New cosmetic uses of closed-pore porous spheres of metal oxides.

Abstract

The present invention relates to the cosmetic use of closed-pore porous spheres containing a metal oxide for improving the appearance and / or comfort of the skin and skin appendages, in particular the hair and / or mucous membranes.The invention further relates to cosmetic or pharmaceutical compositions containing said spheres.

Description

[Technical field]

[0001] The present invention relates to the cosmetic use of porous spheres of metal oxides with closed pores for improving the aesthetic appearance and comfort of the skin and skin appendages, more particularly the hair and / or mucous membranes, as well as to said cosmetic compositions and the resulting cosmetic treatment methods.The present invention also relates to pharmaceutical compositions, in particular dermatological compositions, comprising porous spheres of metal oxides with closed pores for improving the comfort of the skin, skin appendages and / or mucous membranes exhibiting a pathological condition. [Background technology]

[0002] Visually improving the appearance of skin and hair is one of the main challenges in cosmetology. Cosmetic consumers are constantly searching for cosmetic solutions to effectively mask signs on the skin and / or hair that are considered unaesthetic. These signs appear naturally with age, but can also result from chronic exposure to various factors. These can be environmental factors such as pollution, wind, climate change, especially excessive temperature fluctuations due to air conditioning, and dryness. They can also be aggressive factors of a mechanical nature, such as shaving, rubbing and hair removal, and / or aggressive factors of a chemical nature, such as hair treatments, especially coloring (bleaching), permanent waves and straightening, cleansing agents, and exfoliating treatments. These factors cause damage to the skin, skin appendages and / or mucous membranes, which is often reflected in visible symptoms that are considered unaesthetic. Intrinsic factors contribute to their development, especially stress, hormonal changes, weight gain, diet, dehydration and aging. Genetics, especially skin type (sensitive, hyperseborrheic, reactive, etc.), and ethnic origin, e.g. Caucasian, Asian or African, also play an important role in the development of certain manifestations.

[0003] Non-aesthetic skin conditions are in particular wrinkles and fine lines, such as frown lines and crow's feet. They may be aging or senile fine lines. They are initially superficial, such as nasogenic furrows, and then become deeper. Skin conditions also include volume loss, especially sagging skin, signs of loosening of facial contours, leading to sagging facial features that give a sad or tired appearance, or loss of density resulting in thin, weakened skin with loss of radiance and / or so-called dull complexion. Non-aesthetic skin conditions therefore also include color and luster symptoms as well as pigmentary symptoms, such as further loss of complexion and loss of radiance, dark spots, pockets, redness, brown spots or age spots or white spots, especially vitiligo, rosacea, pregnancy complexion, melasma, birthmarks and hemangiomas. They also include skin imperfections such as keratin plugs, visible pores, pimples, scars, especially acne scars, burns, wounds, stretch marks, as well as rough skin and peeling. On mucous membranes, the non-aesthetic symptoms are generally signs of dehydration such as scales and / or cracks. With respect to hair, the non-aesthetic symptoms are generally dull, depigmented, brittle, difficult to style, and unruly hair, especially with split ends.

[0004] These conditions, especially those manifested on the face and eyes, are particularly perceived by consumers as unaesthetic. Some of them can be corrected by cosmetic surgery, but this is not always the case, and the results are unsatisfactory, partial, unnatural, irritating, or even painful, and are often expensive. Many consumers cannot afford the cost, or are opposed to it. To mask or reduce these undesirable conditions, many cosmetic alternatives exist. Makeup, more specifically foundation, aims to provide a solution to hide wrinkles and brighten the complexion. However, consumers also want a good-looking effect that remains natural without the pigment transferring to clothing, and a well-being effect during application.

[0005] The blurring or "soft focus" effect in the cosmetics industry is used in anti-aging creams and make-up. Skin surface imperfections such as fine lines and wrinkles trap light in the microscopic gaps formed by the wrinkles, making the skin appear uneven. The trapped light is then absorbed, producing spots that appear on the surface of the skin. There are special pigments and / or particles, such as transparent alumina platelets coated with a thin layer of titanium dioxide, that are designed to create this artistic blurring effect by diffusing the light evenly at the skin surface. The wrinkles and fine lines are masked by remaining fairly translucent over the entire surface of the skin, thereby giving the skin a natural look while reducing the appearance of the imperfections. To achieve this "soft focus" effect, the pigment / particles must exhibit the following optical properties: -High total transmittance (complete transmission of light) for a natural look, and -Maximum diffusion ("haze") to create a translucent and even distribution of light, which significantly minimizes the appearance of fine lines and wrinkles, helping older consumers achieve a younger looking, brighter skin.

[0006] Total transmittance is affected by light absorption and reflection, while haze is affected by light scattering. Haze is an important appearance attribute because it directly affects human perception and plays a key role in consumer demand. It reflects the degree of blur or cloudiness of a transparent material. The value is expressed as a percentage. The higher the value, the greater the blur.

[0007] Porous metal oxide spheres have already been described in WO 2020 / 183108 and WO 2020 / 182936 in the context of cosmetic applications, more particularly for improving the appearance of the skin, skin appendages and / or mucous membranes by masking non-aesthetic symptoms. However, these spheres have open porosity and therefore no closed pores, as shown in Figure 1B. The percentage of closed pores by volume of these spheres (%age) is therefore less than 5%.

[0008] The inventors have surprisingly determined that porous spheres of metal oxides with closed pores have an improved effect on masking defects compared to the open pore porous spheres of the prior art. Indeed, such spheres have higher total transmittance values ​​and higher blurring or diffusion ("haze") values, thus making it possible to improve their blurring / masking ("soft focus") properties. Moreover, such spheres are easier to formulate, since the external formulation medium, and in particular the compounds present in this medium, cannot penetrate them, and therefore can maintain a constant net refractive index regardless of the formulation medium and / or type of formulation, thus avoiding changes in their optical properties, and therefore their masking properties, depending on the formulation medium used. These spheres are particularly shown in FIG. 1B. Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention therefore aims to meet this constant need for cosmetic alternatives to improve the appearance of the skin, skin appendages and / or mucous membranes, in particular by masking non-aesthetic symptoms, advantageously by a "soft focus" effect. The present invention also aims to provide new cosmetic ingredients that are easy to formulate, have no side effects and in particular do not induce irritation to the skin. [Means for solving the problem]

[0010] The spheres according to the invention have in fact a unique ability to reflect and diffuse light, thus making it possible to smooth the surfaces of the skin, skin appendages and / or mucous membranes, thus concealing their non-aesthetic manifestations and increasing their radiance. They also impart a soft, silky feel to the compositions containing them.

[0011] The spheres according to the invention offer the advantage of being suitable for all skin types, skin tones and radiances. Another advantage of the invention is that the spheres have great stability and can be used in the form of powders or compositions. They are inert, which makes them easy to formulate with any nature of cosmetic or dermatological composition, whether such composition is lipophilic or hydrophilic.

[0012] Another advantage is that the spheres can be used together with conventional components of cosmetic compositions, more particularly cosmetic make-up and / or care compositions, in particular pigments or colorants, to help conceal non-aesthetic conditions, more particularly imperfections.

[0013] According to one advantageous embodiment, the spheres according to the invention can be used in foundations and / or make-up and / or care products.

[0014] Thus, one subject of the present invention is the non-therapeutic cosmetic use of porous spheres with closed pores comprising a metal oxide for improving the appearance and / or comfort of the skin, skin appendages, in particular hair, and / or mucous membranes.

[0015] According to the invention, the expression "porous spheres with closed pores" means a sphere in which the majority of the pores (more than 50% by volume) are closed pores, i.e. pores that do not have an opening outside the sphere. More particularly, at least 90% by volume of the pores are closed pores, more advantageously at least 95% by volume of the pores are closed pores, and even more advantageously at least 99% by volume of the pores are closed pores. The volume percentage of closed pores is measured on the basis of images of the spheres obtained by scanning electron microscopy (SEM). It can be defined as the ratio number of closed pores / total number of pores. The volume of each pore is the same whether it is open or closed, so the percentage by number is the same as the percentage by volume.

[0016] In an advantageous embodiment, the closed pores of the sphere according to the invention are not interconnected with each other. Thus, in this case, the sphere according to the invention comprises a plurality of pores (at least two pores) that are not only closed towards the outside of the sphere but also not interconnected with each other. Thus, the porous sphere according to the invention is advantageously not a hollow sphere. Thus, each pore comprises a void volume (including in particular air) that is inaccessible to the formulation medium, in particular polymers, oligomers and molecules with a molecular weight of more than 5000 g / mol. In an advantageous embodiment, the closed pores are spherical.

[0017] According to the present invention, "sphere" or "spherical" means a particle or pore whose shape has an aspect ratio or width / height ratio close to 1, advantageously between 0.9 and 1.1, more particularly between 0.95 and 1.05, in particular between 0.99 and 1.01, and even more particularly about 1.

[0018] In another advantageous embodiment, the sphere according to the invention is free of pores and / or interconnecting pores.

[0019] Advantageously, the size distribution of the closed pores of the spheres according to the invention is monodisperse or bimodal, advantageously monodisperse.

[0020] According to a preferred embodiment, the porous spheres with closed pores according to the invention have an average diameter measured by scanning electron microscopy (SEM) in the range of 0.5 μm to 100 μm and / or an average porosity in the range of >0.10 to 0.80 and / or an average pore size, more particularly of the closed pores, measured by scanning electron microscopy (SEM) in the range of 50 nm to 800 nm, advantageously in the range of 50 nm to 500 nm.

[0021] According to another preferred embodiment, the porous spheres with closed pores according to the invention have an average diameter measured by scanning electron microscopy (SEM) in the range of 1 μm to 100 μm and / or an average porosity in the range of >0.10 to 0.80 and / or an average pore size, more particularly of the closed pores, measured by scanning electron microscopy (SEM) in the range of 50 nm to 800 nm, advantageously in the range of 50 nm to 500 nm.

[0022] Advantageously, the porous spheres with closed pores according to the invention have an average diameter measured by scanning electron microscopy (SEM) in the range of 0.5 μm to 100 μm, an average porosity in the range of >0.10 to 0.80, and an average pore size, more particularly closed pores, measured by scanning electron microscopy (SEM) in the range of 50 nm to 800 nm.

[0023] In particular, advantageously, the porous spheres with closed pores according to the invention have an average diameter measured by scanning electron microscopy (SEM) in the range of 1 μm to 100 μm, an average porosity in the range of more than 0.10 to 0.80, and an average pore size, more particularly closed pores, measured by scanning electron microscopy (SEM) in the range of 50 nm to 800 nm.

[0024] Preferably, the metal oxide of the porous spheres having closed pores according to the invention is selected from silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, cerium oxide, iron oxide, zinc oxide, indium oxide, tin oxide, chromium oxide, mixed metal oxides and combinations thereof, preferably silicon oxide, titanium oxide, aluminum oxide and zinc oxide and combinations thereof, more preferably silicon oxide, titanium oxide and combinations thereof, particularly preferably silicon oxide.

[0025] In one advantageous embodiment, the porous spheres with closed pores according to the invention comprise, based on the total weight of the sphere, 60% to 99.9% by weight of metal oxide, 0.1% to 40% by weight of light absorber and, advantageously, 0.1% to 40% by weight of carbon black.

[0026] Preferably, the porous spheres having closed pores according to the present invention have an average diameter measured by scanning electron microscopy (SEM) in the range of 1 μm to 100 μm, and an average pore size measured by scanning electron microscopy (SEM) in the range of 50 nm to 800 nm.

