Compositions comprising polyion complexes with low molecular weight chitosan

Abstract

The present invention relates to a composition comprising: (a) at least one cationic polymer; (b) at least one anionic polymer; (c) at least one non-polymeric acid or salt thereof having two or more pKa values; and (d) water wherein (a) the cationic polymer is selected from the group consisting of chitosan having a molecular weight of 20,000 or less. The composition according to the invention is stable and is capable of forming a polyion complex, and is capable of providing good spreadability during application and improved texture, such as reduced tack, after application.

Description

Technical Field

[0001] The present invention relates to a composition comprising a polyion complex and a cosmetic method using the composition. Background Art

[0002] Polyion complexes that can be in particulate form and can be formed using cationic polymers and anionic polymers are known.

[0003] For example, WO 2021 / 125069 discloses a composition that can be used for cosmetic treatment and, in one embodiment, comprises at least one polyion complex particle comprising at least one cationic polymer, at least one anionic polymer based on hyaluronic acid, and at least one non-polymeric acid or its salt having two or more pKa values. Poly-ε-lysine is used as the cationic polymer in the prior art disclosed in WO 2021 / 125069.

[0004] Disclosure of the Invention

[0005] There is still a need for stable compositions that can form polyion complexes and can provide good spreadability during application and an improved texture, such as reduced tackiness, after application.

[0006] Accordingly, an object of the present invention is to provide stable compositions that are capable of forming polyion complexes and are capable of providing good spreadability during application and an improved texture, such as reduced tackiness, after application.

[0007] The above object of the present invention can be achieved by a composition comprising:

[0008] (a) at least one cationic polymer;

[0009] (b) at least one anionic polymer;

[0010] (c) at least one non-polymeric acid or its salt having two or more pKa values; and

[0011] (d) water,

[0012] wherein

[0013] (a) the cationic polymer is selected from chitosan having a molecular weight of 20,000 or less.

[0014] Based on the total weight of the composition according to the present invention, the amount of (a) the cationic polymer in the composition can be 0.01% to 15% by weight, preferably 0.05% to 10% by weight, and more preferably 0.1% to 5% by weight.

[0015] (b) The anionic polymer may have at least one negatively chargeable and / or negatively charged moiety selected from sulfate group, sulfate radical, sulfonic acid group, sulfonate radical, phosphoric acid group, phosphate radical, phosphonic acid group, phosphonate radical, carboxylic acid group and carboxylate radical, and is preferably selected from carboxylic acid group and carboxylate radical.

[0016] (b) The anionic polymer may be selected from polysaccharides such as alginic acid, hyaluronic acid and cellulose polymers; anionic (co)polyamino acids such as (co)polyglutamic acid; (co)poly(meth)acrylic acid; (co)polyamic acid; (co)polystyrene sulfonate; (co)poly(vinyl sulfate); dextran sulfate; chondroitin sulfate; (co)polymaleic acid; (co)polyfumaric acid; maleic acid (co)polymers; and salts thereof.

[0017] (b) The anionic polymer may be selected from polysaccharides, preferably hyaluronic acid and its derivatives, cellulose polymers and their salts, and mixtures thereof, and more preferably hyaluronic acid and its salts, carboxymethyl cellulose and its salts, and mixtures thereof.

[0018] Based on the total weight of the composition according to the present invention, the amount of the (b) anionic polymer in the composition may be from 0.01% by weight to 15% by weight, preferably from 0.05% by weight to 10% by weight, and more preferably from 0.1% by weight to 5% by weight.

[0019] (c) The non-polymeric acid or its salt having two or more pKa values may be an organic acid or its salt, preferably a hydrophilic organic acid or its salt or a water-soluble organic acid or its salt, and more preferably phytic acid or its salt, terephthalylidene dicamphor sulfonic acid or its salt, or a mixture thereof.

[0020] Based on the total weight of the composition according to the present invention, the amount of the (c) non-polymeric acid or its salt having two or more pKa values in the composition may be from 0.001% by weight to 10% by weight, preferably from 0.005% by weight to 5% by weight, and more preferably from 0.01% by weight to 1% by weight.

[0021] Based on the total weight of the composition according to the present invention, the amount of the (d) water in the composition may be from 50% by weight to 99% by weight, preferably from 60% by weight to 98% by weight, and more preferably from 70% by weight to 97% by weight.

[0022] The pH of the composition according to the present invention may be from 3 to 9, preferably from 3.5 to 8.5, and more preferably from 4 to 8.

[0023] The composition according to the present invention may be a cosmetic composition, preferably a skin cosmetic composition, and more preferably a skin care cosmetic composition.

[0024] The present invention also relates to a beauty method for keratinous substances such as skin, which comprises:

[0025] Apply the composition according to the invention to keratinous materials; and

[0026] Dry the composition to form a cosmetic film on the keratinous materials.

[0027] The invention may also relate to the use of (a) at least one cationic polymer in a composition comprising (b) at least one anionic polymer; (c) at least one non-polymeric acid or its salt having two or more pKa values; and (d) water, in order to stabilize the composition and / or improve the spreadability of the composition, wherein (a) the cationic polymer is selected from chitosans having a molecular weight of 20,000 or less.

[0028] The invention may also relate to a film, preferably a cosmetic film, comprising:

[0029] (a) at least one cationic polymer;

[0030] (b) at least one anionic polymer; and

[0031] (c) at least one non-polymeric acid or its salt having two or more pKa values,

[0032] wherein

[0033] (a) the cationic polymer is selected from chitosans having a molecular weight of 20,000 or less.

[0034] The invention may also relate to the use of (a) at least one cationic polymer in a film comprising (b) at least one anionic polymer; and (c) at least one non-polymeric acid or its salt having two or more pKa values, in order to improve the texture of the film, preferably in order to enhance the moisturizing feeling, softness and smoothness provided by the film and / or reduce the stickiness of the film, and more preferably in order to reduce the stickiness of the film, wherein (a) the cationic polymer is selected from chitosans having a molecular weight of 20,000 or less.

[0035] Best Mode for Carrying Out the Invention

[0036] After diligent research, the inventors have found it possible to provide a stable composition which is capable of forming polyion complexes and which is capable of providing good spreadability during application and an improved texture, such as reduced stickiness, after application.

[0037] Thus, the composition according to the invention comprises:

[0038] (a) at least one cationic polymer;

[0039] (b) at least one anionic polymer;

[0040] (c) at least one non-polymeric acid having two or more pKa values or a salt thereof; and

[0041] (d) water,

[0042] wherein

[0043] (a) The cationic polymer is selected from chitosan having a molecular weight of 20,000 or less.

