Title: SPOROPOLLENIN AS A COSMETIC ACTIVE AGENT WITH A MATTIFYING AND/OR SOFT-FOCUS EFFECT

The present invention relates to the use of sporopollenin in cosmetic compositions which afford a mattifying and/or soft-focus effect. The invention also relates to a cosmetic process for improving the surface appearance of skin which has age-related reliefs, irregularities or defects, and more particularly visible and/or tactile irregularities.

These compositions are known as compositions with mattifying properties and/or improved soft- focus properties.

Technical field

The present invention falls within the field of cosmetics, and more particularly of cosmetic compositions intended for improving the surface appearance of the skin.

Prior art

The natural microcapsules produced from plant spores and pollen grains have been the subject of increasing researchs in recent years notably as vehicles for the administration of medicaments or as means for encapsulating biological active agents.

However, none of this research and none of the documents arising from this research mentions the intrinsic properties of sporopollenin particles from the point of view of their optical effect due to interactions of these particles with visible light, which the inventors discovered that it was possible to exploit when they are used in cosmetic compositions.

US7182965 discloses the use of sporopollenin in cosmetic compositions intended for combating wrinkles formed by skin aging or by exposure to sunlight. Direct action on wrinkle reduction is described. No optical effects of this composition are described, and all the less so any soft- focus effect.

FR3063430 relates to a combination of at least one oil and of an agent for promoting the photoprotective efficacy of at least one physical and/or chemical sunscreen, said promoting agent being a promoter of the photoprotective efficacy of sunscreens toward UVA and/or UVB and being chosen from one or more pollen grain extracts. No optical effects of this combination are described, and all the less so any soft-focus effect. Disclosure of the invention

The visible effects (sheen, highlights) brought about on the surface of the skin by the secretion of sebum and/or sweat are considered as unesthetic. The overproduction of sebum may also entail esthetic defects or imperfections, such as nonuniformity of the skin complexion, and increase in the size of the follicular orifices or dilated pores, and/or an irregular appearance of the skin relief. Moreover, shiny or glistening skin generally limits the staying power of makeup: its effect degrades more rapidly over time.

It is known to those skilled in the art to use fillers in order to obtain a mattifying and/or soft- focus effect. These fillers are chosen because they have good properties in terms of sebum and/or sweat absorption and/or in terms of light scattering ("soft-focus" effect). The term "soft- focus filler" used in the context of the present invention is thus equivalent to the term "filler with a soft- focus effect".

The fillers used for absorbing the excess sebum at the surface of the skin and/or for scattering light are often of synthetic origin, such as nylon, polyethylene or polymethyl (meth)acrylate particles.

However, the persistence of the effect is generally low, of the order of 4 hours, and it is particularly limited in the presence of sebum or sweat, which means that it is necessary to refresh the application in order to provide the expected effect. Moreover, the cosmetics market has been marked by a strongly increasing demand for formulations containing ingredients of natural origin. Consumers are thus in search of formulations that are free of chemicals, to which they prefer ingredients of natural origin, which are renowned for their better tolerance and affinity with the skin, and that are more environmentally friendly.

Many cosmetic compositions have been developed for the purpose of attempting to hide skin defects or imperfections by exploiting the optical properties of ingredients, notably of microparticles which reflect and/or scatter light. Emmert, "Quantification of the Soft-Focus Effect," Cosmetics and Toiletries, 111, 57-61 (1996) discusses the production of a soft-focus effect with such light-scattering/light-dispersing agents. When the soft- focus index is high, the composition produces a large soft- focus effect, serving to hide the defects by modifying the perception of the relief. The particles must have optical properties such that they make it possible to give the skin a natural appearance, notably by uniform distribution of the light.

These cosmetic compositions usually contain boron nitride or nylon particles, polymer-coated aluminum flakes, spherical silica particles, silicone elastomers, flat powders, spherical powders such as PMMA, barium sulfate, etc. to obtain a soft-focus effect. However, these products have had drawbacks, for instance unnatural appearance of the skin due to the use of very opaque materials and the exposure of skin defects due to the use of flat materials. Furthermore, these products generally do not have optimum or desirable soft-focus properties.

Consequently, there is still a need to provide ingredients, in particular of natural origin, which can give the skin a soft-focus and/or mattifying effect efficiently, immediately and durably over time, and which are compatible with formulations intended for making up and caring for the skin.

