Use of a personal care composition for improving the barrier function of skin

Abstract

The present invention relates to use of a personal care composition comprising a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof, a resorcinol compound; and an oil-soluble sunscreen, for improving the barrier function of skin.

Description

[0001] P0000699EP CPL

[0002] Use of a personal care composition for improving the barrier function of skin

[0003] Field of the invention

[0004] The present invention relates to use of a personal care composition comprising a combination of certain actives for improving the barrier function of skin.

[0005] Background

[0006] Human skin is an important barrier between the body and the environment. A healthy skin protects the body e.g. from excessive loss or gain of moisture, prevents microorganisms from entering the body and acts as a first line of defense. It also protects the body from ultraviolet radiations contained in the sunlight to certain extent.

[0007] The barrier function of the skin is reported to be dependent on the structure and the composition of the uppermost layer of the epidermis, stratum corneum. Stratum corneum is made up of flattened non nucleated cells surrounded by highly organized and continuous lipid matrix. The interior of the corneocytes consists mainly of keratin filaments aggregated by a protein called filaggrin. Together with several other proteins, filaggrin is cross-linked into a mechanically robust cornified cell envelope providing a scaffold for the extracellular lipid matrix (Kezic and Jakasa; Curr Probl Dermatol, 2016). Further, a healthy matrix within the stratum corneum is one which is rich in about an equimolar mixture of ceramides (45-50% by weight), cholesterol (25% by weight) and fatty acids (10-15% by weight) whereby other lipids, like cholesterol sulfate, make up the balance (Kathi C. Madison, Barrier Function of the Skin: “La Raison d’Etre” of the Epidermis, The Society for Investigative Dermatology, Inc. (2003)). These fatty acids and waxy lipids regulate the water barrier and retention capacity of skin and they also limit the entry of pollutants and microorganisms that contact skin from the environment. Moreover, the production of ceramides in the skin results in the generation of sphingosines that improve a variety of skin characteristics.

[0008] Unfortunately, due to factors e.g. exposure to pollutants, excessive exposure to ultraviolet radiations and age, levels of such fatty acids and lipids decline which invariably results in skin that is not supple, dry and even wrinkled. Depletion of the skin’s lipid matrix also causes the skin to become more sensitive to contaminants in the environment and often is associated with conditions such as eczema, atopic dermatitis and psoriasis.

[0009] A few technologies are known in the art that relate to barrier function of the skin. P0000699EP CPL

[0010] WO2022 / 136357 (Unilever) discloses a prolipid composition that penetrates the stratum corneum. More particularly, it discloses a prolipid composition that provides personalized benefits by rapidly restoring the skin’s natural lipid balance. Such a composition results in elongated fatty acid and / or lipid production deep in the stratum corneum and near the surface of the stratum lucidum. The composition at least comprises a hydrocarbon source comprising a fatty acid, fatty ester and / or an acylglycerol thereof; and an activator of a peroxisome proliferator-activated receptor.

[0011] However, consumers tend to look out for technologies that provide benefits e.g. improved barrier function of skin or provide benefits to an improved extent. A need therefore exists to provide technologies, e.g. an active or a combination of actives, contained in a personal care composition, that provide benefits e.g. improved barrier function.

[0012] To address needs like these, the present inventors, whilst working in the field of personal care, have surprisingly found use of a personal care composition comprising a combination of (i) a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, (ii) a retinoic acid precursor selected from retinyl esters, retinol, retinal retinoic acid and mixtures thereof (iii) a resorcinol compound; and (iv) an oilsoluble sunscreen, for improving the barrier function of the skin.

[0013] Summary of the invention

[0014] In a first aspect, the present invention relates to use of a personal care composition comprising: a. a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, b. a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof, c. a resorcinol compound, d. an oil-soluble sunscreen having solubility in water less than 10 g / L at 25°C, for improving the barrier function of skin.

[0015] In a second aspect, the present invention relates to a method for improving the barrier function of skin comprising: a. applying on to the skin, a personal care composition comprising i. a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, P0000699EP CPL ii. a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof; and iii. a resorcinol compound; and. iv. an oil-soluble sunscreen having solubility in water less than 10 g / L at 25°C.

