MXPA01001094A - Sunscreen compositions - Google Patents

Abstract

The present invention relates to compositions suitable for use as sunscreens which provide excellent stability, efficiency, and UV protection efficacy in a safe, economical and aesthetically appealing manner (on-skin transparency, low skin irritation). Methods of use for these compositions are also disclosed. The compositions comprise:a) a safe and effective amount of a UVA-absorbing dibenzoylmethane sunscreen active;b) a safe and effective amount of a stabilizing agent having formula (I) wherein R1 and R1'are independently in the para or meta position and are independently a hydrogen atom or a straight- or branched chain C1-C8 alkyl radical, R2 is a straight- or branched-chain C1-C12 alkyl radical;and R3 is a hydrogen atom or a -CN radical;c) a safe and effective amount of a UVB sunscreen selected from the group consisting of organic sunscreen actives, inorganic physical sunblocks, and mixtures thereof, wherein the inorganic physical sunblock is present in a total amount of less than or equal to about 5%;and d) a carrier suitable for application to the skin wherein the mole ratio of the stabilizing agent to the UVA-absorbing dibenzoylmethane sunscreen active is less than 0.8 and wherein the composition is substantially free of benzylidene camphor derivatives.

Description

SOLAR FILTER COMPOSITIONS TECHNICAL FIELD The present invention relates to compositions suitable for use as sunscreens which exhibit excellent efficiency, broad spectrum UV efficacy, photostability and transparency on the skin. The compositions comprise a sunscreen active absorbing dibenzoylmethane UVA, a stabilizing agent, an active against UVB sunscreen, and a carrier suitable for application to the skin, and contain substantially no benzylidenecamphor derivatives.

BACKGROUND OF THE INVENTION It is known that exposure to sunlight can involve a series of risks to the skin. These damaging effects can result not only from taking sunbaths, but also from exposure to sunlight associated with daily outdoor activities. The main short-term risk of prolonged exposure to sunlight is erythema, that is, sunburn, which in the first instance is the result of UVB radiation having a wavelength of about 290 nm close to 320 nm. However, in the long term, malignant changes occur on the surface of the skin. Numerous epidemiological studies show a -l, -. i ---. ^ ¿¿^: - »- a? --- i - ^ á- ... ^^. ^: f --_, -. ^ ^ J ^ .AA UBS ÍMMtf'í lrtt - ^ * -. ^ R *, * fc aifc "ü ^ a ^ m strong relationship between sunlight exposure and skin cancer in humans Another risk long-term ultraviolet radiation is premature aging of the skin, which is primarily caused by UVA radiation having a wavelength of about 320 nm to about 5,400 nm. This condition is characterized by wrinkling and changes in pigmentation of the skin, along with other physical changes such as cracking, telangiectasis, ecchymoses, and loss of elasticity. side effects associated with exposure to UV radiation are discussed in greater detail in DeSimone, "Sunscreen and Suntan Products ", Handbook of Nonprescription Drugs, 7th Ed., Chapter 26, pages 499-511 (American Pharmaceutical Association, Washington D.C., 1982); Grove and Forbes, "A Method for Evaluating the Photoprotection Action of Sunscreen Agents Against UV-A Radiation," International Journal of Cosmetic Science, 4, pages 15-24 (1982); and patent of E.U.A. No. 4,387,089, by DePolo, Issued June 7, 1983. As a result of the aforementioned risks associated with exposure to sunlight, the general public interest in the market for sun protection products has greatly increased. Currently, there are not only products with sun filters to take sunbaths, there is also a variety of personal care products containing sunscreens, particularly cosmetic products of daily use. The term "personal care products" refers to ancillary products for health and beauty generally recognized as being formulated to beautify and - * ~ --- ^ --- - ^^^^^ »'^^ * ^ -» - ^ - - > * ^ "¡R ??? Ji ÉililiÉifctiiíiiíiiiMilWtiii fix the skin and hair. For example, personal care products include sunscreen products (eg lotions, skin creams, etc), cosmetics, toiletries , and pharmaceutical products that do not require a prescription created for topical use.5 It is not surprising that consumers want such products with sunscreen, particularly daily products, that are effective, and that have a pleasant appearance to the eye and to the touch As well as economic, unfortunately, most commercially available sunscreen products are not strong in one or more of these areas.10 For example, most commercial sunscreens use high levels of sunscreen assets to achieve desired levels of UV protection These high levels of sunscreen assets not only increase the cost of the product, also tend to contribute to diminish the aesthetic quality (for example, an inadequate sensation in the skin, leave a white layer on the skin, etc.) and irritate the skin. Some conventional sunscreen products are also deficient due to their low capacity to provide effective protection against broad spectrum UV radiation, ie protection against UVB and UVA radiation. Currently, most commercially available sunscreen products 20 are efficient in absorbing UV radiation in the 290 nm to 320 nm region, so as to avoid skin burns caused by sun exposure. They have a lower efficiency when they must absorb light that is in the region of 320 nm to 400 nm, which '* - ^ * fc * »- ^ * fca ^ ^ ^. ^^« JIMfe. -h¿ * '"a,?" fc' leaves the skin vulnerable to premature aging of the skin. This deficieis due in part to the limited number of sunscreen assets that absorb commercially available UVA and are approved for global use. A wide variety of sunscreen assets have been used in personal care products. It is desirable that the active or active solar filter system provide broad spectrum UV protection, particularly protection against UVA and UVB radiation. In addition, the asset must have been approved for human use, preferably on a global basis. It is also desirable that these sunscreen actives have an easy formulation to provide stable, effective sunscreen products that are pleasing to the senses. Dibenzoylmethane compounds are a class of sunscreen compounds that provide protection against broad spectrum UV radiation and are approved for global use. Unfortunately, these sunscreens tend to photodegrade when exposed to UV radiation, thus reducing their effectiveness against UVA radiation. An approach to stabilize these types of sunscreens is described in the U.S.A. with serial number 07 / 929,612 by Deckner, filed on August 13, 1992, involving the use of benzylidenecamphor sunscreens to stabilize the dibenzoylmethane compound. However, such compositions are not currently approved for global use. % ^ 3 ^% ¡«^^ ^ g? Another class of sunscreen assets known as sunscreens has also been used to provide skin protection against broad spectrum UV radiation. Physical sunscreens are inorganic compounds that apparently exert their effects by scattering, reflecting or absorbing UV radiation. See Sayre, R.M. and others, "Physical Sunscreens" J. Soc. Cosmet, volume 41, no. 2, pages 103-109 (1990). Unfortunately, when used at effective levels, such sunscreen actives tend to leave an undesirable white film on the consumer's skin and / or agglomerate in the finished product. Therefore, there is a need to create efficient, stable solar filter products (including photostable), which provide broad spectrum UV protection (ie, against UVA and UVB radiation) in a safe, economical and pleasant manner (transpareover the skin and low skin irritation). Surprisingly, it has been discovered that the compositions of the present invention, which comprise a UVB absorbent dibenzoylmethane sunscreen active, a defined stabilizing agent, a UVB sunscreen active, and a vehicle, and that substantially do not have derivatives of benzylidene camphor, provide excellent stability (especially photostability), efficieand effectiveness of UV protection (including UVA and UVB protection), safely, economically and pleasantly (particularly transpareon the skin and undue skin irritation). ^ y ». . -.- j & ^ 8MMa »BRIEF DESCRIPTION OF THE INVENTION The present invention relates to a composition suitable for use as a sunscreen comprising: a) a safe and effective amount of a dibenzoylmethane sunscreen active absorbing UVA; b) a safe and effective amount of a stabilizing agent that has the formula wherein Ri and Ry are independently at the para or meta-position independently are a hydrogen atom or a branched or straight-chain CrC8 alkyl radical, R2 is a straight-chain C-? branched and R3 is a hydrogen atom or a -CN radical; and c) a safe and effective amount of a sunscreen asset against UVB selected from the group consisting of sunscreen assets, physical, inorganic sun blockers, and mixtures thereof, wherein any inorganic physical sunscreen is present in a total amount of less than or equal to about 5%; and d) a vehicle suitable for application to the skin; wherein the molar ratio of the stabilizing agent to the UVA absorbing sunscreen active is less than 0.8 and the composition has substantially no benzylidenecamphor derivatives. In the preferred embodiments, the molar ratio of the stabilizing agent to the UVA-absorbing dibenzoylmethane sunscreen active is less than 0.75, most preferably 0.70, and much more preferably less than about 0.65. The present invention also relates to methods for providing protection to human skin from the damaging effects of UV radiation by topical application of said compositions.

