A personal care composition

Abstract

The present invention relates to a personal care composition, which provides water-resistant and / or sweat resistant sun protection factor. The composition also provides very good sensorial properties that the consumer prefer when such a composition is applied on the skin. This is achieved through a composition comprising a combination of an oil-soluble sunscreen, a water-soluble sunscreen, a water phase thickener, an oil phase thickener and a film forming polymer.

Description

[0001] A PERSONAL CARE COMPOSITION

[0002] Field of the Invention

[0003] The present invention relates to a personal care composition. Particularly, the present invention relates to a personal care composition that provides water-resistant and / or a sweat- resista nt sun protection factor (SPF) despite the composition is exposed to water or sweat. Preferably, the personal care composition is in a gel format.

[0004] Background of the Invention

[0005] Solar radiation includes about 5% ultraviolet (UV) radiation, wavelength of which is between 200 nm and 400 nm. It is further divided into three regions: from 320 to 400 nm (UV-A), 280 to 320 nm (UV-B) and from 200 to 280 nm (UV-C). Substantial portion of UV-C radiation is absorbed by ozone. Scientific studies have indicated that exposure to UV-A and UV-B radiation for short period causes pigmentation, reddening of the skin and localized irritation, whereas continued or prolonged exposure can lead to sunburn, melanoma, formation of wrinkles and age spots. UV radiation is also thought to cause significant damage to hair. Therefore, it is desirable to protect the skin and other keratinous substrates of the human body from the harmful effects of both UV- A and UV-B radiation. It is well-known that protection from UV-A is measured and expressed as ultraviolet A protection factor (UVAPF) whereas protection from UV-B is measured and expressed as sun protection factor (SPF) which may be collectively or separately referred to as photoprotection.

[0006] Various personal care compositions are reported for preventing and / or protecting the skin from harmful effects of ultraviolet radiation. Numerous organic sunscreen agents capable of absorbing UV-A rays are reported in the field of personal care amongst which a particularly useful sunscreen is t-butylmethoxydibenzoylmethane (also known as Avobenzone and sold as Parsol® 1789). A variety of UV-B sunscreens e.g. octyl salicylate, are used in personal care compositions for protection from UV-B radiation. Many personal care composition manufacturers prefer to include UV-A as well as UV-B sunscreens in photoprotective compositions to provide protection over the entire range of UV radiation.

[0007] Several such compositions are known in the art. WO2023217920 discloses a photoprotective personal care composition, which provides high sun protection factor along with very good sensorial properties that the consumer expects when such a composition is applied on the skin. This is achieved through a composition comprising a combination of an oil-soluble sunscreen, a water-soluble sunscreen, a water phase thickener, an oil phase thickener, a humectant; and a select sensory modifier.

[0008] Thus, consumers tend to rely on using such personal care compositions for obtaining benefits e.g. SPF.

[0009] However, through day-to-day activities e.g. washing, sports activities like swimming, and bodily functions like sweating, consumers tend to keep coming in contact with water and / or sweat, where sunscreens contained in such personal care compositions tend to leach out or be physically removed due to contact with water and / or sweat, resulting in loss of efficacy in providing the photoprotection benefit.

[0010] Therefore, there is still a need to provide a personal care composition comprising sunscreens that provides water-resistant or a sweat-resistant SPF. This is further challenging, especially when a personal care composition itself contains water in substantial amounts.

[0011] There are personal care compositions containing sunscreens available that provide water resistant SPF. However, they are either in anhydrous format or in a water-in-silicone emulsion format. Whilst such compositions may, per se, provide water resistance SPF, they offer an altogether different tactile sensory due to no or low water contained in such compositions.

[0012] It is thus an object of the present invention to provide a personal care composition that provides water-resistant and / or sweat resistant SPF despite the composition is exposed to water and / or sweat. It is another object of the present invention to provide such personal care composition in a gel form. It is another object of the present invention to provide such personal care composition despite the composition itself contains water in substantial amounts. It is another object of the present invention to provide light, i.e. not too oily, tactile sensorial that are preferred by consumers whilst providing water-resistant and / or sweat resistant SPF.

[0013] It has now been found that when select film forming polymers were combined with a water-soluble sunscreen, an oil soluble sunscreen, a water phase thickener and an oil phase thickener, it provided a personal care composition that provided water-resistant or sweat-resistant SPF despite the composition was exposed to water or sweat. Moreover, it was found that such benefit was obtained through a personal care composition in a gel format despite the composition itself contained water in substantial amounts thus providing light tactile sensory that is preferred by consumers.

[0014] Summary of the Invention

[0015] Accordingly, in a first aspect, the present invention relates to a personal care composition comprising:

[0016] (i) 0.1 to 25 wt% of an oil-soluble sunscreen,

[0017] (ii) 0.1 to 5 wt% of a water-soluble sunscreen;

[0018] (iii) 0.25 to 5 wt% of a water phase thickener selected from one or both of a polysaccharide gum and a synthetic polymer selected from ammoniumacryloyldimethyltaurate / VP copolymer, and ammonium acryloyldimethyltaurate / beheneth-25 methacrylate crosspolymer;

[0019] (iv) 0.5 to 10% of an oil phase thickener selected from one or more of an ester of C18 to C36 fatty acid, ester of C8 to C16 fatty acid; and particle selected from organically modified clays, hydrophobically modified fumed silica and aerogels;

[0020] (v) 0.1 to 10 wt% of a film forming polymer selected from alkyl cellulose wherein the solubility of the alkyl cellulose in water is less than 1 % at 25°C; and

[0021] (vi) 0.1 to 10 wt% of one or more solvents having log P in the range from 0 to 10.

