CN112004579A

CN112004579A - Sunscreen compositions

Info

Publication number: CN112004579A
Application number: CN201980027747.7A
Authority: CN
Inventors: R·佩鲁马; A·A·维迪雅
Original assignee: Unilever NV
Current assignee: Unilever IP Holdings BV
Priority date: 2018-04-23
Filing date: 2019-04-15
Publication date: 2020-11-27
Also published as: CA3095273A1; EA202092522A1; JP2021519277A; MX2020011125A; WO2019206714A1; ZA202005699B; PH12020551441A1; EP3784355A1; KR20210005561A; JP7362641B2

Abstract

The present invention relates to a sunscreen composition. In particular, the sunscreen composition is directed to providing improved ultraviolet a protection factor (UVAPF). The composition comprises a UVA organic sunscreen, 2-ethylhexyl 2-cyano-3, 3-diphenyl acrylate, a compound selected from resorcinol, phenylethyl resorcinol, 4-alkyl substituted resorcinol and mixtures thereof, a fatty acid and a soap.

Description

Sunscreen compositions

Technical Field

The present invention relates to a sunscreen composition. In particular, the present invention relates to sunscreen compositions that provide improved Ultraviolet (UV) a protection factor (UVAPF).

Background

People often try to care for themselves and their appearance, such as skin and scalp (including hair), in hopes of enjoying a healthy lifestyle. Concerns related to certain skin conditions include healthy and non-infected skin, good skin tone, adequate moisturization and protection from the ultraviolet radiation contained in sunlight.

Sunlight includes infrared region (700nm to 1mm), visible light region (380-780nm) and ultraviolet region (100-400 nm). The ultraviolet region consists of UVC (100-280nm), UVB (280-315nm) and UVA (315-400 nm). Although the human body requires some uv radiation to synthesize/maintain adequate amounts of vitamin D, the deleterious effects of uv light often outweigh their benefits. Excessive exposure to UVB is said to cause direct damage to DNA and also to cause sunburn; and excessive exposure to UVA is said to cause immediate pigment darkening and a delayed tanning effect. In addition, UVA is said to cause DNA damage by oxidation reactions involving reactive oxygen species (Zhang et al, 1997, Free radial Biology & Medicine,23,980- & 985).

For these reasons, people tend to avoid exposure to sunlight as much as possible. However, in many cases, it is very difficult and sometimes impossible to avoid exposure to sunlight. For this inevitable reason, there is a trend towards the use of various topical compositions, such as sunscreen compositions, which provide at least some protection against the undesirable effects caused by excessive exposure to ultraviolet radiation contained in sunlight. These compositions comprise a sunscreen that absorbs ultraviolet radiation and prevents it from reaching a surface (e.g., the skin of a user on which the composition is applied).

Organic sunscreens such as 4-tert-butyl-4' -methoxydibenzoylmethane (BMDM) absorb UVA radiation. The ability of a sunscreen to provide protection by absorbing UVA radiation is expressed as the UVA protection factor (UVAPF). On the other hand, organic sunscreens such as 2-ethylhexyl 2-cyano-3, 3-diphenyl acrylate (OCR) and octyl Methoxycinnamate (MCX) absorb UVB radiation. The ability of a sunscreen to provide protection by absorbing UVB radiation is expressed as the Sun Protection Factor (SPF).

EP 2431021 (Unilever) discloses a high SPF sunscreen composition comprising less than 8% of total organic sunscreen agents comprising dibenzoylmethane or its derivative, an oil soluble UV-B organic sunscreen agent, a polymer of the class of non-ionic surface active (selected from the class of fatty alcohol ethoxylates with saturated carbon chains and having an HLB above 15.5, or from the class of fatty alcohol ethoxylates with unsaturated carbon chains having an HLB above 12), acrylate/R-methacrylate copolymers; or acrylate/R-alkyl acrylate cross-linked polymers, and cosmetically acceptable bases. The compositions disclosed therein are intended to provide SPF of above 15 without compromising the desired skin sensory properties.

WO 03/080009(Unilever) discloses cosmetic compositions comprising organic sunscreens together with 4-substituted resorcinol derivatives in a cosmetically acceptable base. The compositions exhibit improved storage stability and oxidation stability. WO 03/080009 discloses, inter alia, combinations of butyl methoxydibenzoylmethane, octyl methoxycinnamate, stearic acid and 4-substituted resorcinols.