DETAILED DESCRIPTION OF THE INVENTION The compositions of the present invention are useful for providing protection to human skin against the damaging effects of ultraviolet radiation. The essential components of these compositions are described below. Also included is a non-exclusive description of various optional and preferred components useful in embodiments of the present invention. The present invention may comprise, consist of, or consist essentially of any required or optional ingredients and / or the limitations described herein. All percentages and ratios are calculated on a weight basis, unless otherwise indicated. All percentages ^ g | ^ || i | ^ g ^ ¡^ ^ ¡^ ^ gjtei are calculated based on the total composition, unless otherwise specified. All molar weights are in weight average molecular weight and are given in units of grams per mole. 5 All ingredient levels are given in reference to the active level of that ingredient, and are exclusive of solvents, by-products or other impurities that may be found in commercially available sources, unless otherwise specified. All the elaborated measurements are made at temperature environment, which is approximately 22.7 ° C, unless otherwise indicated. All documents referenced, including patents, patent applications and printed publications are hereby incorporated by reference in their entirety in this description. By "safe and effective amount" is meant an amount of a compound or component composition (as applicable) sufficient to significantly induce a positive effect (e.g., photoprotection or stability), but low enough to avoid serious side effects ( for example, undue toxicity or allergic reaction), is say provide a reasonable benefit to the risk relationship, within the field of the doctor's judgment.

UVA absorbing dibenzoylmethane sunscreen active The compositions of the present invention comprise a UVA absorbing dibenzoylmethane sunscreen active which absorbs ultraviolet radiation having a wavelength of about 320 nm to about 400 nm. Examples of such dibenzoylmethane sunscreen actives are described in U.S. Patent No. 4,489,057, issued to Welters et al. On December 18, 1984, and U.S. Patent No. 4,387,089 issued to Depolo on June 7, 1983; and in Sunscreens: Development, Evaluation, and Regulatory Aspects, edited by N.J. Lowe and N.A. Shaath, Marcel Dekker, Inc. (1990). Suitable dibenzoylmethane sunscreen actives include, but are not limited to those selected from the group consisting of 2-methyldibenzoylmethane, 4-methyldibenzoylmethane, 4-isopropyldibenzoyl methane, 4-tert-butyldibenzoylmethane, 2,4-dimethylbenzoylmethane, 2,5 -dimetil dibenzoylmethane, 4,4'-diisopropylbenzoalmethane, 4- (1,1-dimethylethyl) -4'methoxy dibenzoylmethane, 2-methyl-5-isopropyl-4'-methoxydibenzoylmethane, 2-methyl-5-ter- butyl-4'-methoxy-dibenzoylmethane, 2,4-dimethyl-4'-methoxydibenzoyl methane, 2,6-dimethyl-4'-tert-butyl-4'-methoxydibenzoylmethane, and mixtures thereof. Preferred dibenzoylmethane sunscreen assets include those selected from the group consisting of 4- (1,1-dimethylethyl) -4'methoxy dibenzoylmethane, isopropyldibenzoylmethane, and mixtures thereof. A preferred dibenzoylmethane sunscreen active by preference is 4- (1,1-dimethylethyl) -4'-methoxydibenzoylmethane.

