Mineral sunscreen containing zinc oxide and titanium dioxide

Abstract

The present invention provides a sunscreen composition comprising (i) TiO2, (ii) ZnO, (iii) triacontyl PVP, and (iv) a VP / hexadecene copolymer wherein the composition is an oil-in-water emulsion substantially free of a low molecular weight organic UV absorber, (iii): (iv) a weight ratio of less than 1, and the composition provides an in vitro SPF of at least 25 as measured by the in vitro SPF test method. The composition has a surprisingly low viscosity and provides a high SPF.

Description

[0001] The present invention provides a sunscreen composition comprising: (i) Ti02, (ii) ZnO, (iii) triacontanyl PVP, and (iv) VP / hexadecene copolymer, wherein the composition is an oil-in-water emulsion substantially free of low molecular weight organic UV absorbers, the weight ratio of (iii):(iv) is less than 1, and the composition provides an in vitro SPF of at least 25 as measured by the in vitro SPF test method. The composition has surprisingly low viscosity and provides a high SPF. BACKGROUND

[0002] It is well known that prolonged exposure to ultraviolet radiation, such as from the sun, can cause mild skin conditions and the formation of erythema, and increase the risk of skin cancer, such as melanoma. Exposure to UV radiation also accelerates skin aging, such as loss of skin elasticity and the development of wrinkles.

[0003] For these reasons, sunscreen compositions are commonly used to provide sun protection, and a variety of sunscreen compositions are commercially available. Many contain organic UV absorbers, such as octocrylene, homosalate, avobenzone, oxybenzone, octyl salicylate, and cinnamate esters. While these UV filters are effective at absorbing UV radiation, high amounts are often needed to provide a sunscreen composition with a high SPF. Because they are organic compounds, consumers sometimes have concerns about their potential to penetrate the skin, particularly when used in large amounts.

[0004] As an alternative, mineral-based sunscreens are also commercially available. These typically contain Ti02, ZnO, or both. For example, AVEENO Calm+Restore Daily Moisturizer Mineral Sunscreen SPF 30, commercially available from Johnson & Johnson Consumer Inc, contains 5.8 wt% Ti02, 12.5 wt% ZnO, 1.5 wt% triacontanyl PVP, and 1 wt% VP / hexadecene copolymer.

[0005] Co-assigned U.S. Patent Application No. 18 / 136456, filed April 19, 2023, relates to an anhydrous sunscreen composition comprising TiO2 and ZnO. The anhydrous composition is preferably sprayable and comprises: (a) at least about 15% by weight of a combination of TiO2 and ZnO based on the total weight of the sunscreen composition, wherein the weight ratio of ZnO to TiO2 in the composition is about 0.5 to about 1.5; (b) at least about 50% by weight of a carrier oil based on the total weight of the sunscreen composition, wherein the carrier oil comprises at least 50% by weight of sunflower (Helianthus annuus) seed oil; (c) about 10% by weight to about 20% by weight of a combination of isododecane and diisopropyl adipate based on the total weight of the sunscreen composition; and (d) about 2% by weight to about 6% by weight of a film-forming agent comprising triacontyl PVP based on the total weight of the sunscreen composition. Application '456 discloses the optional use of a combination of triacontyl PVP and VP / hexadecene copolymer, and in one embodiment, the composition comprises about 2.5 wt% to about 3.2 wt% triacontyl PVP and about 2.5 wt% VP / hexadecene copolymer. Example F of application '456 is a comparative anhydrous composition containing 15 wt% TiO2, 10 wt% ZnO, 1.5 wt% triacontyl PVP, and 2.5 wt% VP / hexadecene copolymer. Example F is unstable; sedimentation occurs at room temperature.

[0006] Typically, mineral-based sunscreens cannot provide the highest SPF level without increasing the amount of mineral UV-active ingredients to a high level, which requires high-viscosity formulations to suspend the UV blockers, namely TiO2 and ZnO. For example, there are very few SPF 70 mineral sunscreens on the market that also have the ideal appearance of a low-viscosity liquid.