[0022] Further, in a second aspect, the present invention relates to a method of providing water- or sweat-resistant sun protection factor, measured in terms of percentage water resistance retention, of at least 30% comprising the steps of applying the composition of the first aspect to the skin.

[0023] Further, in a third aspect, the present invention relates to the composition of the first aspect for use in providing water- or sweat- resista nt sun protection factor, measured in terms of percentage water resistance retention, of at least 30%.

[0024] Detailed Description of the Invention

[0025] These and other aspects, features and advantages will become apparent to those of ordinary skill in the art from a reading of the following detailed description and the appended claims. For the avoidance of doubt, any feature of one aspect of the present invention may be utilized in any other aspect of the invention. The word "comprising" is intended to mean "including" but not necessarily "consisting of" or "composed of." In other words, the listed steps or options need not be exhaustive. It is noted that the examples given in the description below are intended to clarify the invention and are not intended to limit the invention to those examples per se. Similarly, all percentages are weight / weight percentages unless otherwise indicated and may be abbreviated as ‘wt%’. Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description and claims 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 in the format "from x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "from x to y", it is understood that all ranges combining the different endpoints are also contemplated.

[0026] A personal care composition of the present invention (the composition) provides protection from UV-A and IIV-B contained in the sunlight. Thus, the composition may alternatively be referred to as a ‘photoprotective composition’. For the same reason, the composition may also be referred to as a ‘sun composition’ or a ‘sun care composition’. The composition is meant to be used for personal care or for cosmetic use and could also be referred to as a cosmetic composition. By a “personal care composition” as used herein, is meant to include a composition for topical application to sun-exposed areas of the skin and / or hair of humans. Such a composition may be classified as a leave-on composition and includes any product applied to a human body for improving appearance or general aesthetics. The composition can be in the form of a liquid, or a gel, preferably a gel. Non-limiting examples of such personal care compositions include leave-on skin products like sunscreen gels. The composition of the present invention is preferably a leave- on composition.

[0027] ‘Skin’ as used herein is meant to include skin on the face and body (e.g., neck, chest, back, arms, underarms, hands, legs and scalp) and especially to the sun exposed parts thereof. Compositions of the invention are also of relevance to applications on any other keratinous substrates of the human body other than skin e.g. hair, where products may be formulated with specific aim of improving photoprotection.

[0028] ‘Water-resistant SPF’ or ‘water-resistance SPF’ as used herein, is expressed in terms of percentage water resistance retention (%WRR); and is preferably measured using a method described by Ahn et al (Skin Research and Technology, 2008; 14: 187-191).

[0029] Thus, a personal care composition of the present invention may preferably be referred to as a water-resistant personal care composition or a water-resistant sun composition or a water- resistant sun care composition. As it is well known that sweat is primarily composed of water, the personal care composition of the present invention may preferably be also referred to as a sweat- resistant personal care composition or a sweat-resistant sun composition or a sweat resistant sun care composition. So, it will be understood that any reference made to water-resistance includes a reference to sweat-resistance.

[0030] The invention and its features are now described in details as follows:

[0031] Oil-soluble sunscreen

[0032] The compositions of the invention comprise 0.1 to 25 wt% of an oil-soluble sunscreen. By oilsoluble is meant those organic sunscreens which have a solubility in water of less than 10 g / l, preferably less than 5 g / l, more preferably less than 2 g / l, at 25 °C. Oil-soluble sunscreens could be of the IIV-B type or of the IIV-A type. It is preferred that the composition in accordance with the invention comprises 0.1 to 20 wt%, preferably 1 to 15 wt%, preferably 3 to 12 wt%, preferably 5 to 10 wt% of a UVB oil soluble sunscreen. It is further preferred that the composition of the invention comprises 0.1 to 5 wt%, preferably 1 to 4 wt% of a UVA oil soluble sunscreen.

[0033] When an oil-soluble UVB sunscreen is included, it is preferably one or more of octyl salicylate (Eusolex® OS), 3,3,5-trimethylclohexyl 2-hydroxybenzoate, ethylhexyl salicylate, 2-ethylhexyl 2- cyano-3,3-diphenyl-2-propenoate which is also known as octocrylene, 2-ethylhexyl-4- methoxycinnamate or octylmethoxycinnamate, ethylhexyl triazone, 3-benzylidene camphor, cinoxate, diethylhexyl butamido triazone, para amino benzoic acid (PABA), ethyl dihydroxypropyl PABA, ethylhexyl dimethoxy benzylidene dioxoimidazoline propionate, isoamyl p- methoxycinnamate, isopentyl trimethoxycinnamate trisiloxane, isopropyl benzyl salicylate, isopropyl methoxycinnamate, 4-methylbenzylidene camphor, PEG-25 PABA, and pentyl dimethyl PABA. More preferred oil-soluble UVB sunscreen is selected from one or more of octyl salicylate, 2-ethylhexyl 2-cyano-3,3-diphenyl-2-propenoate, and octylmethoxycinnamate.

[0034] Some of the well-known brands under which the above sunscreens are sold are Octisalate®, Homosalate®, Neo Heliopan®, Neo Heliopan® AV, Neo Heliopan® OS, Octocrylene® and Parsol® MCX. The oil-soluble UV-B sunscreen has Amax from 280 to 320 nm.