[0027] Preferably, the porous spheres having closed pores according to the present invention have an average diameter measured by scanning electron microscopy (SEM) in the range of 1 μm to 75 μm and an average porosity in the range of 0.45 to 0.70, preferably 0.5 to 0.65.

[0028] According to one particular embodiment of the invention, the porous spheres with closed pores according to the invention have an average diameter measured by scanning electron microscopy (SEM) in the range of 2.5 μm to 8 μm, an average porosity in the range of 0.45 to 0.70, and an average pore size, more specifically closed pores, measured by scanning electron microscopy (SEM) in the range of 100 nm to 200 nm.

[0029] Advantageously, the use according to the invention is for reducing the visibility of non-aesthetic manifestations of the skin, skin appendages and / or mucous membranes, more particularly irregularities in the relief and / or texture of the skin, mucous membranes and / or skin appendages and / or irregularities in the colour of the skin and / or mucous membranes.

[0030] According to one particular embodiment of the invention, the porous spheres having closed pores according to the invention are present in an amount of 1×10 -3 It is present in the cosmetic composition at a concentration ranging from 0.5% to 5% by weight.

[0031] Advantageously, the use according to the invention is for improving the organoleptic properties of a cosmetic composition.

[0032] Another subject of the present invention is a cosmetic care method for improving the appearance and / or comfort of the skin, skin appendages, in particular hair and / or mucous membranes, which comprises the topical application of porous spheres with closed pores comprising a metal oxide and / or a cosmetic composition comprising same to at least one area of ​​the skin and / or skin appendages and / or mucous membranes.

[0033] In particular, porous spheres having closed pores are as described above.

[0034] Advantageously, the cosmetic care method according to the invention is intended to reduce the visibility of non-aesthetic manifestations of the skin, skin appendages and / or mucous membranes, more particularly irregularities in the relief and / or texture of the skin, mucous membranes and / or skin appendages and / or irregularities in the colour of the skin and / or mucous membranes.

[0035] In one advantageous embodiment, the areas of the skin and / or skin appendages and / or mucous membranes of the body are selected from the skin of the forehead, cheeks, nose, temples, the so-called "T" zone (forehead, nose, chin), under the eyes, the facial skin including the periorbital area, more particularly the chin, scalp, neck, back, shoulders, arms, forearms, thorax, hands, hair, beard, eyelashes, eyebrows, bust, more particularly the neckline, abdomen and / or armpits, legs, feet, hands, neck, thighs, hips, buttocks, waist, torso, lip contour, hair, hair and / or eyes, lips and / or cheek mucous membranes, preferably darkened skin of the face, hands or neckline.

[0036] Another subject of the invention is a cosmetic composition containing these porous spheres with closed pores, especially for the uses mentioned, and optionally cosmetically acceptable excipients.

[0037] Advantageously, the cosmetic composition according to the invention is in the form of a serum, a lotion, a cream, a shampoo, a conditioner, an oil, a milk, an ointment, a paste, a mousse or foam, an emulsion, a hydrogel, a shower gel, a mask, a lacquer, a spray, a wax, a powder, in particular a make-up, or a stick.

[0038] Advantageously, the cosmetic composition according to the invention is in the form of a slightly gelled composition and / or comprises an oily phase, preferably an oily composition or an oil-in-water or water-in-oil emulsion or lotion type.

[0039] Another subject of the present invention is a pharmaceutical composition, more particularly a dermatological composition, containing these porous spheres with closed pores and, optionally, pharma- ceutically acceptable, more particularly dermatologically acceptable excipients.

[0040] Another subject of the present invention is a pharmaceutical composition according to the invention, preferably dermatological, for use in improving the comfort of the skin, skin appendages and / or mucous membranes, in particular those which present a pathological condition and in particular which manifest itself in a loss of homogeneity and / or deregulation and / or irregularities in color, complexion, sebum secretion and / or relief, such as hyperpigmented, hypopigmented, hyperseborrheic, reactive, inflammatory and atopic skin, in particular skin affected by vitiligo, melanoma, couperose, telangiectasia, acne, rosacea, urticaria, psoriasis, herpes, impetigo, ecthyma, erysipelas, and / or wounds and / or scars, in particular skin presenting acne, pimples, boils, varicose veins, melasma, folliculitis, abscesses, or any combination thereof.

[0041] The present invention also relates to the use of porous spheres with closed pores according to the invention for preparing a pharmaceutical composition according to the invention, preferably dermatological, intended to improve the comfort of the skin, skin appendages and / or mucous membranes, which present in particular a pathological condition and which manifests itself in particular in a loss of homogeneity and / or deregulation and / or irregularities in color, complexion, sebum secretion and / or relief, such as hyperpigmented, hypopigmented, hyperseborrheic, reactive, inflammatory and atopic skin, in particular skin affected by vitiligo, melanoma, couperose, telangiectasia, acne, rosacea, urticaria, psoriasis, herpes, impetigo, ecthyma, erysipelas, and / or wounds and / or scars, in particular skin presenting acne, pimples, boils, varicose veins, melasma, folliculitis, abscesses, or any combination thereof.

[0042] Such a cosmetic or pharmaceutical, preferably dermatological, composition advantageously contains 1×10 -3 The spheres are contained in a concentration ranging from 0.5% to 5% by weight, preferably from 0.5% to 10% by weight.

[0043] The use according to the invention is preferably cosmetic, preferably by topical application in humans to at least one affected or healthy area of ​​the skin, healthy mucous membranes and / or healthy skin appendages, preferably hair.

[0044] For the purposes of the present invention, "cosmetic use" is understood to mean the non-therapeutic, non-pharmaceutical use of the spheres according to the invention, preferably on healthy skin, in particular on healthy scalp and / or on healthy skin appendages, more particularly on healthy hair and / or on healthy mucous membranes.

[0045] For the purposes of the present invention, the term "healthy" parts of the skin, preferably of the scalp and / or of the mucosa and / or of the skin appendages and / or of areas of the skin, preferably of the scalp and / or of the mucosa and / or of the skin appendages, and / or of areas of the skin, preferably of the scalp and / or of the mucosa and / or of the skin appendages, that have been certified by a dermatologist as non-pathological, i.e. not suffering from skin diseases or conditions such as infection, inflammation, in particular in the form of sunburn, folliculitis, candidiasis, psoriasis, ichthyosis, eczema, acne, impetigo, blisters, abscesses, herpes, eczema, erysipelas or dermatitis, varicose veins, couperose or telangiectasias, pathologies or wounds or burns, sunburn or lesions or not reactive or atopic skin, is understood to mean areas of the skin, preferably of the scalp and / or of the mucosa and / or of the skin appendages and / or of the skin, preferably of the scalp and / or of the mucosa and / or of the skin appendages. In particular, it is the part of the skin and / or mucous membranes that is made up of cells that doctors qualify as "normal", ie non-cancerous cells.

[0046] As used herein, the term "topical application" means the application of the spheres according to the invention, optionally in the form of active ingredients and / or compositions, in particular by direct application or vaporization, to the surface of the skin, including the scalp, skin appendages, in particular the hair, and / or mucous membranes.

[0047] The term "improving appearance" means reducing or diminishing the visibility of non-aesthetic conditions, especially by filling and / or optical effects, and in particular preferably masking or concealing those present on the face.

[0048] According to the invention, a "non-aesthetic condition" is a non-aesthetic irregularity in the relief and / or texture of the skin, mucous membranes and / or skin appendages and / or an irregularity in the colour of the skin, mucous membranes and / or skin appendages.

[0049] According to the invention, non-aesthetic irregularities in the relief and texture of the skin are those caused by wrinkles and fine lines, in particular frown lines and crow's feet, unevenness, wrinkles, dilated pores, rough appearance, marks and scars, in particular wounds, acne, pimples, burns and / or stretch marks.

[0050] According to the invention, skin colour irregularities are pigmented spots, in particular white spots or age spots, in particular age spots or hyper- or hypopigmented spots, pregnancy complexion, moles, melanomas, red spots, redness, but also loss of brightness in the complexion, dull complexion, dark spots and pockets, rosacea and couperose.

[0051] According to one preferred embodiment, the non-aesthetic symptoms are selected from wrinkles, fine lines, keratin plugs, visible pores, loss of complexion radiance, dull complexion, dark spots, pockets, pigmented spots and any mixture thereof.

[0052] The non-aesthetic symptoms of the skin appendages, preferably hair, are a dull and brittle appearance. In the case of hair, symptoms also include a brittle, fragile, damaged appearance and / or difficulties in shaping them, particularly in the case of hair, when styling them, and / or split ends.

[0053] Non-aesthetic symptoms of the mucosa include a dull, cracked, withered and / or damaged appearance, and flaky scaling.

[0054] In general, improvement of non-cosmetic symptoms can be visualized and evaluated by microscopy and / or high resolution photographic analysis, particularly with measurements of brightness of areas of the skin, mucosa and / or skin appendages.

[0055] The improvement in complexion radiance, i.e. "glow", can in particular be measured by objective instrumental methods. This in vivo measurement method consists of taking high-resolution photographs in a cross-polarized configuration of the face of a volunteer taken at 45° before and after application of the test product. Based on these digital photographs, image analysis allows the extraction and quantification of specific parameters (e.g. L*, a*, b*, C, h°) related to skin color, radiance, uniformity and texture.

[0056] Similarly, gloss can be specifically measured according to this method based on high-resolution photographs of the faces of volunteers taken at 45° in cross-polarized and parallel-polarized configurations before and after application of the test product. Based on these digital photographs, image analysis allows the extraction and quantification of specific parameters related to gloss, such as specular gloss and contrast gloss.

[0057] For the purposes of the present invention, the term "reducing the visibility of skin pores" means masking skin pores, especially by filling and / or optical effects.

[0058] The visibility of skin pores can be demonstrated in vivo by objective instrumental methods (image analysis) that allow the extraction and quantification of certain parameters from high-resolution photographs in cross-polarized configuration of the face of volunteers taken before and after application of a composition containing spheres according to the invention. The density of skin pores can also be measured in vivo by measuring the so-called curvature parameters, in particular by imaging with fringe projection techniques.

[0059] In one preferred embodiment of the invention, the spheres according to the invention are in an amount effective to reduce the visibility of skin pores by at least 10%, preferentially at least 20%, after application of a cream containing the spheres according to the invention, more preferentially prepared under the conditions described in any one of Examples 1 to 7 and preferentially formulated in the form of a cosmetic composition as described in Examples 9 and 10.

[0060] "Mucosa" means ocular, vaginal, urogenital, anal, nasal and / or buccal, labial and / or gingival mucosa, preferably ocular, and / or buccal and / or labial and / or gingival mucosa.

[0061] In the context of the present invention, the term "improved comfort" is understood to mean increasing the sensory properties, more particularly the feel and spreadability of the composition, in particular by a soft, silky, light and smooth feel, but also imparting a supple feeling to the area to which the composition containing the spheres is applied. The sensory properties, in particular the feel of the composition, can be evaluated by conventional methods in the art, in particular by evaluation by a person trained to carry out sensory tests on the skin. For a better evaluation, the measurements are made by comparison with a placebo, i.e. by comparison with the same composition that does not contain the spheres according to the invention. This evaluation is preferentially carried out for emulsions.

[0062] Advantageously, the improvement in comfort is analyzed by sensory evaluation of the emulsion described in Example 9. A panel of trained individuals evaluates the composition by applying a given amount of the composition to the forearm. Following a defined procedure, the composition is spread on the skin and its specific properties, such as its absorption, softness and appearance, are evaluated in comparison with a placebo composition. A value between -1 and +1 is given. For example, for the feeling of lightness, the tested composition can be rated +1 to indicate that it is much lighter than a reference composition called placebo, or slightly less light than a placebo composition with a value of -0.5.