[0007] The applicant has now discovered high SPF oil-in-water emulsions containing only mineral UV-active ingredients, which also contain triacontyl PVP and VP / hexadecene copolymer, wherein the weight ratio of triacontyl PVP to VP / hexadecene copolymer is less than 1. These compositions advantageously provide an in vitro SPF level of at least about 25 and an in vivo SPF level of at least 50, preferably at least 70. As emulsions, they also exhibit excellent liquid aesthetics due to their surprisingly low viscosity. Summary of the Invention

[0008] The present invention provides a sunscreen composition comprising: (i) TiO2, (ii) ZnO, (iii) triacontyl PVP and (iv) VP / hexadecene copolymer, wherein the composition is a water-in-oil emulsion substantially free of low molecular weight organic UV absorbers, the weight ratio of (iii):(iv) is less than 1, and the composition provides an in vitro SPF of at least 25 as measured by an in vitro SPF test method. Detailed Implementation

[0009] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. All publications, patent applications, patents, and other references mentioned herein are incorporated herein by reference.

[0010] As used in this article, “topical application” means, for example, applying directly to or spreading on the outer layer of skin or scalp by hand or an applicator (e.g., a wipe, roller, or sprayer).

[0011] As used in this article, "cosmetics" refers to substances or products that preserve, restore, impart, stimulate or enhance physical appearance or appear to improve beauty or youth, especially when it involves the appearance of tissues or skin.

[0012] As used herein, “sunscreen composition” means a formulation (e.g., lotion, spray, gel or other topical product) that absorbs and / or reflects some of the ultraviolet (UV) radiation from the sun and thus helps to prevent the negative effects of sun exposure (e.g., sunburn, premature aging, etc.).

[0013] As used herein, "cosmetically effective amount" means an amount of a physiologically active compound or composition sufficient to treat one or more conditions, but sufficiently low to avoid serious side effects. The cosmetically effective amount of a compound or composition will vary depending on factors such as: the condition being treated, the age and physical condition of the end user, the severity of the condition being treated / prevented, the duration of treatment, the nature of any other treatments, the specific compound or product / composition used, the cosmetically acceptable carrier employed, etc.

[0014] As used herein, “cosmetically acceptable” means that the term describes an ingredient suitable for use in contact with tissues (e.g., skin) without causing undue toxicity, incompatibility, instability, irritation, allergic response, etc.

[0015] As used in this article, "cosmetically acceptable surfactant" refers to a compound (synthetic or natural) that has cosmetic or therapeutic effects on the skin.

[0016] As used in this article, “treatment or therapy” means to reduce, decrease, prevent, improve or eliminate the presence or symptoms of a symptom or disorder.

[0017] As used herein, "substantially free" means that the mentioned ingredients are not added directly or intentionally. Preferably, "substantially free" means containing less than about 1% by weight. More preferably, "substantially free" means containing less than about 0.5% by weight. Even more preferably, "substantially free" means containing less than about 0.1% by weight. The sunscreen composition of the present invention may be completely free of ingredients, i.e., free of any ingredients.

[0018] As used herein, "UV absorber" refers to an active ingredient whose specific function is to absorb radiation in certain portions of the ultraviolet spectrum (290 nm-400 nm), for example, having at least about 1000 mol of [amount missing] for at least one wavelength within the aforementioned ultraviolet spectrum. -1 cm -1 The active ingredient has an extinction coefficient. UV absorbers include, for example, approved sunlight filters, and are distinct from compounds that have other functions and simply absorb UV radiation.

[0019] As used in this article, "UV blocker" refers to a compound that reflects or scatters UV radiation.

[0020] As used in this article, “phase stable” means that the aqueous and oil phases of an emulsion do not show significant separation at room temperature for at least two weeks.

[0021] Unless otherwise specified, percentages or concentrations refer to weight percentages or weight concentrations based on the total weight of the composition (i.e., % (weight / weight)). Unless otherwise stated, all ranges include end values; for example, "4 to 9" includes the end values ​​4 and 9.

