Topical Compositions Containing Vitamin C

Abstract

The present invention provides a topical composition that includes a combination of ascorbic acid, caffeine, inorganic salts, and water, which is a single aqueous phase composition.

Description

[Technical field]

[0001] The present invention provides a topical composition that includes a combination of ascorbic acid, caffeine, inorganic salts, and water, which is a single-phase aqueous composition. [Background technology]

[0002] Ascorbic acid (vitamin C) is widely used in skin care due to its antioxidant and skin brightening properties. Typically, anhydrous formulations are used since the stability of ascorbic acid in aqueous vehicles is known to be difficult as water increases the oxidation rate of ascorbic acid.

[0003] Caffeine is also known to provide certain skin care benefits when used topically.

[0004] Applicants have now discovered improved topical compositions that are single-phase aqueous compositions, preferably in the form of a serum, containing high levels of ascorbic acid and caffeine. These compositions advantageously provide synergistic antioxidant activity and excellent anti-aging and skin brightening benefits. They also contain inorganic salts such as sodium bisulfite and are very stable. Summary of the Invention [Means for solving the problem]

[0005] The present invention provides a topical composition comprising about 5% to about 22% by weight of ascorbic acid, based on the total weight of the composition; about 1% to about 5% by weight of caffeine, based on the total weight of the composition; at least 0.2% by weight, based on the total weight of the composition, of an inorganic salt selected from the group consisting of sodium sulfite, potassium sulfite, sodium bisulfite, and sodium metabisulfite; and at least 28% by weight, based on the total weight of the composition, of water, wherein the composition is a single aqueous phase.

[0006] The present invention also provides a topical composition comprising about 10% by weight of ascorbic acid based on the total weight of the composition, about 2% by weight of caffeine based on the total weight of the composition, about 0.5% by weight of sodium bisulfite based on the total weight of the composition, at least 38% by weight of water based on the total weight of the composition, about 40% by weight of 1,3-propanediol based on the total weight of the composition, and about 0.2% by weight of ethylenediaminetetraacetic acid based on the total weight of the composition, wherein the composition is a single aqueous phase.

[0007] The present invention also provides a topical composition comprising about 15% by weight of ascorbic acid based on the total weight of the composition, about 2% by weight of caffeine based on the total weight of the composition, about 0.5% by weight of sodium bisulfite based on the total weight of the composition, at least 33% by weight of water based on the total weight of the composition, about 45% by weight of 1,3-propanediol based on the total weight of the composition, and about 0.2% by weight of ethylenediaminetetraacetic acid based on the total weight of the composition.

[0008] The present invention also provides a topical composition comprising about 20% by weight of ascorbic acid based on the total weight of the composition, about 2% by weight of caffeine based on the total weight of the composition, at least 0.5% by weight of sodium bisulfite based on the total weight of the composition, at least 28% by weight of water based on the total weight of the composition, about 45% by weight of 1,3-propanediol based on the total weight of the composition, and about 0.2% by weight of ethylenediaminetetraacetic acid based on the total weight of the composition.

[0009] The present invention further provides cosmetic methods for treating skin comprising topically applying these topical compositions to skin in need of treatment to lighten or whiten the skin. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Unless otherwise defined, all technical and scientific terms used herein have the meaning commonly understood by one of ordinary skill in the art to which this invention belongs. All publications, patent applications, patents, and other references mentioned herein are incorporated herein by reference.

[0011] As used herein, "topically apply" means to apply or spread directly onto the skin, scalp, or hair, for example, by using the hands or an applicator such as a wipe, roller, or spray.

[0012] As used herein, "cosmetically acceptable" means that the ingredient it describes is suitable for use in contact with tissue (e.g., skin or hair) without undue toxicity, incompatibility, instability, irritation, allergic response, etc.

[0013] As used herein, a "cosmetically acceptable active agent" is a compound (synthetic or natural) that has a cosmetic or therapeutic effect on the skin or hair.

[0014] The composition of the present invention is suitable for treating signs of skin aging.As used herein, "signs of skin aging" include the presence of lines, including fine lines and wrinkles, loss of elasticity, uneven skin, age spots, reduced skin thickness, and abnormal or reduced synthesis of glycoproteins, including collagen, glycosaminoglycans, proteoglycans, elastin, or fibronectin.In one embodiment, the signs of aging are selected from the presence of lines, fine lines, wrinkles, loss of elasticity, and abnormal or reduced synthesis of glycoproteins, including collagen, glycosaminoglycans, proteoglycans, elastin, or fibronectin.