[0016] In a third aspect, the present invention relates to use of an oil-soluble sunscreen having solubility in water less than 10 g / L at 25°C, in a personal care composition comprising: a. a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, b. a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof; and c. a resorcinol compound, for improving the barrier function of skin.

[0017] Detailed description

[0018] 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. 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 in the format " x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "x to y", it is understood that all ranges combining the different endpoints are also contemplated. Unless specified otherwise, amounts as used herein are expressed in percentage by weight based on total weight of the composition and may be abbreviated as “wt%”. 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 in any way limit the scope of the invention otherwise claimed. Except in the 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 may optionally be understood as modified by the word “about”.

[0019] The composition of the invention is meant to be used for personal care or for cosmetic use and could also be referred to as a personal photoprotective composition when the composition would contain sunscreens in it. By “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 P0000699EP CPL humans. Such a composition may be classified as leave-on or rinse-off, and includes any product applied to the human body for improving appearance, cleansing, odor control or general aesthetics. The composition of the present invention can be in the form of a liquid, lotion, cream, foam, stick or gel. Non-limiting examples of such compositions include leave- on skin lotions, creams, foundations, mascara and sunscreen lotions. The composition of the present invention is preferably a leave-on composition.

[0020] ‘Skin’ as used herein, preferably means to include skin on any part of the body e.g. face, neck, chest, back, arms, underarms, hands, legs, buttocks and scalp and especially to the sun exposed parts thereof. Compositions of the invention is 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.

[0021] It has been found that when a combination of (i) a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, (ii) a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof, (iii) a resorcinol compound; and (iv) an oil-soluble sunscreen having solubility in water of less than 10 g / L at 25°C, contained in a personal care composition, improvement in the barrier function of skin was obtained.

[0022] As used herein, the term ‘barrier function’ preferably means the function of the skin to protect a subject from external hazards, including microbial, chemical and / or mechanical insults. A variety of invasive and non-invasive in vitro and in vivo methods for measuring skin barrier function are described in the literature. A few examples include the measurement of the amount of trans-epidermal water loss (TEWL) and assessment of filaggrin content of the skin cells. Preferably, the barrier function of skin is assessed in terms of filaggrin content of skin cells e.g. keratinocytes.

[0023] Accordingly, in a first aspect, the present invention relates to use of a personal care composition comprising: a. a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, b. a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof, c. a resorcinol compound; and d. an oil-soluble sunscreen having solubility in water less than 10 g / L at 25°C, for improving the barrier function of skin. P0000699EP CPL

[0024] Preferably, the use is non-therapeutic or cosmetic in nature.

[0025] A heteroaromatic compound

[0026] A personal care composition as per the present invention (the composition) comprises a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof. Preferably, the heteroaromatic compound is selected from niacinamide, picolinamide and mixtures thereof. Most preferably, niacinamide is used as the heteroaromatic compound. The heteroaromatic compound is typically included in an amount of 0.01 to 10 wt%, preferably, 0.05 to 7 wt%, and, more preferably, 0.1 to 5 wt% e.g. 3 wt%, including all ranges subsumed therein.

[0027] A retinoic acid precursor

[0028] The composition comprises a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof.

[0029] Examples of retinyl esters suitable for use in the invention include but are not limited to: retinyl palmitate, retinyl formate, retinyl acetate, retinyl propionate, retinyl butyrate, retinyl valerate, retinyl isovalerate, retinyl hexanoate, retinyl heptanoate, retinyl octanoate, retinyl nonanoate, retinyl decanoate, retinyl undecandate, retinyl taurate, retinyl tridecanoate, retinyl myristate, retinyl pentadecanoate, retinyl heptadeconoate, retinyl stearate, retinyl isostearate, retinyl nonadecanoate, retinyl arachidonate, retinyl behenate, retinyl linoleate, and retinyl oleate. The preferred ester for use in the present invention is selected from retinyl palmitate, retinyl acetate, retinyl propionate and mixtures thereof. Retinyl linoleate and retinyl oleate are also preferred. The most preferred retinoic acid precursor is retinyl propionate. The retinoic acid precursor is employed in the inventive composition preferably in an amount from 0.001 to 10 wt%, preferably in an amount from 0.01 to 1 wt%, most preferably in an amount from 0.01 to 0.5 wt%.

