WO2021102873A1

WO2021102873A1 - An oil-in-water sunscreen composition

Info

Publication number: WO2021102873A1
Application number: PCT/CN2019/121807
Authority: WO
Inventors: Shuqin XU; Dongdong SONG
Original assignee: Beiersdorf Daily Chemical (Wuhan) Co., Ltd.; Beiersdorf Ag
Priority date: 2019-11-29
Filing date: 2019-11-29
Publication date: 2021-06-03
Also published as: DE112019007080T5; KR20210148153A; CN114144161A; BR112021017909A2; CN114144161B

Abstract

It relates to a sunscreen composition in form of an oil-in-water emulsion containing one or more SPF booster(s), having a reduced amount of UV filter(s) and not leaving a white film on the skin.

Description

An Oil-in-Water Sunscreen Composition

Technical field

The present invention describes an oil-in-water (O/W) sunscreen composition containing one or more UV filter (s) and one or more SPF booster (s) .

Background art

In western countries, the trend away from genteel pallor towards “healthy, sporty brown skin” has been unbroken for years. In order to achieve this, people subject their skin to solar radiation since this causes pigment formation in the sense of melanin formation. However, the ultraviolet radiation of sunlight also has a harmful effect on the skin. Besides the acute damage (sunburn) , long term damage such as an increased risk of suffering from skin cancer, arises with excessive irradiation with light from the UVB range (wavelength: 280-320 nm) . Moreover, too much UVB and UVA radiation (wavelength: 320-400 nm) leads to a weakening of the elastic and collagenous fibers of connective tissue. This may result in numerous phototoxic and photoallergic reactions, the effect being premature skin aging.

In Asian countries, a pale skin is preferred. Therefore, the people try to protect their skin from sunrays; this can be achieved by using an umbrella, avoiding sunlight, and/or using photoprotective cosmetic means.

In order to protect the skin by cosmetic photoprotective means, a series of photoprotective filter substances has therefore been developed, which can be used in cosmetic preparations. These UVA and UVB filters are summarized in most industrialized countries in the form of positive lists such as for instance Annex 7 of the German Cosmetics Regulation.

The effect of UV filters in a cosmetic preparation has to be determined; in general the sun protection factor (SPF) is used to characterize the sun protection potential of a cosmetic composition intended for the use as a sunscreen means. The sun protection factor (SPF) indicates the increased time of exposure to the sun's rays made possible through use of the sunscreen composition. It is the ratio of the erythema threshold time with sunscreen composition to erythema threshold time without sunscreen composition.

Another test method, which has become established throughout Europe is the Australian standard AS/NZS 2604: 1997. Said standard involves the measurement of the absorption of the preparation in the UV-A range. To comply with the standard, the preparation must absorb at least 90%of the UV-A radiation in the range from 320 to 360 nm.

In general, to ensure a sufficient photo protection a cosmetic composition may be characterized by SPF values of 20 -50. To achieve this comparatively high photo protection quite a high amount of UV filters has to be used in said compositions. However, the incorporation of high amounts of UV filters has drawbacks. High amounts of UV filters worsen the cosmetic properties of a composition, which may become highly viscous, sometimes even pasty-like. After usage of such a composition the skin feeling is described as greasy and oily. Also, skin irritations have been observed after the application of sun screen compositions containing high amounts of UV filters. Moreover, high amounts of UV filters make sunscreen compositions more and more expensive. And finally, there are restrictions in relation to the amount and kind of UV filters depending on different countries.

Therefore, a need exists to improve the UV protection capability of a sunscreen composition without increasing the amount of UV filters. A solution is the concept of SPF booster.

The term "SPF booster" means a compound or composition that increases the SPF of a given preparation when used together with a UV filter. In general, the compound or composition being effective as a SPF booster does not function as an UV filter itself or only to a negligible extent.

The use of SPF booster to increase the SPF of a given sunscreen composition is already disclosed in prior art. A great variety of substances and mixtures of substances have been described to be effective as SPF booster, only a few will be mentioned below.

In the document EP 2201929 A2 a heterogeneous group of substances are disclosed as SPF boosters, namely diesters of carboxylic acids and alcohols having 2 to 10 carbon atoms; 2-propyl heptyl octanoate; sodium acrylate homopolymers, having an average molecular weight of 2,500,000 to 3,500,000 Dalton and the 1 %by weight solution of said sodium acrylate homopolymers having a pH value of 5.5 to 7.5; silica particles not being modified or coated and having an average by number diameter of 2 to 15 μm.

