A personal care composition

Abstract

The present invention relates to a personal care composition. Particularly, the present invention relates to a personal care composition comprising a carboxymethyl cysteine compound, one or more oil-soluble sunscreens and one or more water-soluble sunscreens. The personal care composition provides protection from potentially harmful effects that may be caused by exposure to ultraviolet and visible e.g. blue, light.

Description

[0001] A PERSONAL CARE COMPOSITION

[0002] Field of the invention

[0003] The present invention relates to a personal care composition. Particularly, the present invention relates to a personal care composition that provides protection from potentially harmful effects that may be caused by exposure to sunlight.

[0004] Background of the invention

[0005] Solar radiations include about 5% ultraviolet (UV) radiation, wavelength of which is between 200 nm and 400 nm. It is further divided into three regions: from 320 to 400 nm (UV-A), 280 to 320 nm (UV-B) and from 200 to 280 nm (UV-C). Substantial portion of UV-C radiation is absorbed by ozone. Scientific studies have indicated that exposure to UV-A and UV-B radiation for short period causes pigmentation, reddening of the skin and localized irritation, whereas continued or prolonged exposure can lead to sunburn, formation of wrinkles and age spots. UV radiation is also thought to cause significant damage to hair. Therefore, it is desirable to protect the skin and other keratinous substrates of the human body from the harmful effects of both UV-A and UV-B radiation.

[0006] This is often delivered through personal care compositions e.g. cosmetic compositions, which provide protection from UV-B (measured as sun protection factor; SPF) and / or protection from UV-A (measured as UV-A protection factor; UVAPF). Various personal care compositions are reported for preventing and / or protecting the skin from harmful effects of UV radiation. Numerous organic sunscreen agents capable of absorbing UV-A rays are reported in the field of cosmetics amongst which a particularly useful sunscreen is t-butylmethoxydibenzoylmethane (also known as Avobenzone and sold as Parsol® 1789). A variety of UV-B sunscreens are used in personal care compositions for protection from UV-B radiation e.g. octyl salicylate. Many cosmetic manufacturers prefer to include UV-A as well as UV-B sunscreens in photoprotective compositions to provide protection over the entire range of UV radiation.

[0007] On the other hand, Solar radiations also include of visible spectrum wavelength of which is between 380 to 700 nm which includes blue light (about 450 to 495 nm). Blue light amongst the visible spectrum is also reported to induce undesired effects.

[0008] Thus, exposure to the sunlight tends to give rise to potentially harmful effects e.g. generation of reactive oxygen species (ROS) which exert oxidative stress, hyperpigmentation, age spots, wrinkles and solar lentigens. One of the ways to reduce such potentially harmful effects is to avoid exposure to the sunlight. However, in many instances it is unavoidable; and through day-today activities, people do tend to get exposed to the sunlight.

[0009] Therefore, consumers tend to rely on personal care compositions that protect their skin from such potential harmful effects that may be caused by exposure to the sunlight. Thus, consumers tend to look forward to such compositions that provide protection from such sun induced damages / potentially harmful effects e.g. generation of ROS. Consumers also tend to look forward to such compositions that deliver such benefits to an improved extent.

[0010] Need therefore exists to develop personal are compositions that meet consumers’ expectations and provide protection from sun induced damage. Need also exists to provide personal care compositions that provide such benefits to an improved extent, i.e. improved protection from sun induced damages, using actives or benefits agents in combination with sunscreens.

[0011] It has now been found that when a carboxymethyl cysteine compound was combined with an oilsoluble sunscreen and a water-soluble sunscreen, it provided improved protection from sun induced damages e.g. from generation of ROS. Particularly, it has been found that the combination of a carboxymethyl cysteine compound with an oil-soluble sunscreen and a water- soluble sunscreen, provided improved protection from ROS, i.e. it resulted in reduced generation of ROS thereby reducing the oxidative stress. Thus, a new use of a carboxymethyl cysteine compound as an antioxidant, is also found. Further, it has also been found that a carboxymethyl cysteine compound boosts SPF when used in combination with an oil-soluble sunscreen and a water-soluble sunscreen.

[0012] Summary of the invention

[0013] Accordingly, in a first aspect, the present invention relates to a personal care composition comprising: a. a carboxymethyl cysteine compound selected from carboxymethyl cysteine, ester of carboxymethyl cysteine, amide of carboxymethyl cysteine, a salt of carboxymethyl cysteine and mixtures thereof, b. from 0.1 to 15 wt% one or more oil-soluble sunscreens; and c. from 0.1 to 10 wt% one or more water-soluble sunscreens.

[0014] In a second aspect the present invention relates to a method of providing protection from sun induced damages to a surface comprising: a. a step of applying the composition of the first aspect to the surface; and b. optionally, rinsing the surface,

[0015] In a third aspect, the present invention relates to use of the composition of the first aspect for providing protection from sun induced damages.

[0016] In a fourth aspect, the present invention relates to use of the composition of the first aspect for providing protection from UV induced damages.

[0017] In a fifth aspect, the present invention relates to use of a carboxymethyl cysteine compound in providing protection from visible light induced damages.

[0018] The invention is further described in detail as follows:

[0019] Detailed description of the invention

[0020] Any feature of one aspect of the present invention may be utilized in any other aspect of the invention. 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. Except in the operating and comparative 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 are to be understood as modified by the word “about”. Numerical ranges expressed in the format " x to y" are understood to include x and y. When for a specific feature multiple preferred ranges are described in the format "x to y", it is understood that all ranges combining the different endpoints are also contemplated. Unless specified otherwise, amounts as used herein are expressed in percentage by weight based on total weight of the composition and may be abbreviated as “wt%”. The use of any and all examples or exemplary language e.g. “such as” provided herein is intended merely to better illuminate the invention and does not in any way limit the scope of the invention otherwise claimed.