[0044] The composition according to the present invention is stable, capable of forming a polyion complex, and capable of providing good spreadability during application and an improved texture (such as reduced stickiness) after application.

[0045] The composition according to the present invention is stable such that it can be homogeneous after its preparation.

[0046] The composition according to the present invention can form a polyion complex by using (a) a cationic polymer, (b) an anionic polymer, and (c) a non-polymeric acid having two or more pKa values or a salt thereof as a crosslinking agent. The polyion complex can be in the form of particles.

[0047] The composition according to the present invention can have good spreadability during application. Thus, the composition according to the present invention can be easily spread during application on, for example, keratinous substances (such as the skin).

[0048] The composition according to the present invention can provide an improved texture (such as reduced stickiness), an enhanced sense of moisturization, an enhanced softness, and an enhanced smoothness after application.

[0049] The improvements in stickiness, sense of moisturization, softness, and smoothness after application can be provided by the film formed from the composition according to the present invention.

[0050] Hereinafter, the composition, method, etc. according to the present invention will be explained in more detail.

[0051] [Composition]

[0052] (Cationic Polymer)

[0053] The composition according to the present invention comprises (a) at least one cationic polymer.

[0054] There is no restriction on the type of (a) cationic polymer. Two or more different types of cationic polymers can be used in combination. Thus, a single type of cationic polymer or a combination of different types of cationic polymers can be used.

[0055] Cationic polymers have a positive charge density. (a) The charge density of the cationic polymer can be from 0.01 meq / g to 20 meq / g, preferably from 0.05 meq / g to 15 meq / g, and more preferably from 0.1 meq / g to 10 meq / g.

[0056] (a) The cationic polymer is selected from chitosan having a molecular weight of 20,000 or less, preferably 10,000 or less, and more preferably 7,000 or less.

[0057] Unless otherwise defined in the specification, "molecular weight" means the weight-average molecular weight.

[0058] Preferably, (a) the molecular weight of the cationic polymer is 1,000 or greater, preferably 1,200 or greater, and more preferably 1,500 or greater.

[0059] Chitosan includes chitosan, salts of chitosan such as chitosan hydrochloride, and glycosides of chitosan. Preferably, (a) the cationic polymer is chitosan having a molecular weight of 20,000 or less.

[0060] Chitosan is well-known. Chitosan can be a linear polysaccharide composed of randomly distributed β-(1→4)-linked D-glucosamine (deacetylated units) and N-acetyl-D-glucosamine (acetylated units).

[0061] The degree of acetylation of chitosan can be greater than 3% to less than 10%, preferably 3% to 8%, and more preferably 3% to 5%.

[0062] Chitosan can be prepared, for example, by treating the chitin shells of shrimp and other crustaceans with an alkaline substance (such as sodium hydroxide). However, preferably, chitosan is obtained from fungi, such as Aspergillus Niger, because chitosan obtained from fungi may not contain any allergens. Therefore, preferably, chitosan is obtained from fungi.

[0063] Relative to the total weight of the composition according to the present invention, the amount of (a) cationic polymer in the composition can be 0.01% by weight or more, preferably 0.05% by weight or more, and more preferably 0.1% by weight or more.

[0064] Relative to the total weight of the composition according to the present invention, the amount of (a) cationic polymer in the composition can be 15% by weight or less, preferably 10% by weight or less, and more preferably 5% by weight or less.

[0065] Based on the total weight of the composition according to the present invention, the amount of (a) the cationic polymer in the composition can be 0.01% to 15% by weight, preferably 0.05% to 10% by weight, and more preferably 0.1% to 5% by weight.

[0066] (Anionic polymer)

[0067] The composition according to the present invention comprises (b) at least one anionic polymer.

[0068] There is no restriction on the type of (b) the anionic polymer. Two or more different types of anionic polymers can be used in combination. Therefore, a single type of anionic polymer or a combination of different types of anionic polymers can be used.

[0069] (e) The anionic polymer can form a polyion complex with (a) the cationic polymer.

[0070] The anionic polymer has a positive charge density. If (b) the anionic polymer is a synthetic anionic polymer, the charge density of (b) the anionic polymer can be 0.1 meq / g to 20 meq / g, preferably 1 meq / g to 15 meq / g, and more preferably 4 meq / g to 10 meq / g, and if (b) the anionic polymer is a natural anionic polymer, the average degree of substitution of (b) the anionic polymer can be 0.1 to 3.0, preferably 0.2 to 2.7, and more preferably 0.3 to 2.5.

[0071] Preferably, the molecular weight of the anionic polymer is 300 or higher, preferably 1,000 or higher, even more preferably 5,000 or higher, even more preferably 10,000 or higher, even more preferably 50,000 or greater, even more preferably 100,000 or greater, and even more preferably 1,000,000 or higher.

[0072] Unless otherwise defined in the specification, "molecular weight" can represent the weight-average molecular weight.

[0073] (b) The anionic polymer can have at least one negatively chargeable and / or negatively charged moiety selected from sulfate group, sulfate radical, sulfonic acid group, sulfonate radical, phosphoric acid group, phosphate radical, phosphonic acid group, phosphonate radical, carboxylic acid group and carboxylate radical, and is preferably selected from carboxylic acid group and carboxylate radical.

[0074] (b) The anionic polymer can be a homopolymer or a copolymer. The term "copolymer" is understood to mean both copolymers obtained from two monomers and those obtained from more than two monomers, such as terpolymers obtained from three monomers.

[0075] (b) The anionic polymer can be selected from natural anionic polymers and synthetic anionic polymers.

[0076] (b) The anionic polymer may comprise at least one hydrophobic chain.

[0077] The anionic polymer that may comprise at least one hydrophobic chain can be obtained by copolymerization of a monomer (a) selected from carboxylic acids having α,β-ethylenic unsaturation (monomer a') and 2-acrylamido-2-methylpropanesulfonic acid (monomer a") with a non-surfactant monomer (b) having ethylenic unsaturation different from (a) and / or a monomer (c) having ethylenic unsaturation produced by reaction of an acrylic monomer having α,β-monoethylenic unsaturation or an isocyanate monomer having monoethylenic unsaturation with a monohydroxy nonionic amphiphilic component or with a primary or secondary fatty amine.

[0078] Therefore, there are two synthetic routes to obtain an anionic polymer having at least one hydrophobic chain:

[0079] - Either by copolymerization of monomer (a') and (c), or (a'), (b) and (c), or (a") and (c), or (a"), (b) and (c),

[0080] - Or by modification (and in particular esterification or amidation) of a copolymer formed from monomer (a'), or formed from monomer (a') and (b), or (a") and (b) with a monohydroxy nonionic amphiphilic compound or a primary or secondary fatty amine.

