Patent Description:
Protection against UVA (<NUM>-<NUM>) must be substantial to limit damage related to prolonged exposure that could lead to changes in the skin, acceleration of photoaging, loss of skin elasticity, etc..

First of all, we will review the nomenclature and abbreviations of the main filters involved in the scope of the present invention:.

Butyl Methoxydibenzoylmethane (BMDBM) is not a UV radiation stable filter. A cleavage of the molecule takes place, which breaks down into various chemical elements with no absorbent activity.

In combination with other filters (for example ethylhexyl methoxycinnamate), BMDBM can still break down and lose its photoprotective properties.

BMDBM is often combined with octocrylene, which photostabilizes it, or even PABA® (para-aminobenzoic acid). However, octocrylene has the drawback of being a powerful allergen which causes contact eczema in children and cross allergies with ketoprofen.

More recently, the prior art includes document <CIT> which teaches the stabilization of BMDBM by addition of synthetic or natural phytoene or phytofluene.

<CIT> also provides photostabilized compositions comprising BMDBM, and suggests the use of BEMT to stabilize BMDBM.

The goal of the present invention is to offer a new alternative for photostabilizing BMDBM while developing a photoprotective system according to current regulations.

The present invention concerns a photostabilized combination containing Butyl Methoxydibenzoylmethane (BMDBM), Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine (BEMT), and Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (MBBT):.

said combination containing no octocrylene, PABA or ethylhexyl methoxycinnamate.

In one particular embodiment of the invention, the BEMT/ BMDBM mass ratio is less than or equal to <NUM>, preferably less than or equal to <NUM> and even more preferentially less than or equal to <NUM>.

The BEMT/BMDBM mass ratio will be chosen in the range from <NUM> to <NUM>, preferentially <NUM> to <NUM>.

According to another characteristic of the invention, the BEMT content is comprised between <NUM>% and <NUM>% by weight with regard to the total weight of the composition.

In the framework of the present invention, the BEMT/BMDBM mass ratio has to be considered as a predominantly characteristic feature. That means that the concentration of the different solar filters BEMT, BMDBM and MBBT will have to be adjusted within each concentration rate in order for said mass ratio to be first and foremost respected.

According to another aspect, the present invention concerns the composition as defined above for its use as a photoprotective system.

According to another characteristic of the present invention, the composition above also has another filter, preferably between <NUM> and <NUM> % by weight with regard to the total weight of the composition.

According to another aspect, the invention also concerns the use of a combination of Butyl Methoxydibenzoylmethane (BMDBM) Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine (BEMT), and Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (MBBT), in which:.

"Photostabilization, photostable or photostability" mean, in the sense of the present invention, that after irradiation of <NUM> MED and preferably <NUM> MED, the following is retained:.

The combination or composition according to the present invention also contains no PABA®.

Combinations according to the present invention represent photostable photoprotective systems combining organic fat-soluble filters (such as BMDBM and BEMT) which are perfectly and evenly distributed on the skin and organic screens (like MBBT) dispersed in the aqueous phase for a better absorption response and therefore better efficacy.

Preferably, the compositions according to the present invention are adjusted so as to obtain a photoprotective system:.

More preferentially, the composition according to the present invention may correspond to the maximum category in terms of sun protection, that is, having SPF <NUM>+.

One or more of the following UVB filters can be added to the composition according to the invention:.

The UVB filters indicated above are UVB filters considered satisfactory from the point of view of tolerance, toxicity, photostabilization and UV absorption. Thus, as a precaution regarding homosalate, preferably the following UVB filter or filters are preferred:.

Furthermore, the composition will preferentially be stable to light, air, humidity and temperature.

Another subject of the present invention concerns a composition containing a photostabilized combination comprising.

and a pharmaceutically or cosmetically acceptable excipient.