[0035] Composition of the invention may comprise an oil-soluble UVA sunscreen. When included, it is selected from one or more of a dibenzoylmethane compound, diethylamino hydroxybenzoyl hexyl benzoate and methyl anthranilate. A dibenzoyl methane compound is most preferred for an oilsoluble UVA-sunscreen. Suitable dibenzoyl methane compounds are selected from one of more of t-butylmethoxy dibenzoylmethane, 2-methyldibenzoylmethane, 4-methyl-dibenzoyl-ethane, 4- isopropyldibenzoyl-methane, 4-tert-butyldibenzoylmethane, 2,4-dimethyldibenzoylmethane, 2,5- dimethyldibenzoylmethane, 4,4'-diisopropyl-dibenzoylmethane, 2-methyl-5-isopropyl-4'- methoxydibenzoylmethane, 2-methyl-5-tert-butyl-4'-methoxy-dibenzoyl methane, 2,4-dimethyl- 4'-methoxy dibenzoylmethane and 2,6-dimethyl-4-tert-butyl-4'-methoxy-dibenzoylmethane. The most preferred dibenzoyl methane compound is t-butylmethoxy dibenzoylmethane (commercially available as Parsol®1789).

[0036] The composition of the invention may comprise both an oil-soluble UVB and an oil-soluble UVA sunscreen. Alternately, there are certain oil soluble sunscreens which have both a UVA and UVB screening efficacy. It is selected from one or more bis-ethylhexyloxyphenol methoxyphenyl triazine, drometrizole trisiloxane, benzophenone and its derivatives. The most preferred one is bis-ethylhexyloxyphenol methoxyphenyl triazine, commercially available as Tinosorb S.

[0037] Water-soluble sunscreen

[0038] The composition of the invention comprises 0.1 to 5 wt% of a water-soluble sunscreen.

[0039] By water-soluble sunscreen, whether of the UVA type, or of the UVB type, is meant that the solubility in water of the sunscreen is higher than 10 g / l preferably higher than 50 g / l at 25 °C.

[0040] The preferred water-soluble UVB sunscreen for use in the present invention is one or more of phenyl benzimidazole 5-sulphonic acid (PBSA), benzophenone-4 and benzylidene camphor sulfonic acid, preferably PBSA. PBSA also known as Ensulizole is commercially available as Eusolex 232 (from Merck KGaA). PBSA is also available under the brand names Neo Heliopan Hydro (from Symrise), Parsol HS (from DSM) and Sunsafe ES (from Uniproma). There are certain water-soluble sunscreens which have both a UVA screening efficacy as well as a UVB screening efficacy. Such sunscreens provide both UVA and UVB protection e.g. benzophenone-4 (sold as Sulisobenzone). However, for the purposes of the present invention benzophenone- 4 may be included as a water-soluble UV-B sunscreen.

[0041] The preferred water-soluble UVA sunscreen for use in the present invention is one or more of disodium phenyl dibenzimidazole tetrasulfonate (Neoheliopan AP) or terephthalylidene dicamphor sulfonic acid (TDSA). Of these, di sodium phenyl dibenzimidazole tetra sulfonate is preferred which is also known as bisdisulizole disodium. This is commercially available as Neo heliopan AP (from Symrise Shanghai Ltd) or as Sunsafe DPDT (from Uniproma). Terephthalylidene dicamphor sulfonic acid (TDSA) is also known as Ecamsule. This is commercially available as Mexoryl SX (US4585597) by L’ Oreal or Sunsafe TDSA (from Uniproma). It can be used as parent acid or its salts to deliver the desired benefit.

[0042] The composition comprises 0.1 to 5 wt%, preferably 1 to 4 wt%, preferably 2 to 3 wt% of a water- soluble sunscreen. It is preferred that the composition comprises both a water-soluble UVA and a water-soluble UVB sunscreen. Most preferred is to include one or both of 2- phenylbenzimidazole-5-sulfonic acid and di sodium phenyl dibenzimidazole tetra sulfonate.

[0043] The water-soluble sunscreens for inclusion in the composition of the present invention are generally commercially available in the acid form. When included in the composition in the acid form (pre neutralized forms) i.e. having sulphonic acid group (-SO3H) the composition additionally comprises a neutralising agent to convert the acid form into the salt form, in which form it is known to be active as a sunscreen with an exception to Mexoryl SX which can act as sunscreen with and without neutralization. When included, the neutralising agent is preferably in 0.05% to 4% more preferably 0.2% to 2% by weight of the composition. The neutralising agent is preferably an inorganic or an organic alkali. Organic alkali is preferably an amine such as triethanol amine or diethanol amine. The present inventors have observed that the inorganic alkali is especially preferred. Preferred are alkali metal hydroxides. Most preferred metal hydroxide for inclusion as neutralising agent in the composition of the invention are sodium hydroxide or potassium hydroxide. It is an especially challenging problem to stabilize the salt form of the water-soluble sunscreen in a gel composition and yet get the desired enhancement of SPF and the desired tactile sensory properties. A water phase thickener helps solve this problem.

[0044] Water phase thickener

[0045] The composition of the invention comprises a water phase thickener. The water phase thickener may be selected from one or more of (i) a polysaccharide gum and (ii) a synthetic polymer selected from (a) ammoniumacryloyldimethyltaurate / VP copolymer, and (b) ammonium acryloyldimethyltaurate / beheneth-25 methacrylate crosspolymer. Of the above a polysaccharide gum is most preferred. Preferred polysaccharide gums for inclusion in the composition of the invention are one or more of xanthan gum, guar gum, cellulose gum, tara gum, gellan gum, gum arabic, sclerotium gum, carrageenan gum, and locust bean gum. The most preferred polysaccharide gum is xanthan gum. Xanthan gum is commercially available as Keltrol CG-V from CP Kelco supplier. The synthetic polymers ammoniumacryloyldimethyltaurate / VP copolymer is commercially available as Aristoflex AVC and ammonium acryloyldimethyltaurate / beheneth-25 methacrylate crosspolymer as Aristoflex HMB. In an especially preferred aspect of the present invention both a polysaccharide gum e.g. xanthan gum and synthetic polymers Aristoflex AVC and Aristoflex HMB may be included. The water phase thickener is included in 0.25 to 5 wt%, preferably 0.5 to 4 wt %, most preferably 1 to 3 wt% in the composition.