[0081] As 2-acrylamido-2-methylpropanesulfonic acid copolymers, mention may be made in particular of those disclosed in the article "Micelle formation of random copolymer of sodium 2-(acrylamido)-2-methylpropanesulfonate and nonionic surfactant macromonomer in water as studied by fluorescence and dynamic light scattering – Macromolecules, 2000, Vol. 33, No. 10 – 3694-3704" and applications EP-A-0750899 and EP-A-1069172.

[0082] The carboxylic acid having α,β-monoethylenic unsaturation constituting monomer (a') may be selected from a large number of acids and is in particular selected from acrylic acid, methacrylic acid, crotonic acid, itaconic acid and maleic acid. It is preferably acrylic acid or methacrylic acid.

[0083] The copolymer may comprise monomers (b) containing monoethylenic unsaturation which do not have surfactant properties. Preferred monomers are those which give water-insoluble polymers on homopolymerization. They may be selected, for example, from C1-C4 alkyl acrylates and C1-C4 alkyl methacrylates, such as methyl acrylate, ethyl acrylate, butyl acrylate or the corresponding methacrylates. More particularly preferred monomers are methyl acrylate and ethyl acrylate. Other monomers which may be used are, for example, styrene, vinyltoluene, vinyl acetate, acrylonitrile and vinylidene chloride. Non-reactive monomers are preferred, these being those in which the single alkenyl group is the only reactive group under the polymerization conditions. However, monomers containing groups which react under the action of heat, such as hydroxyethyl acrylate, may optionally be used.

[0084] Monomer (c) is obtained by reaction of an acrylic monomer containing α,β-ethylenic unsaturation (such as (a)) or an isocyanate monomer containing monoethylenic unsaturation with a monohydroxy nonionic amphiphilic compound or a primary or secondary fatty amine.

[0085] The monohydroxy nonionic amphiphilic compounds or primary or secondary fatty amines used to prepare the nonionic monomer (c) are well known. Monohydroxy nonionic amphiphilic compounds are generally alkoxylated hydrophobic compounds which contain an alkylene oxide which forms the hydrophilic part of the molecule. The hydrophobic compound generally consists of an aliphatic alcohol or an alkylphenol, in which a carbonaceous chain containing at least 6 carbon atoms constitutes the hydrophobic part of the amphiphilic compound.

[0086] Preferred monohydroxy nonionic amphiphilic compounds are compounds having the following formula (V):

[0087] R-(OCH2CHR’) m -(OCH2CH2) n -OH(V)

[0088] wherein R is selected from alkyl or alkylene groups containing 6 to 30 carbon atoms and alkylaryl groups having an alkyl group containing 8 to 30 carbon atoms, R’ is selected from alkyl groups containing 1 to 4 carbon atoms, n is an average number in the range of about 1 to 150, and m is an average number in the range of about 0 to 50, provided that n is at least as large as m.

[0089] Preferably, in the compounds of formula (V), the R group is selected from alkyl groups containing 12 to 26 carbon atoms and alkylphenyl groups in which the alkyl group is C8-C 13 ; the R’ group is methyl; m = 0 and n = 1 to 25.

[0090] Preferred primary and secondary fatty amines consist of one or two alkyl chains containing 6 to 30 carbon atoms.

[0091] The monomers used to form the nonionic urethane monomer (c) can be selected from a very diverse range of compounds. Any compound containing copolymerizable unsaturation (such as acrylic, methacrylic or allylic unsaturation) can be used. Monomer (c) can in particular be obtained from isocyanates containing monoethylenic unsaturation (in particular, for example, α,α-dimethyl-m-isopropenylbenzyl isocyanate).

[0092] Monomer (c) can in particular be selected from acrylates, methacrylates or itaconates of oxyethylenated (1 to 50 EO) C6-C 30 fatty alcohols, such as stearyl alcohol polyether-20 methacrylate, oxyethylenated (25 EO) behenyl methacrylate, oxyethylenated (20 EO) monocetyl itaconate, oxyethylenated (20 EO) monostearyl itaconate, or acrylates modified by polyoxyethylenated (25 EO) C 12 -C 24 alcohols; and dimethyl-m-isopropenylbenzyl isocyanates of oxyethylenated (1 to 50 EO) C6-C 30 fatty alcohols, in particular, for example, dimethyl-m-isopropenylbenzyl isocyanate of oxyethylenated behenyl alcohol.

[0093] According to a specific embodiment of the invention, the anionic polymer is selected from acrylic terpolymers obtained from (a) a carboxylic acid containing α,β-ethylenic unsaturation, (b) a non-surfactant monomer containing ethylenic unsaturation different from (a), and (c) a nonionic urethane monomer which is the reaction product of a monohydroxy nonionic amphiphilic compound and an isocyanate containing monoethylenic unsaturation.

[0094] As anionic polymers containing at least one hydrophobic chain, mention may in particular be made of acrylic / ethyl acrylate / alkyl acrylate terpolymers, such as the product sold by Rohm & Haas under the name Acusol 823 as a 30% aqueous dispersion; acrylate / stearyl alcohol polyether-20 methacrylate copolymers, such as the product sold by Rohm & Haas under the name Aculyn22; (meth)acrylic acid / ethyl acrylate / oxyethylenated (25 EO) behenyl methacrylate terpolymers, such as the product sold by Rohm & Haas under the name Aculyn 28 as an aqueous emulsion; acrylic / oxyethylenated (20 EO) monocetyl itaconate copolymer, such as the product sold by National Starch under the name Structure 3001 as a 30% aqueous dispersion; acrylic / oxyethylenated (20 EO) monostearyl itaconate copolymer, such as the product sold by NationalStarch under the name Structure2001 as a 30% aqueous dispersion; acrylate / modified by polyoxyethylenated (25 EO) C12 -C 24 Alcohol-modified acrylate copolymers, such as 30 - 32% copolymer latex sold by 3V SA under the name Synthalen W2000; or dimethyl-m-isopropenylbenzyl isocyanate terpolymers of methacrylic acid / methyl acrylate / ethoxylated behenyl alcohol, such as the product disclosed in document EP-A-0173109 as a 24% aqueous dispersion and containing 40 ethylene oxide groups.

[0095] (e) The anionic polymer can also be a polyester-5, such as the product sold by EASTMAN CHEMICAL under the name Eastman AQ TM 55S Polymer, which has the following chemical formula.