[0063] If two compositions provide the same sensation, the individual will show a value of 0 for the evaluated parameter. Such evaluation is carried out blindly in the same manner under the same climatic conditions for the tested composition and the reference composition.Then, the significance and deviation of the evaluation results are evaluated by statistical analysis.

[0064] According to the invention, the expression "skin appendages" is understood to mean the hair, eyelashes, eyebrows, beard, moustache and / or nails, preferably the hair.

[0065] Advantageously, the use according to the invention makes it possible to improve the appearance of the skin by improving the radiance of the complexion, by making it more uniform and lustrous, by giving it a visually pleasing and fresh luminous effect, in particular by concealing non-aesthetic manifestations of the skin's texture, relief and / or color.

[0066] According to another embodiment, the spheres according to the invention also make it possible to soften the skin and / or mucous membranes and / or skin appendages that show signs of discomfort, in particular skin and / or mucous membranes and / or skin appendages that have been exposed to aggressive conditions of a mechanical nature, such as shaving, rubbing, dryness, wind, sun and hair removal, and / or aggressive conditions of a chemical nature, such as hair treatments, in particular (bleaching) coloring, permanent waving and straightening, cleansing agents and exfoliating treatments.

[0067] According to one particular embodiment, the use according to the invention makes it possible to lighten and illuminate the skin, the skin appendages, in particular the hair and / or the mucous membranes, making them more uniform and in particular creating a blur called "soft focus", softening the features and filling irregular lines and marks (in particular, more particularly as a filler for wrinkles).

[0068] The spheres or microspheres according to the present invention are porous metal oxide spheres with closed pores. Such spheres are photonic beads, which means that they have a degree of periodic color variation that affects light waves, including in particular the perception of color, clarity, transparency or brightness.

[0069] The spheres according to the invention comprise a metal oxide and preferably have an average diameter, as measured by scanning electron microscopy (SEM), in the range of 0.5 μm to 100 μm, and / or an average porosity in the range of >0.10 to 0.80, and / or an average pore size, more particularly of closed pores, as measured by scanning electron microscopy (SEM), in the range of 50 nm to 500 nm.

[0070] The microspheres or porous spheres with closed pores according to the invention contain mainly metal oxides. Advantageously, they consist essentially of metal oxides. Preferably, they consist exclusively of metal oxides.

[0071] Advantageously, the porous spheres with closed pores according to the invention contain between 60% and 99.9% by weight of metal oxide, preferably at least 70%, more preferably at least 80%, more preferably at least 90%, more preferably 99.9% by weight of metal oxide, relative to the total weight of the sphere. Thus, in one advantageous embodiment, the porous spheres according to the invention contain at least 70% by weight of metal oxide, relative to the total weight of the sphere.

[0072] According to the present invention, the metal oxide comprises transition metal oxides, semi-metallic and earth metal oxides suitable for cosmetic and / or dermatological applications, such as silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, cerium oxide, iron oxide, zinc oxide, indium oxide, tin oxide, chromium oxide, mixed metal oxides and combinations thereof.Preferably, the metal oxide is selected from the group consisting of SiO2, TiO2, ZnO and mixtures thereof, advantageously from the group consisting of SiO2, TiO2 and ZnO, more advantageously from the group consisting of SiO2, ZnO and mixtures thereof, even more advantageously from the group consisting of SiO2 and ZnO, and more particularly SiO2.In an advantageous embodiment, the metal oxide does not comprise TiO2 and / or a mixture of two or more metal oxides.

[0073] In one particular embodiment, the porous spheres with closed pores according to the invention, more particularly those in which at least 90% of the pores are closed, have an average diameter measured by scanning electron microscopy (SEM) in the range of 1 μm to 100 μm and an average pore size measured by scanning electron microscopy (SEM) in the range of 50 nm to 800 nm, and contain at least 70% metal oxide. In particular, these spheres do not contain TiO2 and / or are not used in combination with and / or in compositions containing anti-UV filters.

[0074] In an advantageous embodiment, the porous spheres with closed pores according to the invention may for example comprise 60% to 99.9% by weight of metal oxide and 0.1% to 40% by weight of light absorber, based on the total weight of the sphere. According to one embodiment of the invention, the porous spheres with closed pores according to the invention contain 0.3% by weight, preferably 0.5% by weight, preferably at least 1% by weight, more preferably at least 5% by weight of light absorber, based on the total weight of the sphere.

[0075] According to an alternative preferred embodiment, the porous sphere with closed pores according to the present invention does not contain light absorbing agent, and / or the cosmetic composition containing the porous sphere with closed pores according to the present invention does not contain light absorbing agent.In particular, light absorbing agents such as TiO2 may have certain toxicity.The present inventors have surprisingly found that the microsphere or sphere according to the present invention has immediate anti-blue light filter effect even without using light absorbing agent.

[0076] Advantageously, the light absorber is selected from the group consisting of organic and inorganic pigments compatible with cosmetic and / or dermatological applications, more particularly with the skin, mucous membranes and / or skin appendages, and more particularly carbon black.

[0077] According to an advantageous preferred embodiment, the porous spheres with closed pores according to the invention have an average diameter, measured by scanning electron microscopy (SEM), ranging from 0.5 μm to 100 μm, advantageously from 1 μm to 100 μm, in which case they are microspheres. Advantageously, therefore, they are not nanospheres, in order to avoid the microspheres according to the invention penetrating into the deep layers of the skin and / or mucous membranes and to have a preferential surface effect. Thus, the microspheres according to the invention advantageously remain on the surface of the skin and / or mucous membranes and / or skin appendages.

[0078] The term "microscale" or "micro" is understood to mean a size range of about 0.5 μm to about 999 μm. The term "nanoscale" or "nano" is understood to mean a size range of about 1 nm to about 999 nm.

[0079] More advantageously, the porous spheres having closed pores according to the present invention have an average diameter measured by scanning electron microscope (SEM) in the range of 1 μm to 75 μm, preferably 2 μm to 70 μm, preferably 3 μm to 65 μm, 4 μm to 60 μm, 5 μm to 55 μm or 5 μm to 50 μm, more preferably 10 μm to 25 μm, e.g. 1 μm, 2 μm, 3 μm, 4 μm, 5 μm In one embodiment, the nanotube has an average diameter as measured by scanning electron microscope (SEM) selected from among the following: 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, or 30 μm.

[0080] In an alternative embodiment, the porous spheres with closed pores according to the present invention have an average diameter as measured by scanning electron microscope (SEM) selected from 4.5 μm, 4.8 μm, 5.1 μm, 5.4 μm, 5.7 μm, 6.0 μm, 6.3 μm, 6.6 μm, 6.9 μm, 7.2 μm, 7.5 μm, 7.8 μm, 8.1 μm, 8.4 μm, 8.7 μm, 9.0 μm, 9.3 μm, 9.6 μm or 9.9 μm.

[0081] In an alternative embodiment, the porous spheres with closed pores according to the invention have an average diameter, measured by scanning electron microscopy (SEM), in the range of 1.3 μm to 10 μm, more particularly 1.5 to 9.9 μm, even more particularly 2.5 μm to 8 μm, for example an average diameter selected from 1 μm, 2 μm, 2.6 μm, 2.9 μm, 3 μm, 4 μm, 5 μm, 6 μm, 6.7 μm, 7 μm, 8 μm, 9 μm, 10 μm.

[0082] In one preferred embodiment of the present invention, the porous spheres having closed pores according to the present invention, more particularly the average pore diameter of the closed pores, measured by scanning electron microscopy (SEM), is between 50 nm and 800 nm, advantageously between 50 nm and 500 nm, advantageously between 80 nm and 250 nm, advantageously between 100 nm and 245 nm, in particular between 100 nm and 200 nm, more particularly between 145 nm and 180 nm, more particularly between 150 nm and 160 nm, even more particularly between 150 nm and 160 nm, is in the range of 150 nm to 155 nm, for example, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm, 150 nm, 153 nm, 155 nm, 160 nm, 165 nm, 170 nm, 175 nm, 180 nm, 185 nm, 190 nm, 191 nm, 192nm, 193nm, 194nm, 195nm, 196nm, 197nm, 198nm, 199nm, 200nm, 201nm, 202nm, 203nm, 204nm, 205nm, 206nm, 207n m, 208nm, 209nm, 210nm, 211nm, 212nm, 213nm, 214nm, 215nm, 216nm, 217nm, 218nm, 219nm, 220nm, 225nm, 230nm, 235nm , 240nm, 245nm, 250nm, 260nm, 280nm, 300nm, 320nm, 340nm, 360nm, 380nm, 400nm, 420nm, 440nm, 460nm, 480nm, 500nm, 520nm, 540nm, 560nm, 580nm, 600nm, 620nm, 640nm, 660nm, 680nm, 700nm, 720nm, 740nm, 760nm, 780nm or 800nm.

[0083] In another embodiment, the porous spheres according to the invention have an average diameter in the range of 1.3 μm to 10 μm, more particularly 1.5 to 9.9 μm, even more particularly 2.5 μm to 8 μm, as measured by scanning electron microscopy (SEM), for example an average diameter selected from 1 μm, 2 μm, 2.6 μm, 2.9 μm, 3 μm, 4 μm, 5 μm, 6 μm, 6.7 μm, 7 μm, 8 μm, 9 μm, 10 μm, and an average porosity selected from 0.45, 0.47, 0.49, 0.50, 0.51, 0.53, 0.55, 0.57, 0.59, 0.61, 0.63, 0.65, 0.67, 0.69 or 0.70, as measured by scanning electron microscopy (SEM). The average pore diameter measured is selected from 100 nm to 200 nm, more specifically 145 nm to 180 nm, more specifically 150 nm to 160 nm, and even more specifically 150 nm to 155 nm, for example, 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm, 150 nm, 153 nm, 155 nm, 160 nm, 165 nm, 125 nm, 170 nm, 175 nm, 180 nm, 185 nm, 190 nm, 191 nm, 192 nm, 193 nm, 194 nm, 195 nm, 196 nm, 197 nm, 198 nm, 199 nm, or 200 nm.

[0084] In the porous spheres according to the invention, the average diameter of the spheres is significantly larger than the average diameter of the pores, for example the average diameter of the spheres is generally at least 25 times, preferably at least 30 times, preferably at least 35 times, more preferably 4 times the average diameter of the pores.

[0085] In some embodiments, the ratio of the average sphere size to the average pore size is at least 40 / 1, at least 50 / 1, at least 60 / 1, at least 70 / 1, at least 80 / 1, at least 90 / 1, at least 100 / 1, at least 110 / 1, at least 120 / 1, at least 130 / 1, at least 140 / 1, at least 150 / 1, at least 160 / 1, at least 170 / 1, at least 180 / 1, at least 190 / 1, at least 200 / 1, at least 210 / 1, at least 220 / 1, at least 230 / 1, at least 240 / 1, at least 250 / 1, at least 260 / 1, at least 270 / 1, at least 280 / 1, at least 290 / 1, at least 300 / 1, at least 310 / 1, at least 320 / 1, at least 330 / 1, at least 340 / 1, or at least 350 / 1.

[0086] In a preferred embodiment of the invention, the porous spheres with closed pores according to the invention have an average porosity in the range of from >0.10 to 0.80, in particular selected from 0.4, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, 0.56, 0.57, 0.58, 0.59, 0.60, 0.61, 0.62, 0.63, 0.64, 0.65, 0.66, 0.67, 0.68, 0.69 or 0.70, preferably in the range of 0.45 to 0.70, more preferably in the range of 0.50 to 0.65.

