JP2011527304A - Skin whitening method - Google Patents

Abstract

  The present invention relates to methods and products for whitening the skin and also for removing skin spots. The present invention comprises, in any order, a sequential step comprising: a) applying an alcohol having a carbon chain length of 2 to 4 to the skin; and b) applying a skin lightening agent to the skin. A method for skin whitening is provided. The present invention also provides a skin lightening kit comprising an alcohol having a carbon chain length of 2 to 4 and a separately packaged skin lightening agent along with instructions for their use. It is particularly preferred that the alcohol is impregnated on a porous water-insoluble support.

Description

  The present invention relates to a skin whitening method.

  Many people, especially those in the tropics, such as those in Asia and Africa, have darker skin than people living far away from the tropics. People with such dark skin have a desire to become lighter skin. On the other hand, people who live far away from the tropics, such as those in Europe and North America, who are born with generally very light skin, want to have a darker skin. They try to fulfill their wishes by tanning with sunlight. Such tanning efforts create uneven black spots or stains on their skin that people do not want. In order to solve both of the above problems, much research has been advanced over the past several decades, and skin whitening methods have been developed. Many skin whitening compositions are also commercially available.

  Many of these compositions contain two basic components. One component is a skin lightening agent. Skin lightening agents are compounds that are thought to control melanosome dispersion or inhibit tyrosinase. Well known skin lightening agents include niacinamide, carboxylic acids such as azelaic acid and kojic acid, plant extracts, hydroquinone and the like. Niacinamide is a vitamin B3 compound and is a skin lightening agent widely used in externally applied compositions. The second component in the skin lightening composition is a sunscreen that protects the skin color from ultraviolet (UV) rays that are known to cause skin tanning. These sunscreens act by absorbing or blocking incident UV light. The sunscreen compound may be organic or inorganic. They may be naturally occurring or synthetically produced. A skin lightening agent is combined with a sunscreen compound in the skin lightening composition to provide a synergistic beneficial effect.

  A well known skin lightening compound is based on GB 2230186 (Unilever, 1990). The patent discloses a skin whitening composition comprising niacinamide, one or both of a UV-B sunscreen such as Pulsol MCX and a UV-A sunscreen such as Pulsol 1789, and a silicone compound. The composition gave an enhanced skin whitening effect over the compositions known at the time the invention appeared. Since the publication of the above patents, much research has been conducted over the years in the field of skin whitening, and several patents claim the right of improved invention. However, research to develop more efficient and better skin whitening methods and products is still ongoing.

  The inventors of the present invention have been dealing with this problem for several years, and surprisingly, one stage of applying alcohol to the skin, preferably with a wiping pad, and another stage of applying a skin lightening agent to the skin. It has been found that a two-step process comprising, provides enhanced skin whitening compared to known methods. Good results are obtained regardless of the sequence of sequential steps.

  WO 01/78678 (Procter & Gamble, 2001) describes a preformed device that delivers beneficial substances to the skin, hair or nails. The device includes a solid gel sheet having first and second opposing surfaces, the gel sheet including one or more gelling agents and at least 10% dermatologically acceptable hydrophilic solvent; The first surface is characterized in that it is at least partially coated with a discontinuous coating composition comprising at least one substance beneficial to the skin, hair or nails. Among the many active substances, niacinamide may be mentioned as a beneficial substance. Thus, the wiping pad in which the skin lightening agent is incorporated is known.

  JP5317122 (Pierce Anise, 1993) describes a cosmetic / hygiene pad formed from cotton, non-woven fabric, wet tissue paper, etc. used to wipe sweat from the skin. The cosmetic / hygiene pad is impregnated with cosmetics and disinfectants composed of porous hollow spherical fine particles, alcohol, water, allantoin, hydroxy chloride, paraffin, tea extract, L-menthol, fragrance and the like. Thereby, rough skin can be prevented even though it is claimed that the refreshing feeling lasts long. Thus, a wiping pad containing alcohol is also known.

  However, none of the prior art teaches that a two-step process that includes one step of applying alcohol and another step of applying a skin lightening agent provides an enhanced skin whitening effect.