[0096]

[0097] A: Dicarboxylic acid moiety

[0098] G: Diol moiety

[0099] SO3 - Na + : Sodium sulfo

[0100] OH: Hydroxyl

[0101] Preferably, the (e) anionic polymer is selected from polysaccharides such as alginic acid, hyaluronic acid and cellulose polymers (such as carboxymethyl cellulose); anionic (co)polyamino acids such as (co)polyglutamic acid; (co)poly(meth)acrylic acid; (co)polyamic acid; (co)polystyrene sulfonate; (co)poly(vinyl sulfate); dextran sulfate; chondroitin sulfate; (co)polymaleic acid; (co)polyfumaric acid; maleic acid (co)polymers; and their salts.

[0102] The maleic acid copolymer can contain one or more maleic acid comonomers and one or more comonomers selected from: vinyl acetate, vinyl alcohol, vinyl pyrrolidone, olefins containing 2 to 20 carbon atoms and styrene.

[0103] Thus, "maleic acid copolymer" is understood to mean any polymer obtained by copolymerization of one or more maleic acid comonomers and one or more comonomers selected from vinyl acetate, vinyl alcohol, vinyl pyrrolidone, olefins containing 2 to 20 carbon atoms (such as octadecene, ethylene, isobutene, diisobutene or isooctene) and styrene, the maleic acid comonomer being optionally partially or fully hydrolyzed. Hydrophilic polymers will preferably be used, that is to say, polymers with a water solubility greater than or equal to 2 g / l.

[0104] In an advantageous aspect of the present invention, the maleic acid copolymer may have a molar fraction of maleic acid units between 0.1 and 1, more preferably between 0.4 and 0.9.

[0105] The weight average molar mass of the maleic acid copolymer may be between 1,000 and 500,000, and preferably between 1,000 and 50,000.

[0106] Preferably, the maleic acid copolymer is a styrene / maleic acid copolymer, and more preferably sodium styrene / maleic acid copolymer.

[0107] The copolymer of styrene and maleic acid in a 50 / 50 ratio will preferably be used.

[0108] For example, a styrene / maleic acid (50 / 50) copolymer in the form of a 30% ammonium salt in water sold by CrayValley under the label or a styrene / maleic acid (50 / 50) copolymer in the form of a 40% sodium salt in water sold by Cray Valley under the label may be used.

[0109] The use of a styrene / maleic acid copolymer (such as sodium styrene / maleic acid copolymer) can improve the wettability of the membranes prepared from the compositions according to the invention.

[0110] According to one embodiment of the present invention, preferably, (e) the anionic polymer is selected from hyaluronic acid and its derivatives.

[0111] Hyaluronic acid may be represented by the following chemical formula.

[0112]

[0113] In the context of the present invention, the term "hyaluronic acid" particularly encompasses the basic unit of hyaluronic acid of the following formula:

[0114]

[0115] This is the smallest fraction of hyaluronic acid containing a disaccharide dimer (i.e., D-glucuronic acid and N-acetylglucosamine).

[0116] In the context of the present invention, the term "hyaluronic acid and its derivatives" also includes linear polymers containing the above-described polymer units linked together in the chain via alternating β(1,4) glycosidic bonds and β(1,3) glycosidic bonds, having a molecular weight (MW) that can range between 380 daltons and 13,000,000 daltons. This molecular weight depends to a large extent on the source and / or the preparation method from which the hyaluronic acid is obtained.

[0117] In the context of the present invention, the term "hyaluronic acid and its derivatives" also includes hyaluronates. As salts, mention may be made of alkali metal salts (such as sodium and potassium salts), alkaline earth metal salts (such as magnesium salts), ammonium salts, and mixtures thereof.

[0118] In its natural state, hyaluronic acid is present in the extracellular gel, the ground substance of the connective tissue of vertebrate organs (such as dermal and epithelial tissues), and is particularly present in the epidermis, synovial fluid of joints, vitreous humor, human umbilical cord, and crista galli apophysis.

[0119] Thus, the term "hyaluronic acid and its derivatives" includes all fractions or subunits of hyaluronic acid having a molecular weight particularly within the molecular weight range reviewed above.

[0120] In the context of the present invention, hyaluronic acid fractions that do not have inflammatory activity are preferably used.

[0121] As an illustration of various hyaluronic acid fractions, reference may be made to the document "Hyaluronan fragments: an information-rich system", R. Stern et al., European Journal of Cell Biology 58 (2006) 699 - 715, which reviews the biological activities of the listed hyaluronic acids according to their molecular weights.

[0122] According to a preferred embodiment of the present invention, the hyaluronic acid fraction suitable for the uses covered by the present invention has a molecular weight between 50,000 and 5,000,000, particularly between 100,000 and 5,000,000, and especially between 400,000 and 5,000,000 Da. In this case, the term used is high molecular weight hyaluronic acid.

[0123] Alternatively, the hyaluronic acid fraction suitable for the uses covered by the present invention may also have a molecular weight between 50,000 and 400,000 Da. In this case, the term used is medium molecular weight hyaluronic acid.

[0124] Or again, the hyaluronic acid fraction suitable for the uses covered by the present invention may have a molecular weight less than 50,000 Da. In this case, the term used is low molecular weight hyaluronic acid.

[0125] Finally, the term "hyaluronic acid and its derivatives" also includes hyaluronic acid esters, especially those in which all or some of the carboxyl groups of the acid functional groups are esterified with oxyethylated alkyl groups or alcohols containing 1-20 carbon atoms, especially hyaluronic acid esters with a degree of substitution in the range of 0.5-50% at the D-glucuronic acid level of hyaluronic acid.

[0126] Methyl, ethyl, n-propyl, n-pentyl, benzyl, and dodecyl esters of hyaluronic acid may be mentioned in particular. Such esters have been described in particular in "Semisynthetic resorbable materials from hyaluronan esterification" by D. Campoccia et al., Biomaterials 19 (1998) 2101-2127.

[0127] The hyaluronic acid derivative may be, for example, acetylated hyaluronic acid or its salt.

[0128] The molecular weights specified above are also valid for hyaluronic acid esters.

[0129] The hyaluronic acid may in particular be hyaluronic acid supplied by Hyactive under the trade name CPN (MW: 10 kDa to 150 kDa), hyaluronic acid supplied by Soliance under the trade name Cristalhyal (MW: 1.1×10 6 )), hyaluronic acid supplied by Bioland under the name Nutra HA (MW: 820,000 Da), hyaluronic acid supplied by Bioland under the name Nutra AF (MW: 69,000 Da), hyaluronic acid supplied by Bioland under the name Oligo HA (MW: 6,100 Da), or hyaluronic acid supplied by Vam Farmacos Metica under the name D Factor (MW: 380 Da).

