WO2022253516A1

WO2022253516A1 - A cosmetic composition comprising a retinoid for providing antiaging benefits

Info

Publication number: WO2022253516A1
Application number: PCT/EP2022/062084
Authority: WO
Inventors: Xuelan GU; Aditi Jayavant KULKARNI; Sheng MENG; Tingyan MI; Ankita Rutu PAWAR
Original assignee: Unilever Ip Holdings B.V.; Unilever Global Ip Limited; Conopco, Inc., D/B/A Unilever
Priority date: 2021-06-04
Filing date: 2022-05-05
Publication date: 2022-12-08

Abstract

The present invention relates to a cosmetic composition which provides antiaging benefits. This benefit is delivered through a composition that contains retinoid compounds along with certain other actives like fatty acid/ alcohol and a humectant.

Description

A COSMETIC COMPOSITION COMPRISING A RETINOID FOR PROVIDING

ANTIAGING BENEFITS

Field of the invention

The present invention relates to a cosmetic composition which provides antiaging benefits. The invention more particularly relates to cosmetic compositions that deliver superior anti aging benefits compared to compositions that contain retinoid compounds where the efficacy is boosted with known retinoid boosters.

Background of the invention Retinol (vitamin A) is an endogenous compound which occurs naturally in the human body, and is essential for normal epithelial cell differentiation. Natural and synthetic vitamin A derivatives have been used extensively in the treatment of a variety of skin disorders and have been used as skin repair or renewal agents. Retinoic acid has been employed to treat a variety of skin conditions, e.g., acne, wrinkles, psoriasis, age spots and discoloration. There have been several patents published from the present applicants on use of retinoids over the last two decades towards providing antiaging benefits e.g. US5716627 and US2002142016. In the same patent family, US7959913 discloses certain class of retinoid boosters named as B1 to B5 boosters which includes a large number of compounds disclosed and claimed to boost the antiaging efficacy of retinoids. Based on this extensive study, the present applicants have developed, manufactured and sold skin cosmetic compositions towards this benefit for several years now in very large part of the world.

In spite of the extensive knowledge published in this area, the present inventors continue to look for technologies where more efficacious compositions for antiaging can be developed and delivered to the consumers. The direction of research in the present invention was to look for delivering more anti-aging efficacy using lower amount of actives or to make compositions that are more stable than those heretofore known and disclosed.

Towards achieving this goal the present inventors have developed a composition for enhanced antiaging with a synergistic combination of retinoids, certain fatty acids or alcohols and specific classes of humectants. It is thus an object of the present invention to provide for an antiaging composition that delivers improved antiaging efficacy.

It is another object of the present invention to provide for an antiaging composition that in addition to delivering superior antiaging benefits, is more stable.

Summary of the invention

The present invention relates to a cosmetic composition comprising (i) a retinoid; (ii) a fatty acid or a fatty alcohol; and

(iii) a humectant selected from one or more of saccharide isomerate, 1 ,2-hexanediol, 2,3-butanediol, panthenol, pentylene glycol, propanediol, polyglyceryl laurate, sodium PCA, lactic acid, sodium lactate, potassium lactate, acetamide MEA, hydroxyethyl urea, sodium hyaluronate, or hydrolyzed hyaluronic acid.

Another aspect of the present invention relates to method of providing antiaging benefit to skin comprising the step of applying a composition of the invention on to a desired skin surface. Detailed description of the invention

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 is 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. 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.

“Skin” as used herein is meant to include skin on any part of the body (e.g. face, neck, chest, back, arms, underarms, hands, legs, buttocks and scalp).

The composition of the present invention comprises a retinoid. Typically, the retinoid is selected from retinyl ester, retinol, retinal, retinoic acid or a mixture thereof. More preferably the retinoid comprises retinol, retinyl ester, or a mixture thereof and even more preferably the retinoid is selected from retinol, retinyl ester, or a mixture thereof.