[0015] The compositions of the present invention are also suitable for treating skin that requires lightening or whitening treatment. As used herein, the term "lightening" or "whitening" skin generally refers to lightening, brightening, whitening, and / or evenening skin tone, skin color, and / or skin tone, and / or reducing yellowing, and / or lightening and / or fading hyperpigmented marks and / or lesions, including, but not limited to, pigmented spots, melanin spots, age spots, solar spots, age spots, senile lentigines, freckles, lentigines simplex, pigmented solar keratosis, seborrheic keratosis, melasma, acne scars, post-inflammatory hyperpigmentation, lentigines, freckles, combinations of two or more thereof, and the like. "Lightening" or "whitening" the skin also refers to increasing the radiance, complexion, translucency, and / or luminescence of the skin, and / or obtaining a more radiant, radiant, translucent, or luminous skin tone appearance, or a less yellow or yellowish skin tone. In certain preferred embodiments, "lightening" or "whitening" the skin refers to lightening and evening the skin tone, increasing the radiance of the skin, and / or lightening age spots. In certain other preferred embodiments, the present invention is directed to compositions and methods for use on skin in need of skin lightening or whitening treatment selected from yellow and / or dark skin. In certain other preferred embodiments, the present invention is directed to compositions and methods for use on skin in need of skin lightening or whitening treatment selected from the group consisting of age spots, freckles, acne scars, and combinations of two or more thereof.

[0016] As used herein, "treatment" or "treating" refers to the improvement, prevention, or amelioration of a condition, disease, or disorder, or at least one discernible symptom thereof. In one embodiment, "treatment" or "treating" refers to the improvement, prevention, or amelioration of at least one measurable physical parameter associated with the condition, disease, or disorder being treated, which is not necessarily discernible in or by the subject being treated. In another embodiment, "treatment" or "treating" refers to inhibiting or slowing the progression of a condition, disease, or disorder, either physically (e.g., stabilization of a discernible symptom), physiologically (e.g., stabilization of a physical parameter), or both. In another embodiment, "treatment" or "treating" refers to delaying the onset of a condition, disease, or disorder.

[0017] In certain embodiments, the compositions of the invention are administered as a prophylactic measure. As used herein, "prevention" or "preventing" refers to reducing the risk of acquiring a given condition, disease, or disorder.

[0018] More broadly, the compositions of the present invention may also be used to treat or prevent cosmetic, dermatological, or other conditions and disorders, including, but not limited to, infections, disorders, or disorders of the skin or mucocutaneous tissues associated with the skin, nails, and hair; oral, vaginal, and anal mucosa; keratinization disorders; inflammation; changes associated with intrinsic and extrinsic aging, and others that may or may not be associated with the dermatological system. Findings may include: oily skin; acne; rosacea; age spots; blemished skin; age spots; cellulite; dermatomas; dermatitis; skin, nail, and hair infections; dandruff; dry or sagging skin, nails, and hair; xerosis; inflammation or eczema; elastosis; herpes; sebum excess; hyperpigmented skin; ichthyosis; keratosis; lentigines; melasma; patchy skin; pseudofolliculitis barbae; photoaging and photodamage; pruritus; psoriasis; skin lines; stretch marks; thinning of the skin, nail plates, and hair; warts; wrinkles; oral or gum disease; irritated, inflamed, red, unhealthy, damaged, or abnormal mucous membranes, skin, hair, nails, nostrils, ear canals, anus, or vagina. These symptoms include, but are not limited to, a condition of the skin; breakdown, deficient synthesis, or repair of skin components; abnormal or decreased synthesis of collagen, glycosaminoglycans, proteoglycans, and elastin, and reduced levels of such components in the dermis; uneven skin tone; uneven, rough surface of the skin, nails, and hair; loss or reduced resilience, elasticity, and recovery of the skin, nails, and hair; laxity; lack of luster and shine in the skin, nails, and hair; brittle and splitting nails and hair; yellowing skin; reactive, irritable, or telangiectatic skin; and dull, older looking skin, nails, and hair. In addition, the compositions of the present invention can be used for general care of the skin, nails, and hair; to improve skin texture and pores, flaking, and redness; to make the skin soft, smooth, fresh, balanced, visually clear, even-toned, and brighter; to increase the fullness and plumpness of the skin; and to whiten, lighten the skin and for wound healing; to reduce or prevent sweating or perspiration in the armpits, groin, palms, or other parts of the body.