[0021] 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”. The composition of the invention is meant to be used for personal care or for cosmetic use and could also be referred to as a personal photoprotective composition. By “personal care composition” as used herein, is meant to include a composition for topical application to sun- exposed areas of the skin and / or hair of humans. Such a composition may be classified as leave- on or rinse-off, and includes any product applied to a human body for improving appearance, cleansing, odor control or general aesthetics. The composition of the present invention can be in the form of a liquid, lotion, cream, foam, stick or gel. Non-limiting examples of such compositions include leave-on skin lotions, creams, antiperspirants, deodorants, foundations, mascara, sunscreen lotions and wash-off shampoos, conditioners and shower gels. The composition of the present invention is preferably a leave-on composition.

[0022] ‘Skin’ as used herein, preferably means to include skin on any part of the body e.g. face, neck, chest, back, arms, underarms, hands, legs, buttocks and scalp and especially to the sun exposed parts thereof. Compositions of the invention is also of relevance to applications on any other keratinous substrates of the human body other than skin e.g. hair, where products may be formulated with specific aim of improving photoprotection.

[0023] Preferably, the phrase ‘sun-induced damage’ means damages or harmful or potentially harmful effects that may be caused by exposure to the sunlight. Likewise, the phrase ‘UV induced damages’ preferably means damages or harmful or potentially harmful effects that may be caused by exposure to UV. Further, the phrase ‘visible light induced damages’ preferably means damages or harmful or potentially harmful effects that may be caused by exposure to the visible light e.g. blue light.

[0024] In a first aspect, a personal care composition according to the present invention (the composition) comprises: a. a carboxymethyl cysteine compound selected from carboxymethyl cysteine, ester of carboxymethyl cysteine, amide of carboxymethyl cysteine, a salt of carboxymethyl cysteine and mixtures thereof, b. from 0.1 to 15 wt% one or more oil-soluble sunscreens; and c. from 0.1 to 10 wt% one or more water-soluble sunscreens.

[0025] The composition comprises a carboxymethyl cysteine compound.

[0026] A carboxymethyl cysteine compound refers to a compound selected from carboxymethyl cysteine, a salt of carboxymethyl cysteine, an ester of carboxymethyl cysteine, an amide of carboxymethyl cysteine or a mixture thereof. Preferably, a carboxymethyl cysteine compound comprises carboxymethyl cysteine e.g. S- carboxymethyl-L-cysteine, ester of carboxymethyl cysteine, and / or salt of carboxymethyl cysteine. More preferably, a carboxymethyl cysteine compound comprises carboxymethyl cysteine, and / or salt of carboxymethyl cysteine. Even more preferably, a carboxymethyl cysteine compound comprises a salt of carboxymethyl cysteine e.g. L-Lysine, compound with S- (carboxymethyl)-L-cysteine (1 :1) (LCC; CAS Registry Number: 49673-81-6, also known as lysine carboxymethyl cysteinate). Most preferably, the carboxymethyl cysteine compound is LCC.

[0027] Preferably, a carboxymethyl cysteine compound is present in amount of from 0.00001 wt% to 10 wt%, more preferably from 0.0001 wt% to 8 wt%, even more preferably from 0.001 wt% to 5 wt%, still even more preferably from 0.01 % to 3 wt% and most preferably from 0.1 wt% to 1 wt%.

[0028] Preferably, a carboxymethyl cysteine compound is present in amount of no greater than 10 wt%, more preferably no greater than 5 wt%, even more preferably no greater than 3 wt%, still even more preferably no greater than 1 wt%, and most preferably no greater than 0.5 wt%. Preferably, LCC is present in an amount of at least 0.00001 wt%, more preferably at least 0.0001 wt%, even more preferably at least 0.001 wt%, still even more preferably at least 0.01 wt%, and most preferably at least 0.1 wt%.

[0029] Oil-soluble sunscreens

[0030] The composition comprises one or more oil-soluble sunscreens.

[0031] Preferably, the one or more oil soluble sunscreens are selected from UV-A oil-soluble sunscreens selected from a dibenzoylmethane compound, diethylamino hydroxybenzoyl hexyl benzoate (commercially available as Uvinul® A Plus), and menthyl anthranilate and / or a UV-B oil-soluble sunscreens selected from octyl salicylate, 3,3,5- trimethylclohexyl 2-hydroxybenzoate, ethylhexyl salicylate, 2-ethylhexyl 2-cyano- 3,3-diphenyl-2-propenoate, 2-ethylhexyl-4-methoxycinnamate and octylmethoxycinnamate.

[0032] If the one or more oil soluble sunscreen is selected from a dibenzoylmethane compound, then it is preferably selected from 2-methyldibenzoylmethane, 4-isopropyldibenzoyl-methane, 4-tert- butyl-4’-methoxydibenzoylmethane (commercially available as Parsol® 1789 or Avobenzone), 2,4-dimethyldibenzoylmethane, 2,5- dimethyldibenzoylmethane, 4,4'-diisopropyl- dibenzoylmethane, 2-methyl-5- isopropyl-4'-methoxydibenzoylmethane, 2-methyl-5-tert-butyl-4'- methoxy- 5 dibenzoyl methane, 2,4-dimethyl-4'-methoxydibenzoylmethane, 2,6-dimethyl-4-tert- butyl-4'-methoxy-dibenzoylmethane and mixtures thereof. If the one or more oil soluble sunscreen is selected from a dibenzoylmethane compound, then, more preferably, 4-tert- butyl- 4’-methoxydibenzoylmethane (commercially available as Parsol® 1789 or Avobenzone) is used as the dibenzoylmethane compound.