[0046] Oil phase thickener

[0047] The composition of the invention includes an oil phase thickener selected from one or more of an ester of C18 to C36 fatty acid, ester of C8 to C16 fatty acid; and particle selected from organically modified clays, hydrophobically modified fumed silica and aerogels, of these, an ester of C18 to C36 fatty acid is most preferred.

[0048] Suitable commercially available ester of C18 to C36 fatty acid are C18-36 Acid Triglyceride (Syncrowax HGLC), C18-36 Acid Glycol Ester (Syncrowax ERLC), Glyceryl tribehenate (Syncrowax HRC), Glyceryl hydroxystearate (Naturchem GMHS), Glyceryl tri(12- hydroxy stea rate) (Thixcin R), C16-18 triglyceride, C16-24 triglyceride (Cremeol HF-62- SPC). An especially preferred oil phase thickener for use in the composition of the invention is available as Syncrowax HGLC from Croda Personal Care. It has a melting point in the range of 60-70°C which also acts as a structure builder, crystallinity modifier and Emulsion stabilizer.

[0049] Example of esters of C8-C16 fatty acid is Hydrogenated cocoglycerides (Softisan 100).

[0050] Alternatively, an oil phase thickener may be selected from a polymeric oil thickeners selected from Sorbitol / Sebacic Acid Copolymer Behenate (Syncrowax ORM), Tribehenin (and) Sorbitol / Sebacic Acid Copolymer Behenate (Syncrowax OSW), Dextrin Palmitate (Dextrin Palmitate LDXP, HDXP and HDXP-KL), ester terminated polyamides (Uniclear 100VG and C75V), Stearoyl Inulin (Rheopearl ISK2).

[0051] Particles which act as oil phase thickeners could be selected from one or more of an organically modified clay such as Montmorillonite, Hectorite or Bentonite clay, fumed Silica, hydrophobically modified fumed Silica, and Aerogels such as Dow Corning VM-2270 Aerogel Fine particles, Aerosil® R 972 (Silica Silyate-Evonik).

[0052] The oil phase thickener is preferably included in 0.5 to 10 wt%, preferably 0.8 to 5 wt%, preferably 1 to 3 wt% in the composition. Film

[0053] The composition comprises a film forming polymer selected from alkyl cellulose wherein the solubility of alkyl cellulose in water is less than 1% at 25°C.

[0054] The alkyl cellulose as per the present invention are cellulose ethers selected preferably from alkyl cellulose such as methyl cellulose, ethyl cellulose, propyl cellulose, butyl cellulose; more preferably ethyl cellulose. Preferably, cellulose ethers are made by reaction of cellulose with aqueous sodium hydroxide and then with an alkyl halide such as methyl or ethyl chloride.

[0055] Preferably the degree of substitution (DS) of the alkyl cellulose is in the range 0.5 to 3.0. The DS of an alkyl cellulose is sufficient to make the alkyl cellulose insoluble in water but soluble in an organic solvent such that the solubility of alkyl cellulose is less than 1 % in water. The DS is the number of substituted hydroxyl groups per glucose molecule, and ranges between zero and three. The solubility of alkyl cellulose depends on the DS. Alkyl cellulose with a DS lower than 0.1 are generally insoluble in water.

[0056] For example, methyl cellulose with DS in the range 1.3 to 2.5 are water soluble; and DS > 2.5 becomes water insoluble. Similarly, ethyl cellulose with DS > 1.8 becomes water insoluble.

[0057] Thus, if methyl cellulose is used as the alkyl cellulose in the composition, then preferably, methyl cellulose with DS in the range from more than 2.5 to 3.0 is used. Likewise, if ethyl cellulose is used as the alkyl cellulose in the composition, then preferably, ethyl cellulose with DS in the range from more than 1.8 to 3.0 is used.

[0058] The composition comprises from 0.1 to 10 wt%, preferably 0.5 to 8 wt%, preferably 1 to 6 wt%, preferably 2 to 5 wt%, preferably 3 to 4 wt% of the one or more film forming alkyl cellulose polymers described above.

[0059] Solvents having in the range from 0 to 10

[0060] Preferably, the composition further comprises one or more solvents having logwP in the range from 0 to 10, preferably 1 to 9.5, preferably 2 to 9.5.

[0061] Preferably, the one or more solvents having log P in the range from 0 to 10 (as indicated in brackets) is selected from triethyl citrate (0.1), diisopropyl adipate (2.2), Diethyl Phthalate (2.5), Phenylethyl benzoate (4), Dipropylene Glycol Dibenzoate (4), Ethylhexyl benzoate (4.5), Diisopropyl sebacate (4.4), Lauryl alcohol (5.1), isopropyl lauryl sarcosinate (5.6), propanediol dicaprylate (6.4), neopentyl glycol diheptanoate (6.37), diethylhexyl maleate (6.5), octyl dodecanol (9.2), isoamyl laurate (7), C12-15 alkyl benzoate (7.16), isopropyl myristate (7.2), dicaprylyl carbonate (7.4), caprylic capric triglyceride (8 to 10).

[0062] More preferred solvents are diisopropyl adipate (2.2), phenylethyl benzoate (4), isopropyl lauryl sarcosinate (5.6), diethylhexyl maleate (6.5), dicaprylyl carbonate (7.4), octyl dodecanol (9.2) and mixtures thereof.

[0063] As used herein, ‘logioP’ is preferably defined as the log of the water-octanol partition coefficient, i.e. the log of the ratio Pw / P0, wherein Pwis the concentration of an organic acid in water and Pois the concentration of the organic acid in octanol, at equilibrium and 25°C. Log P may be measured by using any suitable method e.g. a shake flask method and HPLC method.