[0019] As used herein, the term "subject" refers to any animal, preferably a mammal, most preferably a human, to which the composition of the present invention is or has been administered. As used herein, the term "mammal" encompasses any mammal. Examples of mammals include, but are not limited to, cows, horses, sheep, pigs, cats, dogs, mice, rats, rabbits, guinea pigs, monkeys, and humans. In a preferred embodiment, the subject is a human.

[0020] As used herein, "wrinkles" includes fine, fine, or coarse wrinkles. Examples of wrinkles include, but are not limited to, fine lines around the eyes (e.g., "crow's feet"), wrinkles on the forehead and cheeks, lines between the eyebrows, and age lines around the mouth.

[0021] As used herein, "loss of elasticity" includes loss of elasticity or structural integrity of skin or tissue, including, but not limited to, sagging, loose, and slack tissue. Loss of elasticity or structural integrity of tissue can be the result of a number of factors, including, but not limited to, disease, aging, hormonal changes, mechanical trauma, environmental damage, or the result of application of products such as cosmetics or pharmaceuticals to the tissue.

[0022] As used herein, "uneven skin" means a skin condition associated with diffuse or patchy pigmentation that can be classified as hyperpigmentation, such as post-inflammatory hyperpigmentation.

[0023] As used herein, "age spots" refers to a skin condition associated with redness or erythema.

[0024] As used herein, "cosmetic," particularly as it relates to the appearance of tissue or skin, refers to beautifying, or maintaining, restoring, imparting, embellishing, or enhancing a physically pleasing appearance, or the appearance of increased beauty or youthfulness.

[0025] As used herein, a "cosmetically effective amount" refers to an amount sufficient to treat or prevent one or more signs of skin aging, but low enough to avoid serious side effects. The cosmetically effective amount of a compound or composition varies depending on the particular condition being treated, the age and health of the end user, the severity of the condition being treated / prevented, the duration of the treatment, the nature of other treatments, the particular compound or product / composition being used, the particular cosmetically acceptable carrier being utilized, and similar factors.

[0026] As used herein, "substantially free" means that the referenced ingredient is not added directly or intentionally to the formulation. Preferably, "substantially free" means that the ingredient contains less than about 1%. More preferably, "substantially free" means that the ingredient contains less than about 0.5%. Even more preferably, "substantially free" means that the ingredient contains less than about 0.1% by weight. The composition may be completely free of an ingredient, i.e., may not contain any ingredient at all.

[0027] Unless otherwise indicated, percentages or concentrations refer to weight percentages or concentrations (i.e., %(W / W)). The weight percent of a component is based on the total weight of the composition containing the component. Unless otherwise stated, all ranges are inclusive of the endpoints, for example, "4 to 9" includes the endpoints 4 and 9.

[0028] Ascorbic acid The composition includes ascorbic acid, also known as vitamin C. Ascorbic acid has the following structure:

[0029] [ka]

[0030] The composition may contain about 5 to about 22% by weight of ascorbic acid based on the total weight of the composition. The composition may contain about 8 to about 12% by weight of ascorbic acid based on the total weight of the composition. The composition may contain about 13 to about 17% by weight of ascorbic acid based on the total weight of the composition. The composition may contain about 18 to about 22% by weight of ascorbic acid based on the total weight of the composition. The composition may contain about 10% by weight of ascorbic acid based on the total weight of the composition. The composition may contain about 15% by weight of ascorbic acid based on the total weight of the composition. The composition may contain about 20% by weight of ascorbic acid based on the total weight of the composition.

[0031] The compositions may contain unexpectedly high levels of Vitamin C that remain stable over time. As is known in the art, compositions containing Vitamin C are preferably prepared with excess amounts of ingredients to allow for some degradation during the shelf life of the product.

[0032] Caffeine The composition also contains caffeine, the amount of which may range from about 1 to about 5% by weight, based on the total weight of the composition.

