Abstract:
Cosmetic compositions for topical use that comprise an exfoliating enzyme for use in removal of at least a portion of the dead skin cells from the outer layer of skin, in conjunction with one or more botanicals, the delivery of which to subsurface layers and cells thereof of the skin is enhanced by the presence of the exfoliating enzyme. These compositions, including gels, lotions, and creams, are gentle, non-irritating and enhance the penetration of biological additives into the subsurface skin layers relative to currently commercially available compositions.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to cosmetic compositions comprising proteolytic enzymes which remove the stratum corneum of the skin, thus enhancing the penetration of other active components, including biological components, into the underlying layers of the skin. 
     2. Description of the Related Art 
     Exfoliants are compounds which remove the dead cell layer (stratum corneum) of the skin, and are used, for example, in the treatment of aging skin (removal of wrinkles), photodamaged skin, acne, dry skin, and other skin conditions. Currently commercially available cosmetic formulations for topical use typically include the following exfoliants: alpha hydroxy acids (AHAs) (e.g. glycolic acid and lactic acid), beta hydroxy acids (BHAs) and retinoids, which may cause adverse reactions including skin irritation, erythema, blistering, particularly in individuals with sun damaged skin, and chronic or unusually high photosensitivity, especially among ethnic groups having darker skin tones. 
     Thus, there is a need for cosmetic preparations comprising exfoliants which are effective and non-irritating, especially in individuals with sun damaged skin. The present invention addresses this need. 
     SUMMARY OF THE INVENTION 
     Performed embodiments of the present invention provide compositions for topical use, including but not limited to lotions, gels and creams, comprising an enzyme in combination with at least one, at least two, at least three or more, biological additive. Said enzyme is preferably papain, derivable from papaya, and is capable of removing the stratum corneum when applied thereto. The biological additives are preferably selected from the group consisting of  Echinacea angustifolia  extract,  mimosa tenuiflora  extract,  hydrocotyl  ( centella asiatica ) extract,  gingko biloba  extract, tea tree oil,  Matricaria chamomila  ( chamomile ) extract,  Hypericum perforatum  extract, and  Aloe barbedensis  extract, catemdiele extract, but may be any biologically-active biologic. The pH of the compositions described herein are preferably greater than about 4.5 or, more preferably, greater than 5.0, and are most preferably about 7.0. 
     Also described is a method for enhancing penetration of at least one, two three, or more biological additive into the skin, comprising applying to said skin a formulation comprising said at least one biological additive and an enzyme capable of removing at least a portion of the stratum corneum. The enzyme is preferably papain, is more preferably papain linked to a high molecular weight polymer, and is preferably papain linked to high molecular weight polyacrylic acid. Also provided is a method for treating an individual having skin exhibiting at least one condition selected from the group consisting of aging skin, photodamaged skin, acne, and dry skin, comprising: diagnosing a individual having said skin, applying to said skin a formulation comprising said at least one biological additive and an enzyme capable of removing at least a portion of the stratum corneum. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Preferred embodiments of the present invention provide effective, non-irritating topical cosmetic formulations comprising an enzyme which promotes removal of at least a portion of the stratum corneum of skin and therefore promotes deeper penetration of other compounds contained within the composition into subsurface skin. Thus, such an enzyme acts as an exfoliant, removing only portions of the dead cell layer of the skin, causing no damage to the underlying living cell layers. Currently available exfoliants, including AHAs, BHAs and retinoids tend to cause adverse topical reactions including but not limited to skin irritation, erythema and blistering. The topical enzymatic compositions disclosed herein have a pH that is more basic than the pH of skin, and preferably have a pH of about 7.0, thus contributing to their non-irritating properties relative to currently commercially available exfoliants. 