[0033] The composition comprises from 0.1 to 15 wt%, preferably from 1 to 13 wt%, preferably from 2 to 10 wt%, preferably from 3 to 8 wt%, preferably from 4 to 6 wt% of one or more oil-soluble sunscreens described above.

[0034] By ‘oil-soluble’ as used in the context of oil-soluble sunscreens, whether of IIV-A type or IIV-B type, it is preferably meant that the solubility of the sunscreen in water is less than 10 g / L, preferably less than 5 g / L, more preferably less than 2 g / L; at 25°C.

[0035] Water-soluble sunscreens

[0036] The composition comprises one or more water-soluble sunscreens. Preferably, the one or more water-soluble sunscreens are selected from UV-B water-soluble sunscreens selected from phenyl benzimidazole sulphonic acid, benzylidene camphor sulfonic acid, benzophenone-4 and / or from UV-A water-soluble sunscreens selected from di sodium phenyl dibenzimidazole tetra sulfonate, terephthalylidene dicamphor sulfonic acid and mixtures thereof. For the purpose of the present invention, benzylidene camphor sulfonic acid and benzophenone-4 are considered as UV-B sunscreens.

[0037] The composition comprises from 0.1 to 10 wt%, preferably from 1 to 8 wt%, preferably from 2 to 6 wt%, preferably from 3 to 5 wt% of one or more water-soluble sunscreens described above.

[0038] By ‘water-soluble’ as used in the context of water-soluble sunscreens, whether of the UV-A type, or of the UV-B type, it is preferably meant that the solubility of the sunscreen in water is higher than 10 g / L, preferably higher than 50 g / L; at 25°C.

[0039] Inorganic sunscreens

[0040] The composition may preferably further comprise an inorganic sunscreen selected from titanium dioxide (Ti®2), zinc oxide (ZnO) and mixtures thereof.

[0041] Preferably, the composition comprises such inorganic sunscreens from 0.1 to 25 wt%, more preferably from 1 to 22 wt%, even more preferably from 3 to 20 wt%, further more preferably from 5 to 15 wt%, still more preferably from 7 to 12 wt% and yet more preferably from 9 to 11 wt%.

[0042] Surfactants

[0043] Preferably, the composition is in the form of an emulsion. It may be an oil-in-water (o / w) emulsion or water-in-oil emulsion (w / o). Preferably, it is in the form of an oil-in-water emulsion. For this, the composition preferably comprises one or more surfactants / emulsifiers. Preferably, the one or more surfactants / emulsifiers is selected from anionic surfactant, nonionic surfactant, amphoteric surfactant and mixtures thereof, of which nonionic surfactants are particularly preferred.

[0044] Preferably, if the one or more surfactants is selected from anionic surfactants it may be selected from alkyl ether sulfate and sulfonates, alkyl sulfates and sulfonates, alkylbenzene sulfonates, alkyl and dialkyl sulfosuccinates, C8-C20 acyl isethionates, C8-C20 alkyl ether phosphates, alkylethercarboxylates and combinations thereof.

[0045] More preferably, the one or more surfactants are selected from nonionic surfactants selected from nonionic surfactants having HLB value in the range 9 to 20, preferably 10 to 19, more preferably 12 to 18, even more preferably 13 to 17 and yet more preferably 15 to 17.

[0046] HLB is calculated using the Griffin method wherein HLB = 20 x Mh / M wherein Mh is the molecular mass of the hydrophilic portion of the molecule and M is the molecular mass of the whole molecule, giving a result on an arbitrary scale of 0 to 20. Typical values for various surfactants are given below:

[0047] A value <10 : Lipid soluble (water insoluble)

[0048] A value >10 : Water soluble

[0049] A value from 4 to 8 indicates an anti-foaming agent

[0050] A value from 7 to 11 indicates a W / O (water in oil) emulsifier

[0051] A value from 12 to 16 indicates oil in water emulsifier

[0052] A value from 11 to 14 indicates a wetting agent

[0053] A value from 12 to 15 is typical of detergents

[0054] A value of 16 to 20 indicates a solubiliser or a hydrotrope.

[0055] Preferably, the one or more nonionic surfactant having HLB value in the range 9 to 20 is selected from fatty alcohol ethoxylates, fatty acid ethoxylate, alkyl phenol ethoxylates, polyoxyethylene sorbitan alkyl esters and mixtures thereof.

[0056] Examples of fatty alcohol ethoxylates that may be used as nonionic surfactants in the composition include polyoxyethylene lauryl ether (HLB= 16.9; commercially available as Brij® 35), polyoxyethylene (20) cetyl ether (HLB=16; commercially available as Brij® 58), polyethylene glycol octadecyl ether (HLB= 18.8; commercially available as Brij® 700) and Laureth - 9 (C12EO9; HLB=14.3; commercially available as Brij® L9). Examples of alkyl phenol ethoxylates that may be used as nonionic surfactant in the composition include octylphenol ethoxylate (HLB=15.5; commercially available as Triton™ X165), octylphenol ethoxylate (HLB=17.6; commercially available as Triton™ X405) and octylphenol ethoxylate (HLB=18.4; commercially available as Triton™ X705).

[0057] Examples of polyoxyethylene sorbitan alkyl esters that may be used as the nonionic surfactant in the composition include polyoxyethylenesorbitan monolaurate (HLB=13.3; commercially available as Tween® 21), polyoxyethylenesorbitan monolaurate (HLB=16.7; commercially available as Tween® 20), Polyoxyethylenesorbitan monopalmitate (HLB=15.6; commercially available as Tween® 40) and polyoxyethylene sorbitan monostearate (HLB= 14.9; commercially available as Tween® 60).