  Accordingly, it is an object of the present invention to develop a method that provides enhanced skin whitening compared to known methods.

  Another object of the present invention is to provide a skin whitening product that is more effective in skin whitening compared to available products.

  Another object of the present invention is to provide a method and skin lightening product effective in removing skin stains.

British Patent No. 2230186 International Publication No. 01/78678 Japanese Patent No. 5317122

In accordance with the first object of the present invention,
a) applying an alcohol having a carbon chain length of 2 to 4 to the skin;
b) applying a skin lightening agent to the skin;
A skin whitening method is provided that comprises sequential steps consisting of:

  It is particularly preferred that the skin whitening application step be performed after the alcohol application step.

  In accordance with a second object of the present invention, there is provided a skin lightening kit comprising an alcohol having a carbon chain length of 2 to 4 and a separately packaged skin lightening agent along with instructions for use thereof.

  All parts in this sentence are parts by weight unless otherwise specified.

  The present invention provides a two-step skin whitening method. This method provides skin whitening superior to currently known methods. One stage involves the act of applying alcohol to the skin. The other stage involves the act of applying a skin lightening agent to the same area of the skin. This is therefore a sequential method. Either step may be performed first, and the other step is performed after that. However, in the preferred sequence, the alcohol is applied first, followed by the skin lightening agent application step. The second stage may be performed immediately after the first stage, that is, a few seconds or a few minutes after the first stage. Preferably, the second stage is performed from about 2 seconds to about 15 minutes after the first stage.

The alcohol has a carbon chain length of 2 to 4. The alcohol is preferably volatile at standard ambient temperatures, i.e. in the range of 10 to 50 ° C. A suitable alcohol for use in the process of the present invention is ethyl alcohol or isopropyl alcohol. The alcohol can be formulated as an alcoholic composition. Suitable forms of alcoholic composition are creams, gels, mousses, aerosol sprays, sticks, powders or granules. Preferably, the porous water insoluble support is impregnated with alcohol. The amount of alcohol applied to the skin is preferably in the range of 5 mg to 50 mg per cm ² of skin surface area. When the alcohol is delivered by an alcoholic composition, the alcohol is preferably present in an amount of 10 to 95% by weight of the alcoholic composition.

  One preferred method for applying alcohol to the skin is from a porous water-insoluble sheet. Such sheets are also known as wiping pads. Suitable components of the wiping pad are woven or non-woven polymer sheets, or natural materials such as cellulose, eg cotton or paper, other natural materials such as silk, wool, or a laminate of the above materials Manufactured from goods. A cotton wiping pad is particularly preferred. The wiping pad can be suitably packaged to ensure that the alcohol is retained in the wiping pad during storage and transportation and until the consumer uses it.

  The skin benefit agent is preferably delivered to the skin via an alcohol / alcoholic composition. Thus, the alcohol / alcoholic composition can dissolve or disperse the beneficial agent therein. Useful skin benefit agents are selected from sunscreens, skin lightening agents, vitamins, pharmaceutically active substances, penetration enhancers, skin texture improving agents, antioxidants, anti-inflammatory agents or skin soothing agents. The skin benefit agent is preferably present in an amount of 0.1 to 10% by weight of the alcohol. Although not wishing to be bound by theory, skin benefit agents delivered via alcohol are better transported to the target site on the skin by higher penetration or by some other mechanism. Another beneficial agent that may not be compatible in a water-based or emulsion-based composition can be delivered via alcohol according to the present invention.

  Alcohol may also be applied to the skin by aerosol spray. In this method, a mixture of alcohol and pressurized propellant is compressed and filled into cans. The can is equipped with a metering valve that can be used to produce a spray for application to the skin. The propellant gas may be a liquefied petroleum gas such as butane or propane.

  Another suitable method for applying volatile alcohol to the skin uses sticks such as are commonly used for the application of deodorants.