[0022] Mineral uv active ingredients

[0023] The sunscreen composition of the present invention contains mineral UV-active ingredients, particularly a combination of titanium dioxide (TiO2) and zinc oxide (ZnO).

[0024] The composition comprises a combination of TiO2 and ZnO in an amount of about 9.0 wt% to about 32.0 wt% based on the total weight of the composition. Preferably, the composition comprises a combination of TiO2 and ZnO in an amount of about 12.0 wt% to about 28.0 wt% based on the total weight of the composition.

[0025] For example, the composition may contain a combination of about 23% by weight of TiO2 and ZnO based on the total weight of the sunscreen composition.

[0026] The weight ratio of zinc oxide to titanium dioxide in the composition is about 3:1 to about 1:1.

[0027] In one embodiment, the composition comprises about 6.64 wt% TiO2 and about 14.4 wt% ZnO.

[0028] Examples of usable titanium dioxide are titanium dioxide; aluminum hydroxide; and stearic acid, which is sold by Tayca Corporation under the trade name MICRO TITANIUM DIOXIDE MT-l00TV.

[0029] Examples of zinc oxide that can be used are zinc oxide; triethoxyoctylsilane, sold by Tayca Corporation under the trade name Micro Zinc Oxide MZX-304OTS.

[0030] Preferably, the composition is substantially free of UV absorbers. In particular, the composition may be substantially free of low molecular weight organic UV absorbers. As used herein, "low molecular weight organic UV absorber" means a UV absorber in the form of an organic molecule, typically an aromatic compound that is conjugated with a carbonyl moiety substituted at the ortho or para position of the aromatic ring and has a molecular weight of less than 900 g / mol.

[0031] Preferably, the composition is completely free of low molecular weight organic UV absorbers.

[0032] Examples of low molecular weight organic UV absorbers include, but are not limited to: methoxycinnamate derivatives, such as octyl methoxycinnamate and isoamyl methoxycinnamate; camphor derivatives, such as 4-methylbenzyl camphor, camphor benzalkonium methyl sulfate and terephthalimide dicamphor sulfonic acid; salicylate derivatives, such as octyl salicylate, ethylhexyl salicylate and homosalyl ester; benzoin derivatives, such as dihydroxybenzone and oxybenzone; benzoic acid derivatives, such as aminobenzoic acid and octyldimethyl-p-aminobenzoic acid; octocrylene and other β,β-diphenylacrylates; dioctylbutyrylaminotriazinone; octyltriazinone; avobenzone (butyl methoxydibenzoylmethane); menthyl anthranilate; triazinone derivatives, such as ethylhexyltriazinone (… T150); Diethylhexylbutyramidotriazinone ( HEB); Diethylhexyloxyphenol methoxyphenyl triazine ( S), benzoate derivatives such as diethylaminohydroxybenzoylhexylbenzoate (S), APlus), benzotriazole derivatives such as cresoltrazoltrisiloxane ( XL), methylenebisbenzotriazolyltetramethylbutylphenol ( M); terphenyltriazine; (2-{4-[2-(4-diethylamino-2-hydroxybenzoyl)-benzoyl]-piperazine-1-carbonyl}-phenyl)-(4-diethylamino-2-hydroxy-phenyl)-methyl ketone; cyanine derivatives; bis(butylbenzoate)diaminotriazine aminopropylsiloxane; and bisethylhexyloxyphenol methoxyphenyltriazine encapsulated in a polymer matrix.

[0033] In some embodiments, the composition may also be free of polymeric organic UV absorbers. As used herein, "polymeric organic UV absorber" means a polymeric compound comprising an organic chromophore linked to a polymer chain. For example, the polymer chain may be a polysiloxane having an average molecular weight, for example, greater than 6000 Daltons. Examples of such polysiloxane UV absorbers include, but are not limited to, those commercially available from DSM. SLX and polysiloxane-15. The UVB (λ) absorption spectra of these polysiloxanes. max =312nm) portion, and is usually combined with UVA filters to achieve broad-spectrum protection.

[0034] Alternatively, the composition may contain one or more polymeric organic UV absorbers. Due to their relatively high molecular weight, they are considered to be substantially non-absorbed by the skin.