[0087] According to the invention, the size of the spheres and / or pores is synonymous with the diameter of the spheres and / or pores and is determined by scanning electron microscopy (SEM). The average sphere diameter and / or pore diameter (or average size) means the average diameter of the spheres and / or pores, which may be supplemented by the measurement of the standard deviation. This is obtained by analyzing 100-150 spheres and / or pores of 50-70 different spheres by scanning electron microscopy using an analysis software, in particular the ImageJ image software.

[0088] The average porosity of a sphere refers to the total pore volume as a fraction of the total sphere volume. The average porosity is sometimes called the "volume fraction". It is a dimensionless quantity. It is calculated by the ratio of the volume of the unoccupied space (inside the pores) to the total volume of the sphere. For example, a porous silica sphere according to the invention with an average diameter of 7.6 μm and containing closed pores with an average diameter of 165 nm has an average porosity of 0.8. The diameter of the pores is determined by the diameter D50 of the nanoparticle polymer of which it is composed. The larger the diameter D50 of the nanoparticle polymer of which it is composed, the larger the average diameter of the pores will be. Similarly, the concentration of nanoparticles is adjusted according to the average sphere diameter that one wishes to obtain. The higher the concentration of nanoparticles, the larger the size of the spheres.

[0089] Analysis by mercury porosimetry is used to characterize the porosity of spheres. Mercury porosimetry involves applying a controlled pressure to the sample being measured, which is immersed in mercury. The external pressure is applied so that the mercury penetrates the pores / pores of the material. The amount of pressure required is inversely proportional to the size of the pores / pores. Mercury porosimetry therefore gives the volume and size distribution of the pores. Mercury porosimetry uses the Washburn equation to generate the volume and pore size distribution from the pressure data versus the intrusion data generated by the instrument.

[0090] In an advantageous embodiment, the spheres according to the invention do not contain and / or are not used in combination with anti-blue light filters and / or anti-UV filters and / or sunscreens and / or cosmetic compositions containing them.Therefore, the spheres according to the invention are not used as boosters of anti-blue light filters and / or to increase the SPF (sun protection factor) of sun compositions.

[0091] In one advantageous embodiment, the porous sphere according to the invention does not comprise a coating layer on its surface that contains a hydrophobic compound. In one particularly advantageous embodiment, the porous sphere according to the invention does not comprise a coating layer on its surface.

[0092] According to one particular embodiment of the invention, the porous spheres according to the invention do not comprise on their surface a coating layer containing a polyorganosiloxane, in particular a silicone compound.

[0093] Porous spheres comprising metal oxides can be prepared using polymer molds, commonly referred to as "polymer templates" or sacrificial polymer models. Such porous spheres may exhibit a color observable by the human eye, i.e., a color observable by the naked eye, or may appear white.

[0094] "Color observable by the naked eye" means a color that is perceived by the majority of people. This is the color that is perceived by the majority of people over a given area, e.g., 1 cm 2 , 2cm 2 , 3cm 2 , 4cm 2 , 5cm 2 Or 6 cm 2 , 7cm 2 , 8cm 2 , 9cm 2 , 10cm 2 , 11cm 2 , 12cm 2 , 13cm 2 , 14cm 2 Or 15cm 2 This may also mean that it is observable by the CIE 1931 2° standard observation model and / or the CIE 1964 10° standard observation model. The color observation background may be of different kinds, for example white, black, or anything intermediate between black and white.

[0095] According to one embodiment, the spheres according to the invention are prepared by a method having three steps: Step 1: Droplets are generated from a dispersion of particles, the dispersion comprising first particles (a) comprising a polymer and second particles (b) comprising a metal oxide or a metal oxide precursor. This dispersion of particles is advantageously an aqueous dispersion, in particular a colloidal dispersion, with a pH in the range of 8 to 10.

[0096] The droplets are advantageously obtained using a microfluidic device. A microfluidic device is, for example, a narrow channel device with microscopic scale junctions adapted to generate uniform droplets, the channels being connected to a collection reservoir. The microfluidic device comprises, for example, junctions with channel widths ranging from 10 μm to about 100 μm. These devices are, for example, made of polydimethylsiloxane (PDMS) and can be prepared, for example, by soft lithography. An emulsion of an aqueous dispersion of particles in a continuous oily phase can be prepared inside the device by pumping the dispersed aqueous phase and the continuous oily phase in a defined ratio, thus forming an emulsion by mixing the two phases. Alternatively, an oil-in-water emulsion can be used, where the particle dispersion is an oily dispersion and the continuous phase is an aqueous phase. The continuous oily phase comprises, for example, an organic solvent, a silicone oil or a fluorinated oil. According to the present invention, the term "oil" denotes an organic phase (for example an organic solvent) that is not miscible with water. Organic solvents include hydrocarbons such as heptane, hexane, toluene, xylene, and alcohols such as methanol, ethanol, and propanol.

[0097] Step 1) can also be carried out not from a dispersion comprising first particles (a) comprising a polymer and second particles (b) comprising a metal oxide or a metal oxide precursor, but from a dispersion comprising particles (a) comprising a polymer in a sol-gel matrix (b) of a metal oxide or a precursor thereof.

[0098] Step 2: The droplets are dried to remove the solvent, obtaining dried spheres in the form of a matrix of second particles (b) or a sol-gel matrix (b) in which the first particles (a) are located. In fact, there is a self-organization between the first particles (a) and the second particles (b) or the sol-gel matrix (b) to form spheres with a matrix based on metal oxides or metal oxide precursors in which the polymer particles (a) are embedded. The spheres obtained are recovered, for example, by filtration or centrifugation.

[0099] Drying is carried out according to conventional techniques, for example by microwave irradiation, in a thermal oven, under vacuum, in the presence of a desiccant / absorbent, or by a mixture of these techniques.

[0100] Steps 1) and 2) can be carried out simultaneously by spraying. In some embodiments of the spray drying technique, a dispersion of particles (first particles (a) comprising a polymer and second particles (b) comprising a metal oxide or a metal oxide precursor, or first particles (a) comprising a polymer in a sol-gel matrix (b) of a metal oxide or its precursor) is fed (e.g. pumped) to a spray nozzle with a compressed gas inlet. The feed is pumped through the spray nozzle to form droplets. The droplets are surrounded by a preheated gas in an evaporation chamber, resulting in evaporation of the solvent and the production of solid particles in the form of spheres (matrix of the second particles (b) or sol-gel matrix (b) in which the first particles (a) are located). The dried particles are transported by the drying gas through a cyclone and deposited in a collection chamber. Gases that can be used include nitrogen and / or air.

[0101] In one embodiment of the spray drying process, the feed liquid contains an aqueous or oily phase in which the particles are dispersed (first particles (a) comprising a polymer and second particles (b) comprising a metal oxide or a precursor of a metal oxide or a sol-gel matrix of a metal oxide or its precursor (b)). Spray drying techniques include inkjet spray drying. Vibrating nozzles are commercially available from Büchi and are equipped, for example, with a syringe pump and a pulsating unit.

[0102] Step 3: Calcining and, optionally, sintering the dried spheres. During this step, the metal oxide spheres or the sol-gel matrix densifies and forms a stable matrix around the polymer particles (a), which are removed by calcination (at a temperature in the range of 200-1200° C. for a period in the range of 0.1 h-10 h, advantageously at a temperature in the range of 300-800° C. for a period in the range of 1-8 h).

[0103] According to one embodiment, the calcination is carried out at a temperature in the range of 200°C to 1200°C. According to one embodiment, the calcination temperature is at least 200°C, preferably at least 500°C, more preferably at least 1000°C. Alternatively, the calcination temperature is in the range of 300°C to 800°C. The calcination is carried out for a suitable period of time, for example, in the range of 0.1 hours to about 10 hours, preferably 1 hour to 8 hours. In some embodiments, the calcination is carried out for at least 0.1 hours, at least 1 hour, at least 5 hours, or at least 8 hours.

[0104] Thus, the first polymer particles (a) were used as a template to form pores in the spheres according to the invention. The polymer particles (a) define the interstitial spaces. Calcination results in the removal of the polymer, thus providing metal oxide spheres with high porosity or large interstitial volume (inverse structure). The porous metal oxide spheres are advantageously sintered to provide a continuous, consolidated, thermally and mechanically stable solid structure.

[0105] The first polymer particles (a) that can be used as templates in this process are nanoparticles. They are also spherical, monodisperse and have a diameter D measured by dynamic light scattering (DLS) measurements or scanning electron microscopy (SEM), preferably by dynamic light scattering (DLS) measurements, ranging from 50 nm to about 800 nm, advantageously from 50 nm to 500 nm. 50 has.

[0106] Diameter D 50 refers to the median diameter, meaning that half of the population is below it and the other half is above it.

[0107] Advantageously, the polymeric nanoparticles (a) have a diameter D measured by dynamic light scattering (DLS) measurement of 50 nm, 75 nm, 100 nm, 130 nm, 160 nm, 190 nm, 210 nm, 240 nm, 270 nm, 300 nm, 330 nm, 360 nm, 390 nm, 410 nm, 440 nm, 470 nm, 500 nm, 530 nm, 560 nm, 590 nm, 620 nm, 650 nm, 680 nm, 710 nm, 740 nm, 770 nm or 800 nm.50 has.

[0108] Preferably, the polymer is selected from the group consisting of poly(meth)acrylic acid, poly(meth)acrylate, polystyrene, polyacrylamide, polyvinyl alcohol, polyvinyl acetate, polyester, polyurethane, polyethylene, polypropylene, polylactic acid, polyacrylonitrile, polyvinyl ether, and derivatives and salts thereof, copolymers thereof, and combinations thereof. For example, the polymer is selected from the group consisting of polymethyl methacrylate, polyethyl methacrylate, poly(n-butyl methacrylate), polystyrene, poly(chlorostyrene), poly(alpha-methylstyrene), poly(N-methylolacrylamide) styrene / methyl methacrylate copolymer, polyalkyl acrylates, polyhydroxyl acrylates, polyaminoacrylates, polycyanoacrylates, polyfluorinated acrylates, poly(N-methylolacrylamide), polyacrylic acid, polymethacrylic acid, methyl methacrylate / ethyl acrylate / acrylic acid copolymer, styrene / methyl methacrylate / acrylic acid copolymer, polyvinyl acetate, polyvinylpyrrolidone, polyvinylcaprolactone, polyvinylcaprolactam, copolymers of methyl methacrylate and [2-(methacryloyloxy)ethyl]trimethylammonium chloride, and derivatives and salts thereof, copolymers thereof, and combinations thereof. Preferably, the polymer is selected from the group consisting of polystyrene, for example polystyrene / acrylic acid, polystyrene / poly(ethylene glycol) methacrylate or polystyrene / styrene sulfonate copolymers.

[0109] The spheres according to the present invention can contain uniform pore sizes due to the use of spherical and monodisperse polymer particles (a).

[0110] The second particles (b) or sol-gel matrices comprising metal oxides or metal oxide precursors which can be used in the method according to the invention may be obtained by sol-gel techniques.

[0111] Advantageously, the second particles (b) that can be used in the process are nanoparticles. They have a diameter D ranging from 1 nm to about 120 nm, for example, as measured by scanning electron microscopy (SEM) or dynamic light scattering (DLS) measurements, preferably by scanning electron microscopy (SEM). 50 has.