The aim of the present invention is, precisely, to meet this need.

Summary of the invention

The invention relates to the use of sporopollenin particles as fillers for limiting skin sheen and/or for hiding imperfections thereof in cosmetic care and/or makeup compositions.

The invention also relates to a cosmetic care and/or makeup process for mattifying the skin, notably greasy and/or shiny skin, and/or for hiding skin imperfections, comprising the application to said skin of a composition comprising, in a physiologically acceptable medium, at least sporopollenin particles.

The invention further relates to the use of sporopollenin particles for limiting skin sheen and/or for hiding skin imperfections, such as wrinkles, fine lines, pores or dilated pores and microrelief irregularities, notably associated with hyperkeratinization and acne scars and a nonuniform complexion.

The invention further relates to the use of fillers consisting of sporopollenin particles for limiting skin sheen and/or for hiding imperfections thereof in cosmetic care and/or makeup compositions.

Brief description of the illustrations [Fig 1] schematically represents a pollen grain from which is obtained a hollow sporopollenin particle as used in the context of the present invention.

[Fig 2] represents an illustration of a process for obtaining hollow sporopollenin particles from pollen grains.

[Fig 3] represents scanning electron microscopy (SEM) images of Lycopodium clavatum particles (particle A) and of Helianthus annuus particles (particle B) which may be used in the context of the present invention.

Detailed description

For the purposes of the present invention, the term skin "imperfections" or "esthetic defects" of the skin means wrinkles, fine lines, pores or dilated pores and microrelief irregularities, notably associated with hyperkeratinization and acne scars and a nonuniform complexion. The term "skin with irregularities" thus denotes skin presenting at least one of these imperfections.

For the purposes of the present invention, the term "skin" denotes all of the skin of the body, including the lips, and preferably the skin of the face, the neck and the neckline, and also the lips.

The term "aged skin" denotes skin presenting signs of aging, such as wrinkles and fine lines.

For the purposes of the present invention, the term "optical effect" means a measurable effect produced on light in the presence of a compound, in comparison with the incident light.

Finally, for the purposes of the present invention, the term "soft- focus effect" means a hazy-focus effect.

In the context of the present invention, it is understood that the particles used are fillers that are directed toward the mattifying and/or soft-focus effect and are not used to convey and/or protect biological active agents, for example by encapsulation.

As emerges from the examples, measurement of the sheen, notably using a glossmeter, makes it possible to evaluate the mattifying effect of a cosmetic composition.

As also emerges from the examples, measurement of the soft- focus effect using a Haze measurement (veil or tracing-paper effect) with a commercial machine such as a Hazemeter, makes it possible to evaluate the soft-focus effect of a cosmetic composition. The greater the Haze value, the higher the soft-focus effect (Haze index).

Sporopollenin particles

The constituents of pollen and/or spores are mainly protected by a cellulose- rich cell wall known as the intine, and a strong outer wall predominantly composed of sporopollenin known as the exine. The morphology of the exine varies significantly between pollen species, with unique reproducible features as regards the 3D architectures and morphologies. Furthermore, the exine also provides the protection with respect to the environment for successful pollination.

The structure of a spore and/or pollen grain is represented schematically in figure 1. The core is commonly known as the sporoplasm, and is covered with a layer known as the cellulose layer or inner cellulose wall, which is itself surrounded with exine, which consists mainly of sporopollenin. Finally, a lipid layer coats this structure.

The term "sporopollenin" thus covers the family of biopolymers that are the main constituents of the outer hard wall - also known as exine - of pollen grains and spores.

In its natural environment, the purpose of this material is more specifically to protect the genetic material contained in the spores and the pollen, in particular the sporoplasm (derivatives notably of nucleic acid type). Thus, sporopollenin, which is highly resistant and inert, is notably known for withstanding non-oxidative physical, chemical and biological decomposition processes.

The chemical structure of these sporopollenin biopolymers may vary from one plant/fungal species to another. It is still relatively unknown and is the subject of debate in the scientific community (G. Mackenzie et al. , “Sporopollenin, the least known yet toughest natural biopolymer”, Front. Mater. 2015, vol. 2, pages 1-5). In general, these biopolymers include saturated and unsaturated aliphatic chains, substituted with conjugated aromatic units and crosslinked by means of ester, ether or acetal functions.

