives (7-hydroxy, 7-methyl, 3-phenyl);

Diazoles (2-acetyl-3-bromoindazole, phenyl benzoxazole, methyl naphthoxazole, various aryl benzothiazoles); Quinine salts (bisulfate, sulfate, chloride, oleate, and tannate);

Quinoline derivatives (8-hydroxyquinoline salts, 2-phenylquinoline); Hydroxy- or methoxy- substituted benzophenones; Uric and vilouric acids; Tannic acid and its derivatives (e.g., hexaethylether); (Butyl carbityl) (6-propyl piperonyl) ether; Hydroquinone; Benzophenones (Oxybenzone, Sulisobenzone, Dioxybenzone, Benzoresorcinol, 2,2',4,4'- Tetrahydroxybenzophenone, 2,2'-Dihydroxy-4,4'-dimethoxybenzophenone, Octabenzone; 4-lsopropyldibenzoylmethane; Butylmethoxydibenzoylmethane; Etocrylene; and 4- isopropyl-dibenzoylmethane). Particularly useful are: 2-ethylhexyl p-methoxycinnamate, 4,4'-t-butyl methoxydibenzoylmethane, 2-hydroxy-4-methoxybenzophenone, octyldimethyl p-aminobenzoic acid, digalloyltrioleate, 2,2-dihydroxy-4-methoxybenzophenone, ethyl 4- [bis(hydroxypropyl)]aminobenzoate, 2-ethylhexyl-2-cyano-3,3-diphenylacrylate, 2- ethylhexylsalicylate, glyceryl p-aminobenzoate, 3,3,5-trimethylcyclohexylsalicylate, methylanthranilate, p-dimethylaminobenzoic acid or aminobenzoate, 2-ethylhexyl p- dimethylaminobenzoate, 2-phenylbenzimidazole-5-sulfonic acid, 2-(p- dimethylaminophenyl)-5-sulfoniobenzoxazoic acid and mixtures thereof.

Particularly preferred are such materials as ethylhexyl p-methoxycinnamate, available as Parsol MCX®, Avobenzone, available as Parsol 1789®, Deimablock OS® (octylsalicylate) and Mexoryl SX® (with INCI name of Terephthalylidene Dicamphor Sulfonic Acid).

Amounts of the organic sunscreen agent may range, for example, from 0.1 to 15%, more preferably from 0.5% to 10%, optimally from 1 % to 8% by weight of the composition.

A variety of thickening agents may be included in the compositions. Illustrative but not limiting are stearic acid, Acrylamide/Sodium Acryloyldimethyltaurate Copolymer (Aristoflex AVC), Hydroxyethyl Acrylate/Sodium Acryloyldimethyltaurate Copolymer, Aluminum Starch Octenyl Succinate, Polyacrylates (such as Carbomers including Carbopol® 980, Carbopol® 1342, Pemulen TR-2® and the Ultrez® thickeners), Polysaccharides (including xanthan gum, guar gum, pectin, carageenan and sclerotium gums), celluloses (including carboxymethyl cellulose, ethyl cellulose, hydroxyethyl cellulose and methyl hydroxymethyl cellulose), minerals (including talc, silica, alumina, mica and clays, the latter being represented by bentonites, hectorites and attapulgites), magnesium aluminum silicate and mixtures thereof. Amounts of the thickeners may range, for example, from 0.05 to 10%, more preferably from 0.3 to 2% by weight of the composition.

Preservatives can desirably be incorporated into the cosmetic compositions of this invention to protect against the growth of potentially harmful microorganisms. Suitable traditional preservatives for compositions of this invention are alkyl esters of para- hydroxybenzoic acid. Other preservatives which have more recently come into use include hydantoin derivatives, propionate salts, and a variety of quaternary ammonium compounds. Cosmetic chemists are familiar with appropriate preservatives and routinely choose them to satisfy the preservative challenge test and to provide product stability. Particularly preferred preservatives are phenoxyethanol, methyl paraben, propyl paraben, butyl paraben, isobutyl paraben, imidazolidinyl urea, sodium dehydroacetate and benzyl alcohol. The preservatives should be selected having regard for the use of the

composition and possible incompatibilities between the preservatives and other ingredients in the composition. Preservatives are preferably employed in amounts ranging from 0.01 % to 2% by weight of the composition.