Likewise in the document DE 102010008321 A1 a heterogeneous group of substances are disclosed as SPF boosters, namely Vitis Vinifera Seed Oil; trimethylsiloxysilicate; talc; stearoxytrimethylsilane + stearyl alcohol; sodium polystyrene sulfonate; sodium hyaluronate; polysorbate 65; polysorbate 40; polymethyl silsesquioxane; phenethyl benzoate; Ginkgo Biloba extract; Oenothera Biennis Oil; octadecenedioic acid; methyl palmitate; Glycyrrhiza Inflata Root Extract; Glycine Soja (isoflavone) ; Arctium Lappa Extract; diethylhexyl 2, 6-naphthalate; ceramide 3; caprylic/capric glycerides; Di-C12-13 alkyl tartrate.

In the document WO 2014/203913 A1 different SPF boosters are disclosed, which are selected from hollow particles. Polymers and copolymers of (meth) acrylic acid, (meth) acrylates, and/or styrene; glass; silica are the materials, said particles are made therefrom.

For instance, the hollow latex particles may be constituted of a copolymer of styrene and (meth) acrylic acid or one of its alkyl esters, known under the INCI name Styrene/Acrylates Copolymer, which may be purchased under the trade name Sunspheres ^TM Powder by the company Rohm &Haas.

In the document EP 2396085 A2 a SPF booster is described, which is composed of a particulate material that is virtually insoluble and a water-soluble or water-dispersible, interfacially-active polymer. The interfacially-active polymer may be chosen from lignosulfonate, lignin, oxylignin, alkali metal salts of humic acid, alkali metal salts of tannic acid, proteins, hydrophobically-modified water-soluble or water-dispersible polymers, and water-soluble or water-dispersible, amphiphilic copolymers. The particulate materials may be chosen from titanium dioxide, zinc oxide, alumina, cerium oxide, silica, bentonite, talc, aluminum hydroxide, calcium sulfate, and polymeric latex particles. A commercially available mixture of said SPF booster is sold under the trade name

UV from AMCOL International Corporation.

In the documents WO 2019/022914 A1 and WO 2019/022913 A1 the synthesis of sophisticated multistage polymeric particles is described, the particles being intended to be effective as SPF boosters.

In the document WO 2017/112982 A1 a sunscreen composition is disclosed containing at least one UV filter and at least one SPF booster comprising a silica aerogel being present in an amount of 0.1 to 5.0 %by weight in the composition.

However, there is still a need to provide sunscreen compositions containing SPF boosters, which contain a well-balanced combination of the SPF booster, UV filter (s) and advantageous accompanying substances supporting the effect of UV filter (s) and SPF booster (s) . Moreover, it is desirable to make available sunscreen compositions, which do not leave a white film on the skin after application.

Summary of the invention

Surprisingly, a sunscreen composition in form of an oil-in-water emulsion containing

- Isoamyl laurate,

- at least one UV-filter,

- at least one SPF booster, and

- at least one film forming polymer,

could fulfil the above mentioned requirements.

According to the present invention the sunscreen composition comprises an aqueous phase, the total amount of water ranges from 45 to 95 %by weight, preferably 60 to 85 %by weight, in relation to the total weight of the composition.

According to the present invention isoamyl laurate is contained in the sunscreen composition. Especially isoamyl laurate is proved to be an advantageous solvent for the one or more UV filter (s) . Isoamyl laurate may be purchased as Mackaderm LIA from Solvay or Dermofeel Sensolv from Evonik Dr. Straetmans.

In the composition according to the present invention isoamyl laurate is contained in an amount of 0.1 to 5.0 %by weight, preferably 0.5 to 3.0 %by weight, in relation to the total weight of the composition.

The sunscreen composition of the present invention contains at least one UV filter; however to provide a composition having a sufficient and broad photo protective potential, advantageously a combination of UV filters is present, which absorb sun rays in a range of about 280 to about 400 nm. This may be achieved by a suitable combination of so called UV A and UV B filters or by using broadband filters or combinations thereof.

If the sun screen composition according to the present invention contains at least one UV B filter, said filter may be an oil-soluble or water-soluble one. According to the present invention suitable oil-soluble UV B filters are:

- 3- (4-methylbenzylidene) camphor, 3-benzylidenecamphor;

- isoamyl p-methoxycinnamate; ethylhexyl cinnamate,

- Ethylhexyl Salicylate (= INCI) ;

- 2-hydroxy-4-methoxybenzophenone (INCI: Benzophenone-3) ;

- 2, 4, 6-trianilino (p-carbo-2'-ethyl-1'-hexyloxy) -1, 3, 5-triazine (INCI: Ethylhexyl Triazone) , 2, 4, -bis- { [4- (2-ethylhexyloxy) -2-hydroxy] phenyl} -6- (4-methoxyphenyl) -1, 3, 5-triazine (INCI: Bisethylhexyloxyphenol Methoxyphenyl Triazine) ;

- Octocrylene (= INCI) ,

- 3, 3, 5-Trimethylcyclohexyl salicylate (INCI = Homosalate) .