^^^^ «^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^ The Sunscreen Active 4- (1,1-dimethyl) -4'methoxydibenzoylmethane, which are also known as butylmethoxydibenzoylmethane or Avobenzone, is commercially available under the names Parsol® 1789 from Givaudan- Roure (International) SA (Basel, Switzerland) and Eusolex® 9020 from Merck & Co., 5 Inc. (Whitehouse Station, NJ). The sunscreen 4-isopropyldibenzoylmethane, which is also known as isopropyldibenzoylmethane, is commercially available from Merck under the tradename Eusolex® 8020. The dibenzoilmentane absorbent sunscreen active of UVA, in the present invention, is present in a safe and stable amount. 10 effective to provide broad spectrum UV protection, either independently or in combination with other UV protective assets that may be present in the composition. Preferably, the composition contains from about 0.1% to about 10%, most preferably from about 0.2% to about 7%, and very much preferably from about 0.4% to about 15 of 5%. The exact amounts of the sunscreen asset will vary depending on the sun protection factor, that is, the "SPF" of the composition, as well as the desired level of UVA protection. (SPF is a commonly used measure of photoprotection of a sunscreen against erythema.) SPF is defined as the ultraviolet energy ratio required to produce minimal erythema 20 on the protected skin, to that required to produce the same minimal erythema on the skin. without protection of the same individual, see Federal Register, 43, number 166, pages 38206-38269, August 25, 1978).

The present compositions also comprise a stabilizing agent having the formula ## STR4 ## wherein the present invention also comprises a stabilizing agent having the formula wherein Ri and R are independently in the para or meta position and independently are a hydrogen atom or a straight or branched chain C-? -C8 alkyl radical, R2 is a straight or branched chain CC? 2 alkyl radical.; R3 is a hydrogen atom or a CN radical, wherein the molar ratio of the stabilizing agent to the UVA-absorbing dibenzoylmethane sunscreen active is less than 0.8, preferably less than about 0.75, most preferably less than about 0.7, and much very preferably less than about 0.65. Suitable stabilizing agents are commercially available from Haarman & Reimer, S.A. (Mexico) and are described in the patents of E.U.A. Nos. 3,215,724 and 5,587,150. The preferred stabilizing agents are selected from the group consisting of 2-ethylhexyl-2-cyano, 3,3-diphenylacrylate (known as octocrylene), ethyl-2-cyano-3,3-diphenylacrylate, 2-ethylhexyl- 3,3-D-phenylacrylate, ethyl-3,3-bis (4-methoxyphenyl) acrylate, and mixtures thereof. The most preferred one is 2-ethylhexyl-2-cyano-3,3, -diphenyl-acrylate. ^^ a * «^?« «> . - ... - ^, .. ^ - M | || rg ||| ^ The stabilizing agent of the present invention is present in a safe and effective amount to reduce the photodegradation of the dibenzoylmethane compound. Photodegradation can be determined by a reduction in UV absorbance capacity, which can be measured using standard UV absorbance methods. Preferred compositions maintain at least about 85%, most preferably at least about 90%, of their initial UV absorbance after irradiation with about 2J / cm2 per desired SPF unit of broadband UV radiation , for example 30 J / cm2 for an SPF composition 15. The stabilizing agent is preferably used in an amount of from about 0.1% to about 6%, most preferably from about 0.3% to about 3%, and very much preferably from about 1.5% to about 2.25% UVB sunscreen active The compositions of the present invention further comprise an active UVB sunscreen which absorbs UVB radiation having a wavelength of about 290 mm about 320 mm. As used herein, active UVB sunscreen means an active agent other than the active sunscreen of dibenzoylmethane which in itself may contain UVB absorption properties. The compositions comprise a quantity of the UVB sunscreen active which is safe and effective to provide UVB protection, either independently or in combination with other UVB active ingredients. ^ .. ^ dlhM - UVB protection that may be present in the composition, preferably from about 0.1% to about 10%, most preferably from about 0.1% to about 4%, and very much preferably about 0.5% to about 2.5% by weight of the composition. 5 A wide variety of UVB sunscreen assets, including organic sunscreen assets and physical inorganic sunscreens, are suitable for use herein. Non-limiting examples of such sunscreen actives are described in U.S. Patent No. 5,087,445, issued February 11, 1992 to Haffey et al .; and the patents of E.U.A. Nos. 5,073,371 and 5,073,372, both issued December 17, 1991 to Turner and other non-limiting examples of suitable physical sunblocks are described in CTFA International Cosmetic Ingredient Dictorionary, sixth edition, 1995, pages 1026-28 and 1103. The assets of UVB sunscreen are selected from the group that consists of 2-phenyl-benzimidazole-5-sulfonic acid, TEA salicylate, octyldimethyl PABA, zinc oxide, titanium dioxide, and mixtures thereof. An organic sunscreen active which is preferred is 2-phenyl-benzimidazole-5-sulfonic acid while the preferred physical inorganic sunblocks are zinc oxide, titanium dioxide and mixtures thereof. Salt and forms Acid neutralized acid sunscreens are also useful herein. When used, physical sunscreens are present in an amount such that the present compositions are transparent on the skin (ie, they do not leave a white layer) preferably less than or equal to about 5%. When titanium dioxide is used, it may have an anatase, rutile or amorphous structure. The physical sunscreen particles, for example titanium dioxide and zinc dioxide, may be uncovered or covered with a variety of materials including, but not limited to, amino acids; aluminum compounds such as alumina, aluminum stearate, aluminum laurate and the like; carboxylic acids and their salts, for example, stearic acid and its salts, phospholipids, such as lecithin; silicone compounds; inorganic silicone compounds, such as silica and silicates; and mixtures thereof. A titanium dioxide which is preferred is commercially available from Tayca (Japan), and is distributed by Tri-K Industries (Emerson, NJ) under the micronized MT series (for example MT 100SAS). Vehicle 15 The compositions of the present invention comprise a vehicle suitable for application to human skin. As used in the present "vehicle suitable for application to human skin", it means that the vehicle and its components are suitable for use in contact with human skin without presenting toxicity, incompatibility, instability, allergic response and the like within the field of the judgment of the doctor or the formulator. Those skilled in the art are already familiar with such vehicles and may include one or more compatible liquid or solid filler or diluents that are suitable for application to human skin. He ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The vehicle may comprise one or more active or inactive materials, including, but not limited to, optional components described below. The vehicle comprises the rest of the composition. The compositions of the present invention preferably comprise from about 74% to about 5 99.7%, most preferably from about 79% to about 99%, by weight vehicle of the composition. The vehicle can be formulated in various ways, including without being limited to emulsions (in the technology of the emulsion, a composition comprising a "dispersed phase" and a "continuous phase"; disperses existing as small particles or droplets that are suspended and surrounded by a continuous phase). For example, suitable emulsions include oil in water, water in oil, water in oil in water, oil in water in oil and oil in water in silicone. Preferred compositions comprise an oil in water emulsion. The compositions of the present invention may be formulated in a wide variety of product types, including creams, lotions, milks, foams, gels, oils, tonics and aerosols. The preferred compositions are formulated in lotions, creams, gels and aerosols. These product forms can be used for various applications, including, but not limited to, hand and body lotions, moisturizing creams, facial moisturizers, anti-acne preparations, topical analgesics, makeups, including make-up bases and lipsticks, and the like. Any additional components required for formulating such products vary with the type of product and the person skilled in the art can choose them routinely. If the compositions of the present invention are formulated as an aerosol and applied to the skin as a product for spraying on the skin, a propellant is added to the composition. Examples of suitable propellants include chlorofluorinated low molecular weight hydrocarbons. A more complete description of the propellants useful in the present invention can be found in Sagarin, Cosmetics Science and Technoloqoy. second edition, volume 2, pages 443-465 (1972).

