A personal care composition

Abstract

Disclosed is a personal care composition comprising carboxymethyl cysteine compound and vitamin C compound selected from ascorbyl glycoside, ascorbyl phosphate, and combination thereof, wherein the carboxymethyl cysteine compound is present in amount of at least 0.00001% and no greater than 10% by weight of the composition.

Description

[0001] A PERSONAL CARE COMPOSITION

[0002] Field of the Invention

[0003] The present invention relates to a personal care composition comprising carboxymethyl cysteine compound and vitamin C compound selected from ascorbyl glycoside, ascorbyl phosphate, and combination thereof. It was surprisingly found that the level of melanin was inhibited by combining carboxymethyl cysteine compound and such vitamin C compound.

[0004] Background of the Invention

[0005] Many consumers are concerned with the characteristics of their skin. For example, consumers are concerned with the degree of pigmentation of their skin, freckles and / or age spots. Other consumers wish to reduce skin darkening caused by exposure to sunlight. To meet the needs of consumers, many attempts have been made to develop products that improve skin characteristics.

[0006] Hyperpigmentation, which is primarily caused by sunlight, is one of the imperfections that affects the skin appearance in considerable extent. Sunlight comprises harmful UV rays which is one of the main components responsible for hyperpigmentation. One of the ways to address the problem of hyperpigmentation is through cosmetic composition that reduces melanin contents in the skin. The products developed thus far, however, often tend to have low efficacy.

[0007] The present inventors have acknowledged that there is an increasing interest to develop a personal care composition capable of reducing melanin contents and therefore develop a personal care composition comprising carboxymethyl cysteine compound and vitamin C compound selected from ascorbyl glycoside, ascorbyl phosphate, and combination thereof. It was surprisingly found that such composition is capable of providing improved efficacy of reducing melanin contents.

[0008] Summary of the Invention

[0009] In a first aspect, the present invention is directed to a personal care composition comprising carboxymethyl cysteine compound and vitamin C compound selected from ascorbyl glycoside, ascorbyl phosphate, and combination thereof, wherein the carboxymethyl cysteine compound is present in amount of at least 0.00001 % and no greater than 10% by weight of the composition.

[0010] In a second aspect, the present invention is directed to a method of improving the appearance of skin; reducing pigmentation, age spots, melanin contents and / or discoloration of skin; and / or brightening skin comprising a step of topically applying to the skin the composition of the present invention.

[0011] In a third aspect, the present invention is directed to use of composition of the present invention for improving the appearance of skin; reducing pigmentation, melanin contents, age spots and / or discoloration of skin; and / or brightening skin.

[0012] All other aspects of the present invention will more readily become apparent upon considering the detailed description and examples which follow.

[0013] Detailed Description of the Invention

[0014] Except in the 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 may optionally be understood as modified by the word “about”.

[0015] All amounts are by weight of the composition, unless otherwise specified.

[0016] It should be noted that in specifying any range of values, any particular upper value can be associated with any particular lower value.

[0017] For the avoidance of doubt, the word “comprising” is intended to mean “including” but not necessarily “consisting of’ or “composed of’. In other words, the listed steps or options need not be exhaustive.

[0018] The disclosure of the invention as found herein is to be considered to cover all embodiments as found in the claims as being multiply dependent upon each other irrespective of the fact that claims may be found without multiple dependency or redundancy.

[0019] Where a feature is disclosed with respect to a particular aspect of the invention (for example a composition of the invention), such disclosure is also to be considered to apply to any other aspect of the invention (for example a method of the invention) mutatis mutandis.