Compositions of the present invention may also contain vitamins and flavonoids. Illustrative water-soluble vitamins are Niacinamide, Vitamin B₂, Vitamin B₆, Vitamin C and Biotin. Among the useful water-insoluble vitamins are Vitamin A (retinol), Vitamin A Palmitate, ascorbyl tetraisopalmitate, Vitamin E (tocopherol), Vitamin E Acetate and DL-panthenol. A particularly suitable Vitamin B₆ derivative is Pyridoxine Palmitate. Among the preferred flavonoids are glucosyl hesperidin and rutin. Total amount of vitamins or flavonoids when present in compositions according to the present invention may range, for example, from 0.001 to 10%, more preferably from 0.01 % to 1 %, optimally from 0.1 to 0.5% by weight of the composition.

Desquamation agents are further optional components. Illustrative are the alpha- hydroxycarboxylic acids and beta-hydroxycarboxylic acids and salts of these acids.

Among the former are salts of glycolic acid, lactic acid and malic acid. Salicylic acid is representative of the beta-hydroxycarboxylic acids. Amounts of these materials when present may range from 0.1 to 15% by weight of the composition.

A variety of herbal extracts may optionally be included in compositions of this invention. Illustrative are pomegranate, white birch (Betula Alba), green tea, chamomile, licorice, boswellia serrata, olive (Olea Europaea) leaf, arnica montana flower, lavandula angustifolia, and extract combinations thereof. The extracts may either be water soluble or water-insoluble carried in a solvent which respectively is hydrophilic or hydrophobic. Water and ethanol are the preferred extract solvents. Miscellaneous other adjunct cosmetic ingredients that may be suitable for the present compositions include ceramides (e.g. Ceramide 3 and Ceramide 6), conjugated linoleic acids, colorants (e.g. iron oxides), metal (manganese, copper and/or zinc) gluconates, allantoin, palmitoyl pentapeptide-3, amino acids (e.g. alanine, arginine, glycine, lysine, proline, serine, threonine, glumatic acid and mixtures thereof), trimethylglycine, sodium PCA, chelator like disodium EDTA, opacifiers like titanium dioxide, magnesium aspartate, and combinations thereof. Amounts may, for example, vary from 0.000001 to 3% by weight of the composition.

A small amount of emulsifying surfactant may be present. Surfactants may be anionic, nonionic, cationic, amphoteric and mixtures thereof. Levels may range, for example, from

0.1 to 5%, more preferably from 0.1 to 2%, optimally from 0.1 to 1% by weight.

Advantageously the amount of surfactant present should not be sufficient for lather formation. In these instances, less than 2% by weight, preferably less than 1 %, and optimally less than 0.5% by weight surfactant is present. Emulsifiers like PEG-100 stearate may be used as well as emulsion stabilizers like cetearyl alcohol and ceteareth-20 may be used and typically in amounts that do not exceed 5 percent by weight of the composition.

Other optional additives suitable for use in the composition of this invention include cationic ammonium compounds to enhance moisturization. Such compounds include salts of hydroxypropyltri (C1-C3 alkyl) ammonium mono-substituted-saccharide, salts of hydroxypropyltri (C1-C3 alkyl) ammonium mono-substituted polyols, dihydroxypropyltri (Ci- C3 alkyl) ammonium salts, dihydroxypropyldi (C1-C3 alkyl) mono(hydroxyethyl) ammonium salts, guar hydroxypropyl trimonium salts, 2,3-dihydroxypropyl tri(Ci-C3 alkyl or

hydroxalkyl) ammonium salts or mixtures thereof. In a most preferred embodiment and when desired, the cationic ammonium compound employed in this invention is the quaternary ammonium compound 1 ,2-dihydroxypropyltrimonium chloride. If used, such compounds typically make up from 0.01 to 30%, and more preferably from about 0.1 to about 15% by weight of the composition.

When cationic ammonium compounds are used, optional additives for use with the same are moisturizing agents such as substituted ureas like hydroxymethyl urea, hydroxyethyl urea, hydroxypropyl urea; bis(hydroxymethyl) urea; bis(hydroxyethyl) urea;

bis(hydroxypropyl) urea; Ν,Ν'-dihydroxymethyl urea; N,N'-di-hydroxyethyl urea; N,N'-di- hydroxypropyl urea; Ν,Ν,Ν'-tri-hydroxyethyl urea; tetra(hydroxymethyl) urea;

tetra(hydroxyethyl) urea; tetra(hydroxypropyl) urea; N-methyl-N'-hydroxyethyl urea; N- ethyl-N'-hydroxyethyl urea; N-hydroxypropyl-N'-hydroxyethyl urea and N,N'dimethyl-N- hydroxyethyl urea or mixtures thereof. Where the term hydroxypropyl appears, the meaning is generic for either 3-hydroxy-n-propyl, 2-hydroxy-n-propyl, 3-hydroxy-i-propyl or 2-hydroxy-i-propyl radicals. Most preferred is hydroxyethyl urea. The latter is available as a 50% aqueous liquid from the National Starch & Chemical Division of ICI under the trademark Hydrovance. Such substituted ureas, while desirable in moisturizing formulations, are only selected for use when compatible with sunless tanning agent or agents (when used) in the compositions of this invention.

