Method of selecting antioxidants for use in topically applied compositions

Abstract

Antioxidant-containing compositions and methods for confirming antioxidant activity of a composition formulated for topical application to skin. Methods for testing a composition for ability to inhibit both ultraviolet radiation-induced lipid peroxidation on skin and ultraviolet radiation-induced reactive oxygen species formation in the stratum corneum. Compositions and methods for treating and preventing photodamage to skin.

1 . A method for confirming antioxidant activity of a composition formulated for topical application to skin, wherein the method comprises testing the composition for ability to inhibit both ultraviolet radiation-induced lipid peroxidation on skin and ultraviolet radiation-induced reactive oxygen species formation in the epidermis. 
     
     
         2 . A method for screening compounds for antioxidant behavior in a composition to be topically applied to skin, wherein the screening method comprises determining the compound's ability to inhibit both ultraviolet radiation-induced skin lipid hydroperoxide formation and ultraviolet radiation-induced reactive oxygen species formation in the epidermis. 
     
     
         3 . The method of  claim 2 , wherein determining inhibition of ultraviolet radiation-induced reactive oxygen species formation in the epidermis comprises imaging skin tissue using two-photon fluorescence intensity imaging. 
     
     
         4 . The method of  claim 2 , wherein determining inhibition of UVR-induced skin lipid hydroperoxide formation comprises determining percent lipid hydroperoxide inhibition of the compound in comparison to placebo. 
     
     
         5 . The method of  claim 4 , comprising the steps of applying to distinct areas of skin of a subject an antioxidant containing composition and a placebo composition to produce an antioxidant skin site containing antioxidant and skin lipids and a placebo skin site containing placebo and skin lipids; applying a strip to the antioxidant skin site and the placebo skin site to produce an antioxidant strip sample containing antioxidant and skin lipids and a placebo strip sample containing placebo and skin lipids; removing said strip samples from the skin and exposing said strip samples to UVR to form a UVR-induced antioxidant/lipid reaction product on the antioxidant strip sample and a UVR-induced placebo/lipid reaction product on the placebo strip sample; separately contacting the antioxidant strip sample and the placebo strip sample with solvent to prepare a first extract containing UVR-induced antioxidant/lipid reaction product and a second extract containing UVR-induced placebo/lipid reaction product; assaying said first and second extracts for lipid hydroperoxide content for each extract; and comparing the lipid hydroperoxide content of the first extract to the lipid hydroperoxide content of the second extract. 
     
     
         6 . The method of  claim 5 , comprising the further steps of applying placebo to two distinct sites on the skin of the subject; producing strip samples from each site; subjecting strip samples from only one of the two placebo sites to UVR to produce a subset of irradiated placebo strip samples and a subset of nonirradiated placebo strip samples; separately contacting nonirradiated placebo strip samples with solvent to prepare a third extract containing placebo and skin lipids; and assaying said third extract for lipid hydroperoxide content to determine background lipid hydroperoxide formation. 
     
     
         7 . The method of  claim 6 , wherein comparing the lipid hydroperoxide content of the first extract to the lipid hydroperoxide content of the second extract comprises calculating percent lipid hydroperoxide formation by the following formula: 
       
         
           
             
               
                 % 
                  
                 
                     
                 
                  
                 LF 
               
               = 
               
                 
                   
                     ( 
                     
                       
                         LOOH 
                          
                         
                             
                         
                          
                         1 
                       
                       - 
                       
                         LOOH 
                          
                         
                             
                         
                          
                         3 
                       
                     
                     ) 
                   
                   
                     ( 
                     
                       
                         LOOH 
                          
                         
                             
                         
                          
                         2 
                       
                       - 
                       
                         LOOH 
                          
                         
                             
                         
                          
                         3 
                       
                     
                     ) 
                   
                 
                 × 
                 100 
               
             
           
         
       
       wherein % LF is the percent lipid hydroperoxide formation, LOOH1 is the lipid hydroperoxide content of the first extract, LOOH2 is the lipid hydroperoxide content of the second extract, and LOOH3 is the lipid hydroperoxide content of the third extract. 
     