WO 11/147738(Unilever) relates to sunscreen compositions providing SPF (equal to or greater than 15) and high UVAPF (equal to or greater than 4). WO 11/147738 discloses a solid sunscreen composition comprising butyl methoxydibenzoylmethane, a selected class of nonionic surfactant, a selected class of polymer in a cosmetically acceptable base. WO 11/147738 further discloses a non-solid sunscreen composition comprising dibenzoylmethane or its derivative, a selected class of nonionic surfactant, a fatty acid and a cosmetically acceptable base.

WO 16/142129(Unilever) discloses the combination of C12-C20 fatty acids with C12-C20 fatty acid soaps, white pigments such as titanium dioxide, in a cosmetically acceptable carrier, wherein the molar ratio of soap to fatty acid is 0.23 to 0.5. WO 16/142129 solves the problem of providing photoprotection whilst maintaining the organoleptic properties of a composition when pigments such as titanium dioxide are added to a fatty acid containing composition.

Despite efforts to date, compositions providing improved UVAPF remain a topic of interest.

Accordingly, there is a need to develop sunscreen compositions that provide improved UVAPF.

It has now been found that compositions comprising a compound selected from resorcinol, phenylethyl resorcinol, 4-alkyl substituted resorcinol and mixtures thereof in combination with a UVA organic sunscreen, a select class of UVB organic sunscreens, a fatty acid and a soap provide improved UVAPF.

Disclosure of Invention

In a first aspect, the present invention relates to a sunscreen composition comprising:

0.1-5% by weight of a UVA organic sunscreen,

b.0.1 to 10% by weight of 2-ethylhexyl 2-cyano-3, 3-diphenylacrylate,

c.0.1 to 2.5% by weight of a compound selected from the group consisting of resorcinol, phenylethyl resorcinol, 4-alkyl substituted resorcinol and mixtures thereof,

4-25 wt.% of fatty acids; and

e.0.1 to 10% by weight of soap.

In a second aspect, the present invention relates to a method of providing improved UVAPF comprising applying to the skin a sunscreen composition of the first aspect and optionally rinsing with water.

In a third aspect, the present invention relates to the use of a composition of the first aspect to provide improved UVAPF.

Detailed Description

Any feature of one aspect of the invention may be used in any other aspect of the invention. The word "comprising" is intended to mean "including", but not necessarily "consisting of …" or "consisting of …". In other words, the listed steps or options need not be exhaustive. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about". Numerical ranges expressed as "x to y" are understood to include x and y. When for a particular feature multiple preferred ranges are described in the form "x to y," it is to be understood that all ranges combining the different endpoints are also contemplated.

Amounts used herein are expressed as weight percent based on the total weight of the composition and are abbreviated as "wt%" unless otherwise indicated.

The use of any and all examples, or exemplary language, e.g., "such as" provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed.

0.1-5% by weight of a UVA organic sunscreen,

b.0.1 to 10% by weight of 2-ethylhexyl 2-cyano-3, 3-diphenylacrylate,

4-25 wt.% of fatty acids; and

e.0.1 to 10% by weight of soap.

UVA organic sunscreen

The composition according to the invention (the composition) comprises a UVA organic sunscreen which absorbs UVA radiation and prevents it from reaching a surface, for example the skin of a user.

Examples of sunscreens which may be used as UVA organic sunscreens in the compositions are dibenzoylmethane compounds, disodium phenyldibenzoimidazole tetrasulfonate (bisdisulizole) (which may be Neo)

Commercially available from AP), diethylamino hydroxybenzoyl hexyl benzoate (as available)

Commercially available as A Plus), Ecamsule (available from commercial suppliers)Commercially available as Mexoryl SX) and methyl anthranilate.

Preferably, the sunscreen agents useful as UVA organic sunscreens are selected from the group consisting of dibenzoylmethane compounds, diethylaminohydroxybenzoylhexylbenzoate and mixtures thereof.

More preferably, the sunscreen agents that may be used as UVA organic sunscreens are selected from BMDM (may be

1789 or commercially available from avobenzone), 2-methyldibenzoylmethane, 4-isopropyldibenzoylmethane, 4-tert-butyldibenzoylmethane, 2, 4-dimethyldibenzoylmethane, 2, 5-dimethyldibenzoylmethane, 4,4' -diisopropyldibenzoylmethane, 2-methyl-5-isopropyl-4 ' -methoxydibenzoylmethane, 2-methyl-5-tert-butyl-4 ' -methoxy-dibenzoylmethane, 2, 4-dimethyl-4 ' -methoxydibenzoylmethane, 2, 6-dimethyl-4-tert-butyl-4 ' -methoxy-dibenzoylmethane and mixtures thereof.