  The other stage of the method of the invention involves the act of applying a skin lightening agent to the skin. The skin lightening agent is preferably delivered to the skin via a skin lightening composition. The most preferred skin lightening agent is a vitamin B3 compound. Suitable vitamin B3 compounds are selected from niacin, niacinamide, nicotinyl alcohol or derivatives or salts thereof. The most preferred skin lightening agent is niacinamide. The skin lightening agent is preferably incorporated in an amount of 0.05 to 10% by weight of the skin lightening composition. A more preferred amount is 0.1 to 10% by weight of the composition, and a most preferred amount is 0.2 to 5% by weight.

  Advantageously, other vitamins that act as skin lightening agents to provide an additional skin lightening effect are included in the skin lightening composition. These include vitamin B6, vitamin C, vitamin A or their precursors. Mixtures of vitamins can also be used in the composition of the present invention. A particularly preferred additional vitamin is vitamin B6.

  Other non-limiting examples of skin lightening agents useful in the present invention include adapalene, aloe extract, ammonium lactate, arbutin, azelaic acid, butylhydroxyanisole, butylhydroxytoluene, citrate ester, deoxyarbutin, 1,3 diphenylpropane derivatives 2,5-dihydroxybenzoic acid and its derivatives, 2- (4-acetoxyphenyl) -1,3 ditan, 2- (4-hydroxyphenyl) -1,3 ditan, ellagic acid, gluco-pyranosyl-1-ascorbate , Gluconic acid, glycolic acid, green tea extract, 4-hydroxy-5-methyl-3 [2H] -furanone, hydroquinone, 4-hydroxyanisole and its derivatives, 4-hydroxybenzoic acid derivatives, hydroxycaprylic acid, inositol ascorbate, kouji Acid, lactic acid, lemon extract, Including Nord acid, magnesium ascorbyl phosphate, 5-octanoyl salicylic acid, 2,4 resorcinol derivatives, 3,5 resorcinol derivatives, salicylic acid, a 3,4,5-trihydroxy-benzyl derivatives, and mixtures thereof.

  The skin whitening composition optionally includes a sunscreen. Ultraviolet light is a major cause of skin darkening. Therefore, compositions containing UVA and / or UVB sunscreens are desirable for skin whitening. Organic or inorganic sunscreens / sunscreens can be used as appropriate in the composition.

  Preferred sunscreens useful in the present invention are 2-ethylhexyl-p-methoxycinnamate, butylmethoxydibenzoylmethane, 2-hydroxy-4-methoxybenzophenone, octyldimethyl-p-aminobenzoic acid and mixtures thereof. . Particularly preferred sunscreens are selected from 2-ethylhexyl-p-methoxycinnamate, 4-t-butyl-4'-methoxydibenzoyl-methane or mixtures thereof.

  Other suitable sunscreens suitable for use in the skin lightening agents of the present invention are 2-hydroxy-4-methoxybenzophenone, octyldimethyl-p-aminobenzoic acid, digalloyl trioleate, 2,2-dihydroxy -4-methoxybenzophenone, ethyl-4- (bis (hydroxypropyl)) aminobenzoate, 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate, 2-ethylhexyl salicylate, glyceryl-p-aminobenzoate, 3 , 3,5-trimethylcyclohexyl salicylate, methyl anthranilate, p-dimethyl-aminobenzoic acid or aminobenzoate, 2-ethylhexyl-p-dimethyl-amino-benzoate, 2-phenylbenzimidazole-5-sulfonic acid, 2- (p-dimethyl Minofeniru) -5-sulfo niobium benzoxazin Zon acid and mixtures of these compounds.

  A safe and effective amount of sunscreen can be incorporated into the compositions used in the present invention. The composition preferably comprises from about 0.1 to about 10% by weight of sunscreen, more preferably from about 0.1 to about 5% by weight.

  Useful inorganic sunscreens can also be preferably used in the present invention. These include, for example, zinc oxide, iron oxide, silica such as fumed silica, and titanium dioxide.

  Particularly suitable for the present invention is ultrafine titanium dioxide which is one of two forms: water dispersible titanium dioxide and oil dispersible titanium dioxide. Water dispersible titanium dioxide is ultrafine titanium dioxide that is either uncoated or coated with a material that imparts hydrophilic surface properties to the particles. Examples of such materials include aluminum oxide and aluminum silicate.