Optional components The compositions of the present invention may contain a variety of other ingredients as conventionally used in a given type of product as long as it does not unacceptably modify the benefits of the invention. These optional components must be suitable for application to human skin, ie, when incorporated into the composition, they are suitable for use in contact with human skin without causing undue toxicity, incompatibility, instability, allergic response, and the like, within the field. of the judgment of the doctor or formulator. The CTFA Cosmetic Ingredient Handbook, Second Edition (1992) describes a wide variety of non-limiting cosmetic and pharmaceutical ingredients commonly used in the skin care industry, which are suitable for use in LtatÜÉHait: - rlnp - TTÍIGTB - - ^ P ^^ BMÉ ^ * «» * > ^ * ^ ** - ^ '- *** compositions of the present invention. Some examples of these kinds of ingredients are: abrasive components, absorbers and appearance enhancers such as fragrances, pigments, colorations / dyes, essential oils, skin sensitizers, astringents, etc. (for example clove oil, menthol, camphor, eucalyptus oil, eugenol, methyl lactate, Hamamelis Virginiana distillate), anti-acne agents (for example resorcinol, sulfur, salicylic acid, erythromycin, zinc, etc.), to prevent the formation of cakes, antifoaming agents, additional antimicrobial agents (eg iodopropylbutylcarbamate), antioxidants, binders, biological additives, pH regulating agents, bulking agents, chelating agents, chemical additives, dyes, cosmetic astringents, cosmetic biocides, denaturing agents, therapeutic astringents, external analgesics, formers or film materials, for example, polymers, to assist the film formation properties and substantivity of the composition (for example with eicosene and vinylpyrrolidone polymer), humectants, opacifiers, pH regulators, propellants, reducing agents, sequestrants, bleaching agents of the p iel (or agents of luminosity) (for example, hydroquinone, kojic acid, ascorbic acid, magnesium ascorbyl phosphate, ascorbylglucosamine), skin conditioning agents (humectants, including heterogeneous and occlusive), skin relaxing and / or healing agents ( for example, panthenol and its derivatives) (for example ethylpantenol), aloe vera, pantothenic acid and its derivatives, allantoin, bisabolol, and dipotassium glycyrrhizinate), agents for treatment of the skin, including agents to prevent, slow, stop and / or reverse the wrinkle formation process in the skin (alpha hydroxy acids, such as lactic acid and glycolic acid and betahydroxy acids such as salicylic acid), thickeners, and vitamins and their derivatives (tocopherol, tocopherol acetate, beta-5 carotene, retinoic acid, retinol, retinoids, retinylpalmitate, niacin, niacinamide, and the like). The compositions of the present invention may contain one or more of said optional components. Preferred compositions optionally contain one or more materials selected from the active anti-acne, artificial tanning agents, moisturizers, moisturizers, skin conditioners, and thickening / structuring agents. a) Anti-acne active The compositions of the present invention may comprise one or more anti-acne active. Some examples of useful anti-acne actives are described in detail in the US patent. No. 5,607,980 issued to McAtee et al. On March 4, 1997. b) Artificial Tanning Agents The compositions of the present invention may optionally comprise one or more artificial tanning agents. Suitable tanning agents include dihydroxyacetone, tyrosine and tyrosine esters. See The Merck Index, tenth edition, entry 3167, p. 463 (1983), and "Dihidroxiacetone for Cosmetics", E. Merck Technical Bulletin, 03-304 110, 319 897, 180 588. c) Structuring agent The compositions of the present invention may contain a structuring agent. Structurants are particularly preferred in the oil-in-water emulsions of the present invention. Without being limited by theory, it is believed that the structuring agent helps to provide the rheological characteristics to the composition that contribute to the stability of the composition. For example, the structuring agent tends to aid in the formation of the liquid crystal gel network structures. The structuring agent can also function as an emulsifying agent or surfactant. Preferred compositions of this invention comprise from about 0.5% to about 20%, most preferably from about 1% to about 10%, most preferably from about 1% to about 5% of one or more structuring agents. The preferred structuring agents of the present invention are selected from the group consisting of stearic acid, palmitic acid, stearyl alcohol, cetyl alcohol, behenyl alcohol, stearic acid, palmitic acid, the polyethylene glycol ether of stearyl alcohol having an average of about 1 to about 21. ethylene oxide units, the polyethylene glycol ether of the cetyl alcohol having an average of about 1 to about 5 ethylene oxide units and mixtures thereof. Preferred structuring agents of the present invention are selected from the group consisting of stearyl alcohol, cetyl alcohol, behenyl alcohol, the polyethylene glycol ether of stearyl alcohol having a percentage of about 2 units of ethylene oxide (steareth-2), having the ether polyethylene glycol of stearyl alcohol an average of about 21 ethylene oxide units (steareth-21), the polyethylene glycol ether of cetyl alcohol having an average of about 2 ethylene oxide units and mixtures thereof. Still more preferred structuring agents are selected from the group consisting of stearic acid, palmitic acid, stearyl alcohol, cetyl alcohol, behenyl alcohol, steareth-2, steareth-21, and mixtures thereof. d) Thickening agent (including thickening agents and queuers) The compositions of the present invention may comprise one or more thickening agents, preferably from about 0.1% to about 5%, most preferably from about 0.1% to about 3% and most preferably from approximately 0.25% a about 2% by weight of the composition. The non-limiting classes of thickening agents include those selected from the group consisting of: ^^^^^^^^^^^^^ gg ^^^^^^^^ g ^ ^ (i) Carboxylic acid polymers These polymers are intertwined compounds that contain one or more monomers derived from acrylic acid, substituted acrylic acids, and salts and esters of these acrylic acids and substituted acrylic acids, in which the crosslinking agent contains two or more carbon-carbon double bonds and is derived from a polyhydric alcohol. The polymers useful in the present invention are described in more detail in the U.S.A. No. 5,087,445 to Haffey et al., Granted on February 11, 1992, patent of E.U.A. No. 4,509,949, to Huang et al., Issued April 5, 1985; patent of E.U.A. No. 2,798,053, to Brown granted on July 2, 1957; and C7F > 4 International Cosmetic Ingredient Dictionary, fourth edition 1991, p. 12 and 80. Some examples of commercially available carboxylic acid polymers useful herein include carbomers, which are homopolymers of acrylic acid crosslinked with allyl ethers of sucrose or pentaerythritol. The carbomers are available as the Carbopol® 900 series from B.F. Goodrich (eg Carbopol® 954). In addition, other polymeric carboxylic acid agents include copolymers of C 10-30 alkyl acrylates with one or more acrylic acid monomers, methacrylic acid or one of their short chain esters (ie C 1-4 alcohol), in which the agent Interlacer is an allyl ether of sucrose or pentaerythritol. These copolymers are known as acrylates / polymers of three dimensions of C? -3o alkyl acrylate and are commercially available such as Carbopol® 1342, Carbopol® 1382, Pemulen TR-1, and Pemulen TR-2, from B.F. Goodrich. In other words, some examples of carboxylic acid polymers thickeners useful herein are those selected from the group consisting of carbomers, acrylates / cross-linked polymers of C 10 -C 30 alkyl acrylate, and mixtures thereof. (ii) Interlaced polyacrylate polymers The compositions of the present invention may optionally comprise entangled polyacrylate polymers useful as thickeners or gelling agents including cationic and non-ionic polymers, being The cationics are generally preferred. Some examples of interlaced nonionic polyacrylate polymers and interlaced cationic polyacrylate polymers are described in the U.S.A. No. 5,100,660 to Hawe et al., Granted on March 31, 1992; patent of E.U.A. No. 4,849,484, to Heard, granted on July 18, 1989; patent of E.U.A. No. 4,835,206 to Farrar et al., Granted May 30, 1989, U.S. Patent No. 4,628,078 to Glover and others granted December 9, 1986, U.S. Patent. No. 4,599,379 to Flesher et al., Granted on July 8, 1989; and EP 228,868, to Farrar et al. published July 15, 1987. (iii) Polyacrylamide polymers. The compositions of the present invention may optionally comprise polyacrylamide polymers, especially nonionic polyacrylamide polymers including branched or non-branched polymers. ... ^ -j ^^, -. ^. ^ ^^^ A ^ * fc ^^^ a ^^. ^ -., ^., ^ ,. It is highly preferred among these polyacrylamide polymers to be the non-ionic polymer which is given the CTFA designation polyacrylamide and is the most preferred among these polyacrylamide polymers. Souzaracine and Laureth-7, available under the tradename Sepigel 305 from Seppic Corporation (Fairfield, NJ) Other polyacrylamide polymers useful herein include multiple block copolymers of acrylamides and substituted acrylamides with acrylic acids and substituted acrylic acids. Commercially available examples of these multi-block copolymers include Hypan SR150H, SS500V, SS500W, SSSA100H, from Lipo Chemicals, Inc., (Patterson, NJ). (iv) polysaccharides. A wide variety of polysaccharides are useful herein. "Polysaccharides" refers to gelling agents that contain a base structure of repeating sugar units (ie, carbohydrate). Some non-limiting examples of polysaccharide gelling agents include those selected from the group consisting of cellulose, carboxymethylhydroxyethylcellulose, cellulose acetate propionate carboxylate, hydroxyethylcellulose, hydroxyethylethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, methylhydroxyethylcellulose, microcrystalline cellulose, sodium cellulose sulfate and mixtures thereof. Alkylsubstituted celluloses are also useful herein. In these polymers, the hydroxy groups of the cellulose polymers are hydroxyalkylated (preferably hydroxyethylated or hydroxypropylated) to form a hydroxyalkylated cellulose which is then modified with a straight or branched chain C-10-C30 alkyl group by means of an ether linkage. Typically these polymers are ethers of straight or branched C10-C30 chain alcohols with hydroxyalkyl celluloses. Some examples of 5 alkyl groups useful herein include those selected from the group consisting of stearyl, isostearyl, lauryl, myristyl, cetyl, isocetyl, cocoyl (i.e., alkyl groups derived from coconut oil alcohols), palmityl, oleyl, linoleyl , linolenyl, resinoleyl, behenyl and their mixtures. Preferred among the alkylhydroxyalkylcellulose ethers is the material to which the CTFA designation cetylhydroxyethylcellulose, which is the ether of cetyl alcohol and hydroxyethylcellulose. This material is sold under the trade name Natrosol ® CS Plus from Aqualon Corporation (Wilmington, DE). Other useful polysaccharides include scleroglucans comprising a linear chain of linked glucose units (1-3) with a glucose linked (1-6) every three units, of which a commercially available example is Clearogel ™ CS11 from Michel Mercier Products Inc. (Mountainside, NJ). (v) Gums 20 Other gelling agents and thickeners useful herein include materials that are derived primarily from natural sources. Some non-limiting examples of these gelling agent gums include materials selected from the group consisting of acacia, agar, algin, acid ? ^^^^^ * ^^^^^^ «» ^^^^^ »^^^^^^^^^^ gd ^^^^^^^ gfetó alginic, alginate ammonium, almylopectin, calcium alginate, calcium carrageenan, carnitine, carrageenan, dextrin, gelatin, gelan gum, guar gum, guar hydroxypropyltrimonium chloride, hectorite, hyalurinic acid, hydrated silica, hydroxypropylchitosan, hydroxypropylguar, karaya gum, 5 locust bean gum , Kelp, natto gum, potassium alginate, potassium carrageenan, propylene glycol alginate, sclerotium gum, sodium carboxymethyl