     One preferred enzyme is papain, an enzyme obtained from unripe papaya. One particularly preferred form of papain is Linked-Papain™ (papain carbomer, as described in CTFA, the International Cosmetic Ingredients Dictionary) in which papain is covalently immobilized to 1% polyacrylic acid (900,000 daltons), commercially available from Collaborative Laboratories, 3 Technology Drive, East Setauket, N.Y. 11733). In a preferred embodiment, the enzyme is present in the formulation in an amount between about 1% and 6%, more preferably between about 2% and 5%, most preferably about 4% by weight. The ability of papain to act as an exfoliant allows enhancement of penetration of any desired medicinal agent beneficial to the skin, such as, for example, biological additives (e.g, botanicals and herbals) and moisturizers. The activity of papain is greatest at a pH of 6, although the enzyme retains about 75% of its activity between pH 5 and 7. The cosmetic compositions preferably have a pH that is basic relative to the pH of skin (the pH of which typically ranging from approximately 4.5 to approximately 5.0), and preferably have a pH of about 7.0. 
     The papain compositions described herein may be formulated for topical application with pharmaceutically acceptable carriers using methods well known in the cosmetic and pharmaceutical arts, including gels, creams, ointments, emulsions, dispersions, salves, pastes, lotions and the like. These formulations may additionally comprise one or more emulsifiers, humectants (e.g., glycerin or glycerol, sorbitol, and the other known polyols), skin conditioning agents (e.g., propylene glycol, sweet almond oil, apricot kernel oil), surfactants (e.g. ceteth-20), colorants such as staining dyes and pigments (e.g, calcium, barium and aluminum lakes, iron oxides, titanium dioxide and mica), antioxidants (i.e., ascorbic acid, tocopherols, ascorbyl palmitate, thiodipropionic acid), viscosity-enhancing agents (e.g., cetearyl alcohol, polyethylene glycol), vitamins, minerals, emollients, skin conditioning agents, biological additives (e.g. botanicals or herbals), sunscreens (e.g. octyl methoxycinnamate, butyl methoxydibenzolylmethane, oxybenzone), pH adjusters, solvents, germicides (e.g., antibiotics, Tricolsan), preservatives (e.g., BHT, methylparaben, ethylparaben, propylparaben, butylparaben) and fragrances (e.g., strawberry extract,  mangifera indica ). It will be appreciated by those of skill in the art that particular compounds may be properly classified in one, or two or more of the above-listed classifications of compound types. 
     The compositions may also include one or more biological additives, such as botanicals or herbals. As used herein, the term “biological additive” indicates any compound obtained from a natural source, including plants, animals, bacteria and yeast, which has a medicinal or otherwise beneficial effect when topically applied to the skin. Examples of biological additives include oil of  Melaleuca alternifolia , oil of  Lavandula angustifolia, Carica papaya  extract,  Echinacea angustifolia  extract,  Mimosa tenuiflora  extract,  Hydrocotyl  ( centella )  asiatica  extract,  gingko biloba  extract, oil of  Melaleuca alternifolia  (tea tree oil),  Matricaria chamomila  ( chamomile ) extract,  Hypericum perforatum  extract,  Aloe barbedensis  extract, and the like. The biological sources for “biological additive” may also include, but are not limited to the following: Aloe Vera,  Aloe Barbedensis ; Arnica,  Arnica Montana ; Bladderwrack (seaweed),  Fucus Vesciculosis ; Birch,  Betula Alba  ( Pendula ); Chamomile,  Matricaria Chamomila  ( Chamomila Recutita );  Marsh Mallow, Althea Officinalis; Meadow Sweet, Spirea Ulmaria  ( Filipendula ); Mint/Lemon Balm,  Melissa Officinalis ; Mimosa,  Mimosa Tenuiflora; Myrrh Tincture, Commiphor Myrrha ; Neem,  Melia Azadirachta ; Nettle (stinging),  Urtica Dioica ; Papaya,  Carica Papaya ; Propolis (bee glue),  Propolis Cera ; Raspberry,  Rubis Idaeus; Red Poppy, Papaver Rhoeas; Rose Hip  (dog rose),  Rosa Carima ; Rosemary,  Rosemarinus Officinalis ; Sage,  Salvia Officinalis ; St. Johns Wort,  Hypericum Perforatum ; Strawberry,  Fragaria Vesca; Thea Sinensis  (green tea),  Camelia Sinensis ; Walnut,  Juglans Regia ; Witchhazel (dist/extr),  Hamamelis Virginiana ; Yarrow,  Achillea Millefolium ; Wild Yam,  Dioscorea Villosa ; Hawthorn,  Crataegus Monogina/Oxyantha ; Herma (black/rod),  Lawsoma Ehemus ; Hops,  Humulus Lupulus ; Horse Chestnut,  Aesculus Hippocastanum;  Horse Tail,  Equisitum Arvense ; Ivy,  Hedera Helix; Linden/Lime  Tree Blossoms,  Tilia Argentea Cordata ; Madder,  Rubia Tinctorum ; Marigold,  Calendula Officinalis; Centella Asiatica, Centella Asiatica Urban  ( hydrocotyl Asiatica ); Carrot (roots),  Daucus Carota ; Comfrey (Allantoine),  Symphytum Officinale ; Coneflower (Echinacea),  Echinacea Angustifolia ; Cucumber,  Cucumis Sativus  ( Frucus Cucumis ); Fenugreek,  Trigonella Foenum Greacum ; Gingko,  Gingko Biloba ; Ginseng,  Panax Ginseng ; Great Burdock,  Radix Bardanea/Arctium Lappa ; Tea Tree Oil, Oil of  Melaleuca Alternifolia ; Colts Foot,  Tussilago Farfara ; Clover,  Trifolium Pratense ; Speedwell,  Veronica Officinalis.    