[0030] A resorcinol compound

[0031] The composition comprises a resorcinol compound. Preferably, the resorcinol compound is selected from phenylethyl resorcinol, 4-alkyl substituted resorcinol, thiamidol and mixtures thereof. More preferably, the resorcinol compounds selected is selected from 4-alkyl substituted resorcinol. Examples of such 4-alkyl substituted resorcinol include but not limited to 4-ethylresorcinol, 4-hexylresorcinol, 4-cyclopentyl resorcinol, 4-cyclohexylresorcinol, 4- octylresorcinol. P0000699EP CPL

[0032] Oil-soluble sunscreens

[0033] The composition further comprises an oil-soluble sunscreen.

[0034] By ‘oil-soluble’, it is meant those organic sunscreens which have a solubility in water less than 10 g / L, preferably less than 5 g / L, more preferably less than 2 g / L, at 25°C.

[0035] Preferably, the composition comprises from 0.1 to 10 wt%, preferably from 1 to 8 wt%, more preferably 2 to 7 wt%, even more preferably 3 to 6 wt% and further more preferably 4 to 5 wt% of an oil-soluble sunscreen described herein.

[0036] The oil-soluble sunscreens could be of the IIV-B type or of the IIV-A type.

[0037] Preferably, the oil-soluble IIV-B sunscreen is selected from octyl salicylate, 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, pentyl dimethyl PABA and mixtures thereof. More preferred oil-soluble UVB sunscreens are selected from octyl salicylate, 3,3,5- trimethylclohexyl 2-hydroxybenzoate, ethylhexyl salicylate, 2-ethylhexyl 2-cyano-3,3- diphenyl-2-propenoate, and 2-ethylhexyl-4-methoxycinnamate and mixtures thereof. Further more preferred oil-soluble sunscreens are selected from 2-ethylhexyl-4-methoxycinnamate, ethylhexyl salicylate 2-ethylhexyl 2-cyano-3,3-diphenyl-2-propenoate and mixtures thereof. 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 IIV-B sunscreen has Amax from 280 to 320 nm.

[0038] Preferably, the oil-soluble IIV-A sunscreen may be selected from a dibenzoylmethane compound, diethylamino hydroxybenzoyl hexyl benzoate, methyl anthranilate and mixtures thereof. A dibenzoyl methane compound is most preferred for an oil-soluble UVA-sunscreen. Suitable dibenzoylmethane compounds are selected from 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 P0000699EP CPL dibenzoylmethane and 2,6-dimethyl-4-tert-butyl-4'-methoxy-dibenzoylmethane and mixtures thereof. The most preferred dibenzoyl methane compound is t-butylmethoxy dibenzoylmethane, commercially available as Parsol®1789.

[0039] Preferably, the composition comprises both an organic oil-soluble UVB and an organic oilsoluble UV-A sunscreens selected from such sunscreens described above.

[0040] Alternately, there are certain oil-soluble sunscreens which have both a UV-A and UV-B screening efficacy. It is selected from bis-ethylhexyloxyphenol methoxyphenyl triazine, drometrizole trisiloxane, benzophenone and its derivatives; and mixtures thereof. The most preferred one is bis-ethylhexyloxyphenol methoxyphenyl triazine, commercially available as Tinosorb S.

[0041] Water-soluble sunscreens

[0042] Preferably, the composition further comprises a water-soluble sunscreen.

[0043] By water soluble sunscreen, whether of the UV-A type, or of the UV-B type, it is preferably meant that the solubility in water of the sunscreen is higher than 10 g / L, preferably higher than 50 g / L, at 25°C.

[0044] Preferably, the composition comprises from 0.1 to 5 wt%, preferably, from 1 to 4 wt%, preferably from 2 to 3 wt% of a water-soluble sunscreen.

[0045] Preferably, the water-soluble sunscreen is selected from UV-B sunscreen selected from phenyl benzimidazole sulphonic acid (PBSA), benzophenone-4 or benzylidene camphor sulfonic acid and mixtures thereof, more 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).