[0058] More preferably, the nonionic surfactant having HLB value in the range 9 to 20 that may be present in the composition is fatty alcohol ethoxylate with saturated carbon chain having HLB higher than 15.5.

[0059] Preferably, if the one or more surfactants are selected from amphoteric surfactants, it may be selected from cocamidopropyl betaine, C12-C20 trialkyl betaines, sodium lauroamphoacetate, and sodium laurodiamphoacetate and a mixture thereof.

[0060] Preferably, the composition comprises from 0.1 to 30 wt%, more preferably from 0.5 to 25 wt%, even more preferably from 1 to 20 wt%, further more preferably from 2 to 15 wt%, still more preferably from 3 to 10 wt% and yet more preferably from 5 to 7 wt% of one or more surfactants described above.

[0061] Other emulsifiers

[0062] Preferably, the composition comprises emulsifiers. Examples of such emulsifiers include glyceryl stearate, glycol stearate, stearamide AMP, PEG-100 stearate (HLB = 18.8), cetyl alcohol as well as emulsifying / thickening additives like hydroxyethylacrylate / sodium acryloyldimethyl taurates copolymer / squalene and mixtures thereof. If present, such emulsifiers may be preferably present in amounts 0.1 to 5 wt%, more preferably 0.5 to 4 wt%, even more preferably from 1 to 3 wt%. Humectant

[0063] Preferably, the composition further comprises one or more humectants selected from butylene glycol, hyaluronic acid, pentylene glycol, propanediol, 1 ,2,6-hexanetriol, 1 ,3-butylene glycol, dipropylene glycol, ethoxylated glycerol, propoxylated glycerol, glycerol, hexylene glycol, hydroxypropyl sorbitol, isoprene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, sorbitol.

[0064] More preferably, a humectant is selected from glycerol, pentylene glycol, butylene glycol and mixtures thereof.

[0065] Preferably, the composition comprises from 0.1 to 20 wt%, more preferably from 1 to 18 wt%, even more preferably from 3 to 15 wt%, further more preferably form 5 to 12 wt% and still more preferably 7 to 10 wt% of one or more humectants described above.

[0066] Fatty acids

[0067] Preferably the composition further comprises fatty acids. Fatty acids when present in a composition along with a soap provides the so-called vanishing cream effect, i.e. a composition, when applied on to the human skin, vanishes on the skin leaving behind no significant streaks of the composition.

[0068] The composition comprises fatty acids having carbon atoms preferably in the range 8 to 22, more preferably 10 to 22, even more preferably 12 to 22, further more preferably 14 to 22, yet more preferably from 16 to 22; and still more preferably from 18 to 22. Examples of fatty acids that may be used in the composition include lauric, myristic, palmitic, stearic, isostearic, oleic, linoleic, arachidic, behenic, erucic acid and mixtures thereof. Preferably, the fatty acids are selected from stearic acid, palmitic acid and a mixture thereof. The fatty acid in the present invention is preferably hystric acid which is substantially (generally about 90 to 95%) a mixture of stearic acid and palmitic acid where amount of palmitic acid may range from 40 to 65% and that of stearic acid may range from 34 to 58%.

[0069] Preferably the composition comprises from 3 to 25 wt%, more preferably from 4 to 22 wt%, even more preferably from 7 to 20 wt%, further more preferably from 10 to 19 wt% and still more preferably from 12 to 18 wt% fatty acids.

[0070] Preferably, the composition further comprises soap. Soap when present in combination with fatty acids in the composition, provides the so-called vanishing effect. Soap of the invention is generally prepared by in-situ neutralization of fatty acid present in the composition. Thus, it is preferred that the soap has a carbon chain length that corresponds to the chain length of a fatty acid described above, that may be present in the composition. The soap is formed from the fatty acid through use of alkali metal hydroxides e.g. sodium hydroxide and potassium hydroxide.

[0071] The composition comprises 0.1 to 10 wt%, preferably 1 to 8 wt%, more preferably 2 to 7 wt%, even more preferably 2 to 6 wt%, further more preferably 2 to 5 wt% and most preferably 2 to 4 wt% soap.

[0072] Preferably, the composition further comprises from 0.25 to 5 wt%, preferably 0.5 to 4 wt%, preferably 1 to 3 wt%, for example 2 wt% of a polymer selected from a polymer of dimethicone / vinyldimethicone crosspolymer with or without silica. Various polymers of the above types could be used in the present invention for improving sensory properties of the composition. Dimethicone / vinyl dimethicone crosspolymer which is a preferred polymer as per the invention is available as KM-9729, DOWSIL™ EP-9215, SeraSnowSP 13, DOWSIL™9506 Powder, SpecsilSPD. An even more preferred polymer as per the invention is Dimethicone / Vinyl Dimethicone Crosspolymer (and) Silica which is available as DOWSIL™9701 Cosmetic Powder. Other suitable examples of such polymers which may be used are as follows:

[0073] Dimethicone / Vinyl Dimethicone Crosspolymer(and) Silica (and) Butylene Glycol available as DOWSIL™ EP-9801 Hydro Cosmetic Powder,

[0074] Dimethicone (and) Dimethicone / Vinyl Dimethicone Crosspolymer(and) Dimethicone Crosspolymer(and) Beeswax (and) Silica (and) Silica Silylate available as DOWSIL™9576 Smooth Away Elastomer,

[0075] Dimethicone / Vinyl Dimethicone Crosspolymer(and) Polymethylsilsesquioxane(and) Silica Dimethyl Silylate Available as SSP100,

[0076] Dimethicone / Vinyl Dimethicone Crosspolymer(and) LauroylLysine available as DOWSIL™ EP-9289 LL,

[0077] Hydrophobically modified silica is preferably selected from Silica Silylate available as DOWSIL™ VM-2270 AerogelFine Particles, HDK® H2000 and

[0078] - Silica dimethyl silylate available as HDK® H15, HDK® H20, HDK® H30, HDK® H18.