[0130] (b) The anionic polymer may be selected from polysaccharides, preferably hyaluronic acid and its derivatives, cellulose polymers and their salts, and mixtures thereof, and more preferably hyaluronic acid and its salts (such as sodium hyaluronate), carboxymethyl cellulose and its salts, and mixtures thereof.

[0131] Relative to the total weight of the composition according to the invention, the amount of the (b) anionic polymer in the composition may be 0.01% by weight or more, preferably 0.05% by weight or more, and more preferably 0.1% by weight or more.

[0132] Relative to the total weight of the composition according to the invention, the amount of the (b) anionic polymer in the composition may be 15% by weight or less, preferably 10% by weight or less, and more preferably 5% by weight or less.

[0133] Based on the total weight of the composition according to the present invention, the amount of the (b) anionic polymer in the composition may be from 0.01% by weight to 15% by weight, preferably from 0.05% by weight to 10% by weight, and more preferably from 0.1% by weight to 5% by weight.

[0134] (Non-polymeric acid having two or more acid dissociation constants)

[0135] The composition according to the present invention comprises (c) at least one non-polymeric acid or a salt thereof having two or more pKa values, i.e., at least one non-polymeric acid or a salt thereof having two or more acid dissociation constants. The pKa value (acid dissociation constant) is well known to those skilled in the art and should be measured at a constant temperature (e.g., 25 °C).

[0136] (c) The non-polymeric acid or a salt thereof having two or more pKa values can act as a crosslinking agent for the (a) cationic polymer. The (a) cationic polymer can be ionically crosslinked by the (c) non-polymeric acid or a salt thereof having two or more pKa values.

[0137] (c) The non-polymeric acid having two or more pKa values can be included in the polyelectrolyte complex formed by the (a) cationic polymer and the (b) anionic polymer. The (c) non-polymeric acid having two or more pKa values can have an effect on the polyelectrolyte complex formed by the (a) cationic polymer and the (b) anionic polymer.

[0138] The term "non-polymeric" herein means that the acid is not obtained by polymerizing two or more monomers. Thus, the non-polymeric acid does not correspond to an acid obtained by polymerizing two or more monomers (e.g., polycarboxylic acid).

[0139] Preferably, the molecular weight of the (c) non-polymeric acid or a salt thereof having two or more pKa values is 1,000 or less, preferably 800 or less, and more preferably 700 or less.

[0140] There is no limitation on the type of the (c) non-polymeric acid or a salt thereof having two or more pKa values. Two or more different types of non-polymeric acids or salts thereof having two or more pKa values can be used in combination. Thus, a single type of non-polymeric acid or a salt thereof having two or more pKa values, or a combination of different types of non-polymeric acids or salts thereof having two or more pKa values can be used.

[0141] The term "salt" as used herein means a salt formed by adding a suitable base to a non-polymeric acid having two or more pKa values, which can be obtained by reacting a non-polymeric acid having two or more pKa values with a base by methods known to those skilled in the art. As salts, mention may be made of metal salts, such as salts with alkali metals (e.g., Na and K), and salts with alkaline earth metals (e.g., Mg and Ca), and ammonium salts.

[0142] (c) The non-polymeric acid having two or more pKa values or its salt can be an organic acid or its salt, and is preferably a hydrophilic organic acid or its salt or a water-soluble organic acid or its salt.

[0143] (c) The non-polymeric acid having two or more pKa values can have at least two acid groups selected from the following: carboxyl group, sulfate group, sulfonic acid group, phosphoric acid group, phosphonic acid group, phenolic hydroxyl group, and mixtures thereof.

[0144] (c) The non-polymeric acid having two or more pKa values can be a non-polymeric polyacid.

[0145] (c) The non-polymeric acid having two or more pKa values can be selected from dicarboxylic acids, disulfonic acids, and diphosphoric acids, and mixtures thereof.

[0146] (c) The non-polymeric acid or its salt having two or more pKa values may be selected from oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, fumaric acid, maleic acid, malic acid, citric acid, aconitic acid, oxaloacetic acid, tartaric acid, and their salts; aspartic acid, glutamic acid, and their salts; terephthalylidene dicamphor sulfonic acid or its salt (Mexoryl SX), benzophenone-9; phytic acid and its salts; Red 2 (amaranth), Red 102 (new carmine), Yellow 5 (tartrazine), Yellow 6 (sunset yellow FCF), Green 3 (fast green FCF), Blue 1 (brilliant blue FCF), Blue 2 (indigo carmine), Red 201 (lithol rubine B), Red 202 (lithol rubine BCA), Red 204 (lake red CBA), Red 206 (lithol red CA), Red 207 (lithol red BA), Red 208 (lithol red SR), Red 219 (bright lake red R), Red 220 (dark brownish purple), Red 227 (fast acid magenta), Yellow 203 (quinoline yellow WS), Green 201 (alizarin cyanine green F), Green 204 (Pyranine Conc), Green 205 (bright green SF pale yellow), Blue 203 (patent blue CA), Blue 205 (seed green FG), Red 401 (vioamine R), Red 405 (permanent Re F5R), Red 502 (ponceau 3R), Red 503 (ponceau R), Red 504 (ponceau SX), Green 401 (naphthol green B), Green 402 (guinea green B), and Black 401 (naphthol blue black); folic acid, ascorbic acid, isoascorbic acid, and their salts; cystine and its salts; EDTA and its salts; glycyrrhizic acid and its salts; and mixtures thereof.

[0147] Preferably, (c) the non-polymeric acid or its salt having two or more pKa values is selected from terephthalylidene dicamphor sulfonic acid and its salt (Mexoryl SX), Yellow 6 (sunset yellow FCF), ascorbic acid, phytic acid and its salts, and mixtures thereof.

[0148] More preferably, (c) the non-polymeric acid or its salt having two or more pKa values is selected from terephthalylidene dicamphor sulfonic acid and its salt (Mexoryl SX), phytic acid and its salts, and mixtures thereof.

[0149] Based on the total weight of the composition according to the present invention, the amount of (c) the non-polymeric acid or its salt having two or more pKa values in the composition may be 0.001% by weight or more, preferably 0.005% by weight or more, and more preferably 0.01% by weight or more.

[0150] Based on the total weight of the composition according to the present invention, the amount of (c) the non-polymeric acid or its salt having two or more pKa values in the composition may be 10% by weight or less, preferably 5% by weight or less, and more preferably 1% by weight or less.