[0020] The carboxymethyl cysteine compound refers to compound selected from carboxymethyl cysteine, salt of carboxymethyl cysteine, ester of carboxymethyl cysteine, amide of carboxymethyl cysteine or a mixture thereof. Preferably, the carboxymethyl cysteine compound comprises carboxymethyl cysteine, ester of carboxymethyl cysteine, and / or salt of carboxymethyl cysteine. More preferably, the carboxymethyl cysteine compound comprises carboxymethyl cysteine, and / or salt of carboxymethyl cysteine. Even more preferably, carboxymethyl cysteine compound comprises salt of carboxymethyl cysteine. Still even more preferably the carboxymethyl cysteine compound comprises lysine carboxymethyl cysteinate and most preferably, the carboxymethyl cysteine compound is lysine carboxymethyl cysteinate.

[0021] The carboxymethyl cysteine compound is present in amount of at least 0.00001%, more preferably at least 0.0001%, even more preferably at least 0.001%, still even more preferably at least 0.01 %, and most preferably at least 0.1 % by weight of the composition. The carboxymethyl cysteine compound is present in amount of no greater than 10%, more preferably no greater than 5%, even more preferably no greater than 3%, still even more preferably no greater than 1%, and most preferably no greater than 0.5% by weight of the composition.

[0022] Preferably, the lysine carboxymethyl cysteinate is present in amount of no greater than 10%, more preferably no greater than 5%, even more preferably no greater than 3%, still even more preferably no greater than 1 %, and most preferably no greater than 0.5% by weight of the composition. Preferably, the lysine carboxymethyl cysteinate is present in amount of at least 0.00001%, more preferably at least 0.0001 %, even more preferably at least 0.001 %, still even more preferably at least 0.01 %, and most preferably at least 0.1 % by weight of the composition.

[0023] The composition of the present invention comprises ascorbyl glycoside and / or ascorbyl phosphate. Preferably, the vitamin C compound is selected from ascorbyl glucoside, sodium ascorbyl phosphate, magnesium ascorbyl phosphate, or mixture thereof. More preferably, the vitamin C compound is ascorbyl glycoside and most preferably the vitamin C compound is ascorbyl glucoside. Preferably, the composition of the present invention comprises carboxymethyl cysteine compound and ascorbyl glycoside. More preferably the composition of the present invention comprises carboxymethyl cysteine compound and ascorbyl glucoside.

[0024] Preferably, the total amount of ascorbyl glycoside and ascorbyl phosphate is 0.0001 to 8% by weight of the composition, more preferably 0.005 to 5% by weight, even more preferably 0.02 to 2% and most preferably 0.1 to 1.2% by weight of the composition. Preferably, the amount of ascorbyl glycoside is 0.0001 to 8% by weight of the composition, more preferably 0.005 to 5% by weight, even more preferably 0.02 to 2% and most preferably 0.1 to 1.2% by weight of the composition. Preferably, the amount of ascorbyl glucoside is 0.0001 to 8% by weight of the composition, more preferably 0.005 to 5% by weight, even more preferably 0.02 to 2% and most preferably 0.1 to 1 .2% by weight of the composition.

[0025] Preferably the weight ratio of the carboxymethyl cysteine compound to the total ascorbyl glycoside and ascorbyl phosphate is 1 :80 to 120:1 , more preferably 1 :30 to 50:1 , even more preferably 1:15 to 25:1 , still even more preferably 1 :8 to 12:1. Preferably the weight ratio of the carboxymethyl cysteine compound to ascorbyl glycoside is 1:80 to 120:1 , more preferably 1 :30 to 50:1 , even more preferably 1 :15 to 25:1 , still even more preferably 1 :8 to 12:1. Preferably the weight ratio of the lysine carboxymethyl cysteinate to ascorbyl glycoside is 1 :80 to 120:1 , more preferably 1 :30 to 50:1 , even more preferably 1 :15 to 25:1 , still even more preferably 1 :8 to 12:1. Preferably the weight ratio of the lysine carboxymethyl cysteinate to ascorbyl glucoside is 1 :80 to 120:1, more preferably 1 :30 to 50:1 , even more preferably 1 :15 to 25:1 , still even more preferably 1:8 to 12:1.