     
         8 . A composition for topical application, wherein the composition comprises an antioxidant compound or combination of antioxidant compounds, wherein the antioxidant compound or combination of antioxidant compounds substantially inhibit both ultraviolet radiation-induced skin lipid peroxidation and ultraviolet radiation-induced reactive oxygen species formation in the epidermis. 
     
     
         9 . The composition of  claim 8  which further comprises at least one sunscreen active agent. 
     
     
         10 . The composition of  claim 9 , wherein the sunscreen active agent is chosen from the group consisting of para aminobenzoic acid, avobenzone, cinoxate, dioxybenzone, homosalate, menthyl anthranilate, octyl salicylate, oxybenzone, padimate O, phenylbenzimidazole sulfonic acid, sulisobenzone, trolamine salicylate, titanium dioxide, zinc oxide, diethanolamine methoxycinnamate, digalloy trioleate, ethyl dihydroxypropyl PABA, glyceryl aminobenzoate, lawsone with dihydroxyacetone, red petrolatum, ethylhexyl triazone, dioctyl butamido triazone, benzylidene malonate polysiloxane, terephthalylidene dicamphor sulfonic acid, disodium phenyl dibenzimidazole tetrasulfonate, diethylamino hydroxybenzoyl hexyl benzoate, bis diethylamino hydroxybenzoyl benzoate, bis benzoxazoylphenyl ethylhexylimino triazine, drometrizole trisiloxane, methylene bis-benzotriazolyl tetramethylbutylphenol, and bis-ethylhexyloxyphenol methoxyphenyltriazine, 4-methylbenzylidenecamphor, and isopentyl 4-methoxycinnamate and mixtures thereof. 
     
     
         11 . The composition of  claim 8  which comprises as an antioxidant Vitamin E in an amount of about 0.25% by weight. 
     
     
         12 . The composition of  claim 8  which comprises as an antioxidant Vitamin E in an amount of about 0.5% by weight. 
     
     
         13 . The composition of  claim 8  which comprises as an antioxidant Vitamin E and at least one additional antioxidant compound. 
     
     
         14 . The composition of  claim 13 , wherein Vitamin E is present in an amount of at least about 0.25% by weight. 
     
     
         15 . The composition of  claim 13 , wherein Vitamin E is present in an amount of about 0.5% by weight. 
     
     
         16 . The composition of  claim 13 , wherein the at least one additional antioxidant compound is chosen from the group consisting of diethylhexyl syringylidene malonate, Diisopropyl vanillidene malonate, Tetrahydrocurcumenoids, Soybean zymbiozome fermentum, Red clover extract,  Vitis vinifera  (grape) seed extract/Brand B, Green tea extract, Pikea robusta extract, Tocopherol (and)  vitis vinifera  (grape) seed extract,  Vitis vinifera  (grape) seed extract/Brand A, Phylanthus emblica fruit extract and combinations thereof. 
     
     
         17 . A composition for topical application, wherein the composition comprises Vitamin E and at least one pro-oxidant compound, wherein the combination of Vitamin E and the pro-oxidant compound substantially inhibits both ultraviolet radiation-induced skin lipid peroxidation and ultraviolet radiation-induced reactive oxygen species formation in the epidermis. 
     
     
         18 . The composition of  claim 17 , wherein the at least one pro-oxidant compound is chosen from the group consisting of Rosemary officinalis oleoresin,  Rosa gallica  extract, Bioactive Photosynthetic complex from green plants, Thermus Thermophillus ferment, ergothiotaine and combinations thereof. 
     
     
         19 . The composition of  claim 17 , wherein Vitamin E is present in an amount of at least about 0.25% by weight. 
     