[0046] Preferably, the water-soluble sunscreen is selected from UV-A sunscreen selected from disodium phenyl dibenzimidazole tetrasulfonate (Neoheliopan AP) or terephthalylidene dicamphor sulfonic acid (TDSA) and mixtures thereof. Di sodium phenyl dibenzimidazole tetra sulfonate 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 P0000699EP CPL 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.

[0047] There are certain water-soluble sunscreens which have both a IIV-A screening efficacy as well as a UVB screening efficacy. Such sunscreens provide both IIV-A and IIV-B 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 IIV-B sunscreen.

[0048] Preferably, the composition comprises both, a water-soluble IIV-B and a water-soluble IIV-A sunscreens selected from such sunscreens described above.

[0049] The water-soluble sunscreens for inclusion in the composition 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 neutralizing 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, a neutralizing agent is preferably included in amounts from 0.05 to 4 wt%, more preferably from 0.2 to 2 wt%. A neutralizing agent is preferably an inorganic or an organic alkali. Organic alkali is preferably an amine such as triethanolamine or diethanolamine. The present inventors have observed that the inorganic alkali is especially preferred. Preferred are alkali metal hydroxides. Most preferred metal hydroxide for inclusion as neutralizing agent in the composition of the invention are sodium hydroxide or potassium hydroxide.

[0050] Humectants

[0051] Preferably, the composition further comprises a humectant. Humectants of the polyhydric alcohol-type can be employed as cosmetically acceptable carriers. Preferably the humectant is selected from propylene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol, sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1 ,3-butylene glycol, isoprene glycol, 1 ,2,6-hexanetriol, glycerol, ethoxylated glycerol, propoxylated glycerol and mixtures thereof. More preferably, the humectant is selected from glycerol, sorbitol, propylene glycol, 1 ,3- butylene glycol and mixtures thereof. Most preferably, glycerol is used as the humectant. It is preferred that the amount of humectant is in the range from 1 to 10 wt%, more preferably from 2 to 8 wt% and further more preferably from 2 to 5 wt%.

[0052] Emulsifiers may be present in the compositions of the present invention. Total concentration of the emulsifier may range from about 0.1 to 40%, and preferably, from 1 to 20%, and most P0000699EP CPL preferably, from 1 to 5% by weight of the composition, including all ranges subsumed therein. The emulsifier may be selected from the group consisting of anionic, nonionic, cationic and amphoteric actives. Particularly preferred nonionic actives are those with a C10-C20 fatty alcohol or acid hydrophobe condensed with from about 2 to about 100 moles of ethylene oxide or propylene oxide per mole of hydrophobe; C2-C10 alkyl phenols condensed with from 2 to 20 moles of alkylene oxide; mono- and di-fatty acid esters of ethylene glycol; fatty acid monoglyceride; sorbitan, mono- and di-C8-C20 fatty acids; and polyoxyethylene sorbitan as well as combinations thereof. Alkyl polyglycosides and saccharide fatty amides (e.g. methyl gluconamides) are also suitable nonionic emulsifiers.

[0053] Preferred anionic emulsifiers include alkyl ether sulfate and sulfonates, alkyl sulfates and sulfonates, alkylbenzene sulfonates, alkyl and dialkyl sulfosuccinates, C8-C20 acyl isethionates, C8-C20 alkyl ether phosphates, alkyl ether carboxylates and combinations thereof.

[0054] Cationic emulsifiers that may be used include, for example, almitamidopropyltrimonium chloride, distearyldimonium chloride and mixtures thereof. Useful amphoteric emulsifiers include cocoamidopropyl betaine, C12-C20 trialkyl betaines, sodium lauroamphoacetate, and sodium laurodiamphoacetate or a mixture thereof.

[0055] Other generally preferred emulsifiers include glyceryl stearate, glycol stearate, stearamide AMP, PEG-100 stearate, cetyl alcohol as well as emulsifying / thickening additives like hydroxyethylacrylate / sodium acryloyldimethyl taurates copolymer / squalane and mixtures thereof.