By way of example, J.-K. Weng et al. have demonstrated that the sporopollenin of Pinus rigida comprises blocks of polyvinyl alcohol/polyketal type, crosslinked with dialdehyde chains, which are themselves substituted with coumarate units (J. K. Weng et al., The molecular structure of plant sporopollenin, Nature Plants 2018, in press, doi: 10.1101/415612). In the context of the present invention, it is understood that the sporopollenin particles used may originate from sporopollenin particles of various origins, namely from several plants.

According to a particular embodiment of the invention, the sporopollenin particles used in the context of the invention are not native.

Processes have already been developed for the preparation of sporopollenin particles making it possible to remove the constituents from the inside and the surface of the pollen grains without impairing the structure or morphology of these exine microcapsules. In other words, advantageously, neither the general form of the particles nor the morphology or typology of their surface is substantially modified during the use of said processes.

The particles used according to the invention may be obtained by chemical and/or enzymatic treatments of spores or pollens, in accordance with the methods described in the scientific literature and known to those skilled in the art.

These chemical treatments are directed toward isolating the sporopollenin from the other components of the spores and/or pollens, in particular the lipids, the cytoplasm, the genetic material, the proteins and the inner wall of the spores and/or pollen, of cellulosic nature.

The conventional scheme of such a process is reported in figure 2.

In general, the sporopollenin particles used in the context of the present invention may thus be obtained by preliminary defatting to remove the lipid envelope, followed by a step of removing the core of the structure from the pollen grains and/or spores.

More precisely, the chemical treatments consist of defatting using organic solvents which dissolve the surface lipids, such as acetone, methanol, ethanol, dichloromethane or toluene, followed by acidic treatments (with strong acids such as sulfuric acid or phosphoric acid) and/or basic treatments (with alkaline agents such as sodium hydroxide or potassium hydroxide) to degrade the constituents other than the sporopollenin capsule (sporoplasm, cellulose wall), before removing them by washing. The sporopollenin particles may also be isolated from the corresponding spores or pollens by hot treatment (100-200°C) of the latter with a mixture of sulfuric acid and anhydride (acetolysis).

An alternative to strong acid-based treatments consists in using enzymes, used sequentially to degrade the genetic material, the proteins and the inner cellulose wall, the residues of which are then removed by washing with one or more organic solvents. Among the enzymes used, use may be made, for example, of proteases, lipases, pectinases, cellulases, etc.

Recently, the use of ionic liquids has been described for removing by dissolution the constituents other than sporopollenin from the pollen of Populus deltoides. The ionic liquids used in this method are, for example, tetra-n-butylphosphonium hydroxide or 1 -butyl-3 -methylimidazolium chloride.

The following references describe in detail these processes for obtaining particles used according to the invention:

- F. Zetzsche et al., Untersuchungen iiber die membrane des sporen und pollen I. 1. Lycopodium clavatum, Justus Liebigs Annalen der Chemie 1928, 461, page 89

- G. Erdtman, The acetolysis method. A revised description, Svensk Botanisk Tidskrift 1960, 54, page 561

- K. Schulze Osthoff et al., Phenols as integrated compounds of sporopollenin from Pinus pollen, J. Plant Physiol. 1987, 131, page 5

- M. Hesse et al., A new look at the acetolysis method, Plant Syst. Evol. 1989, 163, page 147

- M. J. Rodriguez Douton et al., From pollen grains to functionalized microcapsules: a facile chemical route using ionic liquids, Green Chem. 2017, 19, page 1028.

The sporopollenin particles used according to the present invention are known to those skilled in the art, as are processes for obtaining them.

Figure 2 illustrates a process for obtaining hollow sporopollenin particles.

According to a particular embodiment of the invention, the particles used according to the invention are the outer walls (exines) of pollens and spores, obtained according to a process which conserves their integrity. In the context of the present invention, the term "to conserve their integrity" means to substantially maintain, or even to maintain, the same size, the same form and the same surface topology of the exine of the particles in the natural state.

According to a particular embodiment of the invention, the particles obtained on conclusion of the process described previously are subjected to an additional milling step. This step may thus make it possible to obtain other particle shapes.