The term “retinol” includes the following isomers of retinol: all-trans-retinol, 13-cis-retinol, 11-cis-retinol, 9-cis-retinol, 3,4-didehydro-retinol, 3,4-didehydro-13-cis-retinol; 3,4- didehydro-11-cis-retinol; 3,4-didehydro-9-cis-retinol. Preferred isomers are all-trans- retinol, 13-cis-retinol, 3,4-didehydro-retinol, 9-cis-retinol. Most preferred retinol is all- trans-retinol, due to its wide commercial availability. Retinyl ester is an ester of retinol. The term “retinol" has been defined above. Retinyl esters suitable for use in the present invention are preferably C1-C30 esters of retinol, more preferably C2-C20 esters of retinol, and most preferably C2, C3, and Cie esters of retinol. Examples of retinyl esters include but are not limited to: retinyl palmitate, retinyl formate, retinyl acetate, retinyl propionate, retinyl butyrate, retinyl valerate, retinyl isovalerate, retinyl hexanoate, retinyl heptanoate, retinyl octanoate, retinyl nonanoate, retinyl decanoate, retinyl undecanoate, retinyl laurate, retinyl tridecanoate, retinyl myristate, retinyl pentadecanoate, retinyl heptadecanoate, retinyl stearate, retinyl isostearate, retinyl nonadecanoate, retinyl arachidonate, retinyl behenate, retinyl linoleate, retinyl oleate. The retinyl ester for use in the present invention is preferably selected from retinyl palmitate, retinyl acetate, retinyl linoleate, retinyl oleate, retinyl propionate or a mixture thereof. More preferably the retinyl ester is selected from retinyl palmitate, retinyl acetate, retinyl propionate, or a mixture thereof. Most preferably the retinyl ester is selected from retinyl palmitate, retinyl propionate, or a mixture thereof. Between the retinyl palmitate and retinyl propionate, retinyl propionate is more preferred.

Particularly preferred retinoid is selected from all-trans-retinol, retinyl palmitate, retinyl acetate, retinyl propionate, or a mixture thereof. Most preferably the retinoid is selected from retinyl palmitate, retinyl propionate, or a mixture thereof.

Preferably, retinoid is employed in the composition in an amount of 0.0001% to 5%, more preferably in an amount of 0.0005% to 3%, even more preferably from 0.001 to 0.5% and most preferably in an amount of 0.01 % to 0.2% by weight of the composition.

The composition of the invention includes a suitable fatty alcohol or fatty acid. Fatty alcohol or fatty acid for use in the present invention includes those compounds having from 10 to 20 carbon atoms in the fatty chain. It is especially preferred that the fatty alcohol / fatty acid is one of a cetyl, myristyl, palmityl or stearyl alcohol or acid. Between the fatty acid and the fatty alcohol, fatty alcohol is more preferred, The most preferred fatty alcohol for use in the present invention is cetyl alcohol. The fatty alcohol or fatty acid is preferably included in 0.1 to 2%, preferably 0.4 to 1.0% by weight of the composition.

The composition of the invention includes a group of actives that the present inventors have surprisingly found to enhance the antiaging efficacy of the retinoid, viz. specific compounds which have humectant properties. Humectants are compounds that help retain the loss of moisture from composition, but in the present invention they act by synergistically interacting with the other essential ingredients especially the retinoid in the presence of the fatty acid or fatty alcohol to enhance certain gene expressions responsible for providing anti-aging benefits to skin. The humectants that could be used in the present invention for the above purpose is selected from one or more of saccharide isomerate, 1,2-hexane diol, 2,3-butanediol, pentylene glycol, propanediol, polyglyceryl laurate, lactic acid, sodium lactate, potassium lactate, acetamide MEA, hydroxyethyl urea, or hydrolyzed hyaluronic acid.

Acetamide MEA is also known as acetamide monoethanol amine. Preferred humectants for use include one or more of saccharide isomerate, 1,2-hexane diol, 2,3-butanediol, pentylene glycol, propanediol, hydroxyethyl urea, or hydrolyzed hyaluronic acid. Especially preferred humectants for use in the present invention are chosen from one or more of saccharide isomerate, pentylene glycol, propanediol, or hydrolyzed hyaluronic acid. The most preferred humectant for use is saccharide isomerate. Humectants for the above purpose are preferably included in 0.1 to 10.0%, more preferably 0.3 to 8%, and most preferably in 0.5 to 5% by weight of the composition.