[0151] Based on the total weight of the composition according to the present invention, the amount of the non-polymeric acid or its salt (c) having two or more pKa values in the composition may be from 0.001% by weight to 10% by weight, preferably from 0.005% by weight to 5% by weight, and more preferably from 0.01% by weight to 1% by weight.

[0152] (Water)

[0153] The composition according to the present invention comprises (d) water.

[0154] Based on the total weight of the composition, the amount of (d) water may be 50% by weight or more, preferably 60% by weight or more, and more preferably 70% by weight or more.

[0155] Based on the total weight of the composition, the amount of (d) water may be 99% by weight or less, preferably 98% by weight or less, and more preferably 97% by weight or less.

[0156] Based on the total weight of the composition, the amount of (d) water may be from 50% by weight to 99% by weight, preferably from 60% by weight to 98% by weight, and more preferably from 70% by weight to 97% by weight.

[0157] (pH)

[0158] The pH of the composition according to the present invention may be from 3 to 9, preferably from 3.3 to 8.5, and more preferably from 3.5 to 8.

[0159] At a pH of from 3 to 9, the (a) anionic polymer and the (b) anionic polymer and the (c) non-polymeric acid or its salt having two or more pKa values can form a stable polyion complex which may be in particulate form. Thus, the composition according to the present invention can be stable at a pH of from 3 to 9.

[0160] The pH of the composition according to the present invention can be adjusted by adding at least one basic agent and / or at least one acid different from the (c) non-polymeric acid or its salt having two or more pKa values. The pH of the composition according to the present invention can also be adjusted by adding at least one buffer.

[0161] (Basic agent)

[0162] The composition according to the present invention may comprise at least one basic agent. Two or more basic agents can be used in combination. Thus, a single type of basic agent or a combination of different types of basic agents can be used.

[0163] The basic agent can be an inorganic basic agent. Preferably, the inorganic basic agent is selected from ammonia; alkali metal hydroxides; alkaline earth metal hydroxides; phosphates and monohydrogen phosphates of alkali metals, such as sodium phosphate or monosodium hydrogen phosphate.

[0164] Examples of inorganic alkali metal hydroxides include sodium hydroxide and potassium hydroxide. Examples of alkaline earth metal hydroxides include calcium hydroxide and magnesium hydroxide. As the inorganic base agent, sodium hydroxide is preferred.

[0165] The base agent can be an organic base agent. Preferably, the organic base agent is selected from monoamines and their derivatives; diamines and their derivatives; polyamines and their derivatives; basic amino acids and their derivatives; basic amino acid oligomers and their derivatives; basic amino acid polymers and their derivatives; urea and its derivatives; and guanidine and its derivatives.

[0166] Examples of organic base agents include alkanolamines such as monoethanolamine, diethanolamine, and triethanolamine, and isopropanolamine; urea, guanidine, and their derivatives; basic amino acids such as lysine, ornithine, or arginine; and diamines such as those described in the following structures:

[0167]

[0168] wherein R represents an alkylene group (such as a propylene group) optionally substituted with a hydroxyl group or a C1-C4 alkyl group, and R1, R2, R3, and R4 independently represent a hydrogen atom, an alkyl group, or a C1-C4 hydroxyalkyl group, and 1,3-propanediamine and its derivatives can be taken as examples. Arginine, urea, and monoethanolamine are preferred.

[0169] Depending on the solubility of the base agent, the total amount of the base agent used can be 0.01 wt% to 15 wt%, preferably 0.02 wt% to 10 wt%, more preferably 0.03 wt% to 5 wt% based on the total weight of the composition.

[0170] (Acid)

[0171] The composition according to the present invention may contain at least one acid. Two or more acids can be used in combination. Therefore, a single type of acid or a combination of different types of acids can be used.

[0172] As the acid, any inorganic acid or organic acid commonly used in cosmetic products can be mentioned, preferably an inorganic acid. Monovalent acids and / or polyvalent acids can be used. Monovalent acids such as citric acid, lactic acid, sulfuric acid, phosphoric acid, and hydrochloric acid (HCl) can be used. HCl is preferred.

[0173] Depending on the solubility of the acid, the total amount of the acid used can be 0.01 wt% to 15 wt%, preferably 0.02 wt% to 10 wt%, more preferably 0.03 wt% to 5 wt% based on the total weight of the composition.

[0174] (Buffer)

[0175] The composition according to the invention may comprise at least one buffering agent. Two or more buffering agents may be used in combination. Thus, a single type of buffering agent or a combination of different types of buffering agents may be used.

[0176] As buffering agents, mention may be made of acetate buffering agents (such as acetic acid + sodium acetate), phosphate buffering agents (such as sodium dihydrogen phosphate + disodium hydrogen phosphate), citrate buffering agents (such as citric acid + sodium citrate), borate buffering agents (such as boric acid + sodium borate), tartrate buffering agents (such as tartaric acid + sodium tartrate dihydrate), Tris buffering agents (such as tris(hydroxymethyl)aminomethane), and Hepes buffering agents (4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid).

[0177] (Optional additives)

[0178] In addition to the components mentioned above, the composition according to the invention may also comprise components commonly used in cosmetics within the scope that does not impair the effects of the invention, specifically oils, surfactants (especially nonionic surfactants) or emulsifiers, hydrophilic thickeners or lipophilic thickeners, organic volatile solvents or organic non-volatile solvents, hydrophilic UV filters or hydrophobic UV filters, silicones and silicone derivatives, natural extracts derived from animals or plants, waxes, and the like.

[0179] Relative to the total weight of the composition according to the invention, the composition may comprise the following amounts of the above optional additives: 0.01% by weight to 50% by weight, preferably 0.05% by weight to 30% by weight, and more preferably 0.1% by weight to 10% by weight.

[0180] (Preparation)

[0181] The composition according to the invention can be prepared by mixing the essential ingredients as explained above and the optional ingredients as explained above (if necessary).

[0182] The methods and means for mixing the above essential ingredients and optional ingredients are not limited. Any conventional methods and means can be used to mix the above essential ingredients and optional ingredients to prepare the composition of the invention.

[0183] [Composition]

[0184] The composition according to the invention may be intended to be used as a cosmetic composition. Thus, the cosmetic composition according to the invention may be intended to be applied to keratinous substances. Keratinous substances herein denote materials containing keratin as the main constituent element, and examples thereof include skin, scalp, fingernails / toenails, lips, hair, and the like. Thus, preferably, the cosmetic composition according to the invention is used in a cosmetic method for keratinous substances (especially skin).

[0185] Thus, the cosmetic composition according to the present invention may be a skin cosmetic composition, preferably a skin care composition or a skin makeup composition, and more preferably a skin care composition.