The sporopollenin particles obtained as indicated above may thus subsequently be milled or milled and then reagglomerated according to the methods known to those skilled in the art for forming other sporopollenin particles that can be used according to the invention. By way of example, mention may be made of the ball milling as described by J.-K. Weng (J. K. Weng et al., The molecular structure of plant sporopollenin, Nature Plants 2018, in press, doi: 10.1101/415612).

Typically, if spheroid particles are obtained on conclusion of the process described previously, then particles of "bowl" type may be obtained, which may also be used in the context of the present invention.

Other morphological modifications may also be envisaged for forming sporopollenin particles that may also be used in the context of the present invention.

Morphological modifications that may be mentioned include size, shape and surface topology modifications.

All of the sporopollenin particles obtained from pollen grains and/or spores according to a process comprising at least one defatting step followed by at least one step of removing the core formed by the sporoplasm and the inner cellulose wall may thus be used in the context of the present invention.

According to a preferred embodiment, the process for obtaining the sporopollenin particles conserves the integrity of the exine comprised in the pollen grains and/or spores in the natural form, from which they are derived.

In other words, the sporopollenin particles that may be used in the context of the present invention may be defined as pollen grains and/or spores which have undergone a chemical and/or enzymatic treatment for removal of the lipids, the sporoplasm, the genetic material, the proteins and the inner cellulose wall.

Advantageously, the various processes described previously make it possible to obtain particles free of allergenic components, for example proteins.

According to a particular embodiment of the invention, the sporopollenin particles used consist of sporopollenin, in other words they consist solely of the sporopollenin biopolymer.

Preferably, the sporopollenin particles used according to the invention originate from at least one pollen or spore of the following genera:

Ambrosia, preferentially Ambrosia artemisiifolia and Ambrosia trifida, Aspergillus, preferentially Aspergillus niger,

Betula, preferentially Betula pendula,

Brassica, preferentially Brassica napus,

Cannabis, preferentially Cannabis sativa,

Carya, preferentially Carya illinoinensis,

Cucurbita, preferentially Cucurbita pepo,

Helianthus, preferentially Helianthus annuus,

Lycopodium, preferentially Lycopodium clavatum,

Myosotis, preferentially Myosotis arvensis,

Phleum, preferentially Phleum pratense,

Pinus, preferentially Pinus sylvestris,

Platanus, preferentially Platanus hispanica,

Poa, preferentially Poa pratensis,

Secale, preferentially Secale cereale,

Taraxacum, preferentially Taraxacim erythrospermum,

Triticum, preferentially Triticum aestivum and Triticum durum,

Urtica, preferentially Urtica dioica, and

mixtures thereof. The sporopollenin particles used according to the invention have a mean size of between 1 and 60 pm, in particular between 5 and 40 pm and more particularly between 5 and 30 pm or between 5 and 25 pm.

According to a particular embodiment, the sporopollenin particles used according to the present invention are of homogeneous size.

The term "of homogeneous size" means that they have a moderate size polydispersity.

The sporopollenin particles used according to the present invention may be in various forms, as has begun to be described above.

The sporopollenin particles used according to the present invention may be filled or may include at least one cavity, in particular from one to three cavities. Said cavity or cavities denote the hollow or empty central part of the sporopollenin particles obtained on conclusion of the process described above.

Even more preferentially, the form of the sporopollenin particles corresponds to that in which they exist in the natural state, before performing a process as described previously.

Preferably, they may be in the form of spheroids, characterized by an aspect ratio of between 0.2 and 1, preferentially between 0.5 and 1.

The aspect ratio is defined as follows:

Aspect ratio = maximum Feret diameter/minimum Feret diameter with the Feret diameter being a measurement of the size of an object in a specified direction. In general, it may be defined as the distance between the two parallel planes limiting the object perpendicular to this direction. It may be known as the "calliper diameter", in reference to the measurement of the size of the object with a calliper compass. This measurement is used in the analysis of the particle size, for example in microscopy, where it is applied to the projections of a three-dimensional (3D) object onto a 2D plane. In such a case, the Feret diameter is defined as the distance between two parallel tangential lines rather than planes.

Feret diameters are conventionally used for determining the morphologies of particles by image analysis. The sporopollenin particles according to the present invention are thus generally in the form of hollow "shells” which may have more or less pronounced openwork.