Saccharide isomerate is an especially preferred humectant for use in the present invention. It is commercially available under trade name ‘Pentavitin®’ (from DSM), under trade name Waterin (from Clariant), under trade names ‘EPS3 Powder’, ‘EPS4 Powder’, ‘EPS5 Powder’ and ‘EPS15 Powder’ (all from Codif) and under trade name ‘Hyanify’ (from Lipotec S.A.). Preferably, the composition further comprises one or more skin glow agents. These agents may be selected from niacinamide, picolinamide, iso-nicotinamide, resorcinol, phenylethyl resorcinol, 4-alkyl resorcinol, vitamin B6, vitamin C, vitamin A, glutathione precursors, galardin, adapalene, 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, 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-trihydroxybenzyl derivatives, acetylglucosamine, symwhite, calcium pantothenate (Melano-block), seppiwhite, 12-hydroxystearic acid and mixtures thereof. More preferred skin glow agents for use in the composition include niacinamide, picolinamide, isonicotinamide, 12-hydroxystearic acid, resorcinol, phenylethyl resorcinol, 4-alkyl resorcinol, conjugated linoleic acid (CLA) or galardin. Even more preferred skin glow agents are selected from niacinamide, CLA and 4-alkyl resorcinol; and mixtures thereof. Examples of 4-alkyl substituted resorcinol include 4-methyl resorcinol, 4-ethyl resorcinol (ER), 4-propyl resorcinol, IPR, 4-butyl resorcinol (BR), 4-pentyl resorcinol, HR, 4-heptyl resorcinol, 4-octyl resorcinol and mixtures thereof. Preferred 4-alkyl substituted resorcinol are ER, BR, HR and mixtures thereof. More preferred 4-alkyl substituted resorcinol are ER, HR and mixtures thereof. The alkyl group in 4-alkyl substituted resorcinol can be straight chain alkyl or branched chain alkyl. For example, the alkyl group can be straight chain alkyl as in the case of 4-propyl resorcinol or it can be a branched chain alkyl like in the case of 4-isopropyl resorcinol (I PR).

Preferably the composition comprises from 0.001 to 10 wt%, more preferably from 0.005 to 9 wt%, even more preferably from 0.01 to 8 wt%, further more preferably from 0.005 to 7 wt%, still more preferably from 0.1 to 6 wt%, yet more preferably from 0.1 to 5 wt%, still further more preferably from 0.1 to 3 wt% and yet further more preferably from 0.1 to 1 wt% skin glow agent.

The composition may additionally comprise sunscreen agents such as inorganic sunblocks. For example, zinc oxide, titanium dioxide, iron oxide, silica such as fumed silica. The amount of such sunblock agents is preferably incorporated from 0.1 to 5% by total weight of the sunscreen composition.

The composition of the invention may comprise an organic UV-A sunscreen agent selected from the group consisting of a dibenzoylmethane derivative, a triazine derivative, a benzophenone derivative and mixtures thereof. In a preferred embodiment, the UV-A sunscreen agent comprises or is a dibenzoylmethane derivative, for example, butyl methoxydi benzoyl methane (sold under the trade name Parsol 1789).

Typically, the composition of the present invention may comprise from 0.1 to 15% by weight of the UV-A sunscreen agent, more preferably from 0.1 to 10%, most preferably from 1 to 5%, based on the total weight of the composition and including all ranges subsumed therein.

The composition of the invention may also comprise an organic UV-B sunscreen agent. Suitable UV-B sunscreen agent may be selected from the group consisting of a benzophenone, an anthranilate, a salicylate, a cinnamate, a camphor, benzylidene malonate, a triazone, and derivatives thereof. In a preferred embodiment, the organic UV-B sunscreen agent comprises or is a cinnamate derivative, for example, ethylhexyl methoxycinnamate (sold under the trade name Parsol MCX).