  Oil-dispersible titanium dioxide is an ultrafine titanium dioxide whose particles exhibit hydrophobic surface properties and can therefore be coated with a metal soap or organosilicone compound such as aluminum stearate, aluminum laurate or zinc stearate .

  The term “ultrafine titanium dioxide” means titanium dioxide particles having an average particle size of less than 100 nm, preferably less than 70 nm, more preferably 10 to 40 nm, most preferably 15 to 25 nm.

  Achieved enhanced skin defense against the harmful effects of both UV-A and UV-B rays by externally applying a mixture of both water-dispersible ultrafine titanium dioxide and oil-dispersible ultrafine titanium dioxide to the skin. it can.

  Ultrafine titanium dioxide is a preferred inorganic sunscreen. The total amount of sunscreen that is preferably incorporated into the composition of the present invention is 0.1 to 5% by weight of the composition.

Skin whitening compositions are preferably acceptable to cosmetics that act as diluents, dispersants or carriers for other materials present in the composition to facilitate their distribution when the composition is applied to the skin. Vehicle to be included. The skin lightening composition is preferably formulated in the form of a powder, flakes, lotion, cream, gel or mousse. Vanishing cream base is particularly preferred. Vanishing cream base is a base containing both fatty acids and fatty acid soaps. Their concentrations in the vanishing cream base are generally 5 to 25% by weight of C ₁₂ -C ₂₀ fatty acids and 0.1 to 10% by weight of fatty acid soaps.

  Vehicles other than water include liquid or solid emollients, solvents, humectants, thickeners and powders. Examples of these various vehicles that can be used alone or as a mixture of one or more vehicles are given below.

  Emollients such as stearyl alcohol, glyceryl monoricinoleate, mink oil, cetyl alcohol, isopropyl isostearate, stearic acid, isobutyl palmitate, isocetyl stearate, oleyl alcohol, isopropyl laurate, hexyl laurate, decyl Oleate, octadecan-2-ol, isocetyl alcohol, eicosanyl alcohol, behenyl alcohol, cetyl palmitate, silicone oil such as dimethylpolysiloxane, di-n-butyl sebacate, isopropyl myristate, isopropyl palmitate, isopropyl stearate , Butyl stearate, polyethylene glycol, triethylene glycol, lanolin, cocoa butter, corn oil, cottonseed oil, olive oil, palm Oil, rapeseed oil, safflower seed oil, evening primrose oil, soybean oil, sunflower seed oil, avocado oil, sesame seed oil, coconut oil, peanut oil, castor oil, acetylated lanolin alcohol, petroleum jelly, mineral oil, butyl myristate, isostearic acid , Palmitic acid, isopropyl linoleate, lauryl lactate, myristyl lactate, decyl oleate and myristyl myristate.

  Propellants such as propane, butane, isobutane, dimethyl ether, carbon dioxide and nitrous oxide.

Solvents such as ethyl alcohol, isopropanol, acetone, ethylene glycol monoethyl ether, diethylene glycol monobutyl ether and diethylene glycol monoethyl ether. And
Powders such as chalk, talc, fuller's earth, kaolin, starch, gum, colloidal silica, sodium polyacrylate, tetraalkyl and / or trialkylammonium smectite, chemically modified magnesium aluminum silicate, organically Modified montmorillonite clay, hydrated aluminum silicate, fumed silica, carboxyvinyl polymer, sodium carboxymethylcellulose and ethylene glycol monostearate.

  The cosmetically acceptable vehicle is usually present in an amount of 10 to 99.9%, preferably 50 to 99% by weight of the skin whitening composition, and in the absence of other cosmetic additives the composition Can be formed.

Optional Cosmetic Ingredients The compositions of the present invention can include a variety of other optional ingredients. Examples are antioxidants, binders, biological additives, buffers, colorants, thickeners, polymers, astringents, fragrances, moisturizers, opacifiers, conditioning agents, skin exfoliants, Contains pH adjusters, preservatives, natural extracts, essential oils, skin sensates, skin soothing agents and skin rejuvenating agents.