Most preferably, the sunscreen that may be used as a UVA organic sunscreen is BMDM.

The composition comprises from 0.1 to 5 wt%, preferably from 0.5 to 4.5 wt%, more preferably from 1 to 4 wt%, even more preferably from 1 to 3.5 wt%, even more preferably from 1 to 3 wt%, still more preferably from 1 to 2.5 wt% of one or more UVA organic sunscreens.

2-ethylhexyl 2-cyano-3, 3-diphenylacrylate (OCR)

The composition comprises OCR (may be Octocrylene)^TMCommercially available) that absorb UVB radiation and prevent them from reaching surfaces, such as the skin.

The composition comprises from 0.1 to 10 wt%, preferably from 0.5 to 9 wt%, more preferably from 1 to 8 wt%, even more preferably from 1.5 to 7 wt%, even more preferably from 2 to 6 wt%, still more preferably from 2.5 to 5 wt%, most preferably from 3 to 4 wt% OCR.

Resorcinol, phenylethyl resorcinol (PER), 4-alkyl substituted resorcinols

The composition comprises a compound selected from the group consisting of resorcinol, PER, 4-alkyl substituted resorcinol, and mixtures thereof. Such compounds are known to provide skin lightening effects.

Preferably, the selected compound is a 4-alkyl substituted resorcinol. The alkyl group in the 4-alkyl substituted resorcinol can be a straight or branched alkyl group. For example, the alkyl group may be a straight chain alkyl group in the case of 4-propylresorcinol, or it may be a branched chain alkyl group in the case of 4-Isopropylresorcinol (IPR).

Examples of 4-alkyl substituted resorcinols include 4-methylresorcinol, 4-Ethylresorcinol (ER), 4-propylresorcinol, IPR, 4-Butylresorcinol (BR), 4-pentylresorcinol, 4-Hexylresorcinol (HR), 4-heptylresorcinol, 4-octylresorcinol, and mixtures thereof.

Preferred 4-alkyl substituted resorcinols are ER, BR, HR and mixtures thereof. More preferred 4-alkyl substituted resorcinols are ER, HR and mixtures thereof.

It is to be understood that the composition may comprise a combination of one or more compounds selected from the group consisting of resorcinol, PER, and 4-alkyl substituted resorcinol. For example, the composition may comprise one or more 4-alkyl substituted resorcinols, with or without the presence of resorcinols. Preferably, the composition comprises a compound selected from the group consisting of resorcinol, PER and 4-alkyl substituted resorcinol.

The composition comprises 0.1 to 2.5 wt%, preferably 0.1 to 2.25 wt%, more preferably 0.25 to 2 wt%, even more preferably 0.25 to 1.5 wt%, even more preferably 0.25 to 1 wt%, still more preferably 0.25 to 0.75 wt%, most preferably 0.25 to 0.5 wt% of resorcinol, PER, 4-alkyl substituted resorcinol, and mixtures thereof.

Fatty acids

The composition comprises a fatty acid. When the fatty acid is present in the composition together with the soap, the fatty acid provides a so-called vanishing cream effect, i.e. when a composition is applied to human skin, the composition disappears on the skin without leaving any noticeable streaks of the composition.

The composition comprises fatty acids having carbon atoms preferably in the range of 10-22, more preferably 12-22, even more preferably 14 to 22, even more preferably 16-22, still more preferably 18-22. It was found that fatty acids with increased chain length provide increased UVAPF and/or increased SPF.

Examples of fatty acids that may be used in the composition include lauric acid, myristic acid, palmitic acid, stearic acid, isostearic acid, oleic acid, linoleic acid, arachidic acid, behenic acid, erucic acid, and mixtures thereof.

Alternatively, the fatty acid which may preferably be used is stearic acid or palmitic acid or a mixture thereof. The fatty acid in the present invention is preferably a hysteric acid which is a mixture of stearic and palmitic acids substantially (typically about 90% to 95%) in a ratio of 55: 45 to 45: 55.

The composition comprises 4-25 wt.%, preferably 6-22 wt.%, more preferably 8-20 wt.%, even more preferably 10-19 wt.%, and even more preferably 12-18 wt.% fatty acids.

Soap

The composition comprises soap. When present in the composition together with the fatty acid, the soap may provide a so-called vanishing cream effect.