Typically, the composition comprises from 0.1 to 20% by weight of the UV-B sunscreen agent, more preferably from 0.5 to 18%, most preferably from 1 to 15%, based on the total weight of the composition and including all ranges subsumed therein.

The composition of the invention preferably comprises a cosmetically acceptable vehicle. The cosmetically acceptable vehicle is preferably in the form of an oil, liquid, stick, cream, lotion, spray or gel. The cosmetically acceptable vehicle preferably includes ingredients like surfactant e.g. non-ionic surfactant, fatty acid, soap, water, polymer, emollients, solvents, powders, preservatives, or optional ingredients. Details on the various possible ingredients for inclusion in the cosmetically acceptable vehicle are given below. Preferably, the composition comprises a nonionic surfactant. More preferably the nonionic surfactant is selected from those 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. 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.

Preferably, the nonionic surfactant having HLB value in the range 9 to 20 is selected from fatty alcohol ethoxylates, alkyl phenol ethoxylates, polyoxyethylene sorbitan alkyl esters and mixtures thereof. Preferably, the nonionic surfactants are ones with at least 9 alkylene oxide groups preferably at least 9 ethylene oxide groups.

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 (C12E09; 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).

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).

Even 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.

Preferably, the leave-on composition comprises 0.5 to 5 wt%, more preferably 1 to 4 wt%, even more preferably from 2 to 3 wt% nonionic surfactant having HLB in the range 9 to 20.

Preferably, the composition of the invention is delivered in the form of a vanishing cream. A vanishing cream is one which when applied and rubbed on to the human skin, vanishes on the skin leaving behind no significant streaks of the composition. Fatty acids when present in a composition along with a soap provides the so-called vanishing cream effect. Preferably, the leave-on composition comprises fatty acids having 10 to 30, more preferably 12 to 25, even more preferably 14 to 20, further more preferably 16 to 18 carbon atoms. Examples of fatty acids that may be used in the composition include pelargonic, lauric, myristic, palmitic, stearic, isostearic, oleic, linoleic, arachidic, behenic, erucic acid and mixtures thereof. Preferably, the fatty acid that may be used is stearic acid or palmitic acid or 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 in a ratio of between 55:45 to 45:55. Preferably, the composition comprises from 2.25 to 25 wt%, more preferably from 4 to 22 wt%, even more preferably from 6 to 20 wt%, further more preferably from 8 to 19 wt% and still more preferably from 10 to 18 wt% and yet more preferably from 12 to 16 wt% fatty acid.

Preferably, the composition comprises soap. Soap, when present in combination with fatty acid in the composition, provides the vanishing effect described above. Preferably, soap in the composition is generally prepared by in-situ neutralization of fatty acid that may be present in the composition. Thus, it is preferred that the soap has a carbon chain length that corresponds to the chain length of fatty acid in the composition. The soap is formed from the fatty acid through use of alkali metal hydroxides e.g. sodium hydroxide or potassium hydroxide. Of the two, potassium hydroxide is more preferred. Thus, the soap is preferably a potassium soap (potassium salt of fatty acid).

Preferably, the composition comprises from 0.1 to 10 wt%, more preferably from 0.25% to 8 wt%, even more preferably from 0.5 to 7 wt%, further more preferably from 0.5 to 5 wt% soap, even further more preferably 0.5% to 3%. Preferably, the composition comprises water in amount from 5 to 99.9 wt%, more preferably from 10 to 95 wt%, even more preferably from 15 to 90 wt%, further more preferably from 20 to 80 wt%, still more preferably 25 to 75 wt% and yet more preferably 30 to 70 wt%. Preferably, the composition comprises a polymer. The polymer acts as thickener in the composition and improves sensorial properties of the composition.

The polymer is preferably selected from the following classes: acrylate / 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 / 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/C 10-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).