In one particular embodiment of the invention, the quantity of the UVB filter or filters is comprised in total between <NUM> and <NUM>% by weight with regard to the weight of the composition. In another embodiment of the invention, the composition contains a single additional UVB filter in an amount of <NUM>% to <NUM>% by weight with regard to the weight of the composition and preferably in an amount of <NUM>% to <NUM>% by weight with regard to the weight of the composition.

In one particular embodiment of the invention, the composition will contain a single UVB filter chosen from among the following filters:.

The present invention finally concerns the use of a combination containing:.

to photostabilize BMDBM in a photoprotective composition.

"Pharmaceutically or cosmetically acceptable excipient" means any adjuvant or excipient for manufacturing, preserving or administering the composition.

Compositions according to the invention may more particularly be sunscreen compositions. They are particularly intended for protecting skin (face and/or body) and/or hair from ultraviolet radiation.

Compositions according to the invention may also comprise conventional cosmetic or pharmaceutical adjuvants, in particular chosen from among fats, organic solvents, thickeners, softeners, opacifiers, stabilizers, emollients, anti-foaming agents moisturizers, fragrances, preservatives, polymers, fillers, sequestering agents, bactericides, odor absorbers, basifying or acidifying agents, surfactants, free-radical scavengers, antioxidants, vitamins E and C, alpha-hydroxy acids or any other ingredient usually used in cosmetics or pharmaceuticals, particularly for the manufacture of sunscreen compositions.

The fats may consist of an oil or wax or mixtures thereof, and they also include fatty acids, fatty alcohols and fatty acid esters. The oils may be chosen from among animal, vegetable, mineral or synthetic oils and notably Vaseline oil, paraffin oil, volatile or nonvolatile silicone oil, isoparaffins, polyolefins and fluorinated and perfluorinated oils. Likewise, the waxes may be chosen from among animal, fossil, vegetable or synthetic waxes such as beeswax, candelilla wax, carnauba wax, petroleum wax (or microcrystalline wax), paraffin, and mixtures thereof.

The composition may further comprise a water-miscible polyol at room temperature (around <NUM>), in particular chosen from among polyols having from <NUM> to <NUM> carbon atoms, preferably having <NUM> to <NUM> carbon atoms, and preferentially having <NUM> to <NUM> carbon atoms, such as glycerin; glycol derivatives such as propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, dipropylene glycol and diethylene glycol; glycol ethers such as C1-C4 alkyl ethers of mono-, di-or tri-propylene glycol, C1-C4 alkyl ethers of mono-, di-or triethylene glycol and mixtures thereof.

The composition may also comprise thickeners or rheology modifying agents, such as, for example, nonionic ethoxylated hydrophobically modified urethanes, polycarboxylic acid thickeners such as acrylates/steareth <NUM> methacrylate copolymers, carbomers, crosslinked acrylate copolymers and mixtures thereof.

The composition may also comprise acids and bases to adjust the pH zone of said composition. The bases may be mineral (sodium hydroxide, potassium hydroxide, ammonia, etc.) or organic such as mono-, di- or triethanolamine, aminomethylpropanediol, N-methylglucamine, basic amino acids such as arginine and lysine, and mixtures thereof.

The composition may also comprise skin conditioners. Examples of skin conditioners include, but are not limited to, anionic, cationic and nonionic surfactants such as sodium lauryl sulfate, sodium dioctyl sulfosuccinate, sodium stearate, ester sorbitan, ethoxylated fatty acids, ethoxylated fatty alcohols such as trideceth-<NUM> and PEG-<NUM> ethylhexanoate; any other emulsifier and conditioning agent known to the skilled person, and mixtures thereof.

Compositions according to the invention may further comprise additional active agents chosen in particular from among from moisturizers, desquamating agents, agents for improving barrier function, depigmenting agents, antioxidants, skin tighteners, anti-glycation agents, agents stimulating the synthesis of dermal and/or epidermal macromolecules and/or preventing their degradation, agents stimulating fibroblast or keratinocyte proliferation and/or keratinocyte differentiation, NO synthase inhibitors, agents increasing the activity of the sebaceous gland, tensioning agents, lipo-restructuring agents, slimming agents, agents promoting skin microcirculation, soothing and/or irritant agents, sebo-regulating or anti-seborrheic agents, astringents, wound healing agents, anti-inflammatory agents, anti-acne agents, and mixtures thereof.