[0033] Preferably, the composition contains more than 1% caffeine by weight of the total composition, more preferably, the composition contains about 2% caffeine by weight of the total composition.

[0034] Inorganic salts The composition also contains an inorganic salt selected from the group consisting of sodium sulfite, potassium sulfite, sodium bisulfite, and sodium metabisulfite. Preferably, the inorganic salt is sodium bisulfite or sodium metabisulfite or a combination of the two. More preferably, the inorganic salt is sodium bisulfite.

[0035] The amount of inorganic salt in the composition is at least about 0.2% by weight, based on the total weight of the composition.

[0036] Preferably, the composition contains about 0.5% by weight of the inorganic salt, based on the total weight of the composition.

[0037] Preferably, the composition contains about 0.5% by weight of sodium bisulfite, based on the total weight of the composition.

[0038] Aqueous Vehicle The composition is a single-phase aqueous solution. The composition comprises at least about 28% by weight of water based on the total weight of the composition. For example, the composition may comprise at least about 33% by weight of water based on the total weight of the composition. The composition may comprise at least about 38% by weight of water based on the total weight of the composition.

[0039] The composition may also contain 1,3-propanediol.The amount of 1,3-propanediol in the composition is preferably at least about 35% by weight of the composition.More preferably, the amount of 1,3-propanediol in the composition is at least 40% by weight of the composition.For example, the composition may contain about 45% by weight of 1,3-propanediol based on the total weight of the composition.

[0040] The composition may also contain ethylenediaminetetraacetic acid (EDTA). The amount of EDTA in the composition is preferably 0.1% by weight of water based on the total weight of the composition. For example, the composition may contain about 0.2% by weight of EDTA based on the total weight of the composition.

[0041] Other cosmetically acceptable active agents The composition may contain one or more other cosmetically acceptable active agents.

[0042] Cosmetically acceptable active agents include, for example, other anti-aging agents, other antioxidants, anti-acne agents, sheen adjusting agents, antibacterial agents, anti-inflammatory agents, antifungal agents, anti-parasitic agents, topical analgesics, sunscreens, photoprotectants, keratolytic agents, surfactants, moisturizers, nutrients, other vitamins, energy boosters, antiperspirants, astringents, deodorants, firming agents, anti-skin hardening agents, and hair and / or skin conditioning agents.

[0043] The amount of other cosmetically acceptable actives in the composition may range 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, based on the total weight of the composition.

[0044] Cosmetically acceptable active agents include, for example, alpha and polyhydroxy acids such as glycolic acid, lactic acid, malic acid, salicylic acid, citric acid, tartaric acid, and gluconolactone, benzoyl peroxide, D-panthenol carotenoids, retinoids such as retinol and retinyl palmitate, ceramides, polyunsaturated fatty acids, essential fatty acids, enzymes such as laccase, enzyme inhibitors, minerals, hormones such as estrogens, steroids such as hydrocortisone, 2-dimethylaminoethanol, copper salts such as copper chloride, peptides such as dipeptides, tripeptides, argirline, and synake, including N-acyl dipeptide derivatives, copper-containing, amino acids such as coenzyme Q10, proline, other vitamins, lactobionic acid, acetyl-coenzyme A, niacin, riboflavin, thiamine, ribose, electron transporters such as NADH and FADH2, Moringa Oleifera seed, Aloe vera, Feverfew (e.g., Chrysanthemum Parthenium (feverfew flower / leaf / stem juice), oatmeal, natural extracts such as those from dill, blackberry, paulownia, lemon aspen, resorcinols such as 4-hexylresorcinol, curcuminoids, sugar amines such as N-acetylglucosamine, glycosaminoglycans such as hyaluronic acid and hyaluronic acid chondroitin sulfate, and derivatives and mixtures thereof.

[0045] Examples of other vitamins include, but are not limited to, vitamin A, B vitamins (e.g., vitamin B3, vitamin B5, and vitamin B12), vitamin K, and different forms of vitamin E, such as alpha, beta, gamma, or delta tocopherol, or mixtures and derivatives thereof.