Furthermore, the morphology or surface topology of said particles is entirely dependent on the nature of the pollen grains or spores from which said particles are derived. Typically, the particles are not smooth but, on the contrary, have surface roughnesses, either projecting parts or hollows.

According to a preferred embodiment of the invention, the sporopollenin particles used according to the present invention have an outer surface which conforms in terms of topology with the pollen grains and/or spores from which they are derived, i.e. in the natural state.

According to another embodiment, the surface topology of the sporopollenin particles used in the context of the present invention are similar from one particle to another.

Without the Applicant being bound by any theory, the optical properties arising from the sporopollenin particles are estimated to be at least partly due to the presence of repeating units, and in particular the projecting or hollow surface roughnesses, mentioned previously. The light scattering modified by this surface state gives rise to the soft-focus effect that is desired in the context of the present invention.

As regards the mattifying effect, the morphology of the sporopollenin particles, in particular having a hollow core, is also of a nature to absorb excess sebum.

According to another preferred embodiment of the invention, the particles used according to the invention are the outer walls (exines) of pollens of Lycopodium clavatum (particle A) and of Helianthus annuus (particle B). These are preferentially obtained according to a process which conserves their integrity, according to the definition given above. By way of illustration, SEM (scanning electron microscopy) images are shown in figure 3.

Details are provided hereinbelow regarding, respectively, particle A and particle B .

Particle A More particularly, the following reference describes the production of one of the preferred particles used according to the invention derived from Lycopodium clavatum : S. L. Atkin etal., UV and visible light screening by individual sporopollenin exines derived from Lycopodium clavatum (club moss) and Ambrosia trifida (giant ragweed), J. Photochem. Photobiol. B: Biology, 2011, 102, page 209.

Particle A has a potato-like shape, i.e. an imperfect sphere shape, or even a flattened shape, with surface hollows. Particle A has a central cavity. The mean size of particle A is between 25 and 35 pm and is typically equal to 30 pm.

Particle B

Moreover, the following reference describes the production of another of the preferred particles used according to the invention derived from Helianthus annuus : R. C. Mundargi et al., Extraction of sporopollenin exine capsules from sunflower pollen grains, RSC Adv. 2016, 6, page 16533.

Particle B has a shape close to that of a sphere, with projecting surface roughnesses. Particle B has a single central cavity. Particle A has a central cavity. The mean size of particle A is between 20 and 30 pm, in particular between 22 and 28 pm and is typically equal to 25 pm.

The mean sizes of the sporopollenin particles and in particular of particles A and B described above may be measured in particular by laser particle size analysis or by SEM image analysis.

Thus, according to a particular embodiment, the present invention is directed toward the use of sporopollenin particles as fillers for limiting skin sheen and/or form asking skin imperfections in cosmetic care and/or makeup compositions, characterized in that the sporopollenin particles originate from at least one pollen and/or spore of Lycopodium clavatum, of Helianthus annuus or mixtures thereof.

According to a further aspect, the present invention is directed toward the use of sporopollenin particles for limiting skin sheen and/or form asking skin imperfections in cosmetic care and/or makeup compositions, characterized in that the sporopollenin particles originate from at least one pollen and/or spore of Lycopodium clavatum, of Helianthus annuus or mixtures thereof. According to a further aspect, the present invention is directed toward a cosmetic care and/or makeup process for mattifying the skin, notably greasy and/or shiny skin, and/or for hiding skin imperfections, comprising the application to said skin of a composition comprising, in a physiologically acceptable medium, at least sporopollenin particles, characterized in that the sporopollenin particles originate from at least one pollen and/or spore of Lycopodium clavatum, of Helianthus annuus or mixtures thereof.

The sporopollenin particles used according to the invention are in solid form. They are insoluble in the medium of the composition, irrespective of the temperature at which the composition is manufactured.

Furthermore, in the context of the present invention, the sporopollenin particles are not used as vehicle capable of releasing active agents or as particles for encapsulation, or in composite form, as described in the prior art.

As a result of their composition, the particles used according to the invention have great strength, which avoids their chemical degradation (for example acidic or basic pH) and their physical impairment (temperature, light, impacts, friction, etc.).