Preferably, the composition comprises 0.1 to 5 wt%, more preferably 0.25 to 4.5 wt%, even more preferably 0.5 to 4 wt%, further more preferably from 0.75 to 3.5 wt%, still more preferably from 0.75 to 2.75 wt% polymer.

Preferably, the composition comprises emollients. Examples of emollients that may be used in the leave-on composition include stearyl alcohol, glyceryl monoricinoleate, mink oil, 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.

Preferably, the composition comprises solvents. Examples of solvents that may be used in the composition include ethyl alcohol, isopropanol, acetone, ethylene glycol ono ethyl ether, diethylene glycol mono butyl ether, diethylene glycol mono ethyl ether and mixtures thereof. Preferably, the composition comprises powders. Examples of powders that may be used in the composition include chalk, talc, fullers earth, kaolin, starch, gums, colloidal silica sodium polyacrylate, tetra alkyl and/or trialkyl aryl ammonium smectites, chemically modified magnesium aluminium silicate, organically modified montmorillonite clay, hydrated aluminium silicate, fumed silica, carboxyvinyl polymer, sodium carboxymethyl cellulose, ethylene glycol monostearate and mixtures thereof.

Preferably, the composition 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%, even most preferably 0.25 to 1.5%.

Preferably, the composition comprises a range of other optional ingredients that include antioxidants, binders, buffering agents, colorants, astringents, fragrance, opacifying agents, conditioners, exfoliating agents, pH adjusters, skin sensates, skin soothing agents, and skin healing agents.

The invention also relates to a method of providing antiaging benefit to skin comprising the step of applying a composition of the invention on to a desired skin surface. The method is preferably for non-therapeutic use. Yet another aspect of the present invention relates to use of the composition of the invention for providing antiaging benefits.

The invention will now be illustrated with the help of the following non-limiting examples.

Examples

Examples A-C, 1 : The following compositions as shown in Table -1 were prepared.

Table - 1

The above compositions were tested for various gene expressions as described below: Ex vivo study method

The ex vivo human skin used was from the abdomen surgical discards from a 40- year’s old female. Once received, the excess dermal fat of the skin discards was removed uniformly with curved surgical scissors and scalpels after a brief disinfection with iodine and 75 % ethanol. The tissue was then equilibrated with Phosphate-Buffered Saline (PBS) supplemented with antibiotics at room temperature for 1 hour. Then 4 mm skin punch biopsies were taken from the skin discards and cultured on trans-well inserts with medium in the lower chamber contacting the bottom of the skin tissue culture. On the second day, 6 mI_ of each product was applied topically and left on the skin surface for additional 3 days. After 3 days, each punch biopsy tissue culture was cut into half. Half of the tissue was immediately fixed in cold 10% neutral buffered formalin solution (Cat. 252549, Sigma Aldrich, St. Louis, MO, US), dehydrated and embedded in paraffin for structure. Half of tissue samples were briefly rinsed with RNAase-free PBS and placed in vials which pre-loaded with RNAIater, and stored first at 4 °C and then at -20 °C. The samples were sent to an external lab (Shanghai Biotechnology Corp.) for RNA extraction. Briefly, the tissues were homogenised in pre-cold tubes containing 0.5 mL Trizol® and 5 mm stainless-steel beads using a TissueLyser homogenizer. The homogenate was then transferred to a new screw cap tube containing 0.5 mL fresh Trizol® and incubated on the ice for 30 min with occasional vortex and then at room temperature for 5 min. The homogenate was then added with 0.2 mL of chloroform and vigorously shaken for 15 sec.. The samples were then incubated at room temperature for 3 min and centrifuged at 12,000 g for 15 min at 4 °C. Following centrifugation, the upper aqueous phase was carefully aspirated to a new tube containing 0.5 mL isopropanol to precipitate the RNA by gentle pipetting. The samples were then incubated for 10 min at room temperature and then centrifuged at 12,000 g for 10 min at 4 °C. The supernatant was decanted, and the RNA precipitate was washed with 75% ice-cold ethanol by gentle inversions. After wash, the samples were centrifuged at 10,000 g for 5 min at 4 °C. And the supernatant was carefully removed, and the tubes were left open in a biosafety cabinet for around 15-30 min to air dry the RNA pellet. The RNA pellet was then resuspended in 30 pL nuclease-free water by pipetting up and down gently. The RNA was then used for RT-PCR analysis. Briefly, the RNA was first reverse transcribed- to generate the template cDNA using the PrimeScript II 1st Strand cDNA synthesis kit. Amplification of target genes was performed with a SYBR® Premix Ex Taq™ on the ABI Vii 7 Real-Time PCR Systems (Applied Biosystems, Thermo fisher scientific, Carlsbad, CA, USA) with corresponding primers (Table 2). PCR running conditions were set as: 95 °C for 30 s followed by 40 thermal cycles, each consisting of denaturation at 95°C for 5 sec, annealing at 60°C for 34 s, and at the end of amplification a dissociation stage was included to ensure the specificity and quality. The comparative Ct method was employed to calculate the relative quantification of gene expression. All samples were firstly normalized to the housekeeping gene, YWHAZ (Lanzafame et al. , 2015), and then normalized with their related controls to obtain AACt values. The fold changes relative to the control were calculated (2^A(-AACT)) and compared between treatments. Table 2 Primer sequences for the RT-PCR study.