dextran, sodium carrageenan, tragacanth gum, xanthan gum, and mixtures thereof. Preferred compositions of the present invention include a thickening agent selected from the group consisting of carboxylic acid polymers, crosslinked polyacrylate polymers, polyacrylamide polymers and mixtures thereof, most preferably selected from the group consisting of carboxylic acid polymers, polyacrylamide polymers and its mixtures e) Moisturizers, moisturizers and skin conditioners. Preferred compositions optionally comprise one or more humectants, moisturizers or skin conditioners. A variety of these materials may be employed and each may be present at a level of from about 0.01% to about 20%, most preferably from about 0.1% to about 10%, and most preferably from about 0.5% to about 7%. These materials include, but are not limited to, guanidine; glycolic acid and glycolate salts (eg, ammonium and quaternary alkylammonium); lactic acid and lactate salts (eg, ammonium and quaternary alkylammonium); aloe vera in any of its varied ^ a? a ^^ ^^^^ m ^ i?. Am ...,. ... add * forms (eg, aloe vera gel); polyhydroxyalcohols such as sorbitol, glycerol, hexanetriol, propylene glycol, butylene glycol, hexylene glycol and the like; polyethylene glycols; sugars and starches; sugar and starch derivatives (eg, alkoxylated glucose); hyaluronic acid; lactate monoethanolamine; and its 5 mixtures. Also useful herein are the propoxylated glycerols described in the U.S.A. No. 4,976,853, to Orr et al., Issued December 11, 1990. Various monoesters and CrC30 polyesters of sugars and related materials are also useful. These esters are derived from a portion of sugar or polyol and one or more portions of carboxylic acid. These ester materials are described in the U.S.A. No. 2,831, 854; U.S. Patent No. 4,005,195, to Jandacek, issued January 25, 1977, in the patent of E.U.A. No. 5,306,516 to Letton et al., Granted on April 26, 1994; the patent of E.U.A. No. 5,306,515, to Letton et al., Granted the April 26, 1994; the patent of E.U.A. No. 5,305,514 to Letton et al., Granted on April 26, 1994; the patent of E.U.A. No. 4,797,300 to Jandacek et al., Granted on January 10, 1989; U.S. Patent No. 3,963,699, to Rizzi et al., issued June 15, 1976; the patent of E.U.A. No. 4,518,772, to Volpenhein, issued May 21, 1985; the patent of E.U.A. 4,517,360 to Volpenhein, granted on May 21, 1985. f) Emulsifying agents The compositions of the present invention may contain one or more emulsifying agents, for example, to reduce the inter-phase tension between the phases and to improve the formulation and stability of an emulsion. Suitable emulsifying agents include a wide variety of nonionic, cationic, anionic, and zwitterionic emulsifying agents. See McCutcheon, Detergents and Emulsifiers, edition for the United States (1986), published by Allured Publishing Corporation; patent of E.U.A. No. 5,011, 681 granted to Ciotti et al. On April 30, 10 1991; patent of E.U.A. No. 4,421, 769 granted to Dixon et al. On December 20, 1983; and patent of E.U.A. No. 3,755,560 issued to Dickert et al. On August 28, 1973. Suitable types of emulsifying agents include, but are not limited to glycerin esters, propylene glycol esters, polyethylene glycol fatty acid esters, polypropylene glycol fatty acid esters, esters of sorbitol, esters of sorbitan anhydrides, with carboxylic acid polymers, glucose esters and ethers, ethoxylated ethers, ethoxylated alcohols, alkyl phosphates, polyoxyethylene fatty ether phosphates, fatty acid amides, acylactylates, soaps and mixtures thereof. Suitable emulsifying agents include, but are not limited to, TEA stearate, olet-3 phosphate DEA, sorbitan polyethylene glycol 20 monolaturate (polysorbate 20), soy polyethylene glycol 5 sterol, steareth-2, steareth-20, steareth -21, ceteareth-20, PPG-2 distearate - * - - ^^^ - mtTIfli ^ rf n MMrrtftM ii i i gJÍITÍÍMMÍ [íift ?? nr llüf ff IGG TIG * < ^ J * ^ < * S * - ether methylglucose, ceteth-10, polysorbate 80, cetyl phosphate, potassium cetyl phosphate, diethanolamine cetylphosphate, polysorbate 60, glyceryl stearate, PEG-100 stearate, and mixtures thereof. Preferred emulsifying agents are steareth-2, steareth-21, stearate TEA, diethanolamine cetylphosphate, potassium cetyl phosphate, and mixtures thereof. The emulsifying agent may be used individually or as a mixture of two or more and may comprise from about 0.1% to about 10%, most preferably from about 0.15% to about 7%, and most preferably from about 0.25% to about 5% of the compositions of the present invention. Although a variety of optional components can be included in the compositions of the present invention, the compositions substantially do not contain benzylidenecamphor derivatives. As used herein, "substantially does not contain benzylidenecamphor" means that the present compositions comprise less than about 0.1% benzylidene camphor. Preferred compositions contain less than about 0.05% benzylidene camphor. Preferably, the compositions essentially do not have benzylidenecamphor, that is, they do not contain a detectable amount of benzylidenecamphor. 20 Methods to protect the skin from ultraviolet radiation. The compositions of the present invention are suitable for use as a sunscreen to provide protection to human skin against harmful effects of ultraviolet radiation including, but not limited to, sunburn and premature aging of the skin. The present invention therefore also relates to methods for protecting human skin from the damaging effects of UV radiation. Such methods 5 generally involve the attenuation or reduction of the amount of UV radiation reaching the surface of the skin. To protect the skin from UV radiation, a safe and effective (photoprotective) amount of the composition is applied topically to the skin. "Topical application" refers to the application of the present compositions by spreading, spraying, etc. on the surface of the skin. The exact amount applied may vary depending on the level of UV protection desired. Typically they are applied from about 0.5 mg of composition per cm2 of skin to about 25 mg of composition per cm2 of skin.