According to the present invention suitable water-soluble UV B filters are:

- Phenylbenzimidazole Sulfonic Acid (= INCI) and salts thereof;

- 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (INCI: Benzophenone-4) and salts thereof; and

- Benzylidene Camphor Sulfonic Acid (= INCI) and salts thereof.

If the sun screen composition according to the present invention contains at least one UV A filter, said filter may be chosen from

Diethylamino Hydroxybenzoyl Hexyl Benzoate (= INCI) and/or

Butyl Methoxydibenzoylmethane (= INCI) .

In the composition according to the present invention the at least one UV filter is contained in a total amount of 1.0 to 35.0 %by weight, preferably 2.0 to 30.0 %by weight, in relation to the total weight of the composition.

In a preferred embodiment of the invention the sunscreen composition contains the UV filters Butyl Methoxydibenzoylmethane, Ethylhexyl Salicylate, Octocrylene, 3, 3, 5-Trimethylcyclohexyl salicylate, and Phenylbenzimidazole Sulfonic Acid.

However, in a likewise preferred embodiment a combination of the UV filters Butyl Methoxydibenzoylmethane, Ethylhexyl Salicylate, 3, 3, 5-Trimethylcyclohexyl salicylate, and Phenylbenzimidazole Sulfonic Acid are contained.

In a further embodiment of the invention it is advantageous, if the UV B filters Octocrylene and/or 2-hydroxy-4-methoxybenzophenone are not contained in the composition of the invention.

Although not preferred, in the present invention the sunscreen composition may additionally contain inorganic pigments based on metal oxides, which are insoluble or sparingly soluble in water, in particular the oxides of titanium (TiO2) and zinc (ZnO) and mixtures of such oxides, providing an additional photo protective effect.

If in the composition according to the present invention at least one inorganic pigment is contained, the at least one inorganic pigment is contained in a total amount of 0.2 to 10.0 %by weight, preferably 0.5 to 5.0 %by weight, in relation to the total weight of the composition.

For the purposes of the present invention the inorganic pigments may be present in hydrophobic form, i.e. the surface of said pigments has been treated in such a way that water is repelled. This surface-treatment may involve providing the pigments with a thin hydrophobic layer by processes known per se.

The sunscreen composition of the present invention contains at least one SPF booster. SPF boosters do not absorb UV rays themselves or only to a very limited extent. Without being bound to theory the idea exists that the UV rays hitting the UV boosters are scattered. These scattered rays may reach UV filters and may then be absorbed additionally.

According to the invention it is preferred, if the SPF booster is present in form of particles, even more preferred in form of hollow particles and most preferred hydrophobic particles.

Examples of hydrophobic particles are hydrophobic silica particles. They are preferably provided in form of a powder.

The starting point of hydrophobic silica may be synthetically produced SiO2. Starting from silica sand synthetically produced SiO2 is obtained either via silica (water glass) or via silicon tetrachloride as an intermediate. In the first case, so-called precipitated silica is obtained by acid hydrolysis; in the second case, so-called pyrogenic silica is obtained by pyrolysis (thermal decomposition) in an oxyhydrogen gas flame. Subsequently, the silica products are rendered hydrophobic by treatment with halogenated silanes, alkoxysilanes or silazanes. The hydrophobic silica differs from the starting hydrophilic silica, inter alia, by a lower density of silanol groups and by a smaller adsorption of water vapour.

It is preferred that particles of hydrophobic silica modified at the surface with trimethylsilyl groups (trimethylsiloxylated silica) are contained in the sunscreen composition of the present invention. Said particles of hydrophobic silica may be purchased from Dow Corning under the trade name VM-2260 (INCI name: Silica silylate) , exhibiting an average size of approximately 1000 microns and a specific surface per unit of weight ranging from 600 to 800 m2/g.

The at least one SPF booster is contained in a total amount of 0.2 to 5.0 %by weight, preferably 0.5 to 1.5 %by weight, in relation to the total weight of the composition.

The sunscreen composition of the present invention contains at least one film-former. Film-formers are added to skin care compositions in order to contribute to build a film on the skin after the evaporation of the solvent; the film helps to prevent transepidermal water loss and/or maintain a good barrier for ultraviolet radiation protection. In case of sunscreen compositions the film on the skin shall also support the water resistance of the product. Advantageously an oil soluble film-former is used. The oil soluble film-former may be selected from PEG-240/HDI Copolymer Bis-Decyltetradeceth-20 Ether, Vinyl Pyrolidone/Triacontene Copolymer, Acrylates/Octylacrylamide Copolymer, Acrylates Copolymer, Hydroxyesters Acrylates Copolymer, Dimethicone Crosspolymer, VP/Hexadecene Copolymer. It is preferred, if at least one Dimethicone Crosspolymer is contained in the composition of the present invention.

