| PATENT ASSIGNEE'S COUNTRY | USA |
| UPDATE | 03.00 |
| PATENT NUMBER | This data is not available for free |
| PATENT GRANT DATE | 14.03.00 |
| PATENT TITLE |
Gluconolactones and glucarolactones as anti-irritants in cosmetic compositions |
| PATENT ABSTRACT |
Gluconolactone or glucarolactone in cosmetic skin care compositions, as anti-irritants, to reduce skin irritation, which may be intrinsic skin irritation or irritation caused by hydroxy acids or certain retinoids. |
| PATENT INVENTORS | This data is not available for free |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT FILE DATE | 26.02.98 |
| PATENT REFERENCES CITED |
Berardesca, E et al. Alpha hydroxyacids modulate stratum corneum barrier function 1997 British Journal of Dermatology 137:934-938. International Search Report in a corresponding application PC/EP 99/00764. Derwent abstract of FR 2370471. Patent Abstracts of Japan, JP 62 077312, Apr. 9, 1987. Exuviance Sensitive Formula packaging, 1997. Exuviance Essential Multi-Defense Day Creme SPF 15 packaging, 1997. Exuviance Product Information Insert "Advanced Skin Care from the Discoverers of Alpha Hydroxyacid Technology."--4 pages, 1997. |
| PATENT CLAIMS |
What is claimed is: 1. A cosmetic skin care composition comprising: (i) a compound selected from the group consisting of retinol, retinoic acid, retinal, C.sub.2 -C.sub.5 retinyl ester and mixtures thereof; (ii) gluconolactone or glucarolactone in an amount of from about 3% to about 12%; and (iii) cosmetically acceptable vehicle. 2. The composition of claim 1, wherein the composition is an oil-in-water emulsion. 3. The composition of claim 1, wherein the pH of the composition is in the range of from 3 to 5. 4. An oil-in-water cosmetic skin care emulsion composition comprising: (i) a hydroxy acid; (ii) gluconolactone or glucarolactone in an amount of from about 3% to about 12%; and (iii) cosmetically acceptable vehicle. 5. The composition of claim 4, wherein the pH of the composition is in the range of from 3to 5. 6. The composition of claim 4 wherein the hydroxy acid is present in an amount of from about 0.01% to about 20%. 7. The composition of claim 4 wherein the amount of the hydroxy acid is from about 2% to about 12%. -------------------------------------------------------------------------------- |
| PATENT DESCRIPTION |
FIELD OF THE INVENTION Gluconolactone or glucarolactone as an anti-irritant in cosmetic skin care methods and compositions. BACKGROUND OF THE INVENTION Some ingredients used in topical products are potentially irritating, especially to people with "sensitive skin." As an example, hydroxy acids (HAs) and retinoids have been proven to deliver cosmetic benefits, such as improvement in the appearance of photodamaged or naturally aged skin, skin lightening, treatment of age spots, etc. Unfortunately, their use at high concentrations may occasionally be associated with skin irritation, e.g. skin redness and stinging sensation upon application. The irritation can be ameliorated by lowering the amount of an active ingredient in the composition or by reducing the active's penetration through the skin. A serious drawback of both approaches is that the efficacy is impaired. The HA related irritation can be reduced by raising the composition's pH but this method yields reduced efficacy due to a decreased HA penetration through the skin. It is desirable to reduce or eliminate the irritation potential of HAs and/or retinoids while maintaining their efficacy. The occurrence, frequency and nature of irritation often varies from user to user. The severity of irritation to the susceptible user may range from mild to severe. Typical symptoms of irritation include itching (pruritus), stinging, burning, tingling, "tightness," erythema (redness) or edema (swelling). Environmental conditions such as sunlight, wind, cold temperature and dry air, may cause or exacerbate the irritation. Additionally, soaps, detergents, cleansing products, shaving creams, alcohol and other products which remove some of the skin's protective lipids and/or secretions may increase the skin's permeability and sensitivity to topically-applied chemicals which would otherwise not produce irritation. Similarly, the skin may become irritated due to infection, shaving abrasion, repeated or excessive washing or bathing, sun exposure, or other mechanical abrasion or injury. In addition to chemical and environmental causes of skin irritation, many people have an inherent sensitivity or genetic predisposition to skin irritants ("intrinsic skin irritation"). Whatever the exact cause of irritation, many attempts have been made to reduce the irritation potential of topical products by identifying chemicals which tend to cause irritation and reducing their concentration or eliminating them from the products. Unfortunately, it is often not feasible or practical to identify or eliminate all of the irritating chemical(s), particularly when