The soaps of the present invention are typically prepared by in situ neutralization of the fatty acids present in the composition. Thus, it is preferred that the soap has a carbon chain length corresponding to the chain length of the fatty acids in the composition. Soaps are formed from fatty acids by the use of alkali metal hydroxides such as sodium or potassium hydroxide. Among them, potassium hydroxide is more preferable. Therefore, the soap is preferably a potassium soap (potassium salt of fatty acid).

The composition comprises from 0.1 to 10 wt%, preferably from 1 to 8 wt%, more preferably from 2 to 7 wt%, even more preferably from 2 to 6 wt%, even more preferably from 2 to 5 wt%, most preferably from 2 to 4 wt% soap.

Preferably, the composition further comprises a nonionic surfactant having an HLB value in the range of 9 to 20, preferably 10 to 19, more preferably 12 to 18, even more preferably 13 to 17, still more preferably 15 to 17.

HLB B was calculated using the Griffin method, where HLB is 20x Mh/M, where Mh is the molecular mass of the hydrophilic portion of the molecule and M is the molecular mass of the entire molecule, and HLB gives results on an arbitrary scale from 0 to 20. Typical values for the various surfactants are given as follows:

a value of < 10: fat-soluble (water-insoluble)

Values > 10: water solubility

The values of 4 to 8 represent antifoams

The values of 7 to 11 represent W/O (water-in-oil) emulsifiers

Values of 12-16 indicate oil-in-water emulsifiers

Values from 11 to 14 indicate wetting agents

The value of 12 to 15 is generally detergent

Values of 16-20 indicate solubilizers or hydrotropes.

Preferably, the nonionic surfactant having an HLB value ranging from 9 to 20 is selected from fatty alcohol ethoxylates, alkylphenol ethoxylates, polyoxyethylene sorbitan alkyl esters, and mixtures thereof. Preferably, the nonionic surfactant is a surfactant having at least 9 oxirane groups, preferably at least 9 oxirane groups.

Examples of fatty alcohol ethoxylates that may be used as the nonionic surfactant in the composition include polyoxyethylene lauryl ether (HLB ═ 16.9; may be used as the nonionic surfactant

35 commercially available), polyoxyethylene (20) cetyl ether (HLB ═ 16; can be used for

58 commercially available), polyethylene glycol stearyl ether (HLB 18.8; can be used for

700 commercially available) and laureth-9 (C12EO 9; HLB is 14.3; can be used for

L9 commercially available).

Examples of alkylphenol ethoxylates that may be used as nonionic surfactants in the compositions include octylphenol ethoxylate (HLB 15.5; possibly Triton;)^TMX165 commercially available), octylphenol ethoxylate (HLB ═ 17.6; can be Triton^TMX405 commercially available) and octylphenol ethoxylate (HLB 18.4; can be Triton^TMX705 commercially available).

Examples of polyoxyethylene sorbitan alkyl esters which may be used as the nonionic surfactant in the composition include polyoxyethylene sorbitan monolaurate (HLB ═ 13.3; may be used as the nonionic surfactant; polyoxyethylene sorbitan monolaurate

21 commercially available), polyoxyethylene sorbitan monolaurate (HLB ═ 16.7; can be used for

20 commercially available), polyoxyethylene sorbitan monopalmitate (HLB 15.6; can be used for

40 commercially available) and polyoxyethylene sorbitan monostearate (HLB ═ 14.9; can be used for

60 commercially available).

More preferably, the nonionic surfactant having an HLB value in the range of from 9 to 20 that may be present in the composition is a fatty alcohol ethoxylate having a saturated carbon chain with an HLB above 15.5.

Preferably, the composition comprises from 0.5 to 5 wt%, more preferably from 1 to 4 wt%, even more preferably from 2 to 3 wt% of a nonionic surfactant having an HLB in the range of from 9 to 20.

Preferably, the composition further comprises a polymer. The polymer acts as a thickener in the composition and improves the organoleptic properties of the composition.