  According to another object of the present invention, there is provided a skin lightening kit comprising 2 to 4 carbon chain length alcohols and skin lightening agents, packaged separately, together with instructions for their use. The instructions for use indicate the order of use of the contents of the two separate packages. The instructions for use further indicate the use time of the contents of the second package after use of the contents of the first package.

  In the kit, the alcoholic composition is preferably impregnated in a plurality of porous water-insoluble sheets. Alternatively, an alcoholic composition is filled in an aerosol can with a propellant.

  The invention will now be described in further detail by the following non-limiting examples.

(Example)
Example 1-3: Effect of the method of the system compared to the known method in the short-term test A test of 16 volunteers was conducted for 5 days. The test consisted of the procedure described below.

Mark a specific part of the forearm of a volunteer subject and apply a commercial skin lightening composition “Fair & Lovely” containing 1.25% skin whitening active niacinamide in an amount of 3 mg / cm ² 5 times a day. Each time, approximately every 1.5 hours.

  A similar specific part of the forearm of a volunteer subject was marked and washed once a morning with soap for 10 days. Washing was configured to rub solid soap 10 times on the marked area, then rinse with plenty of water to the unmarked area of the marked area to completely remove the soap. After rinsing the soap, the area was tapped dry and the same skin whitening composition used in Example 1 was applied 5 times a day, approximately every 1.5 hours each time.

  A similar specific portion of the volunteer's forearm was wiped once a day in the morning with a muslin cloth impregnated with 0.1 ml of solvent (ethyl alcohol). The skin whitening composition used in Example 1 was applied 5 times a day, approximately every 1.5 hours each time.

  The skin whitening score was measured by a skilled appraiser using a color ruler with a scale from 1 to 10. The data in Table 1 is a summary of the average skin lightening score, which is the change in skin color relative to the initial skin color. The larger the negative value of the score, the higher the degree of skin whitening.

表１のデータは、本発明方法（実施例３）を使用すると従来技術の方法に比較して有意に高度な皮膚美白が観察されることを示す。

The data in Table 1 show that significantly higher skin whitening is observed when using the method of the present invention (Example 3) compared to the prior art method.

Example 4-6: Effect of System Method Compared to Known Methods in Long-Term Tests 36 volunteers were tested for 8 weeks. The test consisted of the procedure described below.

  A commercially available skin lightening composition “Fair & Lovely” containing a mark of a specific part of the forearm dorsal side (the side of the forearm irradiated with sunlight) of a volunteer subject and containing 1.25% skin whitening active niacinamide. Was applied in an amount of 0.5 grams twice a day, once in the morning and once at approximately 4 hour intervals.

  Another portion of the volunteer's dorsal forearm was marked and wiped once a day in the morning with a cotton wiping pad containing 2 ml of ethyl alcohol. Thereafter, the skin whitening composition used in Example 4 was applied to the marked part after 15 minutes. The complete procedure of wiping with an alcohol-impregnated wiping pad and then applying the skin whitening composition was repeated on the same day at intervals of 4 hours.

  Except for the alcohol containing 3% ascorbic acid, the same treatment as in Example 5 was performed on the sway of the forearm dorsal side of volunteer subjects.

  The skin whitening score was measured by a skilled appraiser using a color ruler with a scale from 1 to 10. The data in Table 2 is a summary of the average skin lightening score, which is the change in skin color relative to the initial skin color at 0 weeks. The larger the negative value of the score, the higher the degree of skin whitening.

表２のデータは、本発明方法（実施例５および６）を使用すると従来技術の方法に比較して有意に高度な皮膚美白が得られることを示す。

The data in Table 2 shows that using the method of the present invention (Examples 5 and 6) results in significantly higher skin whitening compared to prior art methods.

Examples 7 and 8: Effect of stage order A 5-day study was conducted on 5 volunteers. The test consisted of the procedure described below.

Mark a specific part of the forearm (1 cm ² area) of a volunteer subject and apply 3 mg / cm ^{2 of the} commercially available skin lightening composition “Fair & Lovely Multivitamin” containing 1.25% skin whitening active niacinamide. The amount was applied 5 times a day, approximately every 1.5 hours each time.