Amounts of substituted urea, when used, in the composition of this invention range from 0.01 to 20%, more preferably from 0.5 to 15%, and most preferably from 2 to 10% based on total weight of the composition and including all ranges subsumed therein. When cationic ammonium compound and substituted urea are used, in a most especially preferred embodiment at least from 0.01 to 25%, more preferably from 0.2 to 20%, and most preferably from 1 to 15% humectant, like glycerine, is used, based on total weight of the composition and including all ranges subsumed therein. When making the compositions of this invention, ingredients are typically mixed with moderate shear under atmospheric conditions. The compositions may be applied topically and preferably 1-4 milligrams of composition is applied per square centimeter of skin. Preferably, the compositions display a pH from 4 to 6. Packaging for the composition of this invention can be a jar or tube as well as any other format typically seen for cosmetic, cream, washing and lotion type products.

The composition may be a leave-on composition or a wash-off composition, but preferably a leave-on composition.

The following examples are provided to facilitate an understanding of the invention. The examples are not intended to limit the scope of the claims.

EXAMPLES

Example 1

This example demonstrates the effect of titanium dioxide particle size on synergistic enhancement of the soft focus by compositions comprising platy particles.

A series of cosmetic compositions were formulated as shown in Table 1 below.

The formulations were prepared by the following process. The optical-effect particles were completely dispersed in the oil phase with the additional ingredients and mixed thoroughly. The resulting oil-based mixture was gradually added to the aqueous phase. The resulting mixture was emulsified under 9,000 rpm of shear stress for 10 minutes and gradually stirred and cooled to room temperature. TABLE 1

1. JTTO-MS7 was Titanium Dioxide (and) Alumina (and) Methicone supplied by KOBO - size in brackets is primary particle size.

2. MPY-1133M was Titanium Dioxide (and) Aluminium Hydroxide supplied by TAYCA - size in brackets is primary particle size.

3. BORONEIGE® #301 supplied by ESK Ceramics - size in brackets is D50.

4. BORONEIGE® #1501 supplied by ESK Ceramics - size in brackets is D50.

5. RonaFlair™ Fines supplied by MERCK - size in brackets is D50. A 75 micron thick film of composition was applied to a glass slide with a cube film applicator (Sheen 1103). The bi-directional reflectance and transmittance distribution function of the films was detected with a goniometer via a method similar to the one described in U.S. Patent Application published as US 2008/0152682 A. Soft focus (SF) was calculated using equation (1 ):

Τ(θ) is the transmittance at angle Θ, ST is the specular transmittance angle. The incident angle was set at 48°.

All soft focus values were measured under same temperature (22 °C) and same humidity (45 %) in a constant temperature and humidity room. The soft focus for the samples was measured after 2h and the results are listed in Table 2.

TABLE 2

1. Value obtained by summing values for platy particles alone and T1O2 alone. It can be seen from above table that the mixture of boron nitride (3 μηι) & titanium dioxide (15 nm) has an obvious synergistic effect to boost the soft focus, even 2 hours after application. For the mixture of bismuth oxychloride and titanium dioxide (15 nm) a synergistic effect to boost the soft focus is also apparent. However, for mixtures with T1O2 having a particle size of 250 nm no synergistic effects are apparent.

Example 2

This example demonstrates the effect of synergistic enhancement of both soft focus and opacity by compositions comprising platy particles and titanium dioxide.

Samples were prepared using the same base formulation as in Example 1 but with the amounts and types of optical-effect particles as shown in Table 3.

TABLE 3

MT100Z was Titanium Dioxide (and) Stearic Acid (and) Aluminium Hydroxide supplied by TAYCA - size in brackets is primary particle size.

Soft focus measurements were made in an identical manner to those described in Example 1. In addition, opacity was measured with a handheld spectrophotometer (MINOLTA CM2600d in SCE mode) as follows: Product films with a thickness of 75 micron were applied on drawdown black and white card using the Sheen cubic film applicator. The opacity (450 nm) was taken as the ratio between the reflectance measured for the film on the black and white cards at the wavelength of 450 nm.

