ANTIOXIDANT COSMETIC FORMULATION FOR TOPICAL APPLICATION WITH AN ASSOCIATION OF PLANT EXTRACTS, USE THEREOF

Description

GENERAL FIELD OF THE INVENTION

[0001] Free radicals are highly reactive molecules with unpaired electrons that can directly damage cell structures, membranes, lipids, proteins and DNA. The production of these reactive species can occur during normal metabolism or by various processes of oxidative stress induced by environmental factors such as pollution, ozone and sunlight. The production of free radicals tends to increase with age, whereas endogenous defence mechanisms tend to decrease. This leads to progressive damage to cell structures and results in aging.

[0002] In the electron transport chain, the formation of highly energetic intermediate species called reactive oxygen species (ROS), also classified as free radicals occurs. These molecules are capable of independent existence, and due to having one or more unpaired electrons have the ability to capture electrons of another molecule to stabilize, causing oxidation thereof.

[0003] Free radicals can initiate chain oxidation reactions that can damage cells or even cause their death. The consumption of oxygen by aerobic organisms and the generation of reactive oxygen species led to the "oxidative stress hypothesis". All cells, regardless of the organism used as the template manifest some level of oxidative stress.

[0004] During aging, the amount of oxidative damage increases exponentially. While damage to lipids and DNA are functional consequences of aging, oxidative damage in proteins may be the crucial factor in aging, leading to loss of catalytic activity and protein structural integrity.

[0005] The body itself has defence systems to neutralize or remove this damage, but the detection of such damage under normal physiological conditions, even in healthy bodies, suggests that the action of repair mechanisms and antioxidants do not reach 100% efficiency in the cell, resulting in an imbalance between the body's antioxidant defences and free radicals formed.

[0006] Antioxidants are substances that may protect against oxidative stress by neutralizing free radicals. Topical antioxidants are available in the market especially in products for skin care with the appeal of prevention of clinical signs of aging.

[0007] The use of antioxidants to neutralize free radicals in skin products is well disseminated. Moreover, antioxidants are essential components in cosmetic formulations to increase the shelf life of the product by reducing oxidative degradation of sensitive ingredients.

[0008] Plant extracts with antioxidant activity are already used in cosmetic compositions for treating keratinous tissues (WO2013016257 and US8318797). Plant extracts with antioxidant activity, are described, for example, by WO2013016257 and Degáspari et al., 2009. WO2010048686 teaches combinations comprising plant extracts with synergistic activity.

[0009] However, for the topical application of antioxidants are effective in preventing the aging, stability of the product is essential. As antioxidants are generally unstable, they can be oxidized and inactivated before reaching the target. The product should remain on the skin to reach the target tissue in the active form, and remain in place for some time to achieve the desired effects.

[0010] FR 2949065 A1 concerns a skin lightening complex, use of the said complex, a cosmetic or pharmaceutical composition consisting of the complex and a process for its application. EP 2545898 A1 concerns uses of cosmetics against infrared radiation. WO 2011 / 103449 A2 concerns a topical skin care formulation. Other published documents are: "Serum", Mintel, September 2010; "Firming Body Cream", Mintel, September 2011; "Body Wash", Mintel, May 2014; "Luxury Squared Highlighter & Concealer", Mintel, March 2010; "Toner", Mintel, April 2012; "DNA Action Complex", Mintel, October 2006; "Very Berry Antioxidant Serum", Mintel, February 2011; "Antioxidant Perfect 10 Serum", Mintel, November 2011;

[0011] Therefore, there is a need in the art for stable cosmetic compositions comprising combinations of antioxidants are able to exert greater anti-oxidant effect.BRIEF DESCRIPTION OF THE INVENTION

[0012] The present invention provides a stable antioxidant cosmetic formulation according to claim 1.DETAILED DESCRIPTION OF THE INVENTION

[0013] The present invention provides a stable antioxidant cosmetic formulation for topical use comprising a combination of: (a) green tea extract; (b) one or more additional active agents selected from the group consisting of aroeira (Schinus terebinthifolius) extract, coffee extract, vitamin E, grape seed oligomeric proanthocyanidins (OPC), cocoa extract, Castanea sativa seed extract, hydrolyzed Candida saitoana extract and soybean protein; and (c) one or more cosmetically acceptable carriers or accessory ingredients. The formulation comprises 0.1% to 15% of a combination of the green tea extract and the one or more additional active agents, and the formulation comprises 0.1% of green tea extract, 0.25% of aroeira (Schinus terebinthifolius) extract, and 0.1% of grape seed oligomeric proanthocyanidins (OPC).