[0079] Preferably, the pH of the composition is in the range from 5.0 to 8.0, more preferably from 5.5 to

[0080] 7.5 and even more preferably from 6.0 to 7.0. When required, pH of the composition may be adjusted using known pH adjusting agents e.g. sodium hydroxide, potassium hydroxide and hydrochloric acid.

[0081] Silicone oils

[0082] If the composition is in the form of a silicone oil-in-water emulsion, it preferably comprises dimethicone which is also known as polydimethylsiloxane (PDMS). Examples of PDMS include dimethicone 10 cSt (commercially available as DC-200 dimethicone 10 cSt), dimethicone 50 cSt (commercially available as DC-200 dimethicone 50cSt). Silicone oils are known to provide smooth feel to the surface they are applied on to.

[0083] Water

[0084] Preferably, the composition comprises water. Water may be present in the composition in an amount from 5 to 99.9 wt%, more preferably from 10 to 95 wt%, even more preferably 15 to 90 wt%, further more preferably 20 to 80 wt%, still more preferably 25 to 75 wt% and yet more preferably 30 to 70 wt%.

[0085] Other Polymers

[0086] Preferably, the composition further comprises polymers other than those described above.

[0087] These polymer act as a thickener in the composition. These polymers are preferably selected from the following classes: acrylate I R-methacrylate copolymer e.g. acrylates / steareth-20 methacrylate copolymer (commercially available as Aculyn™ 22) and acrylates / beheneth-25 methacrylate copolymer (commercially available as Aculyn™ 28), acrylate I R-methacrylate crosspolymer e.g. acrylates / steareth-20 methacrylate crosspolymer (commercially available as Aculyn™ 88), acrylates copolymer (commercially available as Aculyn™ 33), acrylate / R-alkyl acrylate crosspolymer e.g. acrylates / C10-C30 alkyl acrylate crosspolymer (commercially available as Pemulen™ TR-2), copolymer of ammonium acryloyldimethyltaurate with vinyl pyrrolidone (commercially available as Aristoflex® AVC), copolymer of sodium acryloyldimethyltaurate with vinyl pyrrolidone (commercially available as Aristoflex® AVS); and crosspolymer of acryloyldimethyltaurate with R-alkyl acrylate and methyacrylate e.g. Ammonium acryloyldimethyltaurate / beheneth-25 methacrylate crosspolymer (commercially available as Aristoflex® HMB and Aristoflex® BLV); and mixtures thereof. More preferably, the polymer is selected from acrylate I R-methacrylate copolymer, acrylates copolymer and mixtures thereof.

[0088] Preferably, the composition comprises 0.1 to 5 wt%, more preferably 0.5 to 4.5 wt%, even more preferably 1 to 4 wt%, further more preferably from 1.5 to 3.5 wt%, still more preferably from 2 to 3 wt% of these other polymers.

[0089] Skin brightening agents

[0090] Preferably, the composition further comprises one or more skin brightening agents. These one or more skin brightening agents may be selected from niacinamide, vitamin B6, vitamin C, vitamin A, glutathione precursors, galardin, adapalene, aloe extract, ammonium lactate, arbutin, azelaic acid, butyl hydroxy anisole, butyl hydroxy toluene, citrate esters, deoxyarbutin, 1 ,3-diphenyl propane derivatives, 2,5-dihydroxybenzoic acid and its derivatives, 2-(4-acetoxyphenyl)-1 ,3- dithiane, 2-(4-hydroxyphenyl)-1 ,3-dithiane, ellagic acid, gluco pyranosyl-1 -ascorbate, gluconic acid, glycolic acid, green tea extract, 4-Hydroxy-5-methyl-3[2H]-furanone, 4-hydroxyanisole and its derivatives, 4-hydroxybenzoic acid derivatives, hydroxycaprylic acid, inositol ascorbate, lactic acid, linoleic acid, magnesium ascorbyl phosphate, 5-octanoyl salicylic acid, salicylic acid, 3,4,5- tri hydroxy benzyl derivatives, acetylglucosamine, pitera extract, symwhite, calcium pantothenate (Melano-block), seppiwhite, 12-hydroxystearic acid and mixtures thereof. When used in the composition, 12-hydroxystearic acid is used as a skin brightening agent and not as a fatty acid. Preferably, skin brightening agents that may be used in the composition are niacinamide, vitamin B6, 12-hydroxystearic acid, and mixtures thereof.

[0091] When incorporated in the composition, a skin brightening agent may be added in an amount 0.001 to 15 wt%, preferably 0.01 to 10 wt%, more preferably 0.1 to 5 wt%, even more preferably 0.5 to 3 wt%, in the composition.

[0092] Emollient

[0093] Preferably, the composition further comprises emollients. Examples of emollients that may be used in the composition include stearyl alcohol, glyceryl monoricinoleate, mink oil, cetyl alcohol, isopropyl isostearate, isobutyl palmitate, isocetyl stearate, oleyl alcohol, isopropyl laurate, hexyl laurate, decyl oleate, octadecan-2-ol, isocetyl alcohol, eicosanyl alcohol, behenyl alcohol, cetyl palmitate, silicone oils such as dimethylpolysiloxane, din-butyl sebacate, isopropyl myristate, isopropyl palmitate, isopropyl stearate, butyl stearate, polyethylene glycol, triethylene glycol, lanolin, cocoa butter, corn oil, cotton seed oil, olive oil, palm kernel oil, rape seed oil, safflower seed oil, evening primrose oil, soybean oil, sunflower seed oil, avocado oil, sesame seed oil, coconut oil, arachis oil, castor oil, acetylated lanolin alcohols, petroleum jelly, mineral oil, butyl myristate, isopropyl linoleate, lauryl lactate, myristyl lactate, decyl oleate, myristyl myristate and mixtures thereof.