[0064] Humectants

[0065] Preferably, the composition of the invention comprises a humectant. Preferably a humectant is selected from a glycol, glycerol and mixtures thereof. If a glycol is selected as a humectant, then it is preferably selected from one or more of one of propylene glycol, butylene glycol, caprylyl glycol and mixtures thereof. The humectant for use in the present invention is preferably one or both of glycerol and caprylyl glycol. The composition comprises humectant at 0.5 to 15 wt%, preferably 1 to 10 wt%, more preferably 1 to 8 wt% in the composition.

[0066] Sensory modifiers

[0067] Preferably, the composition comprises a sensory modifier selected from one or more of a modified starch, silica microsphere and a polymer of dimethicone / vinyldimethicone crosspolymer and silica.

[0068] Of these, one or both of silica microspheres and the polymer are most preferred to be included in the composition.

[0069] The polymer for use as a sensory modifier is preferably dimethicone / vinyldimethicone crosspolymer (and) silica. Dimethicone / Vinyl Dimethicone Crosspolymer (and) Silica is available as DOWSIL™9701 Cosmetic Powder from Dow Corning and is also known as DC 9701. Silica microsphere is available as MSS-500 / 3H from Kobo. Preferred modified starch is aluminium or sodium starch octenylsuccinate, more preferably aluminium starch octenylsuccinate. Aluminum Starch Octenylsuccinate is a chemically modified starch, in particular starches that have undergone esterification. Such aluminum starch Octenylsuccinate is commercially available from suppliers like Akzo Nobel or Nouryon under the names Dry Flo® Pure and Dry Flo® PC. A variety of other suppliers sell it under their own brand name. In cosmetics and personal care products, Aluminum Starch Octenylsuccinate is used in the formulation of lotions, powders, makeup and underarm deodorants. It is used as a thickener and binder, anticaking agent and oil absorbent. The composition may comprise aluminium starch octenylsuccinate which is further compounded with other ingredients to deliver other benefits, e.g. the ingredient having INCI name Aluminum Starch Octenylsuccinate (and) Acrylates Copolymer (and) Magnesium Carbonate may be included. It is available from Nouryon as NATRASORB® HFB. The natural content is 81% and the suggested applications include moisture resistant products, oil control products, anhydrous products, antiperspirant sticks, sunscreen, and dry shampoo for a variety of benefits including oil-absorption, mitigation of syneresis and fragrance-retention. The literature of the ingredient from Nouryon discloses that it is crosslinked aluminium starch octenyl succinate surface treated with acrylates copolymer and magnesium carbonate.

[0070] The sensory modifier is preferably included in 0.5 to 10 wt%, preferably 1 to 8 wt%, more preferably 1 to 5 wt% in the composition. Of these, the polymer, when included is preferably at 0.2 to 3 wt%, the silica microsphere when included is from 0.2 to 3 wt% and the modified starch when included is from 0.5 to 4 wt% in the composition.

[0071] The composition of the invention is preferably, substantially free of an emulsifier. Emulsifiers are generally surfactants or surface-active agents e.g., anionic surfactants, amphoteric surfactants, zwitterionic surfactants, cationic surfactants, and / or nonionic surfactants. A few examples include glyceryl stearate, glycol stearate and stearamide AMP. Accordingly, the composition is preferably substantially free of such emulsifiers. Preferably, by substantially free of an emulsifier is meant that the emulsifier is included in less than or equal to 2 wt%, more preferably less than 2 wt%, even more preferably less than 1.5 wt%, further more preferably less than 1 wt% and most preferably less than 0.5 wt%, ideally absent from the composition of the invention. Alternatively, the composition preferably comprises 0 to 2 wt%, more preferably from 0.1 to 1.5 wt%, even more preferably from 0.25 to 1 wt% and still more preferably from 0.5 to 0.75 wt% of an emulsifier. It will be understood that the terms e.g. ‘substantially free of an emulsifier’ and ‘emulsifier-free’ may be used interchangeably and they denote the same meaning. Accordingly, the composition is preferably an emulsifier-free personal care composition comprising:

[0072] (i) 0.1 to 25 wt% of an oil-soluble sunscreen,

[0073] (ii) 0.1 to 5 wt% of a water-soluble sunscreen;

[0074] (iii) 0.25 to 5 wt% of a water phase thickener selected from one or both of a polysaccharide gum and a synthetic polymer selected from ammoniumacryloyldimethyltaurate / VP copolymer, and ammonium acryloyldimethyltaurate / beheneth-25 methacrylate crosspolymer;

[0075] (iv) 0.5 to 10% of an oil phase thickener selected from one or more of an ester of C18 to C36 fatty acid, ester of C8 to C16 fatty acid; and particle selected from organically modified clays, hydrophobically modified fumed silica and aerogels;

[0076] (v) 0.1 to 10 wt% of a film forming polymer selected from alkyl cellulose wherein the solubility of the alkyl cellulose in water is less than 1% at 25°C; and

[0077] (vi) 0.1 to 10 wt% of one or more solvents having log P in the range from 0 to 10.

[0078] Water

[0079] Water is generally included in the composition as the cosmetically acceptable base. Water may preferably be included in 10 to 70 wt%, preferably 20 to 70 wt%, preferably 30 to 65 wt%, preferably 40 to 60 wt%, preferably 50 to 55 wt%.

[0080] Preferably, the composition comprises at least 10 wt% water, preferably at least 20 wt% water, preferably at least 30 wt% water, more preferably at least 40 wt% water and even more preferably at least 50 wt% water and further more preferably at least 55 wt% water.

[0081] The present invention has provided a personal care composition that provides water-resistant SPF or sweat-resistant SPF.