Additionally it is advantageous, if one or more silicone (s) is/are contained in the composition according to the invention. Silicones are synthetic polymers containing silicium atoms connected via oxygen atoms. The functional unit consisting of silicium atom and oxygen atom is called siloxane. In case of dimethicones many siloxane units are arranged in a linear way, each silicium atom having two methyl residues and the silicium atoms at the ends having three methyl residues. Dimethicones are varying in length. The differing length accounts for differing viscosity values. Therefore dimethicones can be characterized by these values. Dimethicones, or silicone fluids, as they are also called, may be purchased having varying values of viscosity. Commercial products have viscosity values between 1 centistokes (cst) and 1,000,000 cst. The lower viscosity products are miscible for example with mineral oil and isopropyl myristate and are useful for aerosol applications. The dimethicone products having 100 –500 cst are the traditional silicones used as additives in skin care formulations and products characterized by higher viscosities are used in barrier products or in hair products. The viscosity values are referring to those values which are given by the suppliers of the respective silicone components to characterize these components.

The viscosity values may be determined according to CTM 0004 (Dow Corning) or DIN 53019 (Wacker) .

If the siloxane units are arranged in a linear way, thus creating long-chain molecules, and then crosslinked via C3 to C20 alkyl groups, dimethicone crosspolymers are generated. Said crosspolymers are silicone elastomers being characterized by a network. Dimethicone crosspolymers may be effective as rheology modifiers in O/W-and W/O-emulsions and influence the texture of the compositions they are contained in. Moreover, dimethicone crosspolymers are effective as film-formers, helping to build a film on the skin ensuring an even distribution of UV filters contained in said film.

According to the invention it is preferred, if the one or more dimethicone crosspolymer (s) is contained in a total amount of 0.1 to 10.0 %by weight, preferably 0.5 to 5.0 %by weight, in relation to the active content of the dimethicone crosspolymers and in relation to the total weight of the composition.

Dimethicone crosspolymers are available as combinations with cyclopentasiloxane or low viscosity dimethicone, which may be volatile or non-volatile. A preferred dimethicone crosspolymer is a blend of dimethicone and dimethicone crosspolymer, available as Dowsil 9041 Silicon Elastomer Blend from Dow Corning. According to the invention it is preferred, if the blend of dimethicone and dimethicone crosspolymer is contained in a total amount of 0.1 to 10 %by weight, preferably 0.5 to 5.0 %by weight, in relation to the total weight of the composition.

Additionally, a natural film former may be contained; a preferred example of such a film former is Capryloyl Glycerin/Sebacic Acid Copolymer, which may be purchased from Inolex under trade name LexFilm Sun Natural.

In general, it is understood that emulsions are heterogeneous systems, which consist of two liquids which are immiscible or have only limited miscibility with one another and which are usually referred to as phases. In an emulsion, one of the two liquids is dispersed in the form of very fine droplets in the other liquid. The liquids (pure or as solutions) are present in an emulsion in a more or less fine distribution, which is generally of only limited stability.

If the two liquids are water and oil and oil droplets are present in finely distributed form in water, then this is an oil-in-water emulsion (O/W emulsion, e.g. milk) . The basic character of an O/W emulsion, exemplified by electrical conductivity, sensory properties, ability of the continuous phase to be stained, is determined by the water. In the case of a water-in-oil emulsion (W/O emulsion, e.g. butter) , the basic character is determined by the oil.

To stabilize an emulsion, one or more emulsifier (s) is/are contained in general.

Emulsifiers help to combine two immiscible liquids (for example oil in water) in a way to result in a stable preparation, an emulsion. For that reason emulsifiers have to have an amphiphilic character, the hydrophobic part interacts with the oily or lipid phase and the hydrophilic part interacts with the aqueous phase. By stirring or homogenizing the generated droplets are dispersed in the respective environment, namely aqueous droplets in a lipid environment or lipid droplets in an aqueous environment. Primarily, emulsifiers do not have a detersive, surfactant character. Emulsifiers reduce the interfacial tension between the two phases and, besides reducing the interfacial work, also achieve a stabilization of the emulsion formed. They stabilize the formed emulsion by means of interfacial films, as well as by forming steric or electrical barriers, as a result of which the merging (coalescence) of the emulsified particles is prevented.

HLB values are suitable to characterize emulsifiers, said values specify the hydrophilicity of a given emulsifier. The HLB value may be determined by the following formula:

HLB=20× (1-Mlipophile/M) ,

where Mlipophile represents the molar mass of the lipophilic fraction of a given emulsifier and M represents the molar mass of the total emulsifier.

In general, emulsifiers with an HLB value up to about 8 are considered to be W/O-emulsifiers. By contrast, O/W-emulsifiers have HLB values greater than 8.