Compositions according to the invention may be presented in any appropriate form for topical application, especially on the skin and/or hair. In particular, they may be in the form of emulsions obtained by dispersing a fatty phase in an aqueous phase, for example one or multiple oil-in-water or water-in-oil emulsions, or in the form of a gel or an anhydrous liquid, pasty or solid product, or in the form of a dispersion in the presence of spherules. Compositions according to the invention may also be less fluid and may be in the form of a white or colored cream, ointment, milk, lotion, serum, paste, mask, powder, solid stick or optionally, an aerosol, foam or spray. These compositions may also be water resistant.

The spectrophotometer measures the spectral transmittance through a plate with and without a layer of a sunscreen composition on its surface.

The spectrophotometer should allow measurements comprised between <NUM> and <NUM>. To reduce variability between measurement readings and to compensate for the lack of uniformity of the product layer, it is recommended that the reading zone of the sites be at least <NUM><NUM>.

The spectrophotometer used for these measurements is the Labsphere® UV-<NUM> or <NUM>.

The plate is the material onto which the sunscreen composition is applied. This material must be transparent to UV, non-fluorescent, photostable and inert with regard to the compounds of the compositions tested. For this protocol, polymethyl methacrylate (PMMA) plates proved ideal.

The UV source is a solar simulator with a xenon arc lamp diffusing a visible + UVA + UVB spectrum. The UV source used for this study is Suntest CPS+ (Atlas).

Firstly, it is necessary to determine UV transmission through a control plate. This is prepared by spreading a few microliters of glycerin so that the surface of the plate is completely covered.

The sample to be tested is applied onto the PMMA plate in an amount of <NUM>/cm<NUM> (actual quantity remaining on the plate). To guarantee the accuracy of the amount and the reproducibility of the results, the application zone is larger than <NUM><NUM>.

The sample to be tested is applied in the form of a large number of small drops of the same volume, distributed over the entire surface of the plate.

In order to ensure that the quantity of the product is correct, a method of validating the quantity of product applied must be adopted (for example: weigh the plate before and after application of the product).

After application of the defined quantity of sample, the sample should be spread over the entire plate as quickly as possible (less than <NUM> seconds).

The sample is then placed for <NUM> minutes in the dark at room temperature in order to promote the formation of a homogenous film.

The plate treated with the sample is analyzed with the spectrophotometer and the mean value of UV radiation transmission through the sample is determined for each wavelength from <NUM> to <NUM> (using the monochromatic absorbance data measured on the different areas of the plate).

At least three PMMA plates should be prepared for each sample. Each plate should be measured in at least nine different regions unless almost the entire surface is measured by spectrophotometry.

Calculation of SPF and UVA (PPD) in vitro from absorbance data A(λ) before and after irradiation with doses of <NUM> and <NUM> MED.

Calculation of photostability from the following formulas: <MAT> <MAT>.

Claim 1:
Composition containing a photostabilized combination of Butyl Methoxydibenzoyl methane (BMDBM), Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine (BEMT), and Methylene Bis-Benzotriazolyl Tetramethylbutylphenol (MBBT) wherein:
i. the BEMT/BMDBM mass ratio is chosen in the range from <NUM> to <NUM>;
ii. the content of BMDBM is comprised between <NUM>% and <NUM>% by weight with regard to the total weight of the composition,
iii. the quantity of MBBT is comprised between <NUM>% and <NUM>% by weight with regard to the total weight of the composition,
iv. the content of BEMT is comprised between <NUM>% and <NUM>% by weight with regard to the total weight of the composition,
said combination containing no octocrylene, PABA or ethylhexyl methoxycinnamate, and a pharmaceutically or cosmetically acceptable excipient.