[0186] [Film]

[0187] The composition according to the present invention can be used to prepare a film.

[0188] Therefore, the present invention may also relate to a method for preparing a film (preferably a cosmetic film), which optionally has a thickness preferably greater than 0.1 μm, more preferably 0.5 μm or greater, and even more preferably 1.0 μm or greater. The method includes:

[0189] Applying the composition according to the present invention onto a substrate (preferably a keratinous material, and more preferably the skin); and

[0190] Drying the composition.

[0191] The upper limit of the thickness of the above film is not restricted. Thus, for example, the thickness of the above film can be 1 mm or less, preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 100 μm or less.

[0192] Since the method for preparing a film according to the present invention may involve applying the composition according to the present invention onto a substrate (preferably a keratinous material, and more preferably the skin), and drying the composition, the method does not require any spin coating or spraying, and thus it is possible to easily prepare even a relatively thick film. Therefore, the method for preparing a film according to the present invention can prepare a film without any special equipment (such as a spin coater and a sprayer).

[0193] Even if the film prepared by the above method is relatively thick, it is still thin and can be transparent, and thus it may not be easily noticeable. Therefore, it is preferable to use the film as a cosmetic film.

[0194] If the substrate is not a keratinous material such as the skin, the composition according to the present invention can be applied onto a substrate prepared from any material different from keratin. The material of the non-keratin substrate is not restricted. Two or more materials can be used in combination. Thus, a single type of material or a combination of different types of materials can be used. In any case, it is preferable that the substrate is flexible or elastic.

[0195] If the substrate is not a keratinous material, it is preferable that the substrate is water-soluble, because it is possible to leave the film by washing the substrate with water. As examples of water-soluble materials, poly(meth)acrylic acid, polyethylene glycol, polyacrylamide, polyvinyl alcohol (PVA), starch, cellulose acetate, etc. can be mentioned. PVA is preferred.

[0196] If the non-keratin substrate is in the form of a sheet, its thickness can be greater than the thickness of the film prepared by the above method to facilitate easy handling of the film attached to the substrate sheet. The thickness of the non-keratin substrate sheet is not limited, but can be from 1 μm to 5 mm, preferably from 10 μm to 1 mm, and more preferably from 50 μm to 500 μm.

[0197] More preferably, the film prepared by the above method can be released from the non-keratin substrate. The release mode is not limited. Thus, the film prepared by the above method can be peeled off from the non-keratin substrate, or can be released by dissolving the substrate sheet in a solvent (such as water).

[0198] Therefore, the present invention can also relate to:

[0199] (1) A film (preferably a cosmetic film), which optionally has a thickness preferably greater than 0.1 μm, more preferably 0.5 μm or greater, and even more preferably 1 μm or greater, and which is prepared by a method comprising the following steps:

[0200] Applying the composition according to the present invention to a substrate (preferably a keratinous substance, and more preferably the skin); and

[0201] Drying the composition,

[0202] And

[0203] (2) A film (preferably a cosmetic film), which optionally has a thickness preferably greater than 0.1 μm, more preferably 0.5 μm or greater, and even more preferably 1 μm or greater, and which comprises:

[0204] (a) At least one cationic polymer;

[0205] (b) At least one anionic polymer; and

[0206] (c) At least one non-polymeric acid or its salt having two or more pKa values,

[0207] Wherein

[0208] (a) The cationic polymer is selected from chitosan having a molecular weight of 20,000 or less.

[0209] The above explanations regarding (a) the cationic polymer, (b) the anionic polymer, and (c) the non-polymeric acid or its salt having two or more pKa values are applicable to those in the above films (1) and (2).

[0210] The film thus obtained above can be self-standing. The term "self-standing" herein means that the film can be in the form of a sheet and can be operated as an independent sheet without the assistance of a substrate or a support. Thus, the term "self-standing" can have the same meaning as "self-supporting".

[0211] Preferably, the above film is hydrophobic.

[0212] As used herein, the term "hydrophobic" means that at 20 °C to 40 °C (preferably 25 °C to 40 °C, and more preferably 30 °C to 40 °C), based on the total weight of the polymer, the solubility of the polymer in water (preferably 1 liter in volume) is less than 10% by weight, preferably less than 5% by weight, more preferably less than 1% by weight, and even more preferably less than 0.1% by weight. Most preferably, the polymer is insoluble in water.

[0213] If the above film is hydrophobic, the film may have water-resistant properties, and thus, it can remain on the keratinous material such as skin even when the surface of the keratinous material is moist due to, for example, sweat and rain. Therefore, when the film provides any cosmetic effect, the cosmetic effect can last for a long time.

[0214] On the other hand, the above film can be easily removed from a keratinous material such as skin under alkaline conditions (e.g., pH of 8 to 12, preferably 9 to 11). Therefore, it is difficult to remove the above film with water, however, it can be easily removed with soap that can provide such alkaline conditions.

[0215] The above film may comprise at least one biocompatible and / or biodegradable polymer layer. Two or more biocompatible and / or biodegradable polymers can be used in combination. Therefore, a single type of biocompatible and / or biodegradable polymer or a combination of different types of biocompatible and / or biodegradable polymers can be used.

[0216] As used herein, the term "biocompatible" polymer means that there is no excessive interaction between the polymer and cells in a living body including skin, and the polymer is not recognized as a foreign substance by the living body.

[0217] As used herein, the term "biodegradable" polymer means that the polymer can be degraded or decomposed in a living body due to, for example, the metabolism of the living body itself or the metabolism of microorganisms that may be present in the living body. Additionally, the biodegradable polymer can be degraded by hydrolysis.

[0218] If the above film comprises a biocompatible and / or biodegradable polymer, it is less irritating or non-irritating to the skin and does not cause any rash. Additionally, due to the use of the biocompatible and / or biodegradable polymer, the above film can adhere well to the skin.

[0219] The above film can be used for the cosmetic treatment of keratinous materials, preferably skin, especially the face. The above film can be in any shape or form. For example, it can be used as a full-face mask sheet, or a patch for a part of the face such as the cheeks, nose, and around the eyes.

[0220] [Cosmetic method and use]

[0221] The present invention also relates to:

[0222] A cosmetic method for keratinous materials such as the skin, comprising:

[0223] Applying the composition according to the present invention to the keratinous material; and drying the composition to form a cosmetic film on the keratinous material,

[0224] and

[0225] Use of the composition according to the present invention for preparing a cosmetic film on keratinous materials such as the skin.