Protein coded by listed genes: HAS1 : Hyaluronan synthase 1; HAS3: Hyaluronan synthase 3; SMPD1 : Acid sphingomyelinase; KRT4: Keratin 4; CRABPII: Cellular retinoic acid binding protein II ; YWHAZ: Tyrosine 3-Monooxygenase.

The gene expression fold changes for the various genes are summarised in Table -3 below: Table - 3:

1 :p<0.05 vs Control; 2:p<0.05 vs Example A;

3:p<0.05 vs Example C;

4:p<0.05 vs Example B

The data in the table - 3 above indicates that the composition as per the invention (Example 1 which has a retinol, cetyl alcohol and saccharide isomerate) is far superior to all other Examples ( A, B, C which does not have at least one of the essential ingredients) in almost all the gene expressions responsible for anti-aging benefit which were tested.

Claims

1. A cosmetic composition comprising

(i) 0.001 to 5% a retinoid, by weight of the composition;

(ii) 0.1 to 2% a fatty acid or a fatty alcohol, by weight of the composition; and

(iii) 0.1 to 10% a humectant selected from one or more of saccharide isomerate, 1,2-hexanediol, 2,3-butanediol, pentylene glycol, propanediol, polyglyceryl laurate, lactic acid, sodium lactate, potassium lactate, acetamide MEA, hydroxyethyl urea, and hydrolyzed hyaluronic acid, by weight of the composition.

2. A composition as claimed in claim 1 wherein the humectant is selected from one or more of saccharide isomerate, 1,2-hexane diol, 2,3-butanediol, pentylene glycol, propanediol, hydroxyethyl urea, or hydrolyzed hyaluronic acid.

3. A composition as claimed in claim 2 wherein the humectant is selected from one or more of saccharide isomerate, pentylene glycol, propanediol, or hydrolyzed hyaluronic acid.

4. A composition as claimed in claim 3 wherein the humectant is saccharide isomerate.

5. A composition as claimed in any one of the preceding claims wherein the retinoid is selected from one or more of retinyl ester, retinol, retinal or retinoic acid.

6. A composition as claimed in claim 5 wherein the retinoid is retinyl ester preferably retinyl palmitate, retinyl propionate, or a mixture thereof.

7. A composition as claimed in any one of the preceding claims wherein the fatty acid or fatty alcohol is chosen from one or more of cetyl, myristyl, palmitic or stearyl alcohols or acids.

8. A composition as claimed in claim 7 wherein the fatty acid or fatty alcohol is cetyl alcohol.

9. A method of providing antiaging benefit to skin comprising the step of applying a composition as claimed in any one of the preceding claims to a desired skin surface.

10. Use of a composition as claimed in any one of the preceding claims 1 to 8 for providing antiaging benefits.