[0046] Other examples of antioxidants include, but are not limited to, water-soluble antioxidants such as sulfhydryl compounds and their derivatives (e.g., N-acyl-cysteine), lipoic acid and dihydrolipoic acid, resveratrol, lactoferrin, and ascorbic acid derivatives (e.g., ethyl L-ascorbate, ascorbyl palmitate, and ascorbyl polypeptides), and epigallocatechin gallate (EGCG). 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., tocopherol 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 isoflavonoids and their derivatives (e.g., genistein and daidzein), extracts containing resveratrol, and the like. Examples of such natural extracts include grape seed, pine bark, and propolis.

[0047] Preferably, the composition comprises another cosmetically acceptable active ingredient selected from hyaluronic acid, feverfew, Moringa Oleifera seed extract, EGCG, N-acetylglucosamine, gluconolactone, niacinamide, and ethyl L-ascorbate.

[0048] A preferred composition comprises ascorbic acid, caffeine, sodium bisulfite, and hyaluronic acid, and such a composition may contain from about 8 to about 12% by weight, for example about 10% by weight ascorbic acid, about 2% by weight caffeine, and about 0.05% by weight hyaluronic acid, all based on the total weight of the composition.

[0049] Topical Compositions The compositions of the present invention are applied topically to the skin or hair, preferably to the skin. They are single-phase aqueous compositions.

[0050] The compositions can be made into a wide variety of liquid product types, including, but not limited to, solutions, lotions, creams, gels, sprays, ointments, and cleansers. The compositions are preferably in the form of a serum, which is a liquid that is light, spreads easily on the skin, and is absorbed by the skin.

[0051] The composition may contain one or more emollients as known in the art. As used herein, "emollient" refers to a material used to prevent or alleviate dryness, such as by preventing transepidermal water loss from the skin. Examples of emollients include, but are not limited to, those listed in International Cosmetic Ingredient Dictionary and Handbook, eds. Pepe, Wenninger and McEwen, pp. 2930-36 (The Cosmetic, Toiletry, and Fragrance Assoc., Washington, DC, 9th Edition, 2002) (hereinafter "ICI Handbook"). Examples of particularly suitable emollients include vegetable oils, mineral oils, fatty esters, and the like.

[0052] The composition may also be formulated as a gel (e.g., alcoholic, alcohol / aqueous, or oily gel using a suitable gelling agent). Suitable gelling agents for aqueous and / or alcoholic gels include, but are not limited to, natural gums, acrylic acid and acrylate polymers and copolymers, and cellulose derivatives (e.g., hydroxymethylcellulose and hydroxypropylcellulose). Suitable gelling agents for oils (such as mineral oil) include, but are not limited to, hydrogenated butylene / ethylene / styrene copolymers and hydrogenated ethylene / propylene / styrene copolymers. Such gels typically contain about 0.1% to 5% by weight of such gelling agents.

[0053] In addition to the above ingredients, the compositions may contain a wide variety of additional oil-soluble and / or water-soluble materials, in concentrations established in the art, conventionally used in compositions for use on the skin and hair, including humectants, pH adjusters, fragrances, dyes, and preservatives (e.g., parabens).

[0054] The composition may also include one or more oils. As used herein, the term "oil" refers to hydrophobic materials such as hydrocarbon-based oils, silicones, fatty acid derivatives, glycerides, vegetable oils, vegetable oil derivatives, alkyl esters, wax esters, beeswax derivatives, sterols, and phospholipids.

[0055] Suitable hydrocarbon oils include petrolatum, mineral oil, microcrystalline wax, squalene, and combinations thereof.

[0056] Silicone oils include dimethicones, dimethiconols, phenyl dimethicones, and cyclic polysiloxanes, and combinations thereof. Silicone oils having a viscosity of from about 0.5 to about 100,000 centistokes at 25° C. may also be useful in the composition.

[0057] Glycerides include castor oil, sunflower seed oil, coconut oil and derivatives, vegetable oils and derivatives, palm oil, jojoba oil, shea butter, lanolin, and combinations thereof.

[0058] Alkyl ester oils include, but are not limited to, isopropyl esters of fatty acids and esters of long chain fatty acids. More preferably, the following alkyl esters are useful: isopropyl palmitate, isopropyl myristate, myristyl myristate, isohexyl palmitate, decyl oleate, isononyl isononanoate, and combinations thereof.