     
         20 . The composition of  claim 17 , wherein Vitamin E is present in an amount of about 0.5% by weight. 
     
     
         21 . The composition of  claim 17 , which further comprises diethylhexyl syringylidene malonate. 
     
     
         22 . A topical antioxidant sunscreen formulation comprising about 15% (w/w) homosalate, about 10% (w/w) octocrylene, about 3% avobenzone, about 6% (w/w) oxybenzone, and about 5% (w/w) octisalate, and an antioxidant mixture comprising about 0.9% (w/w) diethylhexyl syringylidene malonate and about 0.5% (w/w) Vitamin E. 
     
     
         23 . A composition for topical application, wherein the composition comprises at least one antioxidant compound that substantially inhibits ultraviolet radiation-induced reactive oxygen species formation in the upper layers of the epidermis and at least one antioxidant compound that substantially inhibits ultraviolet radiation-induced reactive oxygen species formation in the lower layers of the epidermis. 
     
     
         24 . The composition of  claim 23 , which comprises Vitamin E in an amount of about 0.25% by weight. 
     
     
         25 . The composition of  claim 23 , which comprises Vitamin E in an amount of about 0.5% by weight. 
     
     
         26 . The composition of  claim 23 , which comprises diethylhexyl syringylidene malonate. 
     
     
         27 . The composition of  claim 24 , which further comprises diethylhexyl syringylidene malonate. 
     
     
         28 . The composition of  claim 25 , which further comprises diethylhexyl syringylidene malonate. 
     
     
         29 . The composition of  claim 23 , which further comprises at least one sunscreen active agent. 
     
     
         30 . The composition of  claim 29 , wherein the sunscreen active agent is chosen from the group consisting of para aminobenzoic acid, avobenzone, cinoxate, dioxybenzone, homosalate, menthyl anthranilate, octyl salicylate, oxybenzone, padimate O, phenylbenzimidazole sulfonic acid, sulisobenzone, trolamine salicylate, titanium dioxide, zinc oxide, diethanolamine methoxycinnamate, digalloy trioleate, ethyl dihydroxypropyl PABA, glyceryl aminobenzoate, lawsone with dihydroxyacetone, red petrolatum, ethylhexyl triazone, dioctyl butamido triazone, benzylidene malonate polysiloxane, terephthalylidene dicamphor sulfonic acid, disodium phenyl dibenzimidazole tetrasulfonate, diethylamino hydroxybenzoyl hexyl benzoate, bis diethylamino hydroxybenzoyl benzoate, bis benzoxazoylphenyl ethylhexylimino triazine, drometrizole trisiloxane, methylene bis-benzotriazolyl tetramethylbutylphenol, and bis-ethylhexyloxyphenol methoxyphenyltriazine, 4-methylbenzylidenecamphor, and isopentyl 4-methoxycinnamate and mixtures thereof. 
     
     
         31 . A method for treating photodamage of skin of a subject in need thereof, which comprises applying the composition of  claim 8  to the subject's skin that will be or has been exposed to UVR. 
     
     
         32 . A method for preventing photodamage of skin of a subject in need thereof, which comprises applying the composition of  claim 8  to the subject's skin that will be or has been exposed to UVR. 
     
     
         33 . A method for treating photodamage of skin of a subject in need thereof, which comprises applying the composition of  claim 17  to the subject's skin that will be or has been exposed to UVR. 
     
     
         34 . A method for preventing photodamage of skin of a subject in need thereof, which comprises applying the composition of  claim 17  to the subject's skin that will be or has been exposed to UVR. 
     
     
         35 . A method for treating photodamage of skin of a subject in need thereof, which comprises applying the composition of  claim 23  to the subject's skin that will be or has been exposed to UVR. 
     
     
         36 . A method for preventing photodamage of skin of a subject in need thereof, which comprises applying the composition of  claim 23  to the subject's skin that will be or has been exposed to UVR.