[0035] Film-forming agent

[0036] The composition also contains two film-forming agents—trianediyl PVP (a polymer of trianediyl polyvinylpyrrolidone or 1-vinyl-2-pyrrolidone with 1-trianene) and VP / hexadecene copolymer (vinylpyrrolidone / hexadecene copolymer).

[0037] The composition typically contains about 0.5% to about 2.25% triacontyl PVP, preferably about 0.8% to about 1.5% triacontyl PVP.

[0038] The composition typically comprises about 0.5% to about 3% by weight of VP / hexadecene copolymer, preferably about 1% to about 2.5% by weight of VP / hexadecene copolymer.

[0039] Importantly, in order for this composition to achieve a high SPF level, the weight ratio of triacontyl PVP to VP / hexadecene copolymer must be less than 1. For example, the weight ratio of triacontyl PVP to VP / hexadecene copolymer can be about 0.5.

[0040] In one embodiment, the composition comprises about 1% by weight of triacontyl PVP and about 2% by weight of VP / hexadecene copolymer.

[0041] Triacontyl polyvinylpyrrolidone (a polymer of triacontyl polyvinylpyrrolidone or 1-vinyl-2-pyrrolidone with 1-trianene) is available, for example, from ISP Freetown Fine Chemicals Inc. under the trade name Antaron. TM WP-660 polymer was commercially available.

[0042] VP / hexadecene copolymers are also available, for example, from ISP Freetown Fine Chemicals Inc. under the trade name Antaron. TM V216 polymer was commercially available.

[0043] Spf

[0044] The sun protection factor (SPF) of this composition can be tested using the following in vitro SPF testing method. The baseline transmittance of the PMMA plate (substrate, purchased from Helioscience, Marseille, France) was measured using a calibrated... UV-10005UV Transmission Analyzer or UV absorbance was measured using a UV-2000S transmittance analyzer (Labsphere, North Sutton, NH, USA). The test sample was then applied to a PMMA plate at an application density of approximately 0.75 mg / cm² by rubbing it into a uniform thin layer with the operator's fingers. The sample was allowed to dry for 15 minutes, and then UV absorbance was measured in the same manner. SPF was calculated using the following formula with absorbance measurements known in the art:

[0045]

[0046] in:

[0047] E(λ) = Erythema spectrum;

[0048] I(λ) = spectral irradiance received from the UV source;

[0049] A0(λ) = the average monochromatic absorbance of the product layer before UV exposure; and

[0050] d(λ) = wavelength step (1nm).

[0051] In one embodiment, the composition has an SPF of at least about 25, as measured by an in vitro SPF testing method. In another embodiment, the composition has an SPF of at least about 30, as measured by an in vitro SPF testing method.

[0052] Shear viscosity test method

[0053] This composition advantageously exhibits low shear viscosity. Shear viscosity was measured by the following method: A suitable sample was loaded into an Anton Paar MCR302 rheometer equipped with double-wall Couette geometry. The temperature was maintained at 25°C using a Peltier 5 element, and the shear rate was increased from 1,000 s⁻¹ using the default steady-state standard in the rheometer control software, RheoCompass. -1 Accelerate to 0.1s -1 .

[0054] The composition is preferably subjected to 1 second at 25°C. -1 It has a shear viscosity of less than 32 Pa·s.

[0055] Topical composition

[0056] Sunscreen compositions can be used topically on mammals, for example by applying the composition directly to the skin, hair, or nails of mammals (especially humans).

[0057] The sunscreen composition is in the form of an oil-in-water emulsion, which comprises a continuous aqueous phase and a discontinuous oil phase dispersed within the continuous aqueous phase. The composition is preferably phase-stable.

[0058] The oil phase can exist as discrete droplets or units with an average diameter of about one micrometer to about 1,000 micrometers, such as about one micrometer to about 100 micrometers.

[0059] The weight percentage of the aqueous phase contained in the composition can range from about 27.1% to about 85.95%, such as from about 40% to about 50%.