     Further biological additives, along with the biological or medicinal properties of the biological additives described herein and of other known biological additives are know to those of skill in the art. References, including encyclopedias and treatises, known to those of skill in the art, that described such biological additives, along with the biological or medicinal properties of the biological additives described herein, include: Guenther—The Essential Oils, Van Nostrand; Int. Cosmetic Ingredient Dictionary, Vol 1 &amp; 2, C.T.F.A. 1995; Int. Cosmetic Ingredient Handbook, C.T.F.A. 1995; British Herbal Pharmacopoeia, British Herbal Medicine Assoc., 1983; Clinical Applications of Ayurvedic &amp; Chinese Herbs, K. Bone, Phytotherapy Press, 1996; A Handbook of Chinese Healing Herbs, D. Reed, Shambala, Boston, 1995; Echinacea—Nature&#39;s Immune Enhancer, S. Foster, Healing Arts Press, Rochester, 1991; Encyclopedia of Herbs, D. Brown, RD Press, 1995; Encyclopedia of Medicinal Plants, A. Chevalier, Dorling Kingers Ley, 1996; L&#39;Angelica—Herbal Extracts; Cosmetochem—Herbasol Extracts. These references are incorporated herein in their entirety. 
     Emulsifiers contemplated for use include but are not limited to monoacyl glycerol, such as glyceryl monoalkanoates, glyceryl monoalkenoates, diacyl 1,2- or 1,3-disubstituted) glycerol, such as glyceryl dialkanoates, glyceryl dialkenoates, polyglyceryl esters, stearic acid, cetyl alcohol, and sorbitan stearate. 
     Other examples of biological additives include, but are not limited to,  Carica papaya  extract,  Echinacea angustifolia  extract, tea tree oil,  Mimosa tenuiflora  extract,  Hydrocotyl  ( centella asiatica ) extract,  gingko biloba  extract,  Matricaria chamomila  (chamomile) extract,  Hypericum perforatum  extract,  Aloe barbedensis  extract, and the like. A particularly preferred biological additive is  tea tree oil . In a preferred embodiment, one or more biological additives is present in the formulation in a combined amount of from about 1% to 10% by weight, more preferably from about 2% to 8% by weight, and most preferably from about 4% to 6% by weight. 
     In a preferred embodiment, one or more skin conditioning agent(s) is present in the formulation in a combined amount of from about 1% to 20% by weight, more preferably from about 5% to 10% by weight, and most preferably from about 6% to 9% by weight. 
     In another preferred embodiment, one or more emollients or humectants is present in the formulation in a combined amount of from about 1% to 10% by weight, more preferably about 2% to 8% by weight. 
     One or more viscosity increasing agents may be present in the formulations in an amount from about 2% to 10% by weight, preferably about 5% by weight. 
     One or more antioxidants may also be present in a combined amount of between about 0.1% and 5% by weight, preferably between about 0.5% and 2% by weight. 
     In another preferred embodiment, one or more emulsifying agents is present in a combined amount of between about 1% and 20% by weight, more preferably between about 5% and 10% by weight. 
     In another preferred embodiment, one or more antioxidants, preservatives and fragrances is present in the compositions in minor amounts, preferably between about 0.05% and 5% by weight, more preferably between about 0.1% and 2% by weight. 
     Preferably, the compositions and formulations are directly applied to the skin once per week, once per day, twice per day or three times per day. Alternatively, the compositions and formulations may be applied directly to the skin less frequently or only on specific occasions, for example after a sunburn when the skin is peeling, to achieve certain of the benefits described herein. The quantity and extent of application will vary with the particular result desired or condition to be treated. Such preferred application will vary from about 1 mg per cm 2  skin per day to 50 mg per cm 2  skin per day, massaged into the skin, as will be appreciated by those of skill in the art, depending on the severity and the condition to be treated. 
    