The polymer is preferably selected from the following classes:

acrylate/R-methacrylate copolymers, for example acrylate/steareth-20 methacrylate copolymers (may be Aculyn)^TM22 commercially available) and acrylate/beheneth-25 methacrylate copolymer (available as Aculyn)^TM28 commercially available),

acrylate/R-methacrylate crosspolymers, for example acrylate/Steareth-20 methacrylate crosspolymer (which may be Aculyn)^TM88 commercially available),

acrylate copolymers (may be Aculyn)^TM33 commercially available),

acrylates/R-alkyl acrylate crosspolymers, for example acrylates/C10-C30 alkyl acrylate crosspolymers (which may be Pemulen)^TMTR-2 is commercially available),

-copolymer of ammonium acryloyldimethyltaurate and vinylpyrrolidone (may be

Commercially available from AVC),

-copolymer of sodium acryloyldimethyltaurate and vinylpyrrolidone (may be

AVS commercially available); and

crosslinked polymers of acryloyl dimethyltaurates with R-alkyl acrylates and methyl methacrylate, e.g.acryloyl dimethyltaurate ammonium/behenyl polyether-25 methacrylate crosslinked polymer (may be

HMB and

BLV commercially available); and mixtures thereof.

More preferably, the polymer is selected from the group consisting of acrylate/R-methacrylate copolymers, acrylate copolymers and mixtures thereof.

Preferably, the composition comprises from 0.1 to 5 wt%, more preferably from 0.5 to 4.5 wt%, even more preferably from 1 to 4 wt%, even more preferably from 1.5 to 3.5 wt%, still more preferably from 2 to 3 wt% of the polymer.

Preferably, the composition comprises a cosmetically acceptable carrier which comprises water and may be present in the composition in an amount of from 5 to 99.9 wt%, preferably from 10 to 95 wt%, more preferably from 15 to 90 wt%, even more preferably from 20 to 80 wt%, even more preferably from 25 to 75 wt%, still more preferably from 30 to 70 wt%.

Preferably, the composition further comprises one or more skin lightening agents. These one or more skin lightening agents may be selected from niacinamide, vitamin B6, vitamin C, vitamin A, glutathione precursors, galanin (galardin), adapalene, aloe vera extract, ammonium lactate, arbutin, azelaic acid, butylated hydroxyanisole, butylated hydroxytoluene, citric acid esters, deoxyarbutin, 1, 3-diphenylpropane derivatives, 2, 5-dihydroxybenzoic acid and derivatives thereof, 2- (4-acetoxyphenyl) -1, 3-dithiane, 2- (4-hydroxyphenyl) -1, 3-dithiane, ellagic acid, glucopyranosyl-1-ascorbate, gluconic acid, glycolic acid, green tea extract, 4-hydroxy-5-methyl-3 [2H ] -furanone, 4-hydroxyanisole and derivatives thereof, 4-hydroxybenzoic acid derivative, hydroxyoctanoic acid, inositol ascorbate, lactic acid, lemon extract, linoleic acid, magnesium ascorbyl phosphate, 5-octanoylsalicylic acid, salicylic acid, 3,4, 5-trihydroxybenzyl derivative, acetylglucosamine, pitasala (pitera) extract, chamois (symwhite), calcium pantothenate (white-cleansing factor Melano-block), seppiwhite, soybean extract (bowman birk inhibitor), 12-hydroxystearic acid, and mixtures thereof. When used in a composition, 12-hydroxystearic acid is used as a skin lightening agent rather than as a fatty acid.

Preferably, the skin lightening agent useful in the composition is niacinamide, vitamin B6, 12-hydroxystearic acid, glutathione precursor, galanin, and mixtures thereof.

When incorporated into the composition, the skin lightening agent may be added to the composition in an amount of from 0.001 to 15% by weight, preferably from 0.01 to 10% by weight, more preferably from 0.1 to 5% by weight, even more preferably from 0.5 to 3% by weight.

Preferably, the composition further comprises an emollient. Examples of emollients that may be used in the composition include stearyl alcohol, glyceryl monoricinoleate, mink oil, cetyl alcohol, isopropyl isostearate, isobutyl palmitate, isocetyl stearate, oleyl alcohol, isopropyl laurate, hexyl laurate, decyl oleate, 2-octadecyl alcohol, isocetyl alcohol, eicosanyl alcohol, behenyl alcohol, cetyl palmitate, silicone oils such as dimethylpolysiloxane, dibutyl sebacate, isopropyl myristate, isopropyl palmitate, isopropyl stearate, butyl stearate, polyethylene glycol, triethylene glycol, lanolin, cocoa butter, corn oil, cottonseed oil, olive oil, palm kernel oil, rapeseed oil, safflower seed oil, evening primrose oil, soybean oil, sunflower seed oil, avocado oil, sesame seed oil, coconut oil, peanut oil, castor oil, acetylated lanolin alcohols, petrolatum, mineral oil, butyl myristate, coconut oil, safflower seed oil, evening primrose oil, soybean oil, sunflower seed oil, avocado oil, sesame seed oil, coconut oil, peanut oil, castor oil, Isopropyl linoleate, lauryl lactate, myristyl lactate, decyl oleate, myristyl myristate and mixtures thereof.