[0082] As described hereinabove, there are personal care products in anhydrous form or water-in- silicone emulsion format, that may provide water- or sweat-resistance SPF, per se. But, products like these offer an altogether different tactical sensory due to no or low water contained in such compositions. However, the present invention has provided a personal care composition that provides water- resistant SPF or sweat-resistant SPF whilst providing the required tactile sensory e.g. light, i.e. not too oily sensory, despite the composition contained substantial amounts of water.

[0083] The term ‘substantial amounts of water’, preferably means that the water content of the composition is preferably in range 10 to 70 wt%, preferably 20 to 70 wt%, preferably 30 to 65 wt%, preferably 40 to 60 wt%, preferably 50 to 55 wt%.

[0084] Accordingly, in a preferred aspect, the present invention relates to: a personal care composition comprising:

[0085] (i) 0.1 to 25 wt% of an oil-soluble sunscreen,

[0086] (ii) 0.1 to 5 wt% of a water-soluble sunscreen;

[0087] (iii) 0.25 to 5 wt% of a water phase thickener selected from one or both of a polysaccharide gum and a synthetic polymer selected from ammoniumacryloyldimethyltaurate / VP copolymer, and ammonium acryloyldimethyltaurate / beheneth-25 methacrylate crosspolymer;

[0088] (iv) 0.5 to 10% of an oil phase thickener selected from one or more of an ester of C18 to C36 fatty acid, ester of C8 to C16 fatty acid; and particle selected from organically modified clays, hydrophobically modified fumed silica and aerogels;

[0089] (v) 0.1 to 10 wt% of a film forming polymer selected from alkyl cellulose wherein the solubility of the alkyl cellulose in water is less than 1% at 25°C,

[0090] (vi) 0.1 to 10 wt% of one or more solvents having log P in the range from 0 to 10; and

[0091] (vii) 10 to 70 wt%, preferably 20 to 70 wt%, preferably 30 to 65 wt%, preferably 40 to 60 wt%, preferably 50 to 55 wt% water.

[0092] Thus, in another preferred aspect, the present invention relates to an emulsifier-free personal care composition, preferably in the form of an aqueous gel, comprising:

[0093] (i) 0.1 to 25 wt% of an oil-soluble sunscreen,

[0094] (ii) 0.1 to 5 wt% of a water-soluble sunscreen;

[0095] (iii) 0.25 to 5 wt% of a water phase thickener selected from one or both of a polysaccharide gum and a synthetic polymer selected from ammoniumacryloyldimethyltaurate / VP copolymer, and ammonium acryloyldimethyltaurate / beheneth-25 methacrylate crosspolymer; (iv) 0.5 to 10% of an oil phase thickener selected from one or more of an ester of C18 to C36 fatty acid, ester of C8 to C16 fatty acid; and particle selected from organically modified clays, hydrophobically modified fumed silica and aerogels;

[0096] (v) 0.1 to 10 wt% of a film forming polymer selected from alkyl cellulose wherein the solubility of the alkyl cellulose in water is less than 1 % at 25°C,

[0097] (vi) 0.1 to 10 wt% of one or more solvents having log P in the range from 0 to 10; and

[0098] (vii) 10 to 70 wt%, preferably 20 to 70 wt%, preferably 30 to 65 wt%, preferably 40 to 60 wt%, preferably 50 to 55 wt% water.

[0099] In addition to the ingredients disclosed earlier, the composition, may and preferably includes other ingredients in order to perform one or more functions of this invention also include a cosmetically acceptable carrier. Emollient materials may serve as cosmetically acceptable carriers. These may be in the form of silicone oils, natural or synthetic esters, and hydrocarbons. Amounts of the emollients may range anywhere from 0.1 to 25 wt%, preferably between 1 and 10 wt%. Silicone oils may be divided into the volatile and nonvolatile variety. The term "volatile" as used herein refers to those materials which have a measurable vapor pressure at ambient temperature. Volatile silicone oils are preferably chosen from cyclic (cyclomethicone) or linear polydimethylsiloxanes containing from 3 to 9, preferably from 5 to 6, silicon atoms. Colorants, opacifiers and abrasives may also be included in compositions of the present invention. Each of these substances may range from 0.05 to 5 wt%, preferably between 0.1 and 3 wt% in the composition. Preferably, the composition further comprises niacinamide. Preferably, the composition comprises niacinamide in an amount from 0.1 to 10 wt%, more preferably from 1 to 8 wt%, even more preferably from 2 to 7 wt% and further more preferably from 3 to 5 wt%.

[0100] The composition is preferably a leave-on composition. By ‘leave-on’ it preferably means a composition which is not required to be removed from the surface it is applied on to, e.g. skin, after the application of the composition; and such compositions may only get removed when a consumer / user takes a shower or a bath typically after several hours or after about a day.

[0101] Water resistance retention (WRR)

[0102] The composition of the present invention provides a water-resistant or sweat-resistant SPF. The water-resistant or sweat-resistant SPF of the composition is measured in terms of percentage water resistance retention (%WRR) after 40 min or 80 min contact with water. Preferably, the %WRR is calculated using the formula: %WRR =SPFwet 1* 100

[0103] SPF dry-1 where SPFdry and SPFwet are the sun protection factors (SPFs) prior to and after water immersion respectively, as described by Ahn et al (Skin Research and Technology, 2008; 14: 187-191).

[0104] Preferably, the composition provides %WRR that is more than or equal to 30%, preferably more than or equal to 35%, preferably more than or equal to 40%, preferably more than or equal to 45%, preferably more than or equal to 50%. In other words, the %WRR of the composition is preferably at least 30%, preferably at least 35%, preferably at least 40%, preferably at least 45%, preferably at least 50%.