    
     EXAMPLES 
     The following three examples are illustrative, but not limiting, of topical papain formulations. 
     Example 1 
     A preferred moisturizing formulation contains: 
     Papain-containing moisturizer 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
               
               
                   
                 APPROX. 
                   
               
               
                 COMPOUND 
                 WEIGHT % 
                 TYPE OF COMPOUND  
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 deionized water 
                 70.3 
                 solvent 
               
               
                 stearic acid 
                 3.5 
                 emulsifier 
               
               
                 cetyl and/or myristyl alcohol 
                 3.5 
                 emulsifier 
               
               
                 sweet almond oil 
                 3.5 
                 emollient 
               
               
                 propylene glycol 
                 3.5 
                 humectant, solvent, skin 
               
               
                   
                   
                 conditioning agent 
               
               
                 polysorbate-60 
                 2.5 
                 emulsifier 
               
               
                 safflower or sunflower oil 
                 2.5 
                 emollient, skin 
               
               
                   
                   
                 conditioning agent 
               
               
                 jojoba oil 
                 2 
                 skin conditioning agent 
               
               
                 octyl methoxycinnamate 
                 2 
                 ultraviolet light absorber 
               
               
                 papain carbomer 
                 2 
                 exfoliant 
               
               
                 carica papaya extract 
                 0.5 
                 biological additive 
               
               
                 sorbitan stearate 
                 0.5 
                 emulsifier 
               
               
                 tilia cordata (argentea) extr. 
                 0.5 
                 biological additive 
               
               
                 echinacea angustifolia extr. 
                 0.5 
                 biological additive 
               
               
                 mimosa tenuiflora extr. 
                 0.5 
                 biological additive 
               
               
                 hydrocotyl (centella asiatica) 
                 0.5 
                 biological additive 
               
               
                 extract 
               
               
                 aloe barbedensis extract 
                 0.25 
                 biological additive 
               
               
                 matricaria chamomila extr. 
                 0.25 
                 biological additive 
               
               
                 hypericum perforatum extr. 
                 0.25 
                 biological additive 
               
               
                 tocopherol 
                 0.5 
                 antioxidant, skin 
               
               
                   
                   
                 conditioning agent 
               
               
                 methyl/ethyl/propyl/butyl 
                 0.25 
                 preservative 
               
               
                 parabens in phenoxyethanol 
               
               
                 Octhilinone 
                 0.1 
                 preservative 
               
               
                 mangifera indica 
                 0.1 
                 fragrance  
               
               
                   
               
             
          
         
       
     
     Example 2 
     A preferred cream formulation of the present invention was prepared in the 5 following manner: (1) Cetyl and/or myristyl alcohol, stearic acid, polysorbate-60, sorbitan stearate, safflower (or sunflower) oil, jojoba oil, α-tocopherol, sweet almond oil and octylmethoxycinnamate were combined and melted at a temperature not exceeding 70° C. until homogeneous. (2) When molten, but not overheated, half of the deionized water (at approximately 70° C.) was added while mixing, resulting in formation of an emulsion. (3) The remaining deionized water (cold) was then added. (4) The emulsion was cooled to 40° C., followed by addition of propylene glycol,  carica papaya  extract,  tilia cordata  extract,  Echinacea angistifolia  extract,  Mimosa tenuiflora  extract, Centella (hydrocotyl) extract,  aloe barbedensis  (decolorized) extract,  Matricaria chamomila  extract, and  Hypericum perforatum  extract. (5) The emulsion was cooled to 35° C., followed by addition of octhilinone, parabens, papain carbomer and mangifera indica. If necessary, the emulsion is homogenized. 
     Example 3 
     A preferred lotion formulation contains: 
     
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 PAPAIN-CONTAINING LOTION 
               
             
          
           
               
                 compound 
                 weight % 
                 type of compound  
               
               
                   
               
             
          
           
               
                 deionized water 
                 80 
                 solvent 
               
               
                 cetyl or myristyl alcohol 
                 3 
                 emulsifier 
               
               
                 paraffin liquid 
                 2.8 
                 skin conditioning agent, 
               
               
                   
                   
                 emollient 
               
               
                 stearic acid 
                 2.6 
                 emulsifier 
               
               
                 papain carbomer 
                 4.0 
                 exfoliant 
               
               
                 carica papaya extract 
                 2 
                 biological additive 
               
               
                 polysorbate-60 
                 1.4 
                 emulsifier 
               
               
                 propylene glycol 
                 4.0 
                 humectant, solvent, skin 
               
               
                   