[0056] Fatty acids

[0057] Preferably, the composition further comprises from 3 to 25 wt% C8 to C22 fatty acid. The fatty acid is preferably a C10 to C22 fatty acid, more preferably a C16 to C18 fatty acid. Most preferably, the fatty acids are stearic acid or palmitic acid or a mixture thereof. The fatty acid is often hystric acid which is substantially (generally about 90 to 95 %) a mixture of stearic acid and palmitic acid. Preferred hystric acid are ones having 40 to 65% C16 and 34 to 58% C18; or ones having 52 to 58% C16 and 40 to 47% C18 fatty acids.

[0058] Preferably, the composition comprises soap that is formed in-situ. Examples of soap include those formed after saponification of fatty acids having carbon atoms in the range from C8 to 022 with an aqueous alkali e.g. sodium hydroxide, potassium hydroxide and ammonium hydroxide. Typical examples of soap include caprylate (08), caprates (010), laurate (012), P0000699EP CPL myristate (C14), palmitate (C16, stearate (C18) and oleate (C18:1) formed with an aqueous alkali mentioned earlier. Thus, preferred soaps are selected from potassium caprylate, potassium caprate, potassium laurate, potassium myristate, potassium palmitate, potassium stearate, potassium oleate, sodium caprylate, sodium caprate, sodium laurate, sodium myristate, sodium palmitate sodium stearate, sodium oleate and mixtures thereof. Often, soaps may be present as a mixture of soaps formed from fatty acids of varying chain lengths.

[0059] Emollients

[0060] Preferably, the composition further comprises emollients that 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%.

[0061] 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. Nonvolatile silicone oils useful as an emollient material include polyalkyl siloxanes, polyalkylaryl siloxanes and polyether siloxane copolymers.

[0062] Another class is of ester emollients, which are alkyl esters of saturated fatty acids having 10 to 24 carbon atoms. Examples thereof include behenyl neopentanoate, isononyl isonanonoate, isopropyl myristate and octyl stearate. Alternatively, they are ether-esters such as fatty acid esters of ethoxylated saturated fatty alcohols. Further alternatively they are polyhydric alcohol esters such as ethylene glycol mono and di-fatty acid esters, diethylene glycol mono- and di-fatty acid esters, polyethylene glycol (200-6000) mono- and di- fatty acid esters, propylene glycol mono- and di-fatty acid esters, polypropylene glycol 2000 monostearate, ethoxylated propylene glycol monostearate, glyceryl mono- and di-fatty acid esters, polyglycerol poly-fatty esters, ethoxylated glyceryl mono-stearate, 1 ,3-butylene glycol monostearate, 1 ,3-butylene glycol distearate, polyoxyethylene polyol fatty acid ester, sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters are satisfactory polyhydric alcohol esters. Particularly useful are pentaerythritol, trimethylolpropane and neopentyl glycol esters of C1-C30 alcohols. Further, natural ester emollients are those based on mono-, di- and tri- glycerides. Representative glycerides include sunflower seed oil, cottonseed oil, borage oil, borage seed oil, primrose oil, castor and hydrogenated castor oils, rice bran oil, soybean oil, olive oil, safflower oil, shea butter, jojoba oil and combinations thereof. Amounts of the natural esters may range from 0.1 to 20 % by weight of the compositions. P0000699EP CPL

[0063] Hydrocarbons, which are suitable cosmetically acceptable carriers include petrolatum, mineral oil, C8-Ci8 isoparaffins, polybutenes and especially isohexadecane, available commercially as Permethyl® 101 A from Presperse Inc.

[0064] Fatty alcohols

[0065] Preferably, the composition further comprises fatty alcohols having from 10 to 30 carbon atoms as another useful category of cosmetically acceptable carrier. Illustrative of this category are stearyl alcohol, lauryl alcohol, myristyl alcohol, oleyl alcohol and cetyl alcohol and mixtures thereof.