[0112] Advantageously, the nanoparticles comprising a metal oxide or a metal oxide precursor (b) have a diameter D measured by scanning electron microscopy (SEM) of 1 nm, 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 115 nm, or 120 nm. 50 has.

[0113] These nanoparticles (b) may be spherical or non-spherical.

[0114] The second particles (b) or the sol-gel matrix may be made of a metal oxide or a metal oxide precursor, in particular silica, titania, alumina, zirconia, cerium, iron oxide, zinc oxide, indium oxide, tin oxide, chromium oxide, and combinations thereof, the precursors of silicon oxide such as tetraethyl orthosilicate (TEOS) or tetramethyl orthosilicate (TMOS), the precursor of titanium oxide, titanium propoxide, or the precursor of zirconium oxide such as zirconium acetate.

[0115] In one advantageous embodiment, the first polymer nanospheres (a) have a positively charged surface and the second metal oxide particles or their precursors (b) or the sol-gel matrix (b) have a negatively charged surface.

[0116] In another advantageous embodiment, the first polymer nanospheres (a) have a negatively charged surface and the second metal oxide particles or their precursors (b) or the sol-gel matrix (b) have a positively charged surface.

[0117] It is the charge differences at the surface that cause the particles to self-assemble with each other or with the sol-gel matrix during the sphere manufacturing process.

[0118] The weight ratio (w / w) of nanoparticles of metal oxide or precursors thereof or sol-gel matrix / polymer nanoparticles ranges, for example, from 1 / 10 to 10 / 1 or from 1 / 3 to 3 / 2. Advantageously, this ratio is 1 / 10, 2 / 10, 3 / 10, 4 / 10, 5 / 10, 6 / 10, 7 / 10, 8 / 10, 9 / 10, 10 / 9, 10 / 8, 10 / 7, 10 / 6, 10 / 5, 10 / 4, 10 / 3, 10 / 2 or 10 / 1. In particular, it is 1 / 3, 2 / 3, 1 / 1 or 3 / 2.

[0119] Drying of the polymer / metal oxide droplets in the method according to the invention, followed by removal of the polymer, produces spheres with uniform cavities (pores). Generally, in the described process, each droplet forms a single microsphere or sphere. The diameter of the pores depends on the size of the polymer particles (a). Shrinkage or compression may occur during removal of the polymer, resulting in pore sizes slightly smaller than the initial size of the polymer particles, for example in the range of 10% to 40% smaller than the size of the initial polymer particles. The pore size is as uniform as the shape and size of the polymer particles (a).

[0120] In certain embodiments, the porous spheres have a solid center or core and porosity towards the outer surface of the sphere.

[0121] In other, more rare embodiments, the porous sphere has a hollow center with increasing porosity towards the interior of the sphere.

[0122] Thus, in some embodiments, there is a porosity gradient towards the center or outside of the sphere, although more often the sphere will have a uniform porosity distribution within the sphere.

[0123] In another preferred embodiment of the present invention, the porosity is uniformly distributed throughout the volume of the sphere.

[0124] A template of monodisperse polymer spheres (a) can yield metal oxide spheres with pores of similar diameters when the polymer is removed.

[0125] A template of two different sized polymer spheres (a) can result in metal oxide spheres with pores of two different diameters once the polymer is removed.

[0126] Without being bound to one theory, it is believed that when the porosity and / or diameter and / or pore size of the spheres are within a certain range of values, the majority of the spheres will have a saturated color with reduced light scattering. These color properties are particularly important and can be adjusted according to the intensity of light scattering desired for the skin, skin appendages and / or mucosa. In some embodiments, it is preferable to have white spheres, and in other embodiments, it is preferable to have transparent spheres.

[0127] Preferably, the majority of the porous spheres have a structural color observable with the naked eye, especially at wavelengths in the range of 380 nm to 800 nm. One or more so-called light absorbers may also be present in the spheres, thus making it possible to provide a more saturated observable color. Such absorbers are added, for example, during the physical mixing of the spheres or are included in the droplets before drying. Thus, for example, in this case, the spheres according to the invention have no observable color without the light absorber, but have an observable color upon the addition of the light absorber.

[0128] The spheres then have the advantage that they can be used as colorants in cosmetic and / or dermatological compositions.

[0129] The porous spheres according to the invention may have angle-dependent or angle-independent color. "Angle-dependent color" means that the observed color depends on the angle of incident light or the angle between the observer and the observed color area. Angle-independent color means that the observed color is substantially independent of the angle of incident light or the angle between the observer and the observed color area.

[0130] Spheres with angle-dependent color can be obtained especially by using monodisperse polymer nanospheres (a). They can also be obtained when the droplet drying step to provide the polymer sphere model is performed gently, thus allowing the polymer nanospheres to order themselves.

[0131] If the droplet drying step is performed quickly and the polymer nanospheres do not order themselves, or if two sizes of polymer spheres (a) are used in the process (whether these polymer spheres (a) are monodisperse or polydisperse bimodal distributions), spheres with angle-independent colors can be obtained.

[0132] The dependence of color on angle is independent of the polydispersity or shape of the metal oxide particles (b).

[0133] Advantageously, the porous spheres according to the invention are themselves monodisperse.

[0134] The term "majority of spheres" refers to a collection of spheres. The amount can be 0.1 mg or more, 0.2 mg or more, 0.3 mg or more, 0.4 mg or more, 0.5 mg or more, 0.7 mg or more, 1.0 mg or more, 2.5 mg or more, 5.0 mg or more, 10.0 mg or more, or 25.0 mg or more. The majority of the spheres may be devoid of other compounds.

[0135] The term "monodisperse" is understood to refer to particles or pores of uniform shape and uniform diameter for a population of porous spheres or nanospheres of polymer or pores. Thus, a population of spheres and / or pores is one in which 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% or 99% by number of particles or pores have a diameter equal to or smaller than the average diameter of the population of spheres and / or pores or the diameter D of polymer nanospheres. 50 They are said to be monodisperse if they have diameters within ±7%, ±6%, ±5%, ±4%, ±3%, ±2% or ±1% of 0.01 mm (these diameters are measured by scanning electron microscopy (SEM)).

[0136] Removal of the monodisperse population of polymer nanospheres (a) results in metal oxide spheres having a population of pores with an average diameter.

[0137] Thus, the spheres according to the invention comprising metal oxides are hereinafter - forming a liquid dispersion of polymer nanospheres and nanoparticles of metal oxides or precursors thereof or a sol-gel matrix; - forming droplets of the dispersion, - drying the droplets of spheres comprising the polymer nanospheres and nanoparticles of metal oxides or their precursors or a sol-gel matrix, - removing polymer nanospheres from model spheres to provide porous metal oxide spheres according to the invention.

[0138] According to an advantageous embodiment, the droplets are aqueous. According to an alternative, the droplets are oil-based.

[0139] According to a preferred embodiment, the method comprises mixing a continuous phase with a liquid dispersion to form an emulsion containing droplets of the liquid dispersion. According to a particular embodiment, the continuous phase is oily and mixing is performed between the continuous oily phase and the aqueous liquid dispersion to form a water-in-oil emulsion containing aqueous droplets.

[0140] According to another embodiment, the continuous phase is aqueous and mixing is performed between the continuous aqueous phase and the oily liquid dispersion to form an oil-in-water emulsion containing lipid droplets.

[0141] According to an advantageous embodiment, the method includes the subsequent steps of collecting the droplets, drying the droplets and removing the polymer nanospheres from the spherical model.

[0142] According to the invention, the porous spheres according to the invention can be used alone, in particular in powder form (100%) or as a composition, in particular a cosmetic composition, in an amount of 1×10 -3 in the range of 1×10 to 100% by weight, advantageously 1×10 -2It is used at a concentration in the range of 0.01% to 95% by weight, preferably 0.01% to 80% by weight, even more preferably 0.05% to 50% by weight, preferably 0.1% to 30% by weight, preferably up to 20% by weight, even more preferably up to 10% by weight, even more preferably 0.5% to 5% by weight.

[0143] The porous spheres according to the invention can be used alone, in particular in the form of active cosmetic ingredients, or in compositions intended for contact with the skin, skin appendages and / or mucous membranes, such as cosmetic compositions, preferably compositions intended for topical application.

[0144] The active ingredient and / or cosmetic compositions containing the porous spheres according to the invention are preferably intended for the care and / or cosmetic treatment of the skin and / or mucous membranes, including the scalp, and of the skin appendages, preferably the hair.

[0145] In another embodiment, the spheres according to the present invention may be incorporated into a cosmetic composition further comprising at least one cosmetically acceptable excipient.

[0146] For the purposes of the present invention, the expression "cosmetically acceptable" excipient means a compound and / or solvent that is topically acceptable, i.e., that does not induce an allergic reaction, is not toxic, is not unstable, is not equivalent thereto, or is not otherwise unsuitable upon contact with the skin, including the human scalp and skin appendages.

[0147] The cosmetic compositions according to the invention may be provided in all formulation forms conventionally used for topical application to the skin and / or mucous membranes, including the scalp and skin appendages, such as liquid or solid forms, or liquid forms under pressure.They may be formulated in the form of aqueous or oily solutions, especially lotions, creams, aqueous or oily gels, especially in jars or tubes, especially in glass or plastic bottles or measuring bottles, or aerosols or sprays, especially shower gels, shampoos, conditioners, milks, oils, emulsions, hydrogels, micro- or nano-emulsions, especially oil-in-water or water-in-oil or multiple emulsions or silicone-based emulsions, serums, lotions, liquid or solid soaps, pastes, ointments, mousses or foams, masks, lacquers, patches, anhydrous products, preferably liquids, pasties or solids, such as batons, especially sticks, or powders, preferably creams, serums or lotions.

[0148] It may also be a make-up product or a make-up removal product. In particular, the cosmetic composition is selected from the group consisting of serums, lotions, creams, shampoos, conditioners, oils, milks, ointments, pastes, mousses or foams, emulsions, hydrogels, shower gels, masks, lacquers, sprays or waxes, more preferably a cream, serum or lotion. It may also be a powder after shaving and / or hair removal, in particular a make-up, a stick foundation, a beard care composition. According to an advantageous embodiment, the cosmetic composition according to the invention is at least slightly gelled and / or comprises an oily phase, preferably an oily composition or an oil-in-water or water-in-oil emulsion or lotion type.

[0149] The compositions according to the invention may contain any suitable solvent and / or any suitable vehicle and / or any suitable excipient, optionally in combination with other compounds of interest.

[0150] Thus, for these compositions, the excipients include, for example, at least one compound selected from the group consisting of preservatives, emollients, emulsifiers, surfactants, humectants, thickeners, conditioners, matting agents, stabilizers, antioxidants, texturizing agents, gloss agents, film formers, solubilizers, pigments, dyes, fragrances, and sunscreens. These excipients are preferably selected from the group consisting of amino acids and derivatives thereof, polyglycerols, esters, cellulose polymers and derivatives, lanolin derivatives, phospholipids, lactoferrin, lactoperoxidase, sucrose-based stabilizers, vitamin E and derivatives thereof, natural and synthetic waxes, vegetable oils, triglycerides, unsaponifiable matter, phytosterols, vegetable esters, silicones and derivatives thereof, protein hydrolysates, jojoba oil and derivatives thereof, fat-soluble / water-soluble esters, betaines, amine oxides, plant extracts, sucrose esters, titanium dioxide, glycine, and parabens, more preferably butylene glycol, steareth-2, steareth-21, glycol-15 stearyl ether, cetearyl alcohol, phenoxyethanol, methylparaben, ethylparaben, propylparaben, Butylparaben, Butylene Glycol, Natural Tocopherols, Glycerol, Sodium Dihydroxycetyl Phosphate, Isopropyl Hydroxycetyl Ether, Glycol Stearate, Triisononanoin, Octyl Cocoate, Polyacrylamide, Isoparaffin, Laureth-7, Carbomer, Propylene Glycol, Glycerol, Bisabolol, Dimethicone, Sodium Hydroxide, PEG-30 Dipolyhydroxystearate, Capric / Caprylic Triglyceride, Cetyl Octanoate, Dibutyl Adipate, Grape Seed Oil, Jojoba Oil, Magnesium Sulfate, EDTA, Cyclomethicone, Xanthan Gum, Citric Acid, Sodium Lauryl Sulfate, Mineral Waxes & Oils, Isostearyl Isostearate, Propylene Glycol Dipelargonate, Propylene Glycol Isostearate, PEG 8, beeswax, glycerides derived from hydrogenated palm oil, glycerides derived from hydrogenated palm oil, lanolin oil, sesame oil, cetyl lactate, lanolin alcohol, castor oil, titanium dioxide, lactose, sucrose, low density polyethylene, isotonic saline.