Preferably, the composition further comprises a solvent. Examples of solvents that may be used in the composition include ethanol, isopropanol, acetone, ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether, and mixtures thereof.

Preferably, the composition further comprises a powder. Examples of powders that may be used in the composition include chalk, talc, fullers earth, kaolin, starch, gums, colloidal silica sodium polyacrylate, tetraalkyl and/or trialkyl aryl ammonium montmorillonite, chemically modified magnesium aluminium silicate, organically modified montmorillonite clay, hydrated aluminium silicate, fumed silica, carboxyvinyl polymer, sodium carboxymethyl cellulose, ethylene glycol monostearate and mixtures thereof.

Preferably, the composition further comprises a preservative to prevent the growth of potentially harmful microorganisms. Examples of ingredients that can be used as preservatives in the compositions include alkyl esters of p-hydroxybenzoic acid, hydantoin derivatives, propionate salts, and various quaternary ammonium compounds. More preferablyIngredients that may be used as preservatives in the compositions are sodium benzoate, iodopropynyl butyl carbamate, methylisothiazolinone, iodopropynyl butyl carbamate, phenoxyethanol, methyl paraben, propyl paraben, imidazolidinyl urea, sodium dehydroacetate, ethylhexyl glycerol, benzyl alcohol, alkane diol and mixtures thereof. Alkane diols suitable as preservatives are C, substituted in the vicinity by hydroxyl groups₆-C₁₂An alkane. Illustrative examples include 1, 2-octanediol (octanediol), 2, 3-octanediol, 1, 2-nonanediol, 1, 2-decanediol, 1, 2-hexanediol, 3, 4-octanediol, mixtures thereof, and the like, with octanediol generally being most preferred.

When present in the composition, the preservative is preferably added in an amount of 0.001-5 wt%, more preferably 0.01-3 wt% and most preferably 0.02-2 wt%.

The composition may further comprise a range of other optional ingredients including antioxidants, binders, biological additives, buffering agents, colorants, astringents, fragrances, sunscreens, conditioning agents, exfoliating agents, pH adjusting agents, skin soothing agents, and skin rejuvenating agents.

The composition is preferably formulated in the form of a powder, tablet, emulsion, cream, gel or mousse. More preferably, the composition is formulated in the form of a cream or emulsion, most preferably in the form of a cream. The composition may be a leave-on or rinse-off composition. The composition is preferably a leave-on composition. The packaging for the composition of the invention may be a patch, bottle, tube, ball applicator, propellant-driven aerosol device, squeeze container or lidded can.

It was found that resorcinol, phenylethyl resorcinol, 4-alkyl substituted resorcinol and mixtures thereof improve UVAPF when present in a composition according to the first aspect. It has also been found that such improved UVAPF can only be obtained when OCR is used in the presence of a UVA organic sunscreen. When other UVB organic sunscreens such as MCX are used instead of OCR, no improved UVAPF is obtained. OCR is known to stabilize dibenzoylmethane compounds such as BMDM. It was found that the improvement in UVAPF obtained in the presence of a compound selected from resorcinol, phenylethyl resorcinol, 4-alkyl substituted resorcinol and mixtures thereof exceeds and is higher than the UVAPF obtained when OCR is used instead of MCX in the same composition. Thus, surprisingly, replacement of one UVB sunscreen, MCX, with another UVB sunscreen, OCR, surprisingly results in improved UVAPF, where delivery of UVAPF is a function of the UVA sunscreen.

Preferably, the sunscreen composition is a composition comprising:

0.1 to 5% by weight of a dibenzoylmethane compound,

b.0.1 to 10% by weight of 2-ethylhexyl 2-cyano-3, 3-diphenylacrylate,

c.0.1-2.5% by weight of a compound selected from BR, ER, HR and mixtures thereof,

4-25 wt.% of fatty acids; and

e.0.1 to 10% by weight of soap.

More preferably, the sunscreen composition is a composition comprising:

0.1 to 5% by weight of 4-tert-butyl-4' -methoxydibenzoylmethane,

b.0.1 to 10% by weight of 2-ethylhexyl 2-cyano-3, 3-diphenylacrylate,

c.0.1-2.5% by weight of a compound selected from the group consisting of ER, HR and mixtures thereof,

4-25 wt.% of fatty acids; and

e.0.1 to 10% by weight of soap.