The sunscreen composition of the present invention contains at least one O/W-emulsifier.

The at least one O/W emulsifier may be chosen from Ceteareth-12, ceteareth-20, ceteareth-25, ceteareth-3, ceteth-10, ceteth-2, ceteth-20, cetyl phosphate, cetyl stearyl alcohol in combination with PEG-20 stearate, glyceryl stearate citrate, glyceryl stearate in combination with PEG-100 stearate, glyceryl stearate in combination with PEG-30 stearate, glyceryl stearate SE, isosteareth-10, isosteareth-20, isostearyl diglyceryl succinate, laureth-23, laureth-4 phosphate, laureth-4, methyl glucose sesquistearate, PEG-100 stearate, PEG-20 glyceryl stearate, PEG-20 stearate, PEG-20 methyl glucose sesquistearate, PEG-30 stearate, PEG-40 stearate, PEG-45/dodecyl glycol copolymer, PEG-6 caprylic/capric glyceride, polyglyceryl-10 stearate, polyglyceryl-2 laurate, polyglyceryl-2 PEG-4 stearate, polyglyceryl-2 sesquiisostearate, polyglyceryl-3 distearate, polyglyceryl-3 distearate in combination with glyceryl stearate citrate, polyglyceryl-3 methyl glucose distearate, polysorbate 60, potassium cetyl phosphate, sodium cetyl stearyl sulfate, sodium stearoyl glutamate, steareth-10, steareth-2, steareth-20, steareth-21, stearic acid, sucrose polystearate + hydrogenated polyisobutene, triceteareth-4 phosphate, trilaureth-4 phosphate.

Preferably, sodium stearoyl glutamate is contained in the composition according to the present invention.

In the composition according to the present invention the at least one O/W emulsifier is contained in a total amount of 0.2 to 1.2 %by weight, preferably 0.3 to 0.9 %by weight, in relation to the total weight of the composition.

According to the present invention the sunscreen composition comprises an oily phase, which may contain the oil soluble film-former, the SPF booster being hydrophobic, isoamyl laurate and oil-soluble UV filters. Preferably, the oily phase is present in an amount of 6.5 to 55 %by weight, more preferably 7.0 to 45 %by weight, in relation to the total weight of the composition.

According to the present invention the composition may additionally contain at least one thickener in order to adjust the viscosity, especially of the aqueous phase. Examples of advantageous thickeners are:

- organic, natural compounds, such as, for example, agar agar, carrageen, tragacanth, gum arabic, alginates, pectins, polyoses, guar gum, carob bean flower, starch, dextrins, gelatins, casein,

- organic, modified natural substances, such as, for example, carboxymethylcellulose and other cellulose ethers, hydroxyethyl-and-propylcellulose and the like,

- organic, completely synthetic compounds, such as, for example, polyacrylic and polymethacrylic compounds, vinyl polymers, polycarboxylic acids, polyethers, polyimines, polyamides,

- inorganic compounds, such as, for example, polysilicic acids, clay minerals, such as montmorillonites, zeolites, silicas.

Advantageously, in the composition according to the present invention xanthan (CAS No. 11138-66-2) , also called xanthan gum may be contained. Xanthan gum is an anionic heteropolysaccharide, which is generally formed by fermentation from maize sugar and is isolated as the potassium salt. It is produced by Xanthomonas campestris and some other species under aerobic conditions with a molecular weight of 2×10 ⁶ to 24×10 ⁶. Xanthan is formed from a chain having β-1, 4-bonded glucose (cellulose) with side chains. The structure of the subgroups ( "repeat units" ) consists of glucose, mannose, glucuronic acid, acetate and pyruvate. Xanthan gum may be purchased from CP Kelco under the trade name Keltrol CG-F.

If xanthan gum is contained in the composition of the present invention, xanthan gum is contained in an amount of 0.05 to 5 %by weight, preferably 0.1 to 3.0 %by weight, in relation to the total weight of the composition.

Likewise advantageously, acrylate-based thickeners may be contained in the composition of the present invention. These acrylate-based thickeners may be polymers of acrylic acid, in particular those chosen from the group of carbomers or Carbopols (

is actually a registered trade mark of the Lubrizol Company) . Carbopols are compounds of the general structural formula

especially having a molecular weight between about 400,000 and 4,000,000. The group of Carbopols also includes acrylate-alkyl acrylate copolymers, for example those characterized by the following structure:

where R' is an alkyl radical, and x and y are numbers which symbolize the respective stoichiometric content of each comonomer.