EXAMPLES The following examples further describe and demonstrate embodiments within the scope of the present invention. The examples are given merely for purposes of illustration and should not be construed as of the present invention, since various variations thereof are possible without departing from the spirit and scope of the invention. The following sunscreen products are representative of the present invention.

A water phase is prepared by mixing Carbomer 954 and C10-C30 alkyl acrylate crosslinkers / polymers in all water in a suitable vessel, with the exception of 4% of the water. Butylene glycol, glycerin, disodium EDTA and methyl paraben are added to the water and heated to 80 ° C. Prepare an oil phase in a separate container by mixing isopropyl palmitate, butyl methoxydibenzoylmethane, octocrylene, propylparaben, DEA cetylphosphate, stearic acid, alcohol cetyl, stearyl alcohol and eiscosine copolymer PVP and heated to 80 ° C. When both phases reach 80 ° C, the oil phase is slowly added to the water phase while the system is milled to form an emulsion. The system is cooled under agitation. Once the system reaches 70 ° C, the premix containing 0.73% triethanolamine and 1% water is added to the batch. When the batch is cooled to approximately 45 ° C, the premix containing the phenylbenzimidazolesulfonic acid, the remaining triethanolamine and the remaining water are added to the batch, cooled to about 30 ° C and poured into suitable containers.