[0105] It will be understood that the composition coming in contact with water or sweat through e.g. day- to-day activities like washing, sports activities like swimming, and bodily functions like sweating, is different than it coming in contact with water through when a consumer / user takes a shower or a bath. The present invention addresses the water- or sweat-resistance SPF of the composition during such day-to-day activities, sports and bodily function, not the latter like a shower or a bath. During the latter, i.e. whilst taking a shower or a bath, a user typically makes use of personal cleansing products that typically contain surfactants like soap and / or sodium lauryl ether sulfate, to actively cleans their skin and hair. Thus, an intentional step of washing the skin with a desire of cleansing it, is carried out by a user during a shower or a bath.

[0106] Accordingly, in a second aspect, the present invention relates to a method of providing water- or sweat-resistance sun protection factor, measured in terms of percentage water resistance retention, of at least 30%, comprising a step of: a. applying a composition as claimed in the first aspect on to the desired skin surface.

[0107] Preferably, in this second aspect the present invention relates to the composition of the first aspect wherein the skin is protected by applying the composition of the first aspect on to the desired skin surface through providing water- or sweat-resistance sun protection factor or at least 30%, preferably at least 35%, preferably at least 40%, preferably at least 45%, preferably at least 50%.

[0108] Preferably, the %WRR is calculated using the formula:

[0109] %WRR =SPFwet~1* 100

[0110] SPF dry-1 where SPFdry and SPFwet are the sun protection factors prior to and after water immersion respectively, as described by Ahn et al (Skin Research and Technology, 2008; 14: 187-191). Preferably, the method is cosmetic I non-therapeutic.

[0111] In a third aspect, the present invention relates to use of the composition of the first aspect for providing water- or sweat-resistance sun protection factor, measured in terms of percentage water resistance retention, of at least 30%, preferably at least 35%, preferably at least 40%, preferably at least 45%, preferably at least 50%. Preferably, the use is cosmetic / non-therapeutic.

[0112] Alternatively, in this third aspect, the present invention relates to the composition of the first aspect for use in providing water- or sweat-resistance SPF of at least 30%, preferably, at least 35%, preferably at least 40%, preferably at least 45%, preferably at least 50%.

[0113] Preferably, the %WRR is calculated using the formula:

[0114] %WRR =SPFwet~1* 100

[0115] SPF dry-1 where SPFdryand SPFwet are the sun protection factors prior to and after water immersion, respectively, as described by Ahn et al (Skin Research and Technology, 2008; 14: 187-191).

[0116] In use, a small quantity of the composition, for example from 1 to 5 mL, is applied to exposed area of the skin, from a suitable container or applicator and, if necessary, it is then spread over and / or rubbed into the skin using the hand or fingers or a suitable device.

[0117] While the above summarizes the present invention, it will become apparent to those skilled in the art that modifications, variations, and alterations may be made without deviating from the scope and spirit of the present invention as described and claimed herein. The invention will now be further illustrated in the following non-limiting examples.

[0118] Experiments were carried out using an alkyl cellulose e.g. ethyl cellulose, as the film forming polymer and different solvents having log P as indicated in tables below.

[0119] Briefly, the composition in the tables below were prepared as follows: Step 1 : Phase A, In the main container glycerin, Disodium EDTA and water were homogenized at 75°C. In a separate beaker water soluble sunscreen (Phenylbenzimidazole sulphonic acid) was neutralized with sodium hydroxide (pH- 6.5-7). These pre-neutralized water-soluble sunscreens were added and homogenized.

[0120] Step 2: After homogenization, the polymers Aristoflex AVC and Aristoflex HMB were added to the main vessel and homogenized for 10 minutes until the polymers were properly dispersed.

[0121] Step 3: Phase B, the oil phase ingredients such as oil thickener, caprylyl glycol and oil soluble sunscreens were added to a separate beaker and heated at 75°C.

[0122] Step 4: Ethyl cellulose was dissolved in solvents as shown in tables below under overhead stirrer in a separate beaker at 75°C and a premix of ethyl cellulose and a solvent (as shown in tables below) was prepared.

[0123] Step 5: The oil phase prepared in step 3, was added to the main container maintained 75°C and homogenization was continued for 20 minutes.

[0124] Step 6: The premix prepared in step 4 was then added to the main container at 75°C with continued stirring.

[0125] Alternatively, the premix prepared in step 4 may first be added to the oil phase prepared in step 3; and then the mixture so obtained, may be added to the main container maintained at 75°C.

[0126] Step 7: Phase C, in a separate beaker xanthan gum was pre-dispersed in water. Then this predispersed xanthan gum was added to the main vessel and continued for homogenization 10 minutes and removed the main vessel from heating.

[0127] Step 8: Phase D, DC 9701 and MSS 500 / 3H was premixed in cyclopentasiloxane in a separate beaker and added to the main vessel at 60°C and continued mixing.

[0128] Step 9: Phase E, after reaching 40°C, alcohol, perfume and preservatives were added to the main vessel. Homogenization was continued for 10 minutes. In vitro SPF measurement

[0129] Thin film transmittance measurements were done using labsphere 2000 SPF meter. 70 mm x 70 mm roughened PMMA plate - 6 .m roughness (from Schonberg GmbH & Co) was used in this study. The % transmittance of the various compositions was measured using a procedure as outlined below. 2 mg / cm2of sample was applied on the PMMA plate, distributed using a syringe, and spread uniformly. Using para film as a finger cot, the sample was spread on the PMMA plate uniformly swiping alternately, vertically, and horizontally as per the protocol provided by the instrument manufacturers. The drying time for the PMMA plates was 30 minutes. After the drying time, sample plates were exposed, and transmittance scan was done. This scan gives the transmittance as a function of wavelength (290 - 400 nm) for a given sample. For a single plate six different spots were scanned. The same was repeated for 2 plates. The data reported is thus an average over 18 readings. The reference transmittance scan was obtained using a blank plate with no sample on the PMMA plate with glycerine spread on it. The transmittance values were used to arrive at the SPF, UVA- PF and critical wavelength values using the Win SPF software provided with the instrument. This in-vitro SPF may also be referred to as static SPF or SPFdry.