Still as a result of their composition, since sporopollenin is a highly crosslinked material and is thus renowned for its insolubility, the particles used according to the invention are compatible with a very wide variety of solvents, which means that they can be used in a wide variety of cosmetic care and/or makeup formulations.

Cosmetic compositions

The cosmetic compositions in which the sporopollenin particles as described previously are used are intended to limit skin sheen and/or to hide skin imperfections, as described previously.

The sporopollenin particles as described previously are used as fillers, i.e. in the form of dispersed particles, more particularly of soft-focus fillers. In other words, these sporopollenin particles are not used in dissolved form.

The compositions in which the sporopollenin particles in the context of the present invention are used have improved properties in terms of mattifying and/or soft- focus effect. Said cosmetic compositions comprise a physiologically acceptable medium, i.e. a nontoxic medium which can be applied to a human keratin material, in particular the skin, and more particularly to facial skin, and which has a pleasant appearance, odor and feel.

In particular, said cosmetic compositions are intended for mattifying the skin.

Said cosmetic compositions may notably be applied to greasy and/or shiny skin.

In particular, said cosmetic compositions are intended for hiding imperfections chosen from age-related wrinkles or fine lines.

Said cosmetic compositions may notably be applied to aged skin.

In particular, said cosmetic compositions are intended for hiding imperfections chosen from pores or dilated pores, microrelief irregularities, notably associated with hyperkeratinization and acne scars.

Said cosmetic compositions may notably be applied to skin presenting with dilated pores and/or microrelief irregularities.

In particular, said cosmetic compositions are intended for hiding a nonuniform complexion.

Said cosmetic compositions may notably be applied to skin presenting a nonuniform complexion.

According to one aspect of the present invention, the sporopollenin particles may be used in cosmetic compositions in a content of between 0.5% and 30%, in particular between 1% and 20% and even more particularly between 2% and 10% by weight relative to the total weight of the composition.

Said cosmetic compositions may comprise a mixture of sporopollenin particles of different origins.

The compositions in which the sporopollenin particles as described previously are used may be in any form. For example, such a composition may be a paste, a solid, a gel, a cream or a powder. It may be an emulsion, such as an oil-in-water or water-in-oil emulsion, a multiple emulsion such as an oil-in-water-in-oil emulsion or a water-in-oil-in- water emulsion, or a solid, rigid or supple gel, including anhydrous gels. A cosmetic composition may also contain various adjuvants commonly used in the cosmetic field, such as fillers; preserving agents; sequestrants; fragrances; cosmetic active agents, for instance cicatrizing agents and/or antipollution agents.

Needless to say, a person skilled in the art will take care to select this or these optional additional compound(s), and/or the amount thereof, such that the advantageous properties of the cosmetic composition are not, or are not substantially, adversely affected by the envisioned addition.

According to a particular embodiment of the invention, the cosmetic composition may also comprise other mattifying and/or soft-focus fillers.

The term “additional mattifying agent” means agents other than the sporopollenin particles, which are intended to make the skin visibly more matt and less shiny.

The additional mattifying agent may notably be chosen from a rice starch or a corn starch, kaolinite, silicas, talc, a pumpkin seed extract, cellulose microbeads, plant fibers, synthetic fibers, in particular polyamide fibers, expanded acrylic copolymer microspheres, polyamide powders, silica powders, polytetrafluoroethylene powders, silicone resin powders, acrylic copolymer powders, wax powders, polyethylene powders, powders of elastomeric crosslinked organopolysiloxane coated with silicone resin, talc/titanium dioxide/alumina/silica composite powders, amorphous mixed silicate powders, acrylic polymer powders, silicate particles and notably mixed silicate particles, and mixtures thereof.

Preferred mattifying agents that may be used according to the invention include a pumpkin seed extract, a rice or corn starch, kaolinite, silicas, talc, polyamide powders, polyethylene powders, acrylic copolymer powders, expanded acrylic copolymer microspheres, silicone resin microbeads and mixed silicate particles, and mixtures thereof.

In addition, the cosmetic composition used according to the present invention may also comprise an antiaging active agent and/or an active agent acting on greasy skin, a UV-screening agent, a depigmenting agent or a moisturizer.