Advantageously the composition of the present invention may contain copolymers, having a comparable structure as the acrylate-alkyl acrylate copolymers, but R’ being an alkyl radical having 10 to 30 carbon atoms. Said copolymers comprise one or more monomers of acrylic acid, of methacrylic acid and one or more C10-30 alkyl acrylates monomers. The INCl name of such compounds is "Acrylates/C 10-30 Alkyl Acrylate Crosspolymer" . Particularly advantageous are those available under the trade names Pemulen TR1, Pemulen TR2 and Pemulen EZ-4U polymeric emulsifier from Lubrizol.

If at least one Acrylates/C10-30 Alkyl Acrylate Crosspolymer is contained in the composition of the present invention, the at least one Acrylates/C10-30 Alkyl Acrylate Crosspolymer is contained in an amount of 0.1 to 1.5 %by weight, preferably 0.15 to 0.4 %by weight, in relation to the total weight of the composition.

Even likewise advantageously inorganic compounds, especially clay minerals, preferably silica may be contained in the composition of the present invention. These compounds are contributing to a thickening effect. Additionally, they improve the sensory impression of the inventive composition, e.g. they convey an impression of richness. A preferred silica may be purchased from AGC Si-tech under the trade name Sunsphere H-52.

If silica is contained in the composition of the present invention, silica is contained in an amount of 0.1 to 5.0%by weight, preferably 0.5 to 3.0 %by weight, in relation to the total weight of the composition.

In a preferred embodiment, the thickeners xanthan gum, Acrylates/C 10-30 Alkyl Acrylate Crosspolymer and silica are contained in the composition of the present invention.

According to the present invention the composition may additionally contain at least one moisturizer. Moisturizers refer to substances or substance mixtures that give cosmetic preparations the property that, after application and distribution on the skin surface, the release of moisture from the corneal layer of the epidermis (also referred to as transepidermal water loss (TEWL) ) is reduced and/or the hydration of the corneal layer is positively influenced. Examples of advantageous moisturizers within the meaning of the present invention include glycerin, lactic acid and/or lactates, in particular sodium lactate, butylene glycol, propylene glycol, Biosaccharide Gum-1, glycine soja, ethylhexylglycerin, pyrrolidone carboxylic acid, and urea. It is preferred, if glycerin is contained.

If at least one moisturizer is contained in the composition of the present invention, the at least one moistuizer is contained in an amount of 1.0 to 10.0 %by weight, preferably 2.0 to 5.0 %by weight, in relation to the total weight of the composition.

According to the present invention the composition may additionally contain at least one preservative. All preservatives, which are allowed and suitable for cosmetic compositions may be contained. However, it is preferred, if methylparaben, ethylparaben, and Phenoxyethanol, or mixtures thereof, more preferably Phenoxyethanol are contained. Other preservatives may also be used, for example Benzyl Alcohol. These preservatives may be used alone or in combination or in combination with the above mentioned preferred preservatives.

If at least one preservative is contained in the composition of the present invention, the at least one preservative is preferably contained in a total amount of 0.1 to 0.9 %by weight, more preferably 0.4 to 0.8 %by weight, relative to the total weight of the composition. The values are referring to the active content of the preservatives.

According to the present invention the composition may additionally contain cosmetic auxiliaries, which are usually used in such compositions, e.g. preservative aids, complexing agents, electrolytes, perfumes, pigments which have a coloring action, fats, further oils, waxes or other common constituents of a cosmetic composition.

The pH value of the composition according to the present invention may be adjusted by all means suitable for cosmetic compositions. However, it is preferred, if suitable amounts of inorganic base, e.g. sodium hydroxide, are contained to adjust the pH value to a value from 7.0 to 7.8, more preferably 7.2 to 7.8.

The composition according to the invention preferably has a viscosity of 2900 to 4000 mPa·s, more preferably 2900 to 3900 mPa·s. The viscosity is determined by using a Rheomat R123 at 25℃.

Preparation method:

The composition of the present invention may be prepared by any technique known or effective to prepare an O/W-emulsion. The process to prepare the composition of the present invention comprises conventional formulating and mixing techniques. However, it is preferred, if the composition according to the present invention is prepared by the following method:

1. Mix and dissolve the polar oil (s) , non-polar oil (s) and emulsifier (s) and other oil soluble components.

2. Mix and dissolve the water soluble components well.

3. Add the oil soluble components and thickener slowly to water soluble components while stirring to form the O/W emulsion.

Determination of the SPF:

ln Vivo Determination of Sun Protection Factor; the test is based on the international standard ISO 24444: 2010 (E) .

Test areas on subjects’ backs are coated with test product. Between product application and irradiation a waiting time of 15 minutes is realized. Irradiation is carried out by 6 different doses. The resultant erythema is used to ascertain the minimum erythema dose (MED) . The individual Sun Protection Factor (SPF) is determined from the ratio of MEDU (MED of untreated skin) and MED (MED of protected skin) of the area treated with the product in question. The SPF result is expressed as the arithmetical mean of the individual SPF values obtained from the total number of subjects used.