The soft focus values for the samples measured after 30 min and 2 hours following application are given in Table 4, whilst the opacity values are given in Table 5.

TABLE 4

1. Value obtained by summing values for platy particles alone and T1O2 alone. TABLE 5

1. Value obtained by summing values for platy particles alone and T1O2 alone.

These results show that the composition comprising combinations of platy particles and titanium dioxide according to the present invention (Sample 11 ) exhibited synergistically enhanced optical properties in terms of both soft focus and opacity.

Example 3

This example demonstrates the effect of the type of particle compounded with titanium dioxide on the soft focus provided by cosmetic compositions.

Samples were prepared using the same base formulation as in Example 1 but with the amounts and types of optical-effect particles as shown in Table 6.

TABLE 6

1. JTTO-MS7.

2. BORONEIGE®#301.

3. SA-TR-10 was Titanium Dioxide (and) Dimethylpolysiloxane supplied by Miyoshi

Kasei Inc. - size in brackets is primary particle size.

4. Barium Sulfate H supplied by Sakai Chemical Industry Co. Ltd - size in brackets is mean particle size measured by SEM.

5. Timiron® Ultraluster MP-111 supplied by MERCK - size in brackets is D50.

6. Matlake OPA supplied by SENSIENT - size in brackets is mean particle size

measured by SEM.

7. SH219AS was Silica (and) Ti02 and alkyl silane supplied by Sunjin Chemical Co - size in brackets is mean particle size measured by SEM.

Soft focus measurements were made in an identical manner to those described in

Example 1. The soft focus values for the samples measured after 30 min are given in Table 7. TABLE 7

It is apparent from these results that particles which have a refractive index (Rl) outside of the claimed range (titanium dioxide had Rl of 2.7; barium sulphate had Rl of 1.5) were not capable of synergistically enhancing soft focus with the JTTO-MS7 titanium dioxide (Samples 20 and 21).

Particles which were spherical, rather than platy but which had a refractive index within the claimed range (silica-Ti0₂ beads had Rl of 1.8) were also not capable of synergistically enhancing soft focus with the JTTO-MS7 titanium dioxide (Sample 24).

Particles which were platy, had a refractive index within the claimed range (Ti0₂-coated Mica had Rl of 2.0; Ti0₂-coated Alumina had Rl of 2.1 ) but which were composite particles, rather than single-crystals, also showed very little or no ability to synergistically enhance soft focus with the JTTO-MS7 titanium dioxide (Samples 22 and 23).

On the other hand, particles which were platy, had a refractive index within the claimed range (BN had Rl of 1.8) and were single-crystal showed a large ability to synergistically enhance soft focus with the JTTO-MS7 titanium dioxide (Sample 19). Example 4

This example demonstrates the effect of the type and size of metal oxide particle compounded with platy boron nitride on the soft focus provided by cosmetic compositions. Samples were prepared using the same base formulation as in Example 1 but with the amounts and types of optical-effect particles as shown in Table 8.

TABLE 8

1. BORONEIGE®#301.

2. JTTO-MS7.

3. MT100Z.

4. MT700Z was Titanium Dioxide (and) Stearic Acid (and) Aluminium Hydroxide supplied by TAYCA - size in brackets is primary particle size

5. SA-TR-10.

6. Z-Cote® supplied by BASF - size in brackets is primary particle size.

7. BGYO-TTB2 was Iron Oxides (and) Isopropyl Titanium Triisostearate (and)

Triethoxysilylethyl Polydimethylsiloxyethyl Dimethicone supplied by KOBO - size in brackets is mean particle size measured by SEM. Soft focus measurements were made in an identical manner to those described in

Example 1. The soft focus values for the samples measured after 30 min are given in Table 9.

TABLE 9

1. Value obtained by summing values for oxide particles alone and BN alone.

2. JTTO-MS7.

3. MT100Z.

It is apparent from these results that titanium dioxide particles having a particle size of 15 nm showed a large ability to synergistically enhance soft focus with the boron nitride (Samples 32 and 33).