[0014] Preferably the formulations of the present invention may additionally comprise 0.01 to 1% coffee extract, and / or 0.01 to 3% vitamin E and / or 0.01 to 1% cocoa extract, and / or 0.2 to 5% Castanea sativa seed extract (Recoverine ®< ), and / or 0.1 to 3% hydrolyzed Candida saitoana extract (Celldetox ®< ) and / or 0.5 to 15% soy protein.

[0015] The cosmetically acceptable carriers of the present invention include, but are not limited to, aqueous gels, alcoholic gels, ointments, oils, alcoholic or aqueous fluids, water in oil emulsions, oil in water emulsions, and water in silicone emulsions.

[0016] Preferably, the formulations of this invention comprise cosmetically acceptable accessory ingredients, optionally selected from the group comprising xanthan gum, glycerine, EDTA, sodium benzoate, phenoxyethanol, 2-hydroxy fatty alcohol alkoxylate, sodium polyacrylate, polysorbate 20, BHT. disaccharidic gums, ethylhexylglycerin, carbomer, butyleneglycol, acrylate polymers, PEG-40 hydrogenated castor oil, methylisothiazolinone, methylchloroisothiazolinone, propylene glycol, potassium sorbate, polyglyceryl caprylate, fragrance and water.

[0017] Preferably, the formulations of this invention comprise from 0 to 5% of xanthan gum, 0.1 to 3% of glycerin, 0.01 to 0.1% of EDTA, 0.1 to 1.0% of sodium benzoate, 0.1 to 2% of phenoxyethanol. 0.1 to 3% of 2-hydroxy fatty alcohol alkoxylate, 0 to 2% of sodium polyacrylate, 0 to 4% of polysorbate 20, 0.01 to 0.1 of BHT, 0 to 1% of fragrance and from 80 to 98% of water, preferably demineralized water.

[0018] The formulations of the present invention are prepared in a conventional manner known by the skilled technician.

[0019] The present application further discloses a method for reducing and / or preventing oxidative stress in keratinous tissues comprising applying the formulations provided by the present invention to said keratinous tissues, as well as the use of said formulation in the preparation of a cosmetic product for reducing and / or preventing oxidative stress in keratinous tissues.BRIEF DESCRIPTION OF THE FIGURES

[0020] Figure 1 (A-B): Percentage decay of ICL-S compared to the initial value (A) and corrected by the untreated area (B) obtained for the formulations of Example 1 and and Reference Example 2.EXAMPLESExample 1

[0021] A formulation according to the present invention was produced by adding phases 1-8 shown in the table below in sequence. The ninth phase is prepared by mixing solubilizer, fragrance and BHT, stirring the mixture and then adding to the main mixture. The xanthan gum is slowly added until complete dispersion and the pH adjusted to between 5-6. Phase Component Concentration (%) Amount (g) 1Demineralised water94.100094.100010Xantham gum1.00001.00002Disodium EDTA0.05000.05003Sodium benzoate0.30000.30004Phenoxyethanol F0.80000.80005Aroeira extract0.25000.25006Grape seed OPC0.10000.1000 Phase Component Concentration (%) Amount (g) 7Dry refined green tea extract0.10000.10008Glycerine1.50001.500092-hydroxy faty alcohol alkoxylate1.50001.50009BHT0.05000.05009Fragrance0.25000.2500 Reference Example 2

[0022] A formulation was produced by adding the phases 1-10, shown in the table below, according to the indicated sequence. Xanthan gum was then slowly added until complete dispersion. Phase 12 was prepared by mixing solubilizer, fragrance and BHT and added to the main mixture. The pH was adjusted to 5-6. Phase Component Concentration (%) Amount (g) 3Recoverine EL2.20002.20004Celldetox1.65001.65005Sodium Benzoate0.30000.30006Phenoxyethanol0.80000.80007Glycerine1.50001.50008Dry cacao extract0.05000.05009Soybean protein5.50005.500010Dry refined green tea extract0.10000.10001Demineralised water85.050085.05002Disodium EDTA1.00001.000011Xantham gum0.05000.050012BHT0.25000.250012Fragrance1.500015000122-hydroxy fatty alcohol alkoxylate0.15000.1500 IN VIVO EFFICACY TESTS: ANTIOXIDANT POTENTIAL

[0023] The in vivo efficacy test was performed to determine the antioxidant activity of the formulations of Example 1 and Reference Example 2 by a clinical study using the methodology of chemiluminescence.

[0024] UVA radiation is able to induce a cascade of pro-oxidative processes in human skin. This oxidative stress is primarily caused by free radicals and reactive oxygen species (ROS), which disrupt the balance between pro-and antioxidant reactions in living cells.

[0025] Part of the energy of these reactions is released as photons. This chemiluminescence is strongly related to the degree of damage to the skin, resulting from photo-aging to even more serious disorders such as skin cancer.