[0059] Preferably, the composition contains caprylyl glycol.More preferably, the composition contains at least about 0.25% by weight of caprylyl glycol based on the total weight of the composition.For example, the composition can contain at least about 0.5% by weight of caprylyl glycol based on the total weight of the composition.

[0060] Optionally, the composition may be substantially free of phenoxyethanol.

[0061] pH In one embodiment, the topical composition has a pH of about 3.5 to about 4. The composition may include a pH adjuster, such as sodium hydroxide.

[0062] The topical composition may include a buffering agent, such as lactic acid, citric acid, malic acid, tartaric acid, gluconic acid, or gluconolactone, to maintain the pH. Typically, the composition contains from about 2 to about 12, or from about 4 to about 8 weight percent of the buffering agent.

[0063] Preparation method The composition of the present invention can be prepared using methods well known in the art.However, the composition is preferably made by mixing the components in a specific order to optimize their solubility in the composition.In particular, the composition according to the present invention is preferably made by first adding caffeine to the water / inorganic acid mixture to completely dissolve caffeine, followed by other components (if desired) and ascorbic acid.Mixing is preferably carried out at high temperature.

[0064] Skin Treatment Methods In accordance with the present invention, skin in need of treatment for skin lightening or whitening may be treated by topically applying a composition comprising about 5% to about 22% by weight of ascorbic acid, based on the total weight of the composition, about 1% to about 5% by weight of caffeine, based on the total weight of the composition, at least 0.2% by weight, based on the total weight of the composition, of an inorganic salt selected from the group consisting of sodium sulfite, potassium sulfite, sodium bisulfite, and sodium metabisulfite, and at least 28% by weight of water, based on the total weight of the composition, wherein the composition is a single aqueous phase.

[0065] Also according to the present invention, skin in need of treatment for skin lightening or whitening may be treated by topically applying a composition comprising about 10% by weight of ascorbic acid based on the total weight of the composition, about 2% by weight of caffeine based on the total weight of the composition, about 0.5% by weight of sodium bisulfite based on the total weight of the composition, at least 38% by weight of water based on the total weight of the composition, about 40% by weight of 1,3-propanediol based on the total weight of the composition, and about 0.2% by weight of ethylenediaminetetraacetic acid based on the total weight of the composition, wherein the composition is a single aqueous phase.

[0066] Further according to the present invention, skin in need of treatment for skin lightening or whitening may be treated by topically applying a composition comprising about 15% by weight of ascorbic acid based on the total weight of the composition, about 2% by weight of caffeine based on the total weight of the composition, about 0.5% by weight of sodium bisulfite based on the total weight of the composition, at least 33% by weight of water based on the total weight of the composition, about 45% by weight of 1,3-propanediol based on the total weight of the composition, and about 0.2% by weight of ethylenediaminetetraacetic acid based on the total weight of the composition.

[0067] Further according to the present invention, skin in need of treatment for skin lightening or whitening may be treated by topically applying a composition comprising about 20% by weight of ascorbic acid based on the total weight of the composition, about 2% by weight of caffeine based on the total weight of the composition, about 0.5% by weight of sodium bisulfite based on the total weight of the composition, at least 28% by weight of water based on the total weight of the composition, about 45% by weight of 1,3-propanediol based on the total weight of the composition, and about 0.2% by weight of ethylenediaminetetraacetic acid based on the total weight of the composition.

[0068] Compositions according to the present invention comprising ascorbic acid, caffeine, inorganic salts, and water also advantageously and surprisingly provide excellent ascorbic acid solubility and stability.

[0069] The invention is further illustrated by the following non-limiting examples. EXAMPLES

[0070] A series of compositions were made using the ingredients in Table 1.