  The skin whitening composition used in Example 7 was applied to the same specific part of the forearm of a volunteer subject. After 15 minutes, the same area was wiped with a muslin cloth impregnated with 0.1 ml of ethyl alcohol. This procedure was repeated 5 times a day, approximately every 1.5 hours each time.

  The skin whitening score of a specific part was measured by a skilled appraiser using a color ruler with a scale of 1 to 10. The data in Table 3 is a summary of the average skin lightening score, which is the change in skin color relative to the initial skin color on day 0. The larger the negative value of the score, the higher the degree of skin whitening.

表３のデータは、段階の順序が、最初に皮膚美白組成物を塗布し次いでアルコールを皮膚に塗布する行為を含むときに従来技術の方法に比較してよりすぐれた皮膚美白が得られることを示す。

The data in Table 3 shows that better skin whitening is obtained compared to prior art methods when the sequence of steps includes the act of first applying a skin whitening composition and then applying alcohol to the skin. Show.

Examples 9 and 10: Effect of the method of the present invention on skin blemishes and whitening of skin-long-term test An eight-week test was conducted on 16 volunteer subjects. The test consisted of the following procedure.

  We confirmed the problem spots on the cheeks of volunteer subjects. Blot color was graded using a blot color ruler with a scale from 0.5 to 10.

  A commercial product “Fair & Lovely Skin Clarity” with 1.25% niacinamide as a skin lightening agent was applied to the spot in question in an amount of about 0.25 g. The application was performed twice a day with an interval of 90 minutes.

  The procedure consisted of wiping the stain in question with a cotton swab impregnated with about 2 ml of ethyl alcohol. A few seconds (2 to 5 seconds) later, the skin whitening composition used in Example 12 was applied. This procedure was performed twice a day at 90 minute intervals.

  The skin whitening score for each specific spot was measured by a skilled appraiser using a color ruler with a scale of 0.5 to 10. The data in Table 4 is a summary of the average skin lightening score, which is the change in skin color relative to the initial skin color at 0 weeks. The larger the negative value of the score, the higher the degree of skin whitening.

表４のデータは、長期間にわたる使用の場合でも本発明の方法が公知の方法に比較してよりすぐれたしみの皮膚美白を与えることを示す。

The data in Table 4 shows that the method of the present invention gives a better skin whitening of the stain compared to known methods even when used over a long period of time.

Claims (13)

a) applying an alcohol having a carbon chain length of 2 to 4 to the skin;
b) applying a skin lightening agent to the skin;
A method of whitening the skin comprising, in any order, sequential steps comprising:   The method of claim 1 comprising step (b) after step (a).   The method according to claim 1 or 2, wherein the alcohol is ethyl alcohol or isopropyl alcohol.   The method according to any one of claims 1 to 3, wherein the alcohol is impregnated on a porous water-insoluble support.   The method according to any one of claims 1 to 4, wherein the skin benefit substance is dissolved or dispersed in alcohol.   The method according to any one of claims 1 to 5, wherein the skin lightening agent is a vitamin B3 compound.   The method of claim 6, wherein the vitamin B3 compound is selected from the group consisting of niacin, niacinamide, nicotinyl alcohol, derivatives thereof and salts thereof.   The method according to any one of claims 1 to 7, wherein the skin lightening agent is delivered to the skin via the skin lightening composition.   9. The method of claim 8, wherein the vitamin B3 compound is present in an amount of 0.2 to 5% by weight of the skin whitening composition.   10. A method according to claim 8 or 9, wherein the skin whitening composition comprises from 0.1 to 10% by weight of a sunscreen. Skin lightening composition, (i) from 5 and _C 12 _{-C 20} fatty acids 25% by weight, in any one of claims 8 to 10 including the (ii) 0.1 to 10 wt% fatty acid soap The method described.   A skin lightening kit comprising an alcohol having a carbon chain length of 2 to 4 and a separately packaged skin lightening agent together with instructions for their use.   The kit according to claim 12, wherein the alcohol is impregnated in a porous water-insoluble support.