[0026] To prevent the accumulation of ROS in the skin, thus, preventing cell damage, all aerobic cells have an effective endogenous antioxidant system to reduce the negative effects of oxidative stress. Exposure to UVA radiation is able to weaken this endogenous protection system (SHINDO, Y.; WITT, E.; HAN, D.; TZENG, B.; NGUYEN, L.; PACKER, L. "Recovery of antioxidants and reduction in lipid hydroperoxides in murine epidermis. and dermis after acute ultraviolet skin exposure." Photodermatol. Photoimmunol. Photomed. 10, 183-191, 1994).

[0027] Due to its short lifetime and low concentration in human skin, the direct observation of free radicals and ROS is still a challenge. The induced chemiluminescence of human skin (ICL-S) is a convenient way to obtain information on the level of oxidative stress method in vivo. The reduction of ICL-S for active ingredients applied topically is a sensitive monitoring that provides biochemical and biophysical to a cellular level (ROHR, M.; BENARD, S.; SCHRADER, A "Enzymes powerful anti-aging and anti-oxidant-active, ingredients investigated by FOITS and detection of ICL-S. In cosmetic signs for the new century. Proceedings the 21st IFSCC Congress 2000" Verlag für chemische Industrie, Augsburg, Germany, 2000. 28).

[0028] The ICL-S signal is substantially detected by a photomultiplier tube (PMT), providing a continuous and non-invasive monitoring of oxidative stress in skin in vivo following the use of cosmetic products.

[0029] The technique of ICL-S works on the basis of single photon counting. This allows the in vivo data to have high stability and detectability. Among photosensitive devices in use today, the PMT provides extremely high sensitivity and fast response. The ICL-S system has been specially developed to connect the detection of photons and induced UV radiation in the same device.

[0030] The volunteers underwent a two-week period of application of the test samples, and the sample was applied once daily at the same location in a quantity of 2 mg / cm 2< . Two measures of S-ICL were performed: one before the first application and the other about 20 hours after the last application.

[0031] As a reference, an untreated area of skin and an area which received a standard antioxidant, were used as negative and positive control, respectively.

[0032] Figure 1 (A) shows the values of the percentage difference of the measures of ICL-S, relative to initial value, (B) the values of the percentage difference of the measured and corrected by the untreated area.

[0033] The formulations of Example 1 and Reference Example 2 showed a significant decrease in signal ICL-S and significant difference from untreated area. Thus, formulations 1 and 2 show superior antioxidant activity.

Claims

1. A stable antioxidant cosmetic formulation for topical use comprising a combination of: (a) green tea extract; (b) one or more additional active agents selected from the group consisting of aroeira (Schinus terebinthifolius) extract, coffee extract, vitamin E, grape seed oligomeric proanthocyanidins (OPC), cocoa extract, Castanea sativa seed extract, hydrolyzed Candida saitoana extract and soybean protein; and (c) one or more cosmetically acceptable carriers or accessory ingredients, wherein the formulation comprises 0.1% to 15% of a combination of the green tea extract and the one or more additional active agents, and wherein the formulation comprises 0.1% of green tea extract, 0.25% of aroeira (Schinus terebinthifolius) extract, and 0.1% of grape seed oligomeric proanthocyanidins (OPC).

2. The formulation of claim 1, wherein the cosmetically acceptable carriers are aqueous gels, alcoholic gels, ointments, oils, alcoholic or aqueous fluids, water in oil emulsions, oil in water emulsions, and water in silicone emulsions.

3. The formulation of claim 1, wherein the cosmetically acceptable accessory ingredients are selected from the group consisting of xanthan gum, glycerine, EDTA, sodium benzoate, phenoxyethanol, 2-hydroxy fatty alcohol alkoxylate, sodium polyacrylate, polysorbate 20, BHT, disaccharidic gums, ethylhexylglycerin, carbomer, butyleneglycol, acrylate polymers, PEG-40 hydrogenated castor oil, methylisothiazolinone, methylchloroisothiazolinone, propylene glycol, potassium sorbate, polyglyceryl caprylate, fragrance and water.

4. The composition of claim 1, further comprising: from 0 to 5% of xanthan gum, 0.1 to 3% of glycerin, 0.01 to 0.1% of EDTA, 0.1 to 1.0% of sodium benzoate, 0.1 to 2% of phenoxyethanol, 0.1 to 3% of 2-hydroxy fatty alcohol alkoxylate, 0 to 2% of sodium polyacrylate, 0 to 4% of polysorbate 20, 0.01 to 0.1 of BHT, 0 to 1% of fragrance, and from 80 to 98% of water.