[0026] The composition may optionally comprise whitening pigment. Whitening pigments are typically particles of high refractive index materials. For example, the whitening pigment may have a refractive index of greater than 1.3, more preferably greater than 1.8 and most preferably from 2.0 to 2.7. Examples of such whitening pigment are those comprising bismuth oxy-chloride, boron nitride, barium sulfate, mica, silica, titanium dioxide, zirconium oxide, aluminium oxide, zinc oxide or combinations thereof. More preferred whitening pigment are particles comprising titanium dioxide, zinc oxide, zirconium oxide, mica, iron oxide or a combination thereof. Even more preferred whitening pigment are particles comprising zinc oxide, zirconium oxide, titanium dioxide or a combination thereof as these materials have especially high refractive index. Still even more preferably the whitening pigment is selected from titanium dioxide, zinc oxide or a mixture thereof and most preferred whitening pigment is titanium dioxide. The average diameter of whitening pigment is typical from 15 nm to 1 micron, more preferably from 35 nm to 800 nm, even more preferably from 50 nm to 500 nm and still even more preferably from 100 to 300 nm. Amount of whitening pigment may be 0.1 to 15%, preferably 0.5 to 5% by weight of the composition.

[0027] Preferably, the composition comprises a glutamate source selected from the group consisting of glutamine, glutamine ester, glutamic acid, pyroglutamic acid, salts, and mixtures thereof. More preferably, the composition comprises pyroglutamic acid and / or salt of pyroglutamic acid. Even more preferably, the composition comprises sodium salt of pyroglutamic acid. Preferably, the glutamate source is present in amount of 0.0001 to 10% by weight of the composition, more preferably 0.001 to 6%, even more preferably 0.01 to 3% by weight of the composition. Preferably, the composition comprises polyhydric alcohol. Polyhydric alcohols may be selected from group of glycerin, propylyene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol, sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1 ,3-butylene glycol, isoprene glycol, ethoxylated glycerol, propoxylated glycerol or a mixture thereof. Most preferred polyhydric alcohol is glycerol known also as glycerin. The amount of polyhydric alcohol may range anywhere from 0.1 to 20%, preferably 0.5 to 15% and more preferably 2 and 10% by weight of the composition.

[0028] Preferably, the composition comprises emollient materials. Suitable emollient materials include silicones, hydrocarbons, triglycerides or a mixture thereof. These silicones may be organic, silicone-containing or fluorine-containing, volatile or non-volatile, polar or non-polar. Hydrocarbons may include mineral oil, petrolatum and polyalpha-olefins. Examples of preferred volatile hydrocarbons include polydecanes such as isododecane and isodecane (e.g. Permethyl- 99A which is available from Presperse Inc.) and the C7-C8 through C12-C15 isoparaffins (such as the Isopar Series available from Exxon Chemicals). Illustrative triglycerides but not limiting are sunflower seed oil, cotton oil, canola oil, soybean oil, castor oil, borage oil, olive oil, shea butter, jojoba oil and mixtures thereof. Mono- and di- glycerides may also be useful. Particularly preferable are glyceryl monostearate and glyceryl distearate.

[0029] Preferably, the composition comprises moisturizing agents. Particularly preferred moisturizing agents includes, petrolatum, aquaporin manipulating actives, oat kernel flour, substituted urea like hydroxyethyl urea, hyaluronic acid and / or its precursor N-acetyl glucosamine, hyaluronic acid and / or its precursor N-acetyl glucosamine, or a mixture thereof.

[0030] Some compositions may include thickeners. These may be selected from cellulosics, natural gums and acrylic polymers but not limited by this thickening agent types. Among the cellulosics are sodium carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose and combinations thereof. Suitable gums include xanthan, pectin, karaya, agar, alginate gums and combinations thereof. Among the acrylic thickeners are homopolymers and copolymers of acrylic and methacrylic acids including carbomers such as Carbopol 1382, Carbopol 982, llltrez, Aqua SF-1 and Aqua SF-2 available from the Lubrizol Corporation. Amounts of thickener may range from 0.01 to 3% by weight of the active polymer (outside of solvent or water) in the compositions.