                   
                 conditioning agent 
               
               
                 sorbitan stearate 
                 0.4 
                 emulsifier 
               
               
                 tilia cordata (argentea) 
                 0.6 
                 biological additive 
               
               
                 extract 
               
               
                 echinacea augustifolia extr. 
                 0.6 
                 biological additive 
               
               
                 aloe barbedensis extr. 
                 0.6 
                 biological additive 
               
               
                 matricaria chamomila extr. 
                 0.6 
                 biological additive 
               
               
                 calendula officinalis extr. 
                 0.6 
                 biological additive 
               
               
                 hydrocotyl (centella 
                 0.6 
                 biological additive 
               
               
                 asiatica) extract 
               
               
                 hypericum perforatum extr. 
                 0.4 
                 biological additive 
               
               
                 methyl/ethyl/propyl/butyl 
                 0.3 
                 preservative 
               
               
                 parabens in phenoxyethanol 
               
               
                 octhilinone (methylchloro- 
                 0.1 
                 preservative 
               
               
                 isothiazolinone and methyl- 
               
               
                 isothiazoline) 
               
               
                 FD &amp; C Red No. 3 &amp; 
                   
                 colorant 
               
               
                 Yellow No. 5 
               
               
                 mangifera indica 
                 0.2 
                 fragrance  
               
               
                   
               
             
          
         
       
     
     Example 4 
     A preferred lotion formulation of the present invention was prepared in the following manner: Cetyl or myristyl alcohol, stearic acid, polysorbate-60, sorbitan stearate, paraffin liquid and α-tocopherol were combined and melted at 70° C. until homogeneous. Half of the water was added hot (70° C.) and the mixture was mixed thoroughly, followed by addition of the remainder of the water (cold through room temperature; approximately 15° C.-18° C.). The mixture was cooled to 40° C., followed by addition of propylene glycol,  tilia cordata  extract,  Echinacea angustifolia  extract,  aloe barbedensis -distilled extract (aloe vera clear),  Matricaria chamomila  extract,  Calendula officinalis  extract,  Centella  ( hydrocotyl )  asiatica  extract,  Hypericum perforatum  extract. All extracts were diluted 1:5 in either propylene glycol or butylene glycol. When the mixture had cooled to 30-35° C., octhilinone, methyl/ethyl/propylibutyl parabens, colorants (to shade),  mangifera indica  and  papain carbomer  were added. If necessary, the mixture is homogenized. 
     Example 5 
     A preferred gel formulation contains: 
     
       
         
               
             
               
               
               
             
               
               
               
             
           
               
                   
               
               
                 Papain-containing gel 
               
             
          
           
               
                 Compound 
                 weight % 
                 type of compound  
               
               
                   
               
             
          
           
               
                 deionized water 
                 80 
                 solvent 
               
               
                 carbomer 
                 0.9 
                 viscosity increasing agent 
               
               
                 papain 
                 4 
                 exfoliant 
               
               
                 propylene glycol 
                 4 
                 solvent 
               
               
                 triethanolamine 
                 1 
                 pH adjuster 
               
               
                 carica papaya extract 
                 2 
                 biological additive 
               
               
                 betula alba extract 
                 1 
                 biological additive 
               
               
                 cucumis staivus extr. 
                 1 
                 biological additive 
               
               
                 panax ginseng extract 
                 1 
                 biological additive 
               
               
                 aesculus hippocastanum 
                 1 
                 biological additive 
               
               
                 extract 
               
               
                 tilia argentea cordata extr. 
                 0.1 
                 biological additive 
               
               
                 propolis cera extract 
                 0.5 
                 biological additive 
               
               
                 octhilinone 
                 0.1 
                 preservative  
               
               
                   
               
             
          
         
       
     
     Example 6 
     A preferred gel formulation of the present invention was prepared in the following manner: Carbomer was added to cold deionized water while mixing. When dispersed, propylene glycol,  carica papaya  extract,  betula alba  extract,  cucumis sativus  extract,  panax ginseng  extract,  aesculus hippocastanum  extract,  tilia argentea  extract and  propolis cera  extract were added. These ingredients were mixed well, followed by addition of papain carbomer (1-4%) and octhilinone, and thorough mixing. Deionized water and triethanolamine were then added slowly (to prevent introduction of air) to form the clear gel. 
     Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity of understanding, it is readily apparent to those of ordinary skill in the art in light of the teachings of this invention that certain changes and modifications, particularly with regard to specific exemplary components and to the specific ranges of the components of the formulation, may be made thereto without departing from the spirit and scope of protection afforded the present invention described, and claimed, herein.