[0130] After this, SPFwet was measured using a method described by Ahn et al (Skin Research and Technology, 2008; 14: 187-191). Briefly, the PMMA plates were immersed in the water bath having 10L of DI water maintained at 30 to 34°C. The water in the water bath was kept under constant circulation with impeller at 150 rpm. The plates were removed at 40 min interval, 15 min air dry without towelling the test site and the in-vitro SPF was assessed. This measurement was recorded as after 40 min SPF (SPFwet). The PMMA plates were reintroduced in the same water bath and continued the immersion for another 40 mins, if required. Post the immersion was over, in-vitro SPF was measured, and was recorded as after 80 min SPF (SPFwet). The percentage water resistance retention (%WRR) was calculated using the formula:

[0131] %WRR =SPFwet~1* 100

[0132] SPF dry-1 where SPFdry and SPFwet are the sun protection factors (SPFs) prior to and after water immersion, respectively.

[0133] For calculating water-resistant SPF after 40 min; the SPFwet that was recorded after 40 min described above was used; and likewise, SPFwet reading after 80 min was used for calculating water-resistant SPF after 80 min.

[0134] Table 1 : Composition as per the present invention (1 to 5) and control (A)

[0135]

[0136] Table 2: Additional examples

[0137]

[0138] Degree of substitution 1.6 to 1.9

Claims

Claims1. A personal care composition comprising:(i) 0.1 to 25 wt% of an oil-soluble sunscreen,(ii) 0.1 to 5 wt% of a water-soluble sunscreen;(iii) 0.25 to 5 wt% of a water phase thickener selected from one or both of a polysaccharide gum and a synthetic polymer selected from ammoniumacryloyldimethyltaurate / VP copolymer, and ammonium acryloyldimethyltaurate / beheneth-25 methacrylate crosspolymer;(iv) 0.5 to 10% of an oil phase thickener selected from one or more of an ester of C18 to C36 fatty acid, ester of C8 to C16 fatty acid; and particle selected from organically modified clays, hydrophobically modified fumed silica and aerogels;(v) 0.1 to 10 wt% of a film forming polymer selected from alkyl cellulose wherein the solubility of the alkyl cellulose in water is less than 1% at 25°C; and(vi) 0.1 to 10 wt% of one or more solvents having log P in the range from 0 to 10.

2. The composition as claimed in claim 1 wherein the degree of substitution of the alkyl cellulose is in the range 0.5 to 3.0.

3. The composition as claimed in claims 1 or 2 wherein the one or more solvents having log P in the range from 0 to 10 are selected from triethyl citrate, diisopropyl adipate, diethyl phthalate, phenylethyl benzoate, dipropylene glycol dibenzoate, ethylhexyl benzoate, diisopropyl sebacate, lauryl alcohol, isopropyl lauryl sarcosinate, propanediol dicaprylate, neopentyl glycol diheptanoate, diethylhexyl maleate, octyl dodecanol, isoamyl laurate, C12- 15 alkyl benzoate, isopropyl myristate, dicaprylyl carbonate, caprylic capric triglyceride.

4. The composition as claimed in any one of claims 1 to 3 wherein the composition further comprises 0.5 to 15 wt% humectant selected from glycerol or a glycol.

5. The composition as claimed in any one of claims 1 to 4 wherein the composition further comprises 0.5 to 10 wt% of a sensory modifier selected from one or more of a modified starch, silica microsphere and a polymer of dimethicone / vinyldimethicone crosspolymer and silica.

6. A composition as claimed in any one of claims 1 to 5 wherein said oil-soluble sunscreen is selected from a IIV-B sunscreen selected from one or more of octyl salicylate, 2-ethylhexyl2-cyano-3,3-diphenyl-2-propenoate, and octylmethoxycinnamate; and / or a IIV-A sunscreen selected from a dibenzoylmethane compound.

7. A composition as claimed in any one of claims 1 to 6 comprising 0.1 to 5 wt% of an oilsoluble UVA sunscreen.

8. A composition as claimed in any one of claims 1 to 7 comprising 0.1 to 20 wt% of an oilsoluble UVB sunscreen.

9. A composition as claimed in any one of claims 1 to 8 wherein said water-soluble sunscreen is chosen from one or both of 2-phenylbenzimidazole-5-sulfonic acid and di sodium phenyl dibenzimidazole tetra sulfonate.

10. A composition as claimed in any one of claims 1 to 9 wherein the polysaccharide gum is xanthan gum.

11. The composition as claimed in any one of claims 1 to 10 comprising 10 to 70 wt% water.

12. The composition as claimed in any one of claims 1 to 11 wherein the composition is substantially free of an emulsifier.

13. The composition as claimed in any one of claims 1 to 12 wherein the water- or sweatresistance sun protection factor of the composition, measured in terms of percentage water resistance retention, is at least 30% when measured after 40 min contact with water.

14. A method of providing water- or sweat-resistant sun protection factor, measured in terms of percentage water resistance retention, of at least 30%, comprising the steps of applying the composition as claimed in any one of claims 1 to 13 to the skin.

15. The composition as claimed in any one of claims 1 to 13 for use in providing water- or sweat-resistant sun protection factor, measured in terms of percentage water resistance retention, of at least 30%.

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