[0060] Sunscreen compositions can be prepared using mixing and blending methods well-known in the cosmetics industry. Typically, sunscreen compositions are prepared by: preparing an oil phase containing oil-soluble and oil-miscible components, such as caprylic / capric triglycerides, ethylhexylmethoxycrylene, polydimethylsiloxane, polyhydroxystearic acid, titanium dioxide, aluminum hydroxide, stearic acid, zinc oxide, triethoxyoctylsilane, cetyl oleoresin, sorbitol oleoresin, sodium calcium borosilicate, stearyl alcohol polyether-21, triacontyl PVP, and butyl octyl salicylate; and preparing an aqueous phase by mixing water with water-soluble or water-miscible components, such as xanthan gum, disodium EDTA, sodium chloride, chlorophenoxyglycerol, octyl glycol, phenoxyethanol, ethylhexylglycerin, glycerin, and tocopheryl acetate. The oil phase and the water phase can then be mixed in a manner sufficient to ensure that the oil phase is sufficiently and uniformly dispersed in the water phase, such that the water phase is continuous and the oil phase is discontinuous.

[0061] The applicant has discovered that optimal dispersibility of TiO2 in the composition is a driving factor for high SPF. To improve the dispersibility of TiO2, TiO2 is added at room temperature (i.e., without heating) before the addition of ZnO.

[0062] This composition can be combined with a cosmetically acceptable topical carrier, which is a topical carrier that can contain other components dispersed or dissolved therein and has acceptable properties for safe topical application.

[0063] The composition may optionally contain a wide variety of additional oil-soluble and / or water-soluble substances that are commonly used in the composition and applied to the skin at levels established in the art. For example, it may include surfactants, pearlescent or opaque agents, thickeners, emollients, conditioning agents, humectants, chelating agents, exfoliating agents, and additives that enhance the appearance, feel, or fragrance of the cleaning composition, such as colorants, fragrances, preservatives, pH adjusters, etc., provided that these additives do not affect the composition's high SPF and low viscosity.

[0064] In one embodiment, the composition is substantially free of waxes, structuring agents, and fatty alcohols.

[0065] Water-soluble or water-dispersible polymers can be added to the composition. Water-dispersible polymers consist of water-insoluble polymers, which are typically micronized and may be dispersed in an aqueous carrier when using surfactants. Water-dispersible polymers can form films and improve the water resistance of the composition. Examples of water-soluble polymers include those available from Lonza. 10-1-L (polyglycerol-10-laurate). Examples of water-dispersible polymers include water-dispersible polyurethanes, such as those purchased from Bayer. C1000 (Polyurethane-34), purchased from Dow Corning. 2501 (bis-PEG-18 methyl ether dimethyl silane), Eastman AQTM38S (polyester-5) purchased from Eastman Chemical, and [other products] purchased from Air Products. 8600 (C8-22 alkyl acrylate / methacrylic acid crosspolymer).

[0066] Sunscreen compositions may also contain certain additional film-forming agents, provided they do not interfere with the composition's SPF and low viscosity. Acceptable additional film-forming agents include polyethylene, sourced from New Phase Technologies. It was purchased for 400, which is polyethylene with a molecular weight of 400. Another suitable film-forming agent is polyethylene 2000 (molecular weight 2000), which... Purchased from New Phase Technologies. Another suitable film-forming agent is synthetic wax, which is also... V-825 was purchased from New Phase Technologies. Other typical film-forming agents include acrylate / acrylamide copolymers, acrylate copolymers, acrylate / C12-C22 alkyl methacrylate copolymers, polyethylene, waxes, VP / dimethiconyl acrylate / polyurethane, butylated PVP, PVP / hexadecene copolymers, octadecene / MA copolymers, PVP / eicosene copolymers, triacontyl PVP, rapeseed / tung oil copolymers, decamethylcyclopentasiloxane (and) trimethylsiloxysilicate, polydimethylsiloxane; acrylate / polydimethylsiloxane copolymers and mixtures thereof. In some cases, the film-forming agent is Ashland under the trade name Allianz. TM OPT sells acrylate / C12-C22 alkyl methacrylate copolymers.