the irritating chemical(s) are the active ingredient of the product or are required for formulation, preservative or other functional reasons. The need exists, therefore, for a composition and method that prevents or reduces the skin irritation. Van Scott et al. teach in numerous patents (e.g., U.S. Pat. No. 5,654,340; U.S. Pat. No. 5,677,340; U.S. Pat. No. 5,385,938 and U.S. Pat. No. 5,091,171) cosmetic compositions containing alpha-hydroxy acids, which may be present as lactones. Gluconolacone and glucarolactone (a.k.a. "saccharic acid lactone") are mentioned. Other lactones, however, which do not reduce irritation (see Example 1 below) are also mentioned. Van Scott et al. do not teach the use of any of the lactones for controlling or alleviating skin irritation A commercially available product line "Exuviance" includes several products with gluconolactone. For instance, Exuviance Fundamental Multiprotective Day Creme SPF 15--Sensitive Formula includes gluconolactone. The Exuviance product information insert describes gluconolactone as a poly hydroxyacid and teaches that poly hydroxyacids are more gentle to the skin than hydroxy acids. One of the Sensitive Formula products is described as a "soothing toning" formula. It is clear from the product information insert that gluconolactone is included in the formula as an anti-aging ingredient, as a less irritating alternative to a hydroxy acid. The product includes traditional soothing ingredients, e.g. aloe vera extract, further indicating that gluconolactone itself is not included as an anti-irritant. The insert does not teach the use of gluconolactone for treating skin that is already irritated. Another Exuviance product, Exuviance Essential Multi-Defense Day Creme SPF 15, includes gluconolactone in combination with glycolic acid. Again, the product does not describe the use of gluconolactone for alleviating or controlling any skin irritation or skin irritation that may be caused by glycolic acid. Indeed, gluconolactone is used in the amount that appears insufficient to alleviate irritation. In the Exuviance products, gluconolactone is included as an less irritating alternative to an anti-aging ingredient, a hydroxy acid. The Exuviance product does not employ gluconolactone as an anti-irritant and the product information insert does not teach that gluconolactone is an anti-irritant. By contrast, the present invention is based at least in part on the discovery that gluconolactone lowers the irritation of an already irritated skin and prevents irritation that may be caused by topical cosmetic product application. Furthermore, prejudice exists against using gluconolactone as an anti-irritant, since gluconolactone is considered in the art as an irritating ingredient, albeit less irritating than a hydroxy acid. See for instance Hahn et al (U.S. Pat. No. 5,716,625) column 2, lines 44-59, which lists gluconolactone as a chemical which "may cause the skin to become more sensitive to irritation triggered by other topically-applied chemicals . . . " It is, therefore, surprising and unexpected that gluconolactone acts as an anti-irritant on an already irritated skin and was able to reduce irritation associated with the use of skin care cosmetic compositions. SUMMARY OF THE INVENTION The present invention includes, in part, a composition containing a cosmetic benefit ingredient selected from the group consisting of hydroxy acids and certain retinoids and further containing gluconolactone or glucarolactone as an anti-irritant. The invention also provides a method for reducing skin irritation sensitivity (whether caused by the topical application of a composition containing HAs or retinoids or the skin that is intrinsically sensitive) the method comprising topically applying gluconolactone or glucarolactone. Thus, according to the inventive method, gluconolactone or glucarolactone may be co-present with HAs and/or retinoids in the same composition, or gluconolactone or glucarolactone may be applied from a separate composition. According to the present invention, by virtue of topical application of gluconolactone or glucarolactone, the skin irritation is reduced or eliminated. It has been found as part of the present invention that not all known anti-irritants ameliorate HAs/retinoid induced irritation. Furthermore, it has been found that not all lactones are capable of being anti-irritants. DETAILED DESCRIPTION OF THE INVENTION Except in the operating and comparative examples, or where otherwise explicitly indicated, all numbers in this description indicating amounts of material or conditions of reaction, physical properties of materials and/or use are to be understood as modified by the word "about." All amounts are by weight of the composition, unless otherwise specified. Gluconolactone or glucarolactone is an essential ingredient of the inventive methods and compositions. The term "gluconolactone" includes the following structures: ##STR1## delta-gluconolactone ##STR2## R=CH2OH glucono-1,5-lactone The term "glucarolactone" includes the following structures: ##STR3## glucaro-3,6-lactone ##STR4## glucaro-1,4-lactone The gluconolactone or glucarolactone is employed in an amount of at least 3%, preferably at least 4%, more preferably from 3% to 12%, most preferably from 4% to 12%, most preferably from 4% to 8%. The inventive methods employ gluconolactone or glucarolactone, alone, or in combination with a potentially irritating ingredient, to reduce either the intrinsic skin irritation or the irritation caused by the ingredient. The inventive compositions include either a hydroxy acid or a certain retinoid (not all retinoids are potentially irritating). Hydroxyacids enhance proliferation and increase ceramide biosynthesis in keratinocytes, increase epidermal thickness, and increase desquamation of normal skin resulting in smoother, younger looking skin. The hydroxy acid can be chosen from alpha-hydroxy acids, beta-hydroxyacids (e.g. salicylic acid), other hydroxycarboxylic acids (e.g., dihydroxycarboxylic acid, hydroxy-dicarboxylic, hydroxytricarboxylic) and mixtures thereof or combination of their stereoisomers (DL, D or L). Preferably the hydroxy acid is chosen from alpha-hydroxy acids having the general structure (1) ##STR5## where M is H or a saturated or an unsaturated, straight or branched hydrocarbon chain containing from 1 to 27 carbon atoms. Even more preferably the hydroxy acid is chosen from lactic acid, 2-hydroxyoctanoic acid, hydroxylauric acid, glycolic acid, and mixtures thereof. When stereo isomers exist, L-isomer is most preferred. It is to be understood that depending on the pH of the composition, the hydroxy acid may be present as a salt, e.g. ammonium or potassium or sodium salt. Although the inventive compositions may have any pH in the general range of 2.5 to 10, the inventive compositions are particularly useful when they are at an acidic pH (especially if they contain a hydroxy acid), preferably 3-5 and most preferably at a pH of 3-4, because such compositions are particularly irritating. Retinoids enhance keratinocyte proliferation in vitro, increase epidermal thickness and increase collagen synthesis by dermal fibroblasts. This results in protection from sun damage and smoothing of wrinkled skin. The term "retinoids" as used herein includes retinoic acid, retinol, retinal and C.sub.2 -C.sub.5 retinyl esters. Included in the term "retinoic acid" are 13-cis retinoic acid and all-trans retinoic acid. The term "retinol" includes the following isomers of retinal: all-trans-retinol, 13-cis-retinol, 11-cis-retinol, 9-cis-retinol, 3,4-didehydro-retinol. Preferred isomers are all-trans-retinol, 13-cis-retinol, 3,4-didehydro-retinol, 9-cis-retinol. Most preferred is all-trans-retinol, due to its wide commercial availability. Retinyl ester is an ester of retinol. The term "retinol" has been defined above. Retinyl esters suitable for use in the present invention are C.sub.2 -C.sub.5 esters of retinol, preferably C2 and C.sub.3 esters, and most preferably C.sub.2 ester because it is more commonly available. Retinyl esters included in the invention are also known as: retinyl acetate, retinyl propionate, retinyl butyrate, and retinyl pentanolate. A particular advantage of the inventive compositions is that higher amounts of hydroxy acids or retinoids may be employed without causing skin irritation. Preferably the amount of the hydroxy acid component present in the composition according to the invention is from 0.01 to 20%, more preferably from 2 to 12% and most preferably from 4 to 12% by weight. A retinoid may be present in the inventive compositions in an amount 33 to 330,000 IU per gram of the composition, preferably 330 to 16,500 IU, most preferably 1,650 to 6,600 IU. Again, a higher amount of a retinoid may be employed in the inventive compositions without causing skin irritation, due to the co-presence of gluconolactone or glucarolactone. Most preferred inventive compositions containing gluconolactone or glucarolactone anti-irritant include retinol and/or glycolic acid and/or lactic acid because these ingredients have been found to cause irritation yet they were found to be particularly efficacious at delivering cosmetic benefits. The compositions and methods according to the invention also comprise a cosmetically acceptable vehicle to act as a diluent, dispersant or carrier for the active ingredients in the composition, so as to facilitate their distribution when the composition is applied to the skin. Vehicles other than water can include liquid or solid emollients, solvents, humectants, thickeners and powders. An especially preferred nonaqueous carrier is a polydimethyl siloxane and/or a polydimethyl phenyl siloxane. Silicones of this invention may be those with viscosities ranging anywhere from about 10 to 10,000,000 centistokes at 25.degree. C. Especially desirable are mixtures of low