[0151] Many cosmetic active ingredients for improving the appearance of the skin are known to those skilled in the art. Those skilled in the art know how to formulate cosmetic or dermatological compositions to obtain the best effect. Furthermore, the compounds described in this invention may have synergistic effects when combined with each other. These combinations are also included in this invention. The CTFA Cosmetic Ingredient Handbook, Second Edition (1992) describes various cosmetic and medicinal ingredients commonly used in the cosmetic and pharmaceutical industries, which are particularly suitable for topical use. Examples of these types of ingredients include, but are not limited to, the following compounds: Abrasives, absorbents, fragrances, pigments, colorants, essential oils, astringents, anti-acne agents, anti-clumping agents, anti-foaming agents, antimicrobial agents (e.g., iodopropyl butylcarbamate), antioxidants, binders, biological additives, buffers, swelling agents, chelating agents, additives, biocides, denaturants, thickeners, and compounds for aesthetic purposes such as vitamins and their derivatives or equivalents, film forming materials, polymers, opacifiers, pH adjusters, reducing agents, decolorizing or lightening agents (e.g., hydroquinone, kojic acid, ascorbic acid, magnesium ascorbyl phosphate, ascorbyl glucosamine), conditioning agents (e.g., humectants).

[0152] In a particularly advantageous manner, the spheres according to the invention can be used, optionally in cosmetic or pharmaceutical compositions, preferably dermatological compositions, as the sole agent for improving the appearance, in particular the non-aesthetic symptoms and / or comfort, of the skin, the skin appendages and / or the mucous membranes, or in combination in cosmetic or dermatological compositions with other active agents having the same or complementary and conventional properties, for example those selected from: moisturizing agents: one or more agents promoting moisturization, such as polysaccharides extracted from the seeds of Cassia angustifolia, sold under the name Hyalurosmooth™ by the Applicant, or an agent selected from one of the combinations containing pullulan, sodium hyaluronate and sodium alginate, sold under the name PatcH2O™ by the Applicant, or one or more compounds of natural moisturizing factors or natural honey extracts, sold under the name Melhydran™ by the Applicant, and / or compounds of the glucosylglyceride family, in particular hexosylglycerides, an extract of the peel of Litchi chinensis, sold under the name Litchiderm™ by the Applicant; an agent for stimulating fibronectin synthesis, in particular a corn extract, such an extract being sold in particular under the name Deliner™ by the Applicant; an agent for protecting fibroblast growth factor (FGF2) in the extracellular matrix against degradation and / or denaturation, in particular an extract of Hibiscus abelmoscus as described in the French patent application filed in the Applicant's name under the number FR0654316, and / or an agent for stimulating fibroblast proliferation, for example a fermented soy extract containing peptides known under the name Phytokine™, marketed by the Applicant and also as described in EP 1 119 344 B1 (Laboratoires Expanscience), preferably a combination of these two extracts; agents stimulating the synthesis of laminin, in particular a biotechnologically modified malt extract, such an extract being in particular marketed by the Applicant under the name Basaline™, and agents stimulating lipid synthesis, for example a biotechnologically modified potato (Solanum tuberosum) extract marketed by the Applicant under the name Lipidessence™; - agents that stimulate the expression and / or activity of hyaluronan synthase 2 (HAS2), such as the plant extracts described in patent application FR 2 893 252 A1, in particular the aqueous extract of Galanga (Alpinia galanga) marketed by the Applicant under the name Hyalufix™; - agents stimulating the synthesis of lysyl oxidase-like (LOXL), as described in French patent application FR 2 855 968, in particular the dill extract marketed by the Applicant under the name Lys'lastine™; one or more antifouling agents, such as the extract of the leaves of Argania spinosa sold by the Applicant under the name Arganyl™, or the extract of the seeds of Moringa oleifera sold by the Applicant under the name Purisoft™, or the extract of the roots of Eperua falcata sold by the Applicant under the name Eperuline™; -agents that stimulate intracellular ATP synthesis, in particular extracts of the alga Laminaria digitata; -agents with general anti-aging action, in particular niacinamide or vitamin B3, in order to combat pigmentation marks; antibacterial and / or sebum regulators and / or sebum absorbents, such as retinoids, sarcosine, zinc salts, in particular zinc gluconate, zinc salicylate, azelaic acid and / or their derivatives and mixtures, the extract of Orthosiphon stamineus sold by the Applicant under the name MAT XS™ Bright, the extract of Bixa orellana sold by the Applicant under the name Bix'Activ™, the antibacterial extracts described in French patent application FR 2 863 893, in particular the extract of Boldo sold by the Applicant under the name Betapur™, or talc, and any mixtures thereof.

[0153] According to one preferred embodiment of the present invention, the spheres are formulated with a make-up base, conventionally called a "primer," which may contain pigments and / or mica.

[0154] According to an alternative embodiment of the invention, the spheres are preferably formulated in a cosmetic composition in combination with the active cosmetic ingredients listed above, such as whitening agents, anti-ageing agents, in particular those acting against photoinduced ageing, moisturizing agents, anti-staining agents, in particular antioxidants, soothing agents, sebum regulating and / or absorbing agents, mattifying agents, prebiotic agents, active cosmetic agents acting on the surface and / or relief and / or color defects of the skin, antibacterial agents, and / or agents for sensitive skin.

[0155] More preferably, the spheres according to the invention are in a cosmetic composition containing at least one component selected from makeup pigments, mica, moisturizers, anti-ageing agents and / or agents acting on the relief, color and / or surface defects of the skin, and / or mixtures thereof, more preferably moisturizers and / or anti-ageing agents.

[0156] Advantageously, the cosmetic composition according to the invention contains at least one cosmetic excipient and / or cosmetic pigment and / or dye and / or UV filter and / or anti-blue light filter and / or active cosmetic ingredient, preferably chosen from whitening agents, anti-ageing agents, in particular those acting against photoinduced ageing, moisturizing agents, anti-pollution agents, in particular antioxidants, soothing agents, sebum regulating and / or absorbing agents, mattifying agents, prebiotic agents, active cosmetic agents acting on the surface and / or relief and / or colour defects of the skin, agents modifying the skin colour and / or skin radiance, such as antibacterial agents and / or agents for sensitive skin.

[0157] The use of the porous spheres according to the invention is particularly advantageous in that it allows an immediate, effective and sustained action on any type of skin, including the scalp, skin appendages, preferably the hair, and mucous membranes, in particular on skin presenting signs of unaesthetic symptoms or discomfort.

[0158] Preferably, the porous spheres according to the invention, preferably in the form of a cosmetic composition according to the invention, are applied to at least one area of ​​the body where there is an unaesthetic and / or unpleasant symptom, this area or these areas are preferably body surfaces selected from the forehead, cheeks, nose, temples, the so-called "T" zone (forehead, nose and chin), the skin of the face, including under the eyes, the periorbital area, more particularly the chin, scalp, neck, back, shoulders, arms, forearms, thorax, hands, hair, beard, eyelashes, eyebrows, bust, more particularly the neckline, abdomen and / or armpits, legs, feet, hands, neck, thighs, hips, buttocks, waist, torso, lip contour, hair, hair and / or eyes, lips and / or cheek mucosa, preferably darkening of the skin of the face, hands or neckline.

[0159] The present invention therefore also relates to a cosmetic, advantageously non-therapeutic care method for improving the appearance and / or comfort of the skin, the skin appendages, in particular the hair, and / or the mucous membranes, comprising the topical application of porous spheres according to the invention to at least one area of ​​the skin and / or mucous membranes and / or skin appendages, in particular the hair, preferably to at least one surface selected from the following body surfaces: the forehead, the cheeks, the nose, the temples, the so-called "T" zone (forehead, nose and chin), the skin of the face, including under the eyes, the periorbital area, more particularly the chin, the scalp, the neck, the back, the shoulders, the arms, the forearms, the thorax, the hands, the hair, the beard, the eyelashes, the eyebrows, the bust, more particularly the neckline, the abdomen and / or the armpits, the legs, the feet, the hands, the neck, the thighs, the hips, the buttocks, the waist, the torso, the lip contour, the hair, the hair and / or the eyes, the mucous membranes of the lips and / or the cheeks, preferably to darkening of the skin of the face, the hands or the neckline.

[0160] The spheres according to the invention are particularly suitable for use on any type of skin, mucous membranes and / or skin appendages, in particular on Caucasian, Asian or African people, as well as on any type of skin, in particular on sensitive skin, skin with atopic tendencies or on oily skin. They are particularly suitable for masking the first non-aesthetic symptoms of ageing, in particular the first expression wrinkles, and / or on mature skin, i.e. men or women at least 50 years old, in particular postmenopausal women.

[0161] The cosmetic composition according to the present invention is preferably of the no-rinse type.

[0162] Advantageously, the porous spheres according to the invention are used in the form of a composition intended for topical application, preferably a cosmetic application according to the invention, for normal topical application, preferably at least once a day, advantageously twice a day. Preferably, the cosmetic composition is applied to the skin.

[0163] The spheres can be used in powder form, but also in the form of cosmetic ingredients formulated in liquid form.Then, for their formulation as cosmetic ingredients, the spheres are suspended in glycerol and / or another solvent, particularly polar, such as water, alcohol, especially propanediol, glycol, especially butylene glycol, propylene glycol, polyol or mixtures thereof, preferentially water-glycol mixtures, more preferentially water-glycol mixtures containing glycols selected from butylene glycol, propylene glycol, caprylyl glycol, hexylene glycol and mixtures thereof.Particularly advantageously, the spheres according to the invention are suspended in an aqueous solution containing glycerol, hexylene glycol, caprylyl glycol or mixtures thereof.

[0164] Advantageously, another subject of the invention is a method for the cosmetic treatment of individuals in need / desire of such a treatment, for improving the appearance and / or comfort of the skin, the skin appendages, in particular the hair and / or the mucous membranes, comprising the following steps: - individual identification of areas of the skin and / or mucous membranes and / or skin appendages that present non-aesthetic symptoms whose appearance and / or comfort must be improved and / or that are to be concealed, and - the spheres according to the invention are administered in an amount effective to improve the appearance and / or comfort of this area of ​​the skin and / or mucous membranes and / or skin appendages, i.e. advantageously 1×10 -3 ~100% by weight, advantageously 1×10 -2Topical application to this area of ​​the skin and / or mucosa and / or skin appendages of a cosmetic composition containing a sphere content in the range of 0.01% to 80% by weight, more preferably 0.05% to 50% by weight, preferably 0.1% to 30% by weight, preferably up to 20% by weight, more preferably up to 10% by weight, more preferably 0.5% to 5% by weight.