[0066] Thickeners

[0067] Preferably, the composition comprises a thickener. Thickeners can be utilized as part of the cosmetically acceptable carrier of compositions according to the present invention. Typical thickeners include crosslinked acrylates (e.g. Carbopol® 982 and Carbopol® llltrez 10), hydrophobically-modified acrylates (e.g. Carbopol 1382(R)), polyacrylamides (e.g. Sepigel® 305), acryloylmethylpropane sulfonic acid / salt polymers and copolymers (e.g. Aristoflex® HMB and AVC), cellulosic derivatives and natural gums. Among useful cellulosic derivatives are sodium carboxymethylcellulose, hydroxypropyl methocellulose, hydroxypropyl cellulose, hydroxyethyl cellulose, ethyl cellulose and hydroxymethyl cellulose. Natural gums suitable for the present invention include guar, xanthan, sclerotium, carrageenan, pectin and combinations of these gums. Inorganics may also be utilized as thickeners, particularly clays such as bentonites and hectorites, fumed silicas, talc, calcium carbonate and silicates such as magnesium aluminum silicate (Veegum®). Amounts of the thickener may range from 0.0001 to 10 wt%, usually from 0.001 to 2.5 wt%, optimally from 0.01 to 1 wt%, including all ranges subsumed therein.

[0068] Preferably, the composition may optionally include, vitamin B2, vitamin B6, vitamin C, vitamin E, folic acid and biotin. Derivatives of these vitamins may also be employed. For instance, vitamin C derivatives include ascorbyl tetraisopalmitate, magnesium ascorbyl phosphate and ascorbyl glycoside. Derivatives of Vitamin E include tocopheryl acetate, tocopheryl palmitate and tocopheryl linoleate. DL-panthenol and derivatives may also be employed. Total amount of optional vitamins when present in compositions according to the present invention may range from 0.0 to 10 percent, preferably from 0.001 to 1 percent, optimally from 0.01 to 0.5 percent by weight of the composition. P0000699EP CPL

[0069] Other ingredients

[0070] Preferably, the composition further comprises colorants, opacifiers and abrasives. Each of these substances may range from 0.05 to 5 wt%, preferably between 0.1 and 3 wt%. pH of the composition

[0071] Preferably, the pH of the composition is in the range from 5.0 to 8.0, more preferably from 5.5 to 7.5 and even more preferably from 6.0 to 7.0. When required, pH of the composition may be adjusted using known pH adjusting agents e.g. sodium hydroxide, potassium hydroxide, citric acid and hydrochloric acid.

[0072] Water

[0073] Preferably, the composition comprises water in amounts from 35 to 90 wt%, more preferably from 50 to 85 wt% and further more preferably from 50 to 80 wt%.

[0074] Preservatives

[0075] Preservatives could be incorporated into the compositions of this invention to protect against the growth of potentially harmful microorganisms. Suitable traditional preservatives for compositions of this invention are alkyl esters of para-hydroxybenzoic acid. Other preservatives which have come into use include hydantoin derivatives, propionate salts, and a variety of quaternary ammonium compounds. Cosmetic chemists are familiar with appropriate preservatives and routinely choose them to satisfy the preservative challenge test and to provide product stability. Particularly preferred preservatives are iodopropynyl butyl carbamate, phenoxyethanol, alkane diols, C1-6 parabens (especially, methyl paraben and / or propyl paraben), imidazolidinyl urea, sodium dehydroacetate and benzyl alcohol. The alkane diols that are suitable for use as preservative are C6-C12 alkanes that are vicinally substituted with hydroxy groups. Illustrative examples include 1 ,2-octane diol (caprylyl glycol), 2,3-octane diol, 1 ,2-nonane diol, 1 ,2-decane diol, 1 ,2-hexane diol, 3,4-octane diol, mixtures thereof or the like where caprylyl glycol is typically the most preferred. When present in the composition, preservatives are added preferably in an amount 0.001 to 5 wt%, more preferably 0.01 to 3 wt% and most preferably 0.02 to 2 wt%.

[0076] Preferably, the composition may be formulated in the form of a leave-on composition such as a cream, a lotion, a serum. By ‘leave-on’ it is preferably meant that a composition which is not required to be removed from the human body after the application of the composition like e.g. a cream. Such composition may only be actively removed when a user takes a shower or bath. P0000699EP CPL

[0077] In a second aspect, the present invention relates to a method for improving the barrier function of skin comprising: a. applying on to the skin, a personal care composition comprising i. a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, ii. a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof; and iii. a resorcinol compound; and iv. an oil-soluble sunscreen having solubility in water of less than 10 g / L at 25°C.

[0078] Preferably, the method is non-therapeutic or cosmetic in nature.