and high viscosity silicones. These silicones are available from the General Electric Company under trademarks Vicasil, SE and SF and from the Dow Corning Company under the 200 and 550 Series. Amounts of silicone which can be utilized in the compositions of this invention range anywhere from 5 to 95%, preferably from 25 to 90% by weight of the composition. The amount of vehicle may range from about 2 to about 99 wt %, preferably from about 50 to about 99%, most preferably from about 80 to 99%, by weight of the total composition. According to the present invention, the vehicle is preferably at least 60 wt. % water, by weight of the vehicle. The inventive compositions are preferably oil-water emulsions, in order to improve dermal delivery of hydroxy acids (See Sah A., "An in-vitro study of the effect of formulation variables and product structure on the delivery of alpha-hydroxy acid (Lactic acid) to skin", MS Thesis, Department of Pharmaceutical Sciences of the College of Pharmacy, University of Cincinnati, Ohio, July 1996). Such improved delivery is frequently accompanied by increased irritation/sting, making the use of gluconolactone or glucarolactone in such emulsions particularly critical. In the preferred oil-in-water emulsions according to the present invention, water comprises at least 50 wt. % of the inventive emulsion, most preferably from 50 to 70 wt. %, by weight of the composition. Optional Skin Benefit Materials and Cosmetic Adjuncts Various types of active ingredients may be present in cosmetic compositions of the present invention. Actives are defined as skin benefit agents other than emollients and other than ingredients that merely improve the physical characteristics of the composition. Although not limited to this category, general examples include anti-wrinkle compounds and sunscreens and tanning agents. Sunscreens include those materials commonly employed to block ultraviolet light. Illustrative compounds are titanium dioxide, the derivatives of PABA, cinnamate and salicylate. For example, octyl methoxycinnamate and 2-hydroxy-4-methoxy benzophenone (also known as oxybenzone) can be used. Octyl methoxycinnamate and 2-hydroxy-4-methoxy benzophenone are commercially available under the trademarks, Parsol MCX and Benzophenone-3, respectively. The exact amount of sunscreen employed in the emulsions can vary depending upon the degree of protection desired from the sun's UV radiation. Another category of functional ingredients within the cosmetic compositions of the present invention are thickeners. A thickener will usually be present in amounts anywhere from 0.1 to 20% by weight, preferably from about 0.5% to 10% by weight of the composition. Exemplary thickeners are cross-linked polyacrylate materials available under the trademark Carbopol from the B. F. Goodrich Company. Gums may be employed such as xanthan, carrageenan, gelatin, karaya, pectin and locust beans gum. Under certain circumstances the thickening function may be accomplished by a material also serving as a silicone or emollient. For instance, silicone gums in excess of 10 centistokes and esters such as glycerol stearate have dual functionality. Powders may be incorporated into the cosmetic composition of the invention. These powders include chalk talc, Fullers earth, kaolin, starch, smectite clays, chemically modified magnesium aluminum silicate, organically modified montmorillonite clay, hydrated aluminum silicate, fumed silica, aluminum starch octenyl succinate and mixtures thereof. Other adjunct minor components may also be incorporated into the cosmetic compositions. These ingredients may include coloring agents, opacifiers and perfumes. Amounts of these other component materials may range anywhere from 0.001% up to 20% by weight of the composition. Use of the Composition The composition according to the invention is intended primarily as a product for topical application to human skin, especially as an agent for conditioning and smoothening the skin, and preventing or reducing the appearance of wrinkled, aged and/or photodamaged skin. In use, a small quantity of the composition, for example from 1 to 100 ml, is applied to exposed areas of the skin, from a suitable container or applicator and, if necessary, it is then spread over and/or rubbed into the skin using the hand or fingers or a suitable device. According to the present inventive method, the skin irritation, either intrinsic or induced by the active ingredient, is reduced or eliminated by topical application of gluconolactone or glucarolactone. Gluconolactone or glucarolactone may be co-present with the active, or it may be applied to the skin separately from the active. The following specific examples further illustrate the invention, but the invention is not limited thereto. |
| PATENT EXAMPLES | This data is not available for free |
| PATENT PHOTOCOPY | Available on request |
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