The use of the combination of isoamyl laurate, at least one film-former, preferably a dimethicone crosspolymer, and at least one SPF booster, preferably hydrophobic silica particles, results in a sunscreen composition having a reduced amount of UV filter (s) and at the same time reaching an SPF greater than 50. Isoamyl laurate supports the solubility of the UV filter (s) , especially oil-soluble one (s) , the film-former helps to build a film on the skin, and thereby distributing the oil droplets and the UV filters evenly on the skin. Because of the lipophilic character of said components the resulting film gets water resistant. The idea exists that the hydrophobic silica particles may be arranged between the oil droplets and UV filters and by scattering, the UV rays contribute to enhance the UV absorption.

The components isoamyl laurate, UV filter (s) , film-former, and hydrophobic silica particles are interacting and supporting each other in such a way that a well-balanced sunscreen composition results in having a reduced amount of UV filter (s) and not leaving a white film on the skin.

Hence, a further object of the present invention is the use of isoamyl laurate, at least one film-former, and at least one SPF booster to provide a sunscreen composition with a reduced amount of UV filters and an SPF greater than 50.

It is preferred, if isoamyl laurate, dimethicone crosspolymer and hydrophobic silica particles are used to provide a sunscreen composition with a reduced amount of UV filters and an SPF greater than 50.

Examples

The examples below are intended to illustrate the present invention without limiting it. The numerical values in the examples are percentages by weight, based on the total weight of the particular compositions, given as active content, if not denoted otherwise.

*raw material content

Claims

A sunscreen composition in form of an oil-in-water emulsion containing

- Isoamyl laurate,

- at least one UV-filter,

- at least one SPF booster, and

- at least one film forming polymer.
The composition according to claim 1 characterized in that water is contained in total amount of water ranges from 45 to 95 %by weight, preferably 60 to 85 %by weight, in relation to the total weight of the composition.
The composition according to claim 1 or 2 characterized in that isoamyl laurate is contained in an amount of 0.1 to 5.0 %by weight, preferably 0.5 to 3.0 %by weight, in relation to the total weight of the composition.
The composition according to any of the preceding claims characterized in that the at least one UV filter is chosen from

- 3- (4-methylbenzylidene) camphor, 3-benzylidenecamphor;

- isoamyl p-methoxycinnamate; ethylhexyl cinnamate,

- Ethylhexyl Salicylate (= INCI) ;

- 2-hydroxy-4-methoxybenzophenone (INCI: Benzophenone-3) ;

- 2, 4, 6-trianilino (p-carbo-2'-ethyl-1'-hexyloxy) -1, 3, 5-triazine (INCI: Ethylhexyl Triazone) , 2, 4, -bis- { [4- (2-ethylhexyloxy) -2-hydroxy] phenyl} -6- (4-methoxyphenyl) -1, 3, 5-triazine (INCI: Bisethylhexyloxyphenol Methoxyphenyl Triazine) ;

- Octocrylene (= INCI) ,

- 3, 3, 5-Trimethylcyclohexyl salicylate (INCI = Homosalate) ,

- Phenylbenzimidazole Sulfonic Acid (= INCI) and salts thereof;

- 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (INCI: Benzophenone-4) and salts thereof; and