In a second aspect, the present invention further relates to a method of providing improved UVAPF, wherein the method comprises the steps of:

a. applying the sunscreen composition of the first aspect to the skin; and

b. optionally, rinsing with water.

The present invention also provides a method of providing improved UVAPF comprising the step of applying the composition of the first aspect to a surface, such as skin, in the case of a leave-on composition. If in the form of a rinse-off composition, the method optionally includes the additional step of at least partially removing the composition from the surface. Preferably, the method is non-therapeutic, or cosmetic. Improved UVAPF is obtained when the composition is applied to the skin.

The invention will now be demonstrated by the following non-limiting examples.

Detailed Description

Examples

Scheme(s)

Preparation of the composition

Briefly, compositions according to the invention were prepared as follows: deionized water and potassium hydroxide were charged into a beaker (main beaker) mounted on a magnetic stirrer and heater. The aqueous phase was heated to 75 ℃ and kept at the same temperature. In a side pan, the fatty acids mentioned in the examples below were heated to 75 ℃ for melting and added to a main beaker kept at 75 ℃. The system was stirred at 75 ℃ for 5 minutes. The sunscreen agents, other oil soluble ingredients and nonionic surfactants mentioned in the examples were placed in separate beakers and heated to 65-70 ℃ for melting. They were mixed thoroughly and then added to the main beaker. Stirring was continued for another 5 minutes at 75 ℃. The stirrer and heater were turned off and mixing was performed manually until the temperature reached ambient temperature (25 ℃).

In vitro measurement of SPF/UVA-PF

Film transmittance measurements were performed using an SPF-290S SPF Meter (Optometrics Corporation). In this study, a study from

GmbH&Co had a roughness of 6 μm in 70X70mm PMMA plaques. The percent light transmission of each composition was measured as follows. 2mg/cm²The test samples of (a) were applied on a PMMA plate, uniformly distributed using a syringe, and uniformly spread. The drying time of the PMMA plate was 30 minutes. In the dry stateAfter the drying time, the sample plate was exposed to UV light and the transmittance scan was recorded. For a given sample, the scan gives the transmittance as a function of wavelength (290-400 nm). Six to eight different points are scanned for a single plate. The same operation was repeated for 3 plates. Thus, the data reported is the average of 18 readings. The reference transmittance scan was obtained using a blank plate, with no sample on the PMMA plate with the glycerol spread thereon. SPF values were obtained using transmittance values using Win SPF software supplied by the instrument. The transmission values were used to calculate the UVAPF value for each composition.

In vivo SPF/UVAPF

The compositions outlined in the examples shown in table 1 were tested in randomized human volunteer studies with appropriate controls. Briefly, prior to administration of the samples (compositions in table 1), the Minimum Erythemal Dose (MED) and minimum sustained pigment darkening dose (MPPDD) were estimated for each volunteer. The test samples were blind processed with standard samples of known SPF/UVAPF. The required amount of sample (2 mg/cm)²) Applied to the skin of the back of a volunteer. The samples were evenly dispensed using a syringe and evenly coated using a finger stall for a period of 20-50 seconds, depending on the ease of application of the composition. A new finger glove was used for each sample. After sample administration, subjects were exposed to uv light at doses calculated from MED and MPPDD (specifically for each volunteer) and the expected or targeted SPF/UVAPF. After exposure, volunteers were evaluated for erythema and MPPDD. SPF evaluations were performed using ISO standard 24444: 2010. UVAPF evaluations were performed using ISO 24442: 2011. The data reported here averaged 5 volunteers.

TABLE 1

The data in table 1 show that improved UVAPF was obtained using compositions according to the invention (examples 1 and 2) comprising HR in combination with BMDM, OCR, fatty acids and soap, compared to comparative examples (examples a and B; not according to the invention) which did not comprise HR.

Furthermore, the data also show that example 1 achieves improved UVAPF, even though both compositions contain the same amount, i.e. 0.5 wt%, of HR, only when the selected UVB sunscreen, i.e. OCR (example 1), is used instead of MCX (example C). Thus, HR provides improved UVAPF when used in combination with UVA organic sunscreens, 2-ethylhexyl 2-cyano-3, 3-diphenylacrylate, fatty acids and soaps. This improved UVAPF is not obtained when MCX is used instead of OCR.

The data in table 1 also show that the absence or presence of HR in the compositions of examples B and C has no effect on UVAPF.