[0067] Suitable emollients for use in the composition include mineral oils, petrolatum, vegetable oils (e.g., triglycerides, such as caprylic / capric triglyceride, sunflower seed oil), waxes, and other mixtures of fatty esters, including but not limited to glycerides (e.g., isopropyl palmitate, isopropyl myristate, diisopropyl adipate, dioctyl carbonate, C12-15 alkyl benzoate, isononyl isononanoate, neopentyl glycol diheptanoate, neopentyl glycol dibenzoate, butyl octyl salicylate, ethylhexyl methoxycrylene), hydrocarbons (e.g., isododecane, isohexadecane, squalane), ethers (e.g., PPG-15 stearyl ether, dioctyl ether), and silicone oils such as polydimethylsiloxane. In some embodiments, a mixture of triglycerides (e.g., caprylic / capric triglyceride) and esters of glycerol (e.g., isopropyl myristate).

[0068] The sunscreen composition may contain one or more emulsifiers. In one embodiment, the sunscreen composition contains stearyl alcohol polyether-21. Preferably, the sunscreen composition contains stearyl alcohol polyether-21, cetyl oleoresin, and sorbitol oleoresin. The ingredients cetyl oleoresin and sorbitol oleoresin are commercially available from Hallstar under the Olivem 1000 brand.

[0069] Examples of suitable solvents include propylene glycol, polyethylene glycol, polypropylene glycol, glycerol, 1,2,4-butanetriol, sorbitol ester, 1,2,6-hexanetriol, ethanol, and mixtures thereof.

[0070] In some embodiments, the composition comprises a pigment suitable for providing color or coverage. The pigment may be suitable for colored cosmetic products, including compositions applied to hair, nails, and / or skin, particularly the face. Colored cosmetic compositions include, but are not limited to, foundations, concealers, primers, blushes, mascaras, eyeshadows, eyeliners, lipsticks, nail polishes, and tinted moisturizers. The pigment suitable for providing color or coverage may consist of iron oxides (including red and yellow iron oxides), titanium dioxide, ultramarine pigments, and chromium or chromium hydroxide pigment particles, and mixtures thereof. The pigment may be a lake pigment, such as an organic dye precipitated onto an inert binder such as an insoluble salt, such as azo, indigo, triphenylmethane, anthraquinone, and xanthine dyes designated as D&C and FD&C blue, brown, green, orange, red, yellow, etc. Examples of lake pigments include Red#6, Red#7, Yellow#5, Violet#2, and Blue#1. The pigment may be an interference pigment. Examples of interference pigments include those containing mica substrates, bismuth oxychloride substrates, and silica substrates, such as mica / bismuth oxychloride / iron oxide pigments commercially available from CHROMALITE Pigments (BASF); titanium dioxide and / or iron oxide coated onto mica, such as commercially available FLAMENCO Pigments (BASF); mica / titanium dioxide / iron oxide pigments, including commercially available KTZ Pigments (Kobo products) and CELLINI Pearl Pigments (BASF); and borosilicate-containing pigments, such as REFLECKS Pigments (BASF).

[0071] In one embodiment, the sunscreen composition comprises a humectant. Examples of humectants include, but are not limited to, glycerin, pentylene glycol, and butylene glycol. In another embodiment, the sunscreen composition comprises at least 3% by weight of glycerin. The sunscreen composition may comprise, for example, about 5% by weight of glycerin.

[0072] In another embodiment, the sunscreen composition has a pH of about 7.0 to about 8.9. The sunscreen composition may have a pH of about 8.0.

[0073] In another embodiment, the sunscreen composition comprises hyaluronic acid. In yet another embodiment, the sunscreen composition comprises at least 0.01% by weight of hyaluronic acid.

[0074] The composition may also contain one or more other cosmetically acceptable active agents, including, for example, anti-acne agents, shine control agents, antimicrobial agents, anti-inflammatory agents, antifungal agents, antiparasitic agents, topical analgesics, antioxidants, keratolytic agents, moisturizers, nutrients, vitamins, energizers, antiperspirants, astringents, deodorants, hardening agents, anti-hardening agents, and agents for skin conditioning.