[0031] In addition, the compositions of the invention may further include 0.5 to 10% by weight of sequestering agents, such as tetra sodium ethylenediaminetetraacetate (EDTA), EHDP or mixtures; opacifiers and pearlizers such as ethylene glycol distearate, titanium dioxide or Lytron 621 (Styrene / Acrylate copolymer); all of which are useful in enhancing the appearance or properties of the product.

[0032] The composition may comprise water in amount of 10 to 96% by weight of the composition, more preferably from 25 to 92%, even more preferably from 42 to 88%, most preferably from 55 to 82% by weight of the composition.

[0033] Preferably, the composition has a viscosity of at least 10 mPa s, more preferably in the range 30 to 10000 mPa s, even more preferably 50 to 5000 mPa s, and most preferably 100 to 2000 mPa s, when measured at 20 degrees C at a relatively high shear rate of about 20 s'1.

[0034] Preferably, the composition is an emulsion, more preferably an oil-in-water emulsion. Preferably the composition is a fluid liquid at 25 °C and atmospheric pressure.

[0035] Preferably, the personal care composition is a skin care composition. Skin care composition refers to a composition suitable for topical application to human skin, including leave-on and wash-off products but preferably leave-on compositions. The term “leave-on” as used with reference to compositions herein means a composition that is applied to or rubbed on the skin, and left thereon. The term “wash-off” as used with reference to compositions herein means a skin cleanser that is applied to or rubbed on the skin and rinsed off substantially immediately subsequent to application. The term "skin" as used herein includes the skin on the face, neck, chest, abdomen, back, arms, under arms, hands, and legs. Preferably “skin” means includes the skin on the face and under arms, more preferably skin means skin on the face other than lips and eyelids. The composition is particularly preferably a moisturizer rather than a make-up product.

[0036] Preferably, the composition is a topical composition. Preferably, the composition may be in the form of cream, lotion, ointment, solution, suspension, emulsion, paste, gel, powder, powder foundation, emulsion foundation, wax foundation, or spray. More preferably, the composition may be formulated in the form of cream, lotion, ointment, emulsion, gel, or a spray.

[0037] Preferably, the composition is capable of inhibiting melanin by at least 30%, more preferably 35 to 80% most preferably 40 to 70%, typically in comparison to personal care composition comprising neither carboxymethyl cysteine compound nor vitamin C compound selected from ascorbyl glycoside, ascorbyl phosphate, and combination thereof. Preferably the use is non-therapeutic. Preferably the method is non-therapeutic. The term non- therapeutic typically means for cosmetic purposes and not curative or therapeutic purposes.

[0038] The following examples are provided to facilitate an understanding of the invention. The examples are not intended to limit the scope of the claims.

[0039] Examples

[0040] Materials

[0041] Example 1

[0042] This Example demonstrates that the efficacy of reducing melanin of the present invention.

[0043] Normal human epidermal melanocytes (NHEM) (Sciencell, CA, US) were incubated in melanocyte growth medium (MGM) with human melanocyte growth supplement (both from Promocell, Germany). After incubation, media was replaced with fresh media containing test samples for the following 72 hours. At the end of the 72 hours’ incubation period, cell viability was determined using the Cell Counting Kit-8 (CCK8) method (Dojindo, Japan). Briefly, cells were washed once with phosphate buffered saline (PBS) solution. Freshly prepared 300pL of 10 wt% of CCK8 in culture medium was added into each well including the blank control wells without cells. Cells were incubated for 1 hour at 37 °C in the CO2 incubator. Absorbance was then measured at 450 nm using TECAN Safire II plate reader. After CCK8 absorbance readings were obtained, cells were rinsed with PBS and lysed by lysis buffer at 60 °C for 1 hour. Then, 50 pL cell lysates were transferred to a new 96-well plate and absorbance was measured at 405 nm using TECAN plate reader. Serial dilutions of pure melanin were prepared as references.