- Benzylidene Camphor Sulfonic Acid (= INCI) and salts thereof,

- Diethylamino Hydroxybenzoyl Hexyl Benzoate (= INCI) and/or

- Butyl Methoxydibenzoylmethane (= INCI) .
The composition according to any of the preceding claims characterized in that the at least one UV filter is contained in a total amount of 1.0 to 35.0 %by weight, preferably 2.0 to 30.0 %by weight, in relation to the total weight of the composition.
The composition according to any of the preceding claims characterized in that inorganic pigments based on metal oxides, which are insoluble or sparingly soluble in water, in particular the oxides of titanium (TiO2) and zinc (ZnO) and mixtures of such oxides are not contained in the composition.
The composition according to any of the preceding claims characterized in that the UV filters Butyl Methoxydibenzoylmethane, Ethylhexyl Salicylate, Octocrylene, 3, 3, 5-Trimethylcyclohexyl salicylate, and Phenylbenzimidazole Sulfonic Acid are contained in the composition.
The composition according to any of the preceding claims characterized in that the UV filters Butyl Methoxydibenzoylmethane, Ethylhexyl Salicylate, 3, 3, 5-Trimethylcyclohexyl salicylate, and Phenylbenzimidazole Sulfonic Acid are contained in the composition.
The composition according to claim 8 characterized in that UV B filters Octocrylene and/or 2-hydroxy-4-methoxybenzophenone are not contained in the composition.
The composition according to any of the preceding claims characterized in that the at least one SPF booster is present in form of particles, preferably in form of hollow particles and more preferably in form of hydrophobic particles.
The composition according to claim10 characterized in that the at least one SPF booster is chosen from hydrophobic silica particles, preferably from particles of hydrophobic silica modified at the surface with trimethylsilyl groups (trimethylsiloxylated silica) .
The composition according to any of the preceding claims characterized in that the at least one SPF booster is contained in a total amount of 0.2 to 5.0 %by weight, preferably 0.5 to 1.5 %by weight, in relation to the total weight of the composition.
The composition according to any of the preceding claims characterized in that the at least one film-former is an oil soluble film-former, preferably selected from PEG-240/HDI Copolymer Bis-Decyltetradeceth-20 Ether, Vinyl Pyrolidone/Triacontene Copolymer, Acrylates/Octylacrylamide Copolymer, Capryloyl Glycerin/Sebacic Acid Copolymer, Acrylates Copolymer, Hydroxyesters Acrylates Copolymer, Dimethicone Crosspolymer, VP/Hexadecene Copolymer, more preferably a Dimethicone Crosspolymer.
The composition according to claim 13 characterized in that the at least one Dimethicone Crosspolymer is used in combination with a dimethicone, the dimethicone preferably having a low viscosity, more preferably a viscosity of 5 cSt.
The composition according to claim 14 characterized in that a blend of dimethicone and the at least one Dimethicone Crosspolymer is contained in a total amount of 0.1 to 10.0 %by weight, preferably 0.5 to 5.0 %by weight, in relation to the total weight of the composition.
The composition according to any of the preceding claims characterized in that additionally at least one O/W emulsifier is contained, chosen from Ceteareth-12, ceteareth-20, ceteareth-25, ceteareth-3, ceteth-10, ceteth-2, ceteth-20, cetyl phosphate, cetyl stearyl alcohol in combination with PEG-20 stearate, glyceryl stearate citrate, glyceryl stearate in combination with PEG-100 stearate, glyceryl stearate in combination with PEG-30 stearate, glyceryl stearate SE, isosteareth-10, isosteareth-20, isostearyl diglyceryl succinate, laureth-23, laureth-4 phosphate, laureth-4, methyl glucose sesquistearate, PEG-100 stearate, PEG-20 glyceryl stearate, PEG-20 stearate, PEG-20 methyl glucose sesquistearate, PEG-30 stearate, PEG-40 stearate, PEG-45/dodecyl glycol copolymer, PEG-6 caprylic/capric glyceride, polyglyceryl-10 stearate, polyglyceryl-2 laurate, polyglyceryl-2 PEG-4 stearate, polyglyceryl-2 sesquiisostearate, polyglyceryl-3 distearate, polyglyceryl-3 distearate in combination with glyceryl stearate citrate, polyglyceryl-3 methyl glucose distearate, polysorbate 60, potassium cetyl phosphate, sodium cetyl stearyl sulfate, sodium stearoyl glutamate, steareth-10, steareth-2, steareth-20, steareth-21, stearic acid, sucrose polystearate + hydrogenated polyisobutene, triceteareth-4 phosphate, trilaureth-4 phosphate, preferably sodium stearoyl glutamate.
The composition according to claim 16 characterized in that the at least one O/W emulsifier is contained in a total amount of 0.2 to 1.2 %by weight, preferably 0.3 to 0.9 %by weight, in relation to the total weight of the composition.
The composition according to any of the preceding claims characterized in that additionally at least one thickener chosen from organic, natural compounds; organic, completely synthetic compounds; and/or inorganic compounds is contained.
The composition according to claim 18 characterized in that the at least one thickener is chosen from xanthan gum, Acrylates/C 10-30 Alkyl Acrylate Crosspolymer, and/or silica.
The composition according to claim 19 characterized in that xanthan gum, Acrylates/C 10-30 Alkyl Acrylate Crosspolymer, and silica are contained.
The composition according to claim 20 characterized in that xanthan gum is contained in an amount of 0.05 to 5 %by weight, preferably 0.1 to 3.0 %by weight, Acrylates/C10-30 Alkyl Acrylate Crosspolymer is contained in an amount of 0.1 to 1.5 %by weight, preferably 0.15 to 0.4 %by weight, and silica is contained in an amount of 0.1 to 5.0 %by weight, preferably 0.5 to 3.0 %by weight, respectively in relation to the total weight of the composition.
Use of isoamyl laurate, at least one film-former and at least one SPF booster to provide a sunscreen composition with a reduced amount of UV filters and an SPF greater than 50.
The use of isoamyl laurate, dimethicone crosspolymer and hydrophobic silica particles are used to provide a sunscreen composition with a reduced amount of UV filters and an SPF greater than 50.