[0075] The amount of other cosmetic active agents may be from about 0.001% to about 20% by weight of the composition, for example from about 0.005% to about 10% by weight of the composition, such as from about 0.01% to about 5% by weight of the composition.

[0076] Cosmetic-acceptable active agents can be selected from, for example, D-panthenol carotenoids, ceramides, polyunsaturated fatty acids, essential fatty acids, enzymes (such as laccase), enzyme inhibitors, minerals, steroids (such as hydrocortisone), 2-dimethylaminoethanol, copper salts (such as copper chloride), peptides (such as hexapeptides, tripeptides, acetyl dipeptide-31 amides and those containing copper), coenzyme Q10, amino acids (such as proline), vitamins, lacturonic acid, acetyl coenzyme A, niacin, riboflavin, thiamine, ribose, electron transport proteins (such as NADH and FADH2), natural extracts (such as those from aloe vera, chamomile, oatmeal, dill, blackberry, paulownia), Pichia pastoris, as well as chicory, resorcinol (such as 4-hexylresorcinol), curcuminoids, glycosamines (such as N-acetylglucosamine), and their derivatives and mixtures.

[0077] Examples of vitamins and their derivatives include, but are not limited to, vitamin A, B vitamins (such as vitamin B3, nicotinamide, vitamin B5, and vitamin B12), vitamin C, vitamin K, and different forms of vitamin E (such as α, β, γ, or Δ tocopherols or mixtures thereof) and their derivatives.

[0078] Examples of antioxidants include, but are not limited to, water-soluble antioxidants such as thiol compounds and their derivatives (e.g., sodium metabisulfite and N-acetylcysteine), lipoic acid and dihydrolipoic acid, resveratrol, lactoferrin, and ascorbic acid and ascorbic acid derivatives (e.g., ascorbyl palmitate and ascorbyl polypeptide). Oil-soluble antioxidants suitable for use in the compositions of the present invention include, but are not limited to, butylated hydroxytoluene, retinoids (e.g., retinol and retinyl palmitate), tocopherols (e.g., tocopheryl acetate), tocotrienols, and ubiquinone. Natural extracts containing antioxidants suitable for use in the compositions of the present invention include, but are not limited to, extracts containing flavonoids and isoflavones and their derivatives (e.g., genistein and diadzein), extracts containing resveratrol, and so on. Examples of such natural extracts include grape seed, green tea, pine bark, propolis, and ginger root extracts.

[0079] In one embodiment, the composition comprises one or both of tocopherol and chrysanthemum extract (e.g., chrysanthemum flower / leaf / stem juice).

[0080] In one embodiment, the composition comprises phenoxyethanol, chlorphenesin, ethylhexylglycerin, and octanediol. This particular combination of preservatives surprisingly increases the shelf life of the composition according to the invention. Preferably, the composition comprises about 0.6% by weight of phenoxyethanol, about 0.27% by weight of chlorphenesin, about 0.5% by weight of ethylhexylglycerin, and about 0.25% by weight of octanediol.

[0081] The following non-limiting embodiments will further illustrate the present invention.

[0082] Example 1

[0083] A series of TiO2 / ZnO sunscreen compositions free of low molecular weight UV absorbers were prepared using the ingredients shown in Table 1. Compositions 3, 6, and 8-19 are compositions according to the invention, and compositions 1, 2, 4, 5, and 7 are comparative compositions. Composition 1 is AVEENO Calm+Restore Daily Moisturizer Mineral Sunscreen SPF 30, commercially available from Johnson & Johnson Consumer Inc.