[0071] [Table 1]

[0072] The compositions were made as follows: The ingredients, if used, were added in the following order: 1. Add water to main beaker. Begin mixing and heat to 50°C. 2. Add hydrolyzed hyaluronic acid and mix until dissolved. 3. Add disodium EDTA and mix until dissolved. 4. Add sodium bisulfite and mix until dissolved. 5. Add caffeine and mix until dissolved. 6. Add capryl glycol and mix until dissolved. 7. Add the propanediol and mix until uniform. 8. Add ascorbic acid and mix until dissolved. 9. Begin cooling the batch to 25°C. 10. Add sodium hydroxide (20% NaOH solution) to adjust the final pH to 3.5-4.0. EXAMPLES

[0073] Combinations of ascorbic acid with various other known antioxidants were tested for their combined antioxidant effect using the oxygen radical absorbance capacity (ORAC) assay according to the method described by Ou B, Hampsch Woodill M, Prior RL Development and validation of an improved oxygen radical absorbance capacity assay using fluorescein as the fluorescent probe. J Agric Food Chem. 2001, 49:4619 (using a slightly different ex / em wavelength readout and a narrower range Trolox standard). This assay measures the ability of antioxidant "chain breakers" to inhibit the decrease in disodium fluorescein (FL) fluorescence induced by the peroxyl radical generator, 2',2'-azobis(2-amidinopropane) dihydrochloride (AAPH). Distilled water was used as a negative control. Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid, a water-soluble analogue of vitamin E sold by Hoffman-LaRoche with antioxidant properties) was used as a positive control.

[0074] Final ORAC values ​​were calculated from the regression equation of the net area under the FL decay curve using the formula: Area Under the Curve (AUC) = 1 + (Point 1 + Point 2 + Point 3 + ... + Point 15) / Point 1. Trolox standards were then plotted as micromoles versus AUC. Samples were analyzed using their AUC to obtain values ​​of micromoles (μmol) Trolox equivalent (TE) per ml. An Applied BioSystems Cytofluor 4000 fluorometer and software was used for quantification. ORAC values ​​of test materials were expressed as μmoles TE / ml (TE = Trolox equivalent).

[0075] All components were stored at room temperature and then diluted with distilled water to aqueous stock solutions for testing. Further dilutions were made with distilled water within 24 hours of testing.

[0076] The results are shown in Tables 2 and 3, which report two separate test runs.

[0077] [Table 2]

[0078] [Table 3]

[0079] The combination of ascorbic acid and 2% caffeine was one of only four combinations that provided a synergistic ORAC value. The expected (additive) ORAC value for the combination of ascorbic acid and 2% caffeine was 761 TE / ml. However, this combination surprisingly provided an ORAC value of 1111 TE / ml. This combination increased the antioxidant activity of vitamin C by 48%. EXAMPLES

[0080] The stability of ascorbic acid in a composition according to the invention (Composition 7) containing water, ascorbic acid, caffeine, sodium bisulfite, and EDTA was compared to the stability of ascorbic acid in a comparative composition (Composition 8) containing water and ascorbic acid but no caffeine, sodium bisulfite, or EDTA. The components of Compositions 7 and 8 are shown in Table 4. As prepared, both compositions contained 12% by weight ascorbic acid.

[0081] [Table 4]

[0082] The stability of ascorbic acid in the composition was determined using high pressure liquid chromatography (HPLC) to detect the content of ascorbic acid over time. The sample was dispersed and dissolved in the mobile phase, mixed, filtered, and then injected into a HYPERSILODS C18, 250 x 4.6 mm column and detected at 210 nm. The test times and conditions were as follows: Room temperature (1 month, 2 months, and 3 months), 40°C (1 month, 2 months, and 3 months), and 50°C (1 week and 2 weeks).

[0083] The results are shown in Table 5, which shows the weight percent of ascorbic acid remaining in the two compositions over time.

[0084] [Table 5]

[0085] Composition 7 according to the present invention maintained good ascorbic acid stability at all time points and conditions. In contrast, the amount of ascorbic acid in comparative composition 8 at 40°C was reduced relative to the amount in composition 7. In particular, the amount of ascorbic acid in comparative composition 8 after 2 and 3 months at 40°C was significantly lower than the amount of ascorbic acid in composition 7 at the same time points.

[0086] [Embodiment] (1) A topical composition comprising about 5% to about 22% by weight of ascorbic acid, based on the total weight of the composition; about 1% to about 5% by weight of caffeine, based on the total weight of the composition; at least 0.2% by weight, based on the total weight of the composition, of an inorganic salt selected from the group consisting of sodium sulfite, potassium sulfite, sodium bisulfite, and sodium metabisulfite; and at least 28% by weight, based on the total weight of the composition, of water, wherein the composition is a single aqueous phase. (2) The composition of embodiment 1, further comprising at least 35% by weight of 1,3-propanediol, based on the total weight of the composition. (3) The composition of embodiment 1, further comprising at least 0.1% by weight of ethylenediaminetetraacetic acid, based on the total weight of the composition. (4) The composition of claim 1, wherein the inorganic salt is sodium bisulfite. (5) The composition described in embodiment 1, further comprising hyaluronic acid.