[0079] In another preferred aspect, the present invention relates to use of a personal care composition comprising: a. a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, b. a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof, c. a resorcinol compound; and d. an oil-soluble sunscreen having solubility in water less than 10 g / L at 25°C, for improving the barrier function of skin despite the skin is exposed to UV and / or blue light. Preferably, the use is non-therapeutic or cosmetic in nature.

[0080] In a third aspect, the present invention relates to use of an oil-soluble sunscreen having solubility in water less than 10 g / L at 25°C, in a personal care composition comprising: d. a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, e. a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof; and f. a resorcinol compound, for improving the barrier function of skin.

[0081] Preferably, the use is non-therapeutic or cosmetic in nature.

[0082] Preferably, such improvement in barrier function of skin is obtained despite the skin is exposed to UV and / or blue light. Preferably, the sunscreen is selected from an oil-soluble sunscreen and / or a water-soluble sunscreen described hereinabove. P0000699EP CPL

[0083] The invention is further described with the help of the following non-limiting examples.

[0084] Examples

[0085] Cell culture:

[0086] Keratinocytes

[0087] Human neonatal epidermal keratinocytes (NHEK) were obtained from Lonza and were maintained in EpiLife M154 medium from Cascade Biologies. NHEK were seeded in 48-well plates at a density of 3.5 x 104cells / well and were maintained in the normal growth medium for 48h. Experiments were carried out once at -80% cell culture confluence was achieved. To study the effect of UV or Blue light exposure on the release of filaggrin by keratinocytes, on the day of exposure to UV or blue light, the media was carefully removed, and the cells were gently washed with sterile 1X PBS. NHEK were then exposed to UVA or Blue Light as described below with the compositions in table 1. The supernatant was collected after 24h and filaggrin was estimated by ELISA according to the manufacturer’s instructions.

[0088] Exposure to UV and blue light

[0089] NHEK cells were exposed to UV light using a Solar simulator comprising a Xenon arc lamp; or to blue light using LED source, as required. Cells that were not exposed to either to UV or to blue light, were used as control. Prior to exposure, compositions (as shown in table 1 below) were applied evenly on PMMA plate (2 mg / cm2). For the UV or Blue light exposure, the media was carefully removed, and the cells were gently washed with sterile 1X Phosphate buffered saline (PBS). Exposure was carried out with a PMMA plate on top of the culture plate with a lid and minimal levels of 1X PBS coating the cell layer. After exposure, PBS was removed and replaced with the media with and without the test compositions in all wells. Plates were incubated in 5% CO2 / 37°C incubator for 6 h and post incubation, cells were harvested.

[0090] SPF and UVAPF Measurements

[0091] The invitro SPF and UVAPF values for the samples shown in table 1 and table 4 below were measured using the following procedure:

[0092] Thin film transmittance measurements were done using Labsphere’s Ultraviolet transmittance analyzer. In this study, 70 x 70 mm PMMA plate with -6 pm roughness from Schonberg GmbH & Co were used. The percent transmittance of the various compositions was measured using a procedure as outlined below. 2 mg / cm2of sample was applied on PMMA plate, distributed uniformly using a syringe, and spread uniformly. The drying time for the PMMA plates was 30 minutes. After the drying time, sample plates were exposed to UV light and transmittance scan was recorded. This scan gives the transmittance as a function of wavelength (290 - 400 nm) P0000699EP CPL for a given sample. For a single plate six to nine different spots were scanned. The same was repeated for 2 or 3 plates. The data reported is thus an average over 12 -18 readings. The reference transmittance scan was obtained using a blank plate, with no sample on the PMMA plates with glycerin spread on it. The transmittance values were used to arrive at the SPF values using the UV -2000s application provided with the instrument.

[0093] Table 1 : A composition as per the present invention (examples 1 and 2) and controls (examples A and B) P0000699EP CPL

[0094] Table 2: Filaggrin expression (%)

[0095] Note: NHEK that were not exposed to UV or blue light, were taken as control with filaggrin levels to be 100%]

[0096] The data in table 2 above shows that when NHEK cells were exposed to UV or blue light, filaggrin expression reduced drastically. However, when the combination of (i) a carboxylic acid functionalized heteroaromatic compound e.g. niacinamide, (ii) retinoic acid precursor e.g. retinyl propionate; and (iii) a resorcinol compounds e.g. 4-hexyl resorcinol, was used in the personal care composition, filaggrin expression was boosted to 86% despite exposure to UV; and to 140% despite exposure to blue light. Thus, the personal care composition comprising the combination of the three ingredients improved the barrier function of skin. However, when the oil-soluble sunscreens, as shown in table 1 above, were added in the composition, it boosted the filaggrin expression further despite being exposed to UV.