[0084] All compositions are water-in-oil emulsions. They are typically prepared by mixing the oil and aqueous phases in a manner sufficient to ensure the oil phase is sufficiently and uniformly dispersed in the aqueous phase, resulting in a continuous aqueous phase and a discontinuous oil phase. The oil phase components are caprylic / capric triglyceride, ethylhexylmethoxycrylene, polydimethylsiloxane, polyhydroxystearic acid, titanium dioxide, aluminum hydroxide, stearic acid, zinc oxide, triethoxyoctylsilane, cetyl oleoresin, sorbitol oleoresin, sodium calcium borosilicate, stearyl alcohol polyether-21, triacontyl PVP, and butyl octyl salicylate. The aqueous phase components are water, xanthan gum, disodium EDTA, sodium chloride, chlorophenoxyglycerol, octyl glycol, phenoxyethanol, ethylhexylglycerin, glycerol, and tocopheryl acetate.

[0085] The in vitro SPF of each composition was tested using the above-described in vitro SPF test method. The results are also shown in Tables 1, 2, and 3.

[0086] The shear viscosity of several compositions was also measured using a shear viscosity test method, and the results are shown in the table.

[0087] The results showed that, when measured by in vitro SPF testing methods, only the compositions according to the invention containing TiO2, ZnO, triacontyl PVP, and VP / hexadecene copolymer provided an SPF measurement value of at least 25, wherein the weight ratio of triacontyl PVP to VP / hexadecene copolymer was less than 1. Furthermore, these compositions all exhibited a shear viscosity of less than 32 Pa·s, indicating an ideal lightweight skin feel.

[0088] Table 1

[0089]

[0090]

[0091] Table 2

[0092]

[0093] Table 3

[0094]

[0095]

[0096] Example 2

[0097] The SPF of compositions 1 and 3 were tested in vivo using the methods described in the U.S. FDA OTC Sunscreen Monograph (FDA OTC Sunscreen Monograph M020: Sunscreens for Nonprescription Human Use (issued September 24, 2021)). Final Executive Order (OTC000006), effective after the enactment of the Coronavirus Aid, Relief, and Economic Security Act (CARES Act), Public Law 116-136, on March 27, 2020.

[0098] Composition 3 according to the invention provides an in vivo SPF of 70, while composition 1 provides an in vivo SPF of only 33. These results confirm the unexpectedly high photoprotective activity of the compositions according to the invention containing triacontyl PVP and VP / hexadecene copolymer, wherein the weight ratio of triacontyl PVP to VP / hexadecene copolymer is less than 1. Both compositions 1 and 3 contain triacontyl PVP and VP / hexadecene copolymer. However, the weight ratio of film-forming agent in composition 1 is 1.5, while the weight ratio of film-forming agent in composition 3 is 0.5.

Claims

1. A sunscreen composition comprising: (i) TiO2, (ii) ZnO, (iii) triacontyl PVP and (iv) VP / hexadecene copolymer, wherein the composition is a water-in-oil emulsion substantially free of low molecular weight organic UV absorbers, the weight ratio of (iii):(iv) is less than 1, and the composition provides an in vitro SPF of at least 25 as measured by an in vitro SPF testing method.

2. The sunscreen composition according to claim 1, wherein the sunscreen composition comprises a combination of titanium dioxide and zinc oxide in an amount of less than 25% by weight based on the total weight of the sunscreen composition.

3. The sunscreen composition according to claim 1, wherein the sunscreen composition comprises about 8% by weight TiO2 and about 15% by weight ZnO.

4. The sunscreen composition according to claim 1, wherein the weight ratio of (iii):(iv) is less than 0.

60.

5. The sunscreen composition according to claim 1, wherein the weight ratio of (iii):(iv) is about 0.

50.

6. The sunscreen composition according to claim 1, wherein the sunscreen composition further comprises about 5% by weight of glycerin.

7. The sunscreen composition according to claim 1, wherein the sunscreen composition further comprises stearyl alcohol polyether-21, cetyl oleoresin, and sorbitol oleoresin.

8. The sunscreen composition according to claim 1, wherein the sunscreen composition exhibits a 1-second reaction time at 25°C. -1 It has a shear viscosity of less than 32 Pa·s.

9. The sunscreen composition according to claim 1, wherein the sunscreen composition further comprises phenoxyethanol, chlorphenesin, ethylhexylglycerin, and octanediol.

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