It was surprisingly found that the improvement in UVAPF was independent of the dose of HR used. As can be seen from example 2(0.25 wt% HR), a UVAPF equal to 17 is obtained, whereas example 1(0.5 wt% HR) shows a UVAPF equal to 14. This effect is believed to be due to the superoxide quenching effect, which was found to increase with increasing HR concentration up to concentrations (2 mM). Thereafter, the superoxide quenching efficacy decreased despite the increased HR concentration under uniform exposure conditions.

Effect of the amount of soap in the composition on UVAPF and SPF

The compositions summarized in table 2 demonstrate the effect of the presence of soap in the composition compared to the control (no soap).

TABLE 2

The data in table 2 show that soap increases SPF as well as UVAPF when present in the composition according to the invention.

In addition, additional compositions shown in table 3 below were prepared as previously described and UVAPF and SPF were measured as previously described. The results found are provided in table 3 below.

TABLE 3

The data in table 3 show that enhanced UVAPF is obtained when either palmitic acid as shown in example 6 or stearic acid as shown in example 7 is used in the composition.

The data in table 3 also show that enhanced UVAPF is obtained when a BR as shown in example 8 or an ER as shown in example 9 is used in the composition.

In summary, sunscreen compositions according to the present invention provide improved UVAPF.

Claims

1. A sunscreen composition comprising:

0.1-5% by weight of a UVA organic sunscreen,

b.0.1 to 10% by weight of 2-ethylhexyl 2-cyano-3, 3-diphenylacrylate,

4-25 wt.% of fatty acids; and

e.0.1 to 10% by weight of soap.

2. The sunscreen composition according to claim 1, further comprising a nonionic surfactant having an HLB value ranging from 9 to 20.

3. A sunscreen composition according to claim 1 or 2, wherein the non-ionic surfactant is a fatty alcohol ethoxylate having a saturated carbon chain with an HLB in the range of 15.5-20.

4. A sunscreen composition according to any of claims 1 to 3, further comprising 0.1-5% by weight of a polymer.

5. A sunscreen composition according to any of claims 1 to 4 comprising 0.1-3% by weight soap.

6. A sunscreen composition according to any of claims 1 to 5 comprising 8-20% by weight fatty acids.

7. The sunscreen composition according to any one of claims 1 to 6, wherein the 4-alkyl substituted resorcinol is selected from the group consisting of 4-methyl resorcinol, 4-ethyl resorcinol, 4-propyl resorcinol, 4-isopropyl resorcinol, 4-butyl resorcinol, 4-pentyl resorcinol, 4-hexyl resorcinol, 4-heptyl resorcinol, 4-octyl resorcinol, and mixtures thereof.

8. A sunscreen composition according to any of claims 1 to 7 wherein the 4-alkyl substituted resorcinol is selected from 4-ethyl resorcinol, 4-hexyl resorcinol and mixtures thereof.

9. The sunscreen composition according to any one of claims 1 to 8, further comprising 0.001-15% by weight of a skin lightening agent.

10. A sunscreen composition according to any of claims 1 to 9 wherein the UVA sunscreen is selected from 4-tert-butyl-4 ' -methoxydibenzoylmethane, 2-methyldibenzoylmethane, 4-isopropyldibenzoylmethane, 4-tert-butyldibenzoylmethane, 2, 4-dimethyldibenzoylmethane, 2, 5-dimethyldibenzoylmethane, 4' -diisopropyl-dibenzoylmethane, 2-methyl-5-isopropyl-4 ' -methoxydibenzoylmethane, 2-methyl-5-tert-butyl-4 ' -methoxy-dibenzoylmethane, 2, 4-dimethyl-4 ' -methoxydibenzoylmethane or 2, 6-dimethyl-4-tert-butyl-4' -methoxy-dibenzoylmethane.

11. A sunscreen composition according to any of claims 1 to 10 wherein the UVA sunscreen is 4-tert-butyl-4' -methoxydibenzoylmethane.

12. The sunscreen composition according to any one of claims 1 to 11, wherein the composition is a leave-on composition.

13. The sunscreen composition according to any one of claims 1 to 11, wherein the composition is a rinse-off composition.

14. A method of providing improved UVAPF, wherein the method comprises the steps of:

a. applying a sunscreen composition according to any one of claims 1 to 13 to the skin; and

b. optionally rinsed with water.

15. Use of a composition according to any one of claims 1 to 13 for improved uv a protection factor.