[0226] The cosmetic method herein refers to a non-therapeutic cosmetic method for caring for and / or making up the surface of keratinous materials such as the skin.

[0227] In both of the above methods and uses, the above cosmetic film is resistant to water with a pH of 7 or less, and can be removed with water having a pH greater than 7 (preferably 8 or greater, and more preferably 9 or greater).

[0228] In other words, the above cosmetic film can be water-resistant under neutral or acidic conditions (e.g., pH of 7 or less, preferably in the range of 6 or greater and 7 or less, and more preferably in the range of 5 or greater and 7 or less), yet the above cosmetic film can be removed under alkaline conditions (e.g., pH greater than 7, preferably 8 or greater, and more preferably 9 or greater). The upper limit of the pH is preferably 13, more preferably 12, and even more preferably 11.

[0229] Therefore, the above cosmetic film can be water-resistant, and it can remain on the keratinous material (such as the skin) even when the surface of the keratinous material (such as the skin) is wet due to, for example, sweat and rain. On the other hand, the above cosmetic film can be easily removed from the keratinous material (such as the skin) under alkaline conditions. Therefore, it is difficult to remove the above film with water, yet it can be easily removed with soap that can provide alkaline conditions.

[0230] Furthermore, due to the nature of the polyelectrolyte complex in the above cosmetic film, even if the cosmetic film does not contain any cosmetic active ingredients, the cosmetic film can have cosmetic effects, such as reducing the shine of keratinous materials such as the skin, absorbing or adsorbing sebum or unpleasant odors and / or protecting the keratinous material from, for example, dirt or contaminants.

[0231] In addition, even if the above cosmetic film does not contain any cosmetic active ingredients, the cosmetic film can immediately change or modify the skin appearance by changing the light reflection on the skin, etc. Therefore, the above cosmetic film has the potential to hide skin defects such as pores or wrinkles. In addition, the above cosmetic film can immediately change or adjust the skin feel by changing the surface roughness on the skin, etc. In addition, the above cosmetic film can immediately protect the skin by covering the skin surface and acting as a barrier to protect the skin from environmental stresses (such as pollutants, dirt-causing substances, etc.).

[0232] The above cosmetic effects can be adjusted or controlled by changing the chemical composition, thickness, and / or surface roughness of the above cosmetic film.

[0233] If the above cosmetic film contains at least one additional cosmetic active ingredient, the cosmetic film can have cosmetic effects provided by the additional cosmetic active ingredient. For example, if the cosmetic film contains at least one cosmetic active ingredient selected from anti-aging agents, anti-sebum agents, deodorants, antiperspirants, whitening agents, and mixtures thereof, the cosmetic film can treat skin aging, absorb sebum on the skin, control the odor on the skin, control sweating on the skin, and / or whiten the skin.

[0234] It is also possible to apply a makeup cosmetic composition to the above cosmetic film or sheet after the above cosmetic film or sheet has been applied to the skin.

[0235] The present invention may also relate to the use of (a) at least one cationic polymer in a composition comprising (b) at least one anionic polymer; (c) at least one non-polymeric acid or its salt having two or more pKa values; and (d) water, in order to stabilize the composition and / or improve the spreadability of the composition, wherein (a) the cationic polymer is selected from chitosan having a molecular weight of 20,000 or less.

[0236] The composition is stable so that it can be homogeneous after its preparation. The composition can be easily spread during application to, for example, keratinous substances (such as the skin).

[0237] The present invention may also relate to the use of (a) at least one cationic polymer in a film comprising (b) at least one anionic polymer; and (c) at least one non-polymeric acid or its salt having two or more pKa values, in order to improve the texture of the film, preferably in order to enhance the moisturizing feeling, softness, and smoothness provided by the film, and / or reduce the stickiness of the film, and more preferably in order to reduce the stickiness of the film, wherein (a) the cationic polymer is selected from chitosan having a molecular weight of 20,000 or less.

[0238] The above explanations regarding (a) a cationic polymer, (b) an anionic polymer, and (c) a non-polymeric acid or its salt having two or more pKa values, and (d) water are applicable to those in the above uses. Examples

[0239] The present invention will be described in more detail by way of examples. However, the examples should not be construed as limiting the scope of the present invention.

[0240] [Examples 1-9 and Comparative Examples 1-5]

[0241] [Preparation]

[0242] The compositions according to Examples 1-9 and Comparative Examples 1-5 were each prepared by mixing the components shown in Tables 1 and 2.

[0243] The numerical values for the amounts of the components in Tables 1 and 2 are all based on "wt%" based on the raw materials.

[0244] The preparation details are as follows.

[0245] (Example 1)

[0246] First, sodium hyaluronate was added to water and dissolved to prepare an aqueous solution of a polyanion. After dissolution, an appropriate amount of sodium hydroxide was added to the aqueous solution of the polyanion to make the aqueous solution alkaline. Next, chitosan with a molecular weight of 3,000 was added as a polycation to the alkaline aqueous solution. Due to the alkaline conditions of the aqueous solution, the formation of polyion complexes in the aqueous solution was avoided. Next, an appropriate amount of phytic acid was added to the aqueous solution. Polyion complexes in the form of particles were formed.

[0247] (Examples 2 and 3)

[0248] The preparation steps of Example 1 were repeated, with the limitation that the amounts of the polyanion (sodium hyaluronate) and the polycation (chitosan) were changed.

[0249] (Example 4)

[0250] The preparation steps of Example 1 were repeated, with the limitation that the amounts of the polyanion and the polycation were changed, and chitosan with a molecular weight between 10,000 and 20,000 was used instead of chitosan with a molecular weight of 3,000.

[0251] (Example 5)

[0252] The preparation steps of Example 1 were repeated, with the limitation that carboxymethyl cellulose was used instead of sodium hyaluronate.

[0253] (Example 6)

[0254] Repeat the preparation steps of Example 1, with the limitation that the molecular weight of chitosan is changed from 3,000 to 5,000.

[0255] (Example 7)

[0256] Repeat the preparation steps of Example 1, with the limitation that the molecular weight of chitosan is changed from 3,000 to 7,000.

[0257] (Example 8)

[0258] Repeat the preparation steps of Example 5, with the limitation that the molecular weight of chitosan is changed from 3,000 to 5,000.

[0259] (Example 9)

[0260] Repeat the preparation steps of Example 5, with the limitation that the molecular weight of chitosan is changed from 3,000 to 7,000.

[0261] (Comparative Example 1)

[0262] Repeat the preparation steps of Example 2, with the limitation that chitosan with a molecular weight of 100,000 or greater is used instead of chitosan with a molecular weight of 3,000.

[0263] (