[0087] (6) A topical composition comprising about 10% by weight of ascorbic acid based on the total weight of the composition, about 2% by weight of caffeine based on the total weight of the composition, about 0.5% by weight of sodium bisulfite based on the total weight of the composition, at least 38% by weight of water based on the total weight of the composition, about 40% by weight of 1,3-propanediol based on the total weight of the composition, and about 0.2% by weight of ethylenediaminetetraacetic acid based on the total weight of the composition, wherein the composition is a single aqueous phase. (7) A topical composition comprising about 15% by weight of ascorbic acid based on the total weight of the composition, about 2% by weight of caffeine based on the total weight of the composition, about 0.5% by weight of sodium bisulfite based on the total weight of the composition, at least 33% by weight of water based on the total weight of the composition, about 45% by weight of 1,3-propanediol based on the total weight of the composition, and about 0.2% by weight of ethylenediaminetetraacetic acid based on the total weight of the composition. (8) A topical composition comprising about 20% by weight of ascorbic acid based on the total weight of the composition, about 2% by weight of caffeine based on the total weight of the composition, about 0.5% by weight of sodium bisulfite based on the total weight of the composition, at least 28% by weight of water based on the total weight of the composition, about 45% by weight of 1,3-propanediol based on the total weight of the composition, and about 0.2% by weight of ethylenediaminetetraacetic acid based on the total weight of the composition. (9) A cosmetic method for treating the skin, comprising topically applying the topical composition of embodiment 1 to skin in need of treatment to lighten or whiten the skin.

Claims

1. 1. A topical composition comprising: about 5% to about 22% by weight of ascorbic acid, based on the total weight of the composition; about 1% to about 5% by weight of caffeine, based on the total weight of the composition; at least 0.2% by weight, based on the total weight of the composition, of an inorganic salt selected from the group consisting of sodium sulfite, potassium sulfite, sodium bisulfite, and sodium metabisulfite; and at least 28% by weight, based on the total weight of the composition, of water, wherein the composition is a single aqueous phase.

2. The composition of claim 1 further comprising at least 35% by weight of 1,3-propanediol, based on the total weight of the composition.

3. 10. The composition of claim 1, further comprising at least 0.1 wt. % ethylenediaminetetraacetic acid, based on the total weight of the composition.

4. The composition of claim 1 , wherein the inorganic salt is sodium bisulfite.

5. The composition of claim 1 further comprising hyaluronic acid.

6. 1. A topical composition comprising about 10% by weight of ascorbic acid based on the total weight of the composition, about 2% by weight of caffeine based on the total weight of the composition, about 0.5% by weight of sodium bisulfite based on the total weight of the composition, at least 38% by weight of water based on the total weight of the composition, about 40% by weight of 1,3-propanediol based on the total weight of the composition, and about 0.2% by weight of ethylenediaminetetraacetic acid based on the total weight of the composition, wherein the composition is a single aqueous phase.

7. 1. A topical composition comprising about 15% by weight of ascorbic acid based on the total weight of the composition, about 2% by weight of caffeine based on the total weight of the composition, about 0.5% by weight of sodium bisulfite based on the total weight of the composition, at least 33% by weight of water based on the total weight of the composition, about 45% by weight of 1,3-propanediol based on the total weight of the composition, and about 0.2% by weight of ethylenediaminetetraacetic acid based on the total weight of the composition.

8. 1. A topical composition comprising about 20% by weight of ascorbic acid based on the total weight of the composition, about 2% by weight of caffeine based on the total weight of the composition, about 0.5% by weight of sodium bisulfite based on the total weight of the composition, at least 28% by weight of water based on the total weight of the composition, about 45% by weight of 1,3-propanediol based on the total weight of the composition, and about 0.2% by weight of ethylenediaminetetraacetic acid based on the total weight of the composition.

9. 13. A cosmetic method for treating skin comprising topically applying the topical composition of claim 1 to skin in need of treatment to lighten or whiten the skin.

Images