[0097] Further, SPF obtained for the compositions of examples A, B, C and 1 were as shown in table 3 below:

[0098] Table 3: In vitro Sun Protection Factor (SPF)

[0099] The data in table 3 above showed that not only SPF benefit was obtained but also filaggrin expression; and thereby barrier function improvement, was obtained when the oil-soluble sunscreens was used with the combination of (i) a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, (ii) a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof; and (iii) a resorcinol compound, were used in combination in a personal care composition.

Claims

P0000699EP CPLClaims1. Use of a personal care composition comprising a. a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, b. a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof, c. a resorcinol compound; and d. an oil-soluble sunscreen having solubility in water less than 10 g / L at 25°C, for improving the barrier function of skin.

2. Use as claimed in claim 1 wherein the heteroaromatic compound is selected from niacinamide, picolinamide and mixtures thereof.

3. Use as claimed in claim 2 wherein the heteroaromatic compound is niacinamide.

4. Use as claimed in any one of claims 1 to 3 wherein the resorcinol compound is selected from phenylethyl resorcinol, 4-alkyl substituted resorcinol and mixtures thereof.

5. Use as claimed in claim 4 wherein the 4-alkyl substituted resorcinol is selected from 4- ethyl resorcinol, 4-butyl resorcinol, 4-pentyl resorcinol, 4-hexyl resorcinol, 4-heptyl resorcinol, 4-octyl resorcinol and mixtures thereof.

6. Use as claimed in claim 5 wherein the 4-alkyl substituted resorcinol is 4-hexyl resorcinol.

7. Use as claimed in any one of claims 1 to 6 wherein the retinoic acid precursor is selected from retinyl esters, retinal and mixtures thereof.

8. Use as claimed in any one of claims 1 to 7 wherein the oil-soluble sunscreen is selected from: a. a UV-B sunscreen selected from octyl salicylate, 3,3,5-trimethylclohexyl 2- hydroxybenzoate, ethylhexyl salicylate, 2-ethylhexyl 2-cyano-3,3-diphenyl-2- propenoate, 2-ethylhexyl-4-methoxycinnamate and octylmethoxycinnamate; and mixtures thereof and / or b. a UV-A sunscreen selected from a dibenzoylmethane compound, diethylamino hydroxybenzoyl hexyl benzoate and methyl anthranilate and mixtures thereof.P0000699EP CPL9. Use as claimed in any one of claims 1 to 8 wherein the composition further comprises a water-soluble sunscreen having solubility in water higher than 10 g / L at 25°C selected from a. a UV-B sunscreen selected from 2-phenylbenzimidazole-5-sulfonic acid, benzophenone-4 and benzylidene camphor sulfonic acid; and mixtures thereof and / or b. a water-soluble UV-A sunscreen selected from di sodium phenyl dibenzimidazole tetra sulfonate, terephthalylidene dicamphor sulfonic acid and mixtures thereof.

10. Use as claimed in any one of claims 1 to 9 wherein the composition is in the form of a leave-on composition such as a cream, a lotion and a serum.11 . A method for improving the barrier function of skin comprising: a. applying on to the skin, a personal care composition comprising i. a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, ii. a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof; and iii. a resorcinol compound; and iv. an oil-soluble sunscreen having solubility in water of less than 10 g / L at 25°C.

12. Use of an oil-soluble sunscreen having solubility in water less than 10 g / L at 25°C, in a personal care composition comprising: a. a heteroaromatic compound selected from nicotinic acid, picolinic acid, niacin, niacinamide, picolinamide and mixtures thereof, b. a retinoic acid precursor selected from retinyl esters, retinol, retinal, retinoic acid and mixtures thereof; and c. a resorcinol compound, for improving the barrier function of skin.

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