This or these active agent(s) may represent from 0.01% to 50%, preferably from 0.1% to 25% and better still from 0.5% to 10% by weight relative to the total weight of the composition. The cosmetic compositions may be in the form of dyed or undyed dermatological compositions, or in the form of skincare and/or lipcare compositions, or in the form of antisun compositions or makeup-removing products. They may notably be used as a care base for the skin or the lips (lip balm for protecting the lips against the cold and/or sunlight and/or the wind, or a care cream for the skin, the nails or the hair).

The cosmetic compositions may also be in the form of colored skin makeup products, in particular a foundation, optionally having care properties, a blusher, a face powder, an eyeshadow, a concealer product, an eyeliner, a body make up product; a lip makeup product such as a lipstick, optionally having care or treating properties.

Dyestuffs

A cosmetic composition in which the sporopollenin particles are used may comprise at least one dyestuff (also known as a coloring agent), which may be chosen from water-soluble or liposoluble dyes, pigments and nacres, and mixtures thereof.

The presence of a dyestuff is more particularly advantageous for affording, in combination, a coloring makeup effect, but also coverage of the skin.

Thus, according to one variant, a cosmetic composition also contains at least one dyestuff, notably at least one pigment. According to this variant, a cosmetic composition may be in the form of a foundation.

In particular, a cosmetic composition may comprise one or more dyestuffs chosen from water-soluble dyes and pulverulent dyestuffs, for instance the pigments, nacres and glitter flakes that are well known to those skilled in the art.

The dyestuffs may be present in the composition in a content ranging from 0.01% to 20% by weight, relative to the weight of the composition, preferably from 0.1% to 15% by weight.

The term "pigments" should be understood as meaning white or colored, mineral or organic particles that are insoluble in an aqueous solution, which are intended to color and/or opacify the resulting film.

The pigments may be present in a proportion of from 0.01% to 20% by weight, notably from 0.1% to 15% by weight and in particular from 0.2% to 10% by weight, relative to the total weight of the cosmetic composition. As mineral pigments that may be used in the invention, mention may be made of titanium oxides, zirconium oxides or cerium oxides, and also zinc oxides, iron oxides or chromium oxides, ferric blue, manganese violet, ultramarine blue and chromium hydrate.

Among the organic pigments that may be used in the invention, mention may be made of carbon black, pigments of D&C type, lakes based on cochineal carmine or on barium, strontium, calcium or aluminum, or alternatively the diketopyrrolopyrroles (DPPs) described in EP-A-542 669, EP-A-787 730, EP-A-787 731 and WO-A-96/08537.

The term“nacres” should be understood as meaning colored particles of any form, which may or may not be iridescent, notably produced by certain molluscs in their shell, or alternatively synthesized, and which have a color effect via optical interference.

The nacres may be chosen from nacreous pigments such as titanium mica coated with an iron oxide, titanium mica coated with bismuth oxychloride, titanium mica coated with chromium oxide, titanium mica coated with an organic dye and also nacreous pigments based on bismuth oxychloride. They may also be mica particles, at the surface of which are superposed at least two successive layers of metal oxides and/or of organic dyestuffs. Examples of nacres that may also be mentioned include natural mica coated with titanium oxide, with iron oxide, with natural pigment or with bismuth oxychloride.

Among the nacres available on the market, mention may be made of the nacres TIMICA, FLAMENCO and DUOCHROME (based on mica) sold by the company ENGELHARD, the TIMIRON nacres sold by the company MERCK, the PRESTIGE mica- based nacres sold by the company ECKART, and the SUNSHINE synthetic mica-based nacres sold by the company SUN CHEMICAL.

Preferably, the pigments and/or nacres may be present in the cosmetic composition in a total content ranging from 0.01% to 20% by weight, relative to the weight of the composition, preferably from 0.1% to 15% by weight.

The term "dyes" should be understood as meaning compounds that are generally organic, which are soluble in fatty substances such as oils or in an aqueous- alcoholic phase.

The cosmetic composition may also comprise water-soluble or liposoluble dyes. The liposoluble dyes are, for example, Sudan red, DC Red 17, DC Green 6, b- carotene, Sudan brown, DC Yellow 11, DC Violet 2, DC Orange 5 and quinoline yellow. The water-soluble dyes are, for example, beetroot juice or methylene blue.

Needless to say, according to another variant, a cosmetic composition is free of dyestuff and in particular of color other than white.