[0044] The melanin content was calculated from the melanin standard curve. The melanin concentrations (pg / mL) were then normalized to the relative cell viability. The melanin inhibition rates were then calculated using the following equation: Normalized melanin content (Vehicle control) — Normalized melanin content ( Test sample) % Inhbition = - - - - — - - —:- - — — — - - - x 100%

[0045] Normalized melanin content (vehicle control)

[0046] Melanin inhibition effect of the tested actives are summarized in Table 1.

[0047] Table 1

[0048] *: The level of actives is based on the amount of medium.

[0049] *: Significantly better (p<0.05) than A, D, or 2.

[0050] As demonstrated in Table 1 , it was surprisingly found that when combining lysine carboxymethyl cysteinate with sodium ascorbyl phosphate or L-Ascorbic Acid 2-Glucoside, the melanin inhibition rate was improved. Particularly, when combining lysine carboxymethyl cysteinate with L-Ascorbic Acid 2-Glucoside, the melanin inhibition rate was significantly improved. In contrast, the melanin inhibition rate was compromised when combining lysine carboxymethyl cysteinate with L- Ascorbic acid or Ascorbyl Palmitate.

Claims

Claims1. A personal care composition comprising carboxymethyl cysteine compound and vitamin C compound selected from ascorbyl glycoside, ascorbyl phosphate, and combination thereof, wherein the carboxymethyl cysteine compound is present in amount of at least 0.00001% and no greater than 10% by weight of the composition.

2. The composition according to claim 1 wherein the carboxymethyl cysteine compound comprises carboxymethyl cysteine, ester of carboxymethyl cysteine, and / or salt of carboxymethyl cysteine.

3. The composition according to claim 2 wherein the carboxymethyl cysteine compound comprises salt of carboxymethyl cysteine and preferably the carboxymethyl cysteine compound comprises lysine carboxymethyl cysteinate.

4. The composition according to any one of the preceding claims wherein the carboxymethyl cysteine compound is present in amount of at least 0.01% and no greater than 3% by weight of the composition.

5. The composition according to any one of the preceding claims wherein the vitamin C compound is selected from ascorbyl glucoside, sodium ascorbyl phosphate, magnesium ascorbyl phosphate, or mixture thereof, preferably the vitamin C compound is ascorbyl glucoside.

6. The composition according to any one of the preceding claims wherein the total amount of ascorbyl glycoside and ascorbyl phosphate is 0.0001 to 8% preferably 0.02 to 2% by weight of the composition.

7. The composition according to any one of the preceding claims wherein the weight ratio of the carboxymethyl cysteine compound to the total ascorbyl glycoside and ascorbyl phosphate is 1 :80 to 120:1 , preferably 1 :8 to 12:1.

8. The composition according to any one of the preceding claims wherein the weight ratio of the carboxymethyl cysteine compound to ascorbyl glycoside is 1:80 to 120:1.

9. The composition according to any one of the preceding claims wherein the composition is an emulsion, preferably an oil-in-water emulsion.

10. The composition according to any one of the preceding claims wherein the composition is a fluid liquid at 25 °C and atmospheric pressure.11 . The composition according to any one of the preceding claims wherein the composition comprises water in amount of 10 to 96% by weight of the composition, preferably from 42 to 88% by weight of the composition.

12. A method for improving the appearance of skin; reducing pigmentation, age spots, melanin contents and / or discoloration of skin; and / or brightening skin comprising a step of topically applying to the skin the composition as claimed in any one of the preceding claims 1 to 11.

13. Use of the composition of any one of the preceding claims 1 to 11 for improving the appearance of skin; reducing pigmentation, melanin contents, age spots and / or discoloration of skin; and / or brightening skin.

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