[0094] Solvents

[0095] Preferably, the composition further comprises solvents. Examples of solvents that may be used in the composition include ethyl alcohol, isopropanol, ethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol monoethyl ether and mixtures thereof. Preferably, such solvents may be present in an amount from 1 to 10 wt%, more preferably from 3 to 5 wt%.

[0096] Preservatives

[0097] Preferably, the composition further comprises preservatives to protect against the growth of potentially harmful microorganisms. Examples of ingredients that may be used as preservatives in the composition include alkyl esters of para-hydroxybenzoic acid, hydantoin derivatives, propionate salts, and a variety of quaternary ammonium compounds. More preferably, ingredients that may be used as preservative in the composition are sodium benzoate, iodopropynyl butyl carbamate, methylisothiazolinone, iodopropynylbutylcarbamate, phenoxyethanol, methyl paraben, propyl paraben, imidazolidinyl urea, sodium dehydroacetate, ethylhexylglycerin, benzyl alcohol, alkane diols and mixtures thereof. The alkane diols that are suitable for use as preservative are C6-C12 alkanes that are vicinally substituted with hydroxy groups. Illustrative examples include 1 ,2-octane diol (caprylyl glycol), 2,3-octane diol, 1 ,2-nonane diol, 1 ,2-decane diol, 1 ,2-hexane diol, 3,4-octane diol, mixtures thereof or the like where caprylyl glycol is typically the most preferred. When present in the composition, preservatives are added preferably in an amount 0.001 to 5 wt%, more preferably 0.01 to 3 wt% and most preferably 0.02 to 2 wt%.

[0098] Other optional ingredients

[0099] The composition may further comprise a range of other optional ingredients that include antioxidants, binders, buffering agents, colorants, astringents, fragrance, opacifying agents, conditioners, exfoliating agents, skin soothing agents, and skin healing agents.

[0100] Product format

[0101] The composition may be formulated in the form of a cream, a lotion, a serum, a mousse, a spray, a stick. Preferably, the composition is in the form of a cream.

[0102] In a second aspect, the present invention related to a method of providing protection from sun induced damages to a surface comprising: a. a step of applying the composition of the first aspect to the surface; and b. optionally, rinsing the surface, In step a., the composition of the first aspect is applied on to a surface e.g. skin. This step may be carried out in such a way that a consumer applies an appropriate quantity of the composition e.g. 2 grams, or in case of liquid products e.g. 5 mL, on to a surface. The step of applying the composition may be carried out using hands or may be using applicators e.g. a spatula and a sponge. The composition so applied is spread over the area so as to form a layer of appropriate thickness.

[0103] Optionally, the method of the invention comprises a further step where the surface on to which the composition is applied in the previous step, step a., is rinsed with water. In other words, the surface is washed with water at the same time of removing the composition so applied. The step b. is an optional step which is not required to be carried out when the composition is formulated as a leave-on composition. However, it is an essential step if the composition is formulated as a wash-off composition.

[0104] The term ‘leave-on’ composition preferably means a composition which is not required to be removed from the human body after the application of the composition like e.g. a cream.

[0105] The term ‘wash-off’ composition preferably means a composition which is intended / required to be removed from the body by washing with solvent, preferably water, after the application of the composition like e.g. hand wash composition and face wash composition. When the composition is formulated in the format of a wash-off composition, the step b. is preferably carried out within 15 minutes from carrying out step a., more preferably, step b. is carried out within 10 minutes, even more preferably within 5 minutes and further more preferably within 1 minute e.g. 15 seconds, 30 seconds. Preferably, the method is non-therapeutic or cosmetic in nature.

[0106] In third aspect, the preset invention relates to use of the composition of the first aspect for providing protection from sun induced damages. When the composition of the first aspect is applied on a surface e.g. skin, it protects the surface from potentially harmful effects that may be induced by exposure to the sunlight. Preferably, the use is non-therapeutic or cosmetic in nature.

[0107] In a fourth aspect, the present invention relates to use of the composition of the first aspect for providing protection from UV induced damages. Preferably, the use is non-therapeutic or cosmetic in nature.

[0108] In a fifth aspect, the present invention relates to use of a carboxymethyl cysteine compound in providing protection from visible light induced damages. Preferably, the use is non-therapeutic or cosmetic in nature. In another aspect, the present invention relates to use of a carboxymethyl cysteine compound, in a personal care composition comprising one or more oil-soluble sunscreens and one or more water-soluble sunscreens, for providing protection from visible light induced damages. Preferably, the use is non-therapeutic or cosmetic in nature.

[0109] In a sixth aspect, the present invention relates to use of a carboxymethyl cysteine compound as an antioxidant. It has been found that a carboxymethyl cysteine compound reduced generation of ROS. When such carboxymethyl cysteine compound was combined with one or more sunscreens, it provided synergistic antioxidant effect. Preferably, the use is non-therapeutic or cosmetic in nature.

[0110] The invention is further described with the help of the following non-limiting examples.

[0111] Examples

[0112] Protocols

[0113] Media and reagents

[0114] Growth media and growth supplements for Keratinocytes (HaCaT cell line), DMEM were purchased from Cascade Biologies (USA) and were reconstituted as per the supplier’s instructions, with supplied growth factors and antibiotics (100 U / mL penicillin and 100 pg / mL streptomycin). Trypsin EDTA and trypsin neutralizer were obtained from Cascade Biologies (USA). LCC (commercially available as HAIR APP; 98% active) was procured from Sinerga.