Titanium dioxide particles having a particle size of 80 nm also showed some ability to synergistically enhance soft focus with the boron nitride (Sample 34) but this was less than that exhibited by the smaller titanium dioxide particles. Furthermore (and as in Example 1 ), titanium dioxide particles having a particle size of greater than 100 nm showed no ability to synergistically enhance soft focus with the boron nitride (Sample 35). Particles of oxides of metals other than titanium showed very little or no ability to

synergistically enhance soft focus with the BN (Samples 36 and 37). Example 5

This example demonstrates the effect of the amount of platy boron nitride particles compounded with titanium dioxide on the soft focus provided by cosmetic compositions.

Samples were prepared using the same base formulation as in Example 1 but with the amounts and types of optical-effect particles as shown in Table 10.

TABLE 10

2. JTTO-MS7.

Soft focus measurements were made in an identical manner to those described in Example 1. The soft focus values for the samples measured after 30 min are given ^' Table 11.

TABLE 11

1. Value obtained by summing values for T1O2 particles alone and BN alone

These results demonstrate that boron nitride particles synergistically enhance soft focus with the titanium dioxide when used in amounts of up to and including 6 wt% (Samples 47 to 53). However at 7 wt%, no synergistic enhancement was observed (Sample 54). Example 6

This example demonstrates the effect of the amount of titanium dioxide particles compounded with platy boron nitride on the soft focus provided by cosmetic compositions.

Samples were prepared using the same base formulation as in Example 1 but with the amounts and types of optical-effect particles as shown in Table 12.

TABLE 12

1. BORONEIGE®#301.

2. JTTO-MS7.

Soft focus measurements were made in an identical manner to those described in Example 1. The soft focus values for the samples measured after 30 min are given in Table 13.

TABLE 13

These results demonstrate that titanium dioxide particles synergistically enhance soft focus with the boron nitride when used in amounts of up to and including 4 wt% (Samples 61 to 64). However at 5 wt%, no synergistic enhancement was observed (Sample 65).

Example 7

This example demonstrates the effect of the size of platy boron nitride particles

compounded with titanium dioxide on the soft focus provided by cosmetic compositions.

Samples were prepared using the same base formulation as in Example 1 but with the amounts and types of optical-effect particles as shown in Table 14.

TABLE 14

2. BORONEIGE® #602 supplied by ESK Ceramics - size in brackets is D50.

BORONEIGE®#1501

JTTO-MS7.

Soft focus measurements were made in an identical manner to those described in Example 1. The soft focus values for the samples measured after 30 min are given ^' Table 15.

TABLE 15

alone.

These results demonstrate that the smallest particles of boron nitride (Sample 70) show the largest synergistic effect on soft focus. A synergistic effect was also apparent with the largest particle size (Sample 72). No synergistic effect on soft focus was apparent in this experiment with the boron nitride having particle size of 6 micron (Sample 71 ).

Claims

1. A cosmetic composition comprising:

(a) 0.1% to 6% by weight of the composition of single-crystal platy particles having a refractive index of from 1.7 to 2.3;

(c) cosmetically acceptable vehicle.

2. The cosmetic composition as claimed in claim 1 , wherein the platy particles have a particle size of from 0.1 to 20 microns, preferably from 1 to 9 microns.

3. The cosmetic composition as claimed in any one of the preceding claims, wherein the platy particles comprise boron nitride, bismuth oxychloride or a mixture thereof.

4. The cosmetic composition as claimed in claim 3, wherein the platy particles

comprise boron nitride and have a particle size of from 1 to 5 micron.

5. The cosmetic composition as claimed in claim 4, wherein the platy particles consist essentially of boron nitride.

6. The cosmetic composition as claimed in any one of the preceding claims, wherein the particles comprising titanium dioxide have a particle size of less than 70 nm, preferably a particle size of from 5 to 50 nm.

7. The cosmetic composition as claimed in any one of the preceding claims, wherein the particles comprising titanium dioxide have a refractive index greater than 2.3, preferably a refractive index in the range 2.4 to 2.8.

8. The cosmetic composition as claimed in claim 7, wherein the particles comprising titanium dioxide consist essentially of titanium dioxide.

9. The cosmetic composition as claimed in any one of the preceding claims, wherein the composition comprises the platy particles in an amount of less than 4% by weight, preferably in an amount of from 1 to 3% by weight.

10. The cosmetic composition as claimed in any one of the preceding claims, wherein the cosmetically acceptable vehicle is an emulsion, preferably an oil-in-water emulsion.

11. A method for improving skin characteristics comprising the step of topically applying to skin the composition of any one of claims 1 to 10.

12. Use of a composition as claimed in any one of claims 1 to 10 for improving soft focus, radiance and/or opacity of the skin of an individual.