[0165] The spheres according to the invention may also be used to improve the comfort of affected skin, mucous membranes and / or skin appendages.

[0166] The skin, mucosa and / or skin appendages are preferentially altered in the context of, in particular, reactive, inflamed and atopic skin, hyperpigmented, hypopigmented and hyperseborrheic skin, in particular vitiligo, melanoma, couperose, telangiectasia, acne, rosacea, urticaria, psoriasis, herpes, impetigo, ecthyma, erysipelas, and / or wound and / or scar presentation, in particular lesions selected from the group consisting of acne, pimples, blisters, varicose veins, melasma, folliculitis, abscesses, or any combination thereof.

[0167] In one preferred embodiment of the invention, the spheres according to the invention are in the form of a pharmaceutical composition further comprising a pharma- ceutically acceptable excipient, and are present in an amount of 1×10 -3 ~100% by weight, advantageously 1×10 -2 The pharmaceutical composition is present with a sphere content in the range of 0.01% to 80% by weight, more preferentially 0.05% to 50% by weight, preferentially 0.1% to 30% by weight, preferentially 20% by weight, more preferentially 10% by weight, more preferentially 0.5% to 5% by weight.

[0168] Other objects, features and advantages of the present invention will become apparent to those skilled in the art upon reading the following explanatory description with reference to the embodiments thereof, which are given purely by way of illustration and are not intended to limit the scope of the invention in any way.

[0169] The examples form an integral part of the invention, and any feature believed to be novel over any prior art from the description taken as a whole including the examples, forms an integral part of the invention in its function and in its general nature. Each example therefore has a general scope. Furthermore, in the examples, all percentages are given by weight unless otherwise indicated, temperatures are expressed in degrees Celsius unless otherwise indicated, and pressures are atmospheric unless otherwise indicated. [Brief description of the drawings]

[0170] [Figure 1] FIG. 1A represents a cross-section of a sphere according to the invention having closed pores, and FIG. 1B is a diagram of a prior art porous sphere, in particular according to WO 2020 / 183108 and WO 2020 / 182936. [Diagram 2] FIG. 2 shows an SEM image of a porous sphere according to the invention obtained according to example 1 (top image) and a cross-section of this sphere (bottom image). [Diagram 3] FIG. 3 shows an SEM image of a porous sphere according to the invention obtained according to example 2 (top image) and a cross-section of this sphere (bottom image). [Figure 4] FIG. 4 shows an SEM image of porous spheres according to the invention obtained according to Example 7. EXAMPLES

[0171] Example 1: Porous silica spheres with closed pores according to the present invention Diameter D measured by dynamic light scattering (DLS) at 210 nm 50 An aqueous dispersion of positively charged poly(meth)acrylate nanoparticles with a diameter D measured by SEM of 7 nm was diluted to 1% (w / w) in deionized water. 503% (w / w) of negatively charged silica nanoparticles with 2% (w / w) of ethylene glycol-co-perfluoropolyester surfactant was added. The mixture was subjected to ultrasound for 30 seconds to prevent aggregation. The nanoparticle-loaded dispersion and the oil phase (continuous oil phase containing 2% (w / w) of polyethylene glycol-co-perfluoropolyester surfactant in fluorinated oil) were each injected into a microfluidic device with a junction to obtain a droplet size of 50 μm via a syringe connected to a pump. The whole is kept in equilibrium until monodisperse droplets are generated. These droplets are then collected in a tank.

[0172] The collected droplets are then dried in an oven at 50°C for 4 hours to obtain dried spheres (dry powder). These spheres are then calcined by placing them on a silicone plate and heating from ambient temperature to 500°C for 4 hours, then maintaining the temperature at 500°C for 2 hours. The spheres are cooled to ambient temperature over a period of 4 hours. The porous monodisperse silica oxide spheres with closed pores thus obtained have an average diameter measured by scanning electron microscopy (SEM) of 15 microns and an average porosity measured by mercury porosimetry of 0.55.

[0173] An SEM image (top image) of one of the resulting spheres and its cross-section (bottom image) are shown in Figure 2. The cross-section clearly shows the interior of the sphere's structure, which contains a relatively monodisperse and ordered closed pore network. 97% by volume of the pores in these spheres are closed pores.

[0174] In another embodiment, Example 1 can be repeated by carrying out the drying step with microwave irradiation, vacuum drying and / or in the presence of a desiccant.

[0175] Example 2: Porous silica spheres with closed pores according to the invention obtained by atomization Diameter D measured by dynamic light scattering (DLS) at 210 nm 50An aqueous suspension of positively charged spherical nanoparticles of methyl methacrylate-2-[(methacryloyloxy)ethyl]trimethylammonium chloride copolymer having the formula: and negatively charged silica nanoparticles (average diameter measured by scanning electron microscopy (SEM) of 7 nm) was prepared. The aqueous suspension contained 2.25 wt. % of the copolymer nanoparticles and 0.75 wt. % of the silica nanoparticles, based on the total weight of the suspension (weight ratio of copolymer nanoparticles:silica nanoparticles=3:1).

[0176] The aqueous suspension is dried by atomization using a Büchi laboratory size atomizer under a nitrogen atmosphere (inlet temperature 100° C., outlet temperature 45° C., feed rate 10 mL / min, atomization gas pressure 40 mm).

[0177] The microspheres obtained are then calcined in a muffle furnace to sinter and densify the silica nanoparticles and remove the polymer by placing them on a silicone plate, increasing the temperature from ambient to 550°C over 5 hours, then maintaining the temperature at 550°C for 2 hours, and then finally decreasing the temperature from 550°C to ambient over 3 hours. The monodisperse porous SiO2 microspheres with closed pores thus obtained have an average diameter measured by scanning electron microscopy (SEM) of 2.9 μm (with a standard deviation of 1.5 μm), an average pore size measured by scanning electron microscopy (SEM) of 165 nm, and an average porosity measured by mercury porosimetry of 0.55. 94% by volume of the pores in these spheres are closed pores.

[0178] Another sphere with an average diameter of 2.9 μm and an average pore size of 210 nm was obtained following the same protocol by simply changing the nanoparticle content: the aqueous suspension used contained 2.25 wt.% content of copolymer nanoparticles and 0.75 wt.% content of silica nanoparticles with respect to the total weight of the suspension (weight ratio copolymer nanoparticles:silica nanoparticles = 3:1). An SEM image of one of the obtained spheres (upper image) and its cross section (lower image) are shown in Figure 3. The cross section clearly shows the interior of the structure of the spheres, which contains a relatively monodisperse and ordered closed pore network. 96% by volume of the pores of these spheres are closed pores.

[0179] Example 3: Porous silica spheres with closed pores according to the invention obtained by atomization An aqueous suspension of positively charged spherical nanoparticles of methyl methacrylate-2-[(methacryloyloxy)ethyl]trimethylammonium chloride copolymer with a diameter D50 measured by dynamic light scattering (DLS) measurement at 210 nm and negatively charged silica nanoparticles (average diameter measured by scanning electron microscopy (SEM) of 7 nm) was prepared. The aqueous suspension contained a content of 7.5% by weight of the copolymer nanoparticles and a content of 2.5% by weight of the silica nanoparticles, based on the total weight of the suspension (weight ratio of copolymer nanoparticles:silica nanoparticles=3:1).

[0180] The aqueous suspension is dried by atomization using a Büchi laboratory size atomizer under a nitrogen atmosphere (inlet temperature 100° C., outlet temperature 45° C., feed rate 10 mL / min, atomization gas pressure 40 mm).

[0181] The microspheres obtained are then calcined in a muffle furnace to sinter and densify the silica nanoparticles and remove the polymer by placing them on a silicone plate, increasing the temperature from ambient to 550°C over 5 hours, then maintaining the temperature at 550°C for 2 hours, and then finally decreasing the temperature from 550°C to ambient over 3 hours. The monodisperse porous SiO2 microspheres with closed pores thus obtained have an average diameter measured by scanning electron microscopy (SEM) of 7.6 μm (with a standard deviation of 3.5 μm), an average pore size measured by scanning electron microscopy (SEM) of 165 nm, and an average porosity measured by mercury porosimetry of 0.55. At least 90% by volume of the pores in these spheres are closed pores.

[0182] Example 4: Porous silica spheres with closed pores according to the invention containing carbon black The product of Example 1 was physically mixed with an aqueous dispersion of carbon black or carbon black powder at different weight contents, and the resulting porous spheres contained carbon black in amounts of 0.5%, 1%, 2%, 3%, 4% and 5% by weight based on the total weight of the particles.

[0183] Example 5: Color change of a sphere A quantity of 0.5 mg of porous spheres from Example 1 was placed on a 6 cm 2 The mixture is placed in a 20 ml transparent glass flask with a base area of ​​1.5 mL. A blue color is observed with the naked eye.

[0184] A sample of porous spheres is prepared according to Example 1, except that the polymer / silica weight ratio is 2 / 1. The prepared sample has a green color observable by the naked eye.

[0185] Example 6: Porous titanium spheres Diameter D measured by dynamic light scattering (DLS) at 197 nm 50An aqueous suspension of negatively charged spherical polystyrene nanoparticles having a molecular weight of 1.8% and positively charged titanium nanoparticles (average diameter measured by scanning electron microscopy (SEM) of 15 nm) was prepared. The aqueous suspension contained 1.8% by weight of polymer nanoparticles and 1.2% by weight of titanium nanoparticles relative to the total weight of the suspension (weight ratio of polymer nanoparticles:titanium nanoparticles=3:2).

[0186] The aqueous suspension is dried by atomization using a Büchi laboratory size atomizer under a nitrogen atmosphere (inlet temperature 100° C., outlet temperature 45° C., feed rate 10 mL / min, atomization gas pressure 55 mm).

[0187] The microspheres obtained are then calcined in a muffle furnace to sinter and densify the titanium nanoparticles and remove the polymer by placing them on a silicone plate and increasing the temperature from ambient temperature to 300°C over 4 hours, then maintaining at 300°C for 6 hours, then increasing the temperature to 550°C over 2 hours, then maintaining at 550°C for 2 hours, then finally decreasing the temperature from 550°C to ambient temperature over 4 hours. The porous TiO2 microspheres with closed pores thus obtained have an average diameter measured by scanning electron microscopy (SEM) of 2.8 μm with a standard deviation of 1.5 μm, an average pore size measured by scanning electron microscopy (SEM) of 142 nm with a standard deviation of 15 nm, and an average porosity measured by mercury porosimetry of 0.55. 95% by volume of the pores in these spheres are closed pores.

[0188] Example 7: Porous silica spheres with closed pores according to the invention obtained by a sol-gel process Diameter D measured by dynamic light scattering (DLS) at 254 nm 50An aqueous suspension of positively charged spherical nanoparticles of methyl methacrylate-2-[(methacryloyloxy)ethyl]trimethylammonium chloride copolymer having the formula (I) and tetramethyl orthosilicate (TMOS) silica precursor was mixed at a pH range of 2 to 5. The aqueous suspension contained 1.8 wt% copolymer nanoparticles and 3.6 wt% TMOS with respect to the total weight of the suspension (weight ratio of copolymer nanoparticles:TMOS=1:3).

[0189] The aqueous suspension is dried by atomization using a Büchi laboratory size atomizer under a nitrogen atmosphere (inlet temperature 100° C., outlet temperature 45° C., feed rate 10 mL / min, atomization gas pressure 40 mm).