[0115] Cell culture and exposure to UV and blue light

[0116] Keratinocytes (HaCaT cells) were seeded in 48-well plates at a density of 3.5 x 104cells / well and were maintained in the DMEM medium reconstituted as described above, for 24 to 48 h. The cells were exposed to UV light using a Solar simulator comprising a Xenon arc lamp and to blue light using LED source, as required. As control (example A) below, cells that were not exposed to either to UV or to blue light, were used as control. Prior to exposure, compositions (as shown in table 1 below) were applied evenly on PMMA plate (2 mg / cm2). For the UV / Blue light exposure, the media was carefully removed, and the cells were gently washed with sterile 1X Phosphate buffered saline (PBS). Exposure was carried out with a PMMA plate on top of the culture plate with a lid and minimal levels of 1X PBS coating the cell layer. After exposure, PBS was removed and replaced with the media in all wells. To mimic the penetration of LCC into the skin, some cells were treated with media containing LCC as shown in case of examples D and 1 in tables 2 and 3 below. Plates were incubated in 5% CO2 / 37°C incubator for 6 h and post incubation, cells were harvested and measured ROS level by DCFDA assay. DC FDA Assay

[0117] Cells were exposed with and without UVA at 100 mJ / cm2and then incubated at 37°C in the CO2 incubator for 6 h. Post 6 h, cells were washed with 1X PBS and treated with media containing DCFDA reagent and incubated at 37°C in the CO2 incubator for 30 minutes. Then cells were washed with 1x PBS once followed by the addition of fresh PBS. The plates were then wrapped with aluminum foil and taken reading at an excitation wavelength of 485 nm and emission wavelength of 535 nm. The amount of ROS generated was calculated as percentage control after background subtraction.

[0118] SPF and UVAPF Measurements

[0119] The invitro SPF and UVAPF values for the samples shown in table 4 below were measured using the following procedure:

[0120] Thin film transmittance measurements were done using Labsphere’s Ultraviolet transmittance analyzer. In this study, 70 x 70 mm PMMA plate with ~6 pm roughness from Schonberg GmbH & Co were used. The percent transmittance of the various compositions was measured using a procedure as outlined below. 2 mg / cm2of sample was applied on PMMA plate, distributed uniformly using a syringe, and spread uniformly. The drying time for the PMMA plates was 30 minutes. After the drying time, sample plates were exposed to UV light and transmittance scan was recorded. This scan gives the transmittance as a function of wavelength (290 - 400 nm) for a given sample. For a single plate six to nine different spots were scanned. The same was repeated for 2 or 3 plates. The data reported is thus an average over 12 -18 readings. The reference transmittance scan was obtained using a blank plate, with no sample on the PMMA plates with glycerin spread on it. The transmittance values were used to arrive at the SPF values using the UV -2000s application provided with the instrument.

[0121] Percentage of transmittance (and therefore the SPF) was measured invitro SPF at zero time (line 0 min). Same plate was exposed to solar simulated light and % of transmittance measured at designated time intervals from 0 and 60 min. Average absorbance at 310 and 355 nm was recorded to measure % UVB & UVA photostability respectively. UV was generated using solar simulator (Atlas kW system) using irradiance of 550 W nr2, at a distance of ~ 20 cm.

[0122] Examples

[0123] As described above, cells that were not exposed to UV or blue light were taken as control, example A. Further, compositions as shown in table 1 , examples B, C, D and 1 , were prepared. Briefly, these compositions were prepared as follows:

[0124] In a container phenylbenzimidazole sulfonic Acid (Ensulizole) was neutralized by pre-weighed sodium hydroxide to obtain a homogenous transparent solution. The pre-neutralized Ensulizole, EDTA and Glycerin were added to water in the main container and homogenized at 75°C (water phase). Hysteric acid, glyceryl stearate, glycol monostearate, PEG- 100 stearate, octocrylene, butyl methoxydibenzoylmethane, octyl salicyalte and emollients were added to separate containers and melted at 75°C to obtain the clear oil phase. DC 9701 or acrylate crosspolymer (e.g available as Ganezpearl 820 GMP) are pre-dispersed using spatula in the molten oil phase before addition. In the meantime, in a separate container, required polymers like xanthan gum and llltrez 10 (carbomer, crosslinked polyacrylic acid) were dispersed in water (polymer phase). The molten oil phase containing sunscreens and sensory modifying agents added to the main container and homogenized for complete mixing. The pre-dispersed polymers were added to this mix and continued mixing. At this stage, the polymer neutralized using KOH (45%). Post neutralization, dimethicone was added to the main container and continued mixing for another 5 to 8 minutes. With continuous mixing the temperature of the main container was brought down to 45°C to add bioactive and continued mixing to attain room temperature. The formulation was stored overnight; and in-vitro SPF was measured the next day.

[0125] Table 1: pH = 6.0 to 7.0 The compositions as shown in table 1 above were exposed to blue light as described earlier; and ROS generation was measured with example A (unexposed control) using the DCFDA assay as described earlier; and are shown in table 2 below:

[0126] Table 2:

[0127] The data in the table 2 above shows that when a carboxymethyl cysteine compound e.g. LCC, is used in combination with one or more sunscreens, it synergistically reduced the ROS production despite the cells were exposed to blue light.

[0128] Further, the compositions as shown in table 1 above were exposed to UV light as described earlier; and ROS generation was measured as described above. Here too, example A was taken as unexposed control:

[0129] Table 3:

[0130] The data in the table 3 above shows that when a carboxymethyl cysteine compound e.g. LCC, is used in combination with one or more sunscreens, it synergistically reduced the ROS production despite the cells were exposed UV light.