Claims (9)

NOVELTY OF THE INVENTION CLAIMS

1. - A composition suitable for use as a sunscreen characterized in that the composition comprises: a) a safe and effective amount of a dibenzoylmethane sunscreen active absorbing UVA; b) a safe and effective amount of a stabilizing agent that has the formula Wherein Ri and R are independently in the para or meta position and are independently a hydrogen atom or a straight or branched chain d-Cβ alkyl radical, R 2 is an alkyl radical of C? -C-? 2 chain straight or branched, and R3 is a hydrogen atom or a -CN radical; c) a safe and effective amount of a UVB sunscreen that is 2-phenyl-benzimidazole, provided 20 when the composition comprises an amount less than or equal to 5% of an inorganic sunblock; and d) a suitable vehicle for applying to the skin; wherein the molar reaction of the stabilizing agent with the sunscreen active UVA-absorbing dibenzoylmethane is less than 0.8 and wherein the composition substantially does not contain benzylidenecamphor derivatives.

2. The composition according to claim 1, further characterized in that the composition comprises from 0.1% to 10% of the composition of a dibenzoylmethane sunscreen active absorbing UVA.

3. The composition according to any of the preceding claims, further characterized in that the UVA absorbing dibenzoylmethane sunscreen active is selected from the group consisting of 2-methyldibenzoylmethane, 4-methyldibenzoylmethane, 4-isopropyl dibenzoylmethane, 4-ter. -butyldibenzoylmethane, 2,4-dimethyldibenzoylmethane, 2,5-dimethyldibenzoylmethane, 4,4'-diisopropylbenzoylmethane, 4- (1,1-dimethylethyl) -4'methoxydibenzoylmethane, 2-methyl-5-isopropyl-4 ' -methoxydibenzoylmethane, 2-methyl-5-tert-butyl-4'-methoxy-dibenzoylmethane, 2,4-dimethyl-4'-methoxydibenzoylmethane, 2,6-dimethyl-4'-tert-butyl-4, -methoxydibenzoylmethane, and mixtures thereof.

4. The composition according to any of the preceding claims, further characterized in that the composition comprises from 0.1% to 6% by weight of the composition of a stabilizing agent.

5. The composition according to any of the preceding claims, further characterized in that the stabilizing agent is selected from the group consisting of 2-ethylhexyl-2-cyano-3,3- jtíÉ Hj j ^^^ ^ j diphenylacrylate, ethyl-2-cyano-3,3-diphenylacrylate, 2-ethylhexyl-3,3-diphenylacrylate, ethyl-3,3-bis (4-methoxyphenyl) acrylate > and mixtures thereof.

6. The composition according to any of the preceding claims, further characterized in that the molar ratio of the stabilizing agent to the active of the UVA-absorbing dibenzoylmethane sunscreen is less than 0.65.

7. The composition according to any of the preceding claims, further characterized in that the composition comprises from 0.1% to 4% by weight of the composition of 2-phenyl-benzimidazole-5-sulfonic acid.

8. The composition according to claim 1, further characterized in that the composition additionally comprises a UVB sunscreen active which is an inorganic physical sunscreen selected from the group consisting of zinc oxide, titanium dioxide and mixtures thereof. .

9. A composition suitable for use as a sunscreen characterized in that the composition comprises: a) from 2% to 3% by weight of the composition, a dibenzoylmethane sunscreen active absorbing UVA selected from the group consisting of 4- isopropyldibenzoylmethane, 4- (1, 1-dimethylethyl) -4'-methoxy-benzoylmethane, and mixtures thereof; b) from 1.5% to 2.25% by weight of the composition, of a stabilizing agent of a group consisting of 2-ethylhexyl-2-cyano-3,3-diphenylacrylate, ethyl-2-cyano-3,3-diphenylacrylate, 2-ethylhexyl-3,3-diphenylacrylate, ethyl-3,3-bis (4-methoxyphenyl) acrylate, and gség? mixtures thereof; c) from 1.0% to 1.5% by weight of the composition of 2-phenyl-benzimidazole-5-sulfonic acid and d) a vehicle suitable for application to the skin; wherein the molar ratio of the stabilizing agent to the absorbent dibenzoylmethane sunscreen active UVA is less than 0.65. ^ j ^^ jjt ^ aÉaitii ^^ iatíjiB-i? iífc. SUMMARY OF THE INVENTION The present invention relates to compositions suitable for use as sunscreens that provide excellent stability, efficiency and effectiveness of UV protection in a safe, economical and pleasing appearance (transparency on the skin, low skin irritation); methods for using these compositions are also described; the compositions comprise: a) a safe and effective amount of a UVA absorbing dibenzoylmethane sunscreen active; b) a safe amount and 10 effective of a stabilizing agent having the formula (I) wherein Ri and Rr are independently in the para or meta position and are independently a hydrogen atom or a straight or branched chain C-C alkyl radical, R2 is a straight-chain C -? - C-? 2 alkyl radical. or branched; and R3 is a hydrogen atom q a -CN radical; c) an amount 20 safe and effective of a UVB sunscreen selected from the group consisting of organic sunscreen assets, inorganic physical sunblocks and mixtures thereof, wherein the inorganic physical sunscreen is present in a total amount less than or equal to about 5%. %; and d) a ^ Mj -jm - *** - ** ----------- mid suitable vehicle for application on the skin, where the molar ratio of the stabilizing agent to the absorbent dibenzoylmethane sunscreen active of UVA is less than 0.8 and wherein the composition has substantially no benzylidenecamphor derivatives. HL / jtr * sff * kra * jtc * P00 / 1801 F