[0190] The resulting microspheres are then calcined in a muffle furnace by placing them on a silicone plate and increasing the temperature from ambient to 200 °C for 3 hours, then maintaining the temperature at 200 °C for 2 hours, then increasing the temperature to 550 °C for 2 hours, then maintaining the temperature at 550 °C for 2 hours, then finally decreasing the temperature from 550 °C to ambient temperature for 3 hours, in order to convert the silica precursor into silica nanoparticles, densify the silica and remove the polymer. The porous SiO2 microspheres with closed pores thus obtained have an average diameter measured by scanning electron microscopy (SEM) of 3 μm with a standard deviation of 1.7 μm, an average pore size measured by scanning electron microscopy (SEM) of 212 nm with a standard deviation of 15 nm, and an average porosity measured by mercury porosimetry of 0.5 to 0.65. 90% by volume of the pores in these spheres are closed pores.

[0191] An SEM image of one of the resulting spheres is shown in FIG.

[0192] Example 8: Porous silica spheres with closed pores according to the present invention with irregularly sized pores Two different sizes (diameter D measured by dynamic light scattering (DLS) measurement of 254 nm and 142 nm) 50) and negatively charged silica nanoparticles (diameter D measured by dynamic light scattering (DLS) measurement of 7 nm). 50 An aqueous suspension of 1.8 wt. % copolymer nanoparticles (0.9% of each size) and 0.6 wt. % silica nanoparticles was prepared based on the total weight of the suspension (weight ratio copolymer nanoparticles:silica nanoparticles=3:1).

[0193] The aqueous suspension is dried by atomization using a Büchi laboratory size atomizer under a nitrogen atmosphere (inlet temperature 100° C., outlet temperature 45° C., feed rate 10 mL / min, atomization gas pressure 40 mm).

[0194] The microspheres obtained are then calcined in a muffle furnace to sinter and densify the silica nanoparticles and remove the polymer by placing them on a silicone plate and increasing the temperature from ambient to 550°C for 6 hours, then maintaining the temperature at 550°C for 2 hours, and then finally decreasing the temperature from 550°C to ambient for 4 hours. The porous SiO2 microspheres with closed pores thus obtained have an average diameter measured by scanning electron microscopy (SEM) of 2 μm. They have a bimodal distribution of the average pore size estimated at 165 nm. 93% by volume of the pores in these spheres are closed pores.

[0195] The porous spheres thus obtained, weighing 0.5 mg, were placed on a 6 cm 2 The solution is placed in a 20 ml transparent glass flask with a base area of ​​1.5 mL. An angle-independent blue color is observed with the naked eye.

[0196] Example 9: Evaluation of the improvement of "soft focus" properties by cosmetic compositions according to the invention The spheres obtained according to Example 3, having a mean diameter of 7.6 μm measured by scanning electron microscopy (SEM), a mean pore size of 165 nm measured by scanning electron microscopy (SEM) and a porosity of 0.55 (Example 3), were incorporated in an oil-based formulation shown in Example 10 below, at a content of 1.5% by weight relative to the total weight of the formulation.

[0197] Average diameter D measured by scanning electron microscope (SEM) 50 The spheres obtained according to Example 2, having a diameter of 2.9 μm, an average pore size of 165 nm measured by scanning electron microscopy (SEM) and a porosity of 0.55 (Example 2), were incorporated in an oil-based formulation shown in Example 10 below, at a content of 1% by weight relative to the total weight of the formulation.

[0198] The optical properties of transmittance and diffusion (haze) of these formulations were measured and compared to those measured for porous spheres described in WO2020183108 (open porosity), with a percentage of closed pores by volume of less than 5%. Spheres (Comparative Example 3) having an average diameter measured by scanning electron microscopy (SEM) of -6.7 μm, an average pore size measured by scanning electron microscopy (SEM) of 153 nm, and a porosity of 0.55 were incorporated into the oil-based formulation shown in Example 10 below at a content of 1.5% by weight relative to the total weight of the formulation. Spheres (Comparative Example 2) having an average diameter measured by scanning electron microscopy (SEM) of -2.6 μm, an average pore size measured by scanning electron microscopy (SEM) of 153 nm, and a porosity of 0.55 were incorporated, under vigorous stirring, into the oil-based formulation shown in Example 10 below at a content of 1% by weight relative to the total weight of the formulation.

[0199] Measurements were performed after placing 3 ml of the formulations (3 samples per formulation) on a glass plate and letting it dry for at least 1 h. Total transmittance and diffusion (haze) measurements were performed using a BYK-Gardner Hazegard instrument (BYK-Gardner GmbH, Germany).

[0200] The results are summarized in Table 1 below.

[0201] [Table 1]

[0202] The spheres according to the invention have higher values ​​of total transmittance and blurring or diffusion ("haze") than those of the prior art, thus making it possible to improve the properties of blurring / masking / artistic blurring ("soft focus"). Indeed, particles with a "soft focus" effect must exhibit the following properties: -High total transmittance for a natural look, and - Maximum diffusion ("haze") to create a translucent and even distribution of light.

[0203] Example 10: Oil-based formulation used in Example 8 This is an emulsion, the composition of which is shown in Table 2 below.

[0204] [Table 2]

[0205] The emulsion is prepared by the usual methods in the art, well known to those skilled in the art, by heating phases A and B separately to 75-80°C with stirring. Phase C is added to phase A with stirring, and when the phases are homogenous, phase B is added to phase AC with stirring until completely dispersed. The mixture is cooled to ambient temperature with gentle stirring, and the compounds of the additional phases are added one after the other. The whole is homogenized for 2 minutes. The pH is adjusted to 5.2.

[0206] Example 10: Cosmetic composition according to the present invention The porous spheres used are those in powder form obtained in Examples 1-7.

[0207] Example 10a): Fluid Facial Emulsion

[0208] [Table 3]

[0209] The emulsion is prepared by the usual methods in the art, well known to those skilled in the art, by introducing phase B into phase A and stirring until completely dispersed. The mixture is heated separately to 75-80°C, as is phase C. Phase C is then added to the mixture with stirring. The mixture is cooled to room temperature with gentle stirring and the compounds of phases E and F are added in turn. The whole is homogenized for 2 minutes. The pH is adjusted to 5.2.

[0210] Example 10b): Facial cream

[0211] [Table 4]

[0212] The cream is prepared by the usual methods in the art, well known to those skilled in the art, by mixing phases A and B, previously heated to 75° C., then adding and mixing phases C and D, and adjusting the composition with phase E to a pH of 6.2 and a viscosity of 15 000 mPas, measured with a Brookfield apparatus (RVT; 23° C., spindle TC; 20 revs / min).

[0213] Example 10c): Shampoo

[0214] [Table 5]

[0215] The shampoo is prepared by conventional methods well known to those skilled in the art by mixing the four phases and adjusting the composition to a pH of 5.2 and a viscosity of 2200 mPas (measured with a Brookfield apparatus (RVT; 23° C., spindle 5; 50 rpm)).

Claims

1. Non-therapeutic cosmetic use of porous spheres having closed pores comprising a metal oxide for improving the appearance and / or comfort of the skin, skin appendages, and / or mucous membranes, the cosmetic use excluding methods for the treatment of humans.

2. 2. The use according to claim 1, characterized in that at least 90% by volume of the pores of the spheres are closed pores.

3. 2. Use according to claim 1, characterized in that the spheres have an average diameter measured by scanning electron microscopy (SEM) in the range of 1 μm to 100 μm and / or an average porosity in the range of >0.10 to 0.80 and / or an average pore size measured by scanning electron microscopy (SEM) in the range of 50 nm to 800 nm.

4. 2. Use according to claim 1, characterized in that the spheres have an average diameter measured by scanning electron microscopy (SEM) in the range of 1 μm to 100 μm, an average porosity in the range of >0.10 to 0.80, and an average pore size measured by scanning electron microscopy (SEM) in the range of 50 nm to 800 nm.

5. 2. The use according to claim 1, characterized in that the metal oxide is silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, cerium oxide, iron oxide, zinc oxide, indium oxide, tin oxide, chromium oxide, mixed metal oxides and combinations thereof.

6. The metal oxide is SiO ２ , TiO ２ 6. The use according to claim 5, characterized in that the oxide is selected from the group consisting of ZnO, ZnO and mixtures thereof.

7. 2. The use according to claim 1, characterized in that the porous spheres comprise, based on the total weight of the spheres, 60% to 99.9% by weight of metal oxide and 0.1% to 40% by weight of light absorber.

8. 2. Use according to claim 1, characterized in that the spheres have an average diameter measured by scanning electron microscopy (SEM) ranging from 1 μm to 75 μm and an average porosity ranging from 0.45 to 0.

70.

9. 2. Use according to claim 1, characterized in that the spheres have an average diameter measured by scanning electron microscopy (SEM) in the range of 2.5 μm to 8 μm, an average porosity in the range of 0.45 to 0.70, and an average diameter measured by scanning electron microscopy (SEM) of the pores in the range of 100 nm to 200 nm.

10. 2. The use according to claim 1 for reducing the visibility of unaesthetic conditions of the skin, the skin appendages and / or the mucous membranes.

11. The spheres are present in the cosmetic composition in an amount of 1×10 based on the total weight of the composition. －３ 2. The use according to claim 1, wherein the composition is present in a concentration ranging from 0.1 to 100% by weight.

12. 12. Use according to claim 11, also for improving the organoleptic properties of said cosmetic composition.

13. A cosmetic care method for improving the appearance and / or comfort of the skin, skin appendages, and / or mucous membranes, comprising topical application of porous spheres having closed pores containing a metal oxide and / or a cosmetic composition containing the same to at least one area of ​​the skin and / or skin appendages and / or mucous membranes, excluding methods for the treatment of humans.

14. The beauty care method according to claim 13, characterized in that the spheres are those according to any one of claims 1 to 9 and 11.

15. 14. A cosmetic care method according to claim 13 for reducing the visibility of unaesthetic conditions of the skin, the skin appendages and / or the mucous membranes.

16. 14. A cosmetic care method according to claim 13, characterized in that at least one area of ​​the skin and / or skin appendages and / or mucous membranes is selected from the forehead, cheeks, nose, temples, the so-called "T" zone (forehead, nose and chin), under the eyes, facial skin including the periorbital area, chin, scalp, neck, back, shoulders, arms, forearms, thorax, hands, hair, beard, eyelashes, eyebrows, bust, abdomen and / or armpits, legs, feet, hands, neck, thighs, hips, buttocks, waist, torso, lip contour, hair and / or the mucous membranes of the eyes, lips and / or cheeks.

17. A cosmetic or pharmaceutical composition, comprising 1 x 10 －３ A cosmetic or pharmaceutical composition, characterized in that it contains the porous spheres having closed pores according to any one of claims 1 to 9 in a concentration ranging from 1 to 10% by weight.

18. A cosmetic composition according to claim 17, characterized in that it contains at least one cosmetic excipient and / or cosmetic pigment and / or dye and / or UV filter and / or active cosmetic ingredient.

19. 18. Cosmetic composition according to claim 17, characterized in that it is in the form of a serum, lotion, cream, shampoo, conditioner, oil, milk, ointment, paste, mousse or foam, emulsion, hydrogel, shower gel, mask, lacquer, spray, wax, powder or stick.

20. 18. Cosmetic composition according to claim 17, characterized in that it is in the form of a slightly gelled composition and / or comprises an oily phase.

21. 18. A pharmaceutical composition according to claim 17 for use in improving the comfort of skin, skin appendages and / or mucous membranes that present lesions and / or that present wounds and / or scars.

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