[0131] The data in table 2 and 3 above shows that a carboxymethyl cysteine compound, e.g. LCC, functions as an antioxidant as it reduced ROS generation. Further, compositions as shown in table 4 below were prepared as described earlier; and SPF and LIVAPF measurements were recorded using the protocol mentioned earlier.

[0132] Table 4: pH = 6.0 to 7.0 Table 5:

[0133] The SPF and LIVAPF data obtained for compositions shown in table 4 above was as follows:

[0134] The data in table 5 above shows that a carboxymethyl cysteine compound improves SPF of the composition.

[0135] Further, compositions as shown in table 6 below, were prepared:

[0136] Table 6:

[0137] Skin brightening efficacy of compositions shown in examples H, I and 3 was evaluated in the UV challenged pigmented living skin equivalent (PLSE) (MelaKuits®, Biocell, Xi’an, China) models.

[0138] After the model is constructed (day 0), the models were irradiated with UVB at 50 mJ / cm2, once per day, for 6 days. The compositions of examples H, I and 3, were applied topically at 5 pL on day 2, 4 and 6. On day 7, the L* of each model was measured using the DSM II ColorMeter. The results obtained were as shown in table 7 below: Table 7: L* measurements in the UV irradiated PLSE models

[0139] #, p<0.01 , vs. untreated control

[0140] 1, p<0.01 vs. UV

[0141] 2, p<0.01 vs. UV+ example 3, p<0.05 vs UV + Prototype with SPF only

Claims

Claims1. A personal care composition comprising: a. a carboxymethyl cysteine compound selected from carboxymethyl cysteine, ester of carboxymethyl cysteine, amide of carboxymethyl cysteine, a salt of carboxymethyl cysteine and mixtures thereof, b. from 0.1 to 15 wt% one or more oil-soluble sunscreens; and c. from 0.1 to 10 wt% one or more water-soluble sunscreens.

2. The composition according to claim 1 wherein the composition comprises from 0.00001 to 10 wt% of the carboxymethyl cysteine compound.

3. The composition according to any one of claims 1 or 2 wherein the carboxymethyl cysteine compound comprises carboxymethyl cysteine, ester of carboxymethyl cysteine, a salt of carboxymethyl cysteine and mixtures thereof.

4. The composition according to any one of claims 1 to 3 wherein the carboxymethyl cysteine compound comprises L-Lysine, compd. with S-(carboxymethyl)-L-cysteine 1 :1.

5. The composition according to any one of claims 1 to 4 wherein the one or more oilsoluble sunscreens are selected from: a. a UV-B sunscreen selected from one or more of octyl salicylate, 3,3,5- trimethylclohexyl 2-hydroxybenzoate, ethylhexyl salicylate, 2-ethylhexyl 2-cyano- 3,3-diphenyl-2-propenoate, 2-ethylhexyl-4-methoxycinnamate and octylmethoxycinnamate; and / or b. a UV-A sunscreen selected from one or more of a dibenzoylmethane compound, diethylamino hydroxy benzoyl hexyl benzoate and methyl anthranilate.

6. The composition according to claim 5 wherein the dibenzoylmethane compound is selected from one or more of t-butylmethoxydibenzoylmethane, 2- methyldibenzoylmethane, 4-methyl-dibenzoyl-ethane, 4-isopropyldibenzoyl-methane, 4- tert-butyl-4’-methxydibenzoylmethane, 2,4-dimethyldibenzoylmethane, 2,5- dimethyldibenzoylmethane, 4,4'-diisopropyl-dibenzoylmethane, 2-methyl-5-isopropyl-4'- methoxydibenzoylmethane, 2-methyl-5-tert-butyl-4'-methoxy-dibenzoyl methane, 2,4- dimethyl-4'-methoxy dibenzoylmethane and 2,6-dimethyl-4-tert-butyl-4'-methoxy- dibenzoylmethane.

7. The composition as claimed in any one of claims 1 to 6 wherein the one or more water- soluble sunscreen is selected from:a. a UV-B sunscreen selected from one or more of 2-phenylbenzimidazole-5- sulfonic acid, benzophenone-4 and benzylidene camphor sulfonic acid; and / or b. a UV-A sunscreen selected from one or more of di sodium phenyl dibenzimidazole tetra sulfonate and terephthalylidene dicamphor sulfonic acid.

8. The composition as claimed in any one of claims 1 to 7 wherein the composition further comprises one or more non-ionic surfactants having an HLB value in the range from 9 to 20 selected from a fatty alcohol ethoxylate, a fatty acid ethoxylate, an alkyl phenol ethoxylate, and polyoxyethylene sorbitan alkyl esters; preferably from a fatty alcohol ethoxylate or a fatty acid ethoxylate.

9. The composition as claimed in any one of claims 1 to 8 wherein the composition further comprises one or more humectants selected from propylene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol, sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1,3-butylene glycol, isoprene glycol, 1,2,6-hexanetriol, glycerol, ethoxylated glycerol and propoxylated glycerol.

10. The composition as claimed in any one of claims 1 to 9 wherein the composition further comprises from 3 to 25 wt% Cs to C22 fatty acid, preferably from palmitic acid and / or stearic acid.

11. The composition as claimed in any one of claims 1 to 10 wherein the composition further comprises a polymer of dimethicone / vinyldimethicone crosspolymer with or without silica.

12. A method of providing protection from sun induced damages to a surface comprising: a. a step of applying the composition as claimed in any one of claims 1 to 11 to the surface; and b. optionally, rinsing the surface.

13. Use of the composition as claimed in any one of claims 1 to 11 for providing protection from sun induced damages.

14. Use of the composition as claimed in any one of claims 1 to 11 for providing protection from UV induced damages.

15. Use of a carboxymethyl cysteine compound in providing protection from visible light induced damages.

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