According to this variant, a composition may notably be in the form of a white cream. The main purpose of such a composition is usually to afford a moisturizing effect in combination with the effect desired according to the invention.

The invention also relates to the cosmetic use of a cosmetic composition comprising, in a physiologically acceptable medium, sporopollenin particles as described previously, to limit skin sheen and/or to hide skin imperfections, such as wrinkles, fine lines, pores or dilated pores and microrelief irregularities, notably associated with hyperkeratinization and acne scars and a nonuniform complexion.

Finally, the invention relates to a cosmetic care and/or makeup process for mattifying the skin, notably greasy and/or shiny skin, and/or for hiding skin imperfections, comprising the application to said skin of a composition comprising, in a physiologically acceptable medium, sporopollenin particles, said imperfections possibly being chosen from wrinkles, fine lines, pores or dilated pores and microrelief irregularities, notably associated with hyperkeratinization and acne scars and a nonuniform complexion.

The invention will now be illustrated by the nonlimiting examples that follow.

Example

Particles consisting of sporopollenin were used in cosmetic compositions of emulsion type. These compositions comprising sporopollenin particles were compared with compositions free of fillers (reference composition).

Particles A and B are those mentioned in the description above.

The proportions indicated in the table below are indicated as mass percentages. [Table 1]

¹ Trade name HOST ACERIN AMPS sold by the company CLARIANT 2Trade name Silsoft 880 sold by the company MOMENTIVE PERFORMANCE MATERIALS

3 Trade name FUCOGEL 1.5P sold by the company SOLABIA

Demonstration of the efficacy (optical effects)

A/ Evaluation of the mattifying effect (gloss measurement)

The gloss of a deposit resulting from the application of a composition may be commonly measured according to various methods, such as the method using a Byk MicroTri- Gloss glossmeter.

Principle of the measurement using this glossmeter

The machine illuminates the sample to be analyzed at a certain incidence and measures the intensity of the specular reflection. The intensity of the reflected light depends on the material and on the angle of illumination. For non-ferrous materials (paint, plastic), the intensity of reflected light increases with the angle of illumination. The rest of the incident light penetrates the material and, depending on the shade of the color, is either partly absorbed or scattered.

The reflectometer measurement results are not based on the amount of incident light but on a polished black glass standard of defined refractive index. The measurement is normalized relative to an internal standard and brought to a value out of 100: for this calibration standard, the measurement value is set at 100 gloss units (calibration). The closer the measured value is to 100, the more glossy the sample. The measurement unit is the Gloss Unit (GU).

Test protocol

a- Spread a coat with a wet thickness of 30 pm of the composition whose mean gloss value it is desired to evaluate onto a LENETA brand contrast card of reference FORM 1A PENOPAC, using an automatic spreader. The coat covers the white background and the black background of the card.

b- Leave to dry for 24 hours at 37°C.

c - Measure the gloss at 60° on the absorbent white background

(3 measurements) using a Byk Gardner brand glossmeter of reference microTri-Gloss.

The measured values in GU obtained for the various test compositions should then be compared. The lower the value measured, the more matt the deposit (desired effect).

B / Evaluation of the correcting effect on skin imperfections (soft-focus)

Operating conditions

The optical properties of the test compositions are characterized by means of a Haze measurement (veil or tracing-paper effect) with a commercial Hazemeter machine.

The measurements are taken according to the following protocol: a- On a transparent plastic film (Byk), spread a coat with a wet thickness of 25.4 pm of the composition whose Haze it is desired to evaluate, using an automatic spreader. b- Leave to dry for 1 hour at room temperature (20°C-25°C). c- Measure the Haze index using a BYK GARDNER brand HAZEGARD machine. The Haze corresponds to the scattered transmitted light/total transmitted light. The results are expressed as percentages. The greater the Haze value, the higher the soft- focus effect (Haze index).

C/ Results

[Table 2]

A significant increase in the soft focus (Haze) is observed with composition A or, respectively, with composition B, comprising the sporopollenin particles A or, respectively, the sporopollenin particles B, used according to the invention, relative to the reference composition not containing any sporopollenin particles.

A significant decrease in the gloss is also observed with compositions A and B comprising the particles used according to the invention. This gloss-reducing effect is significantly greater than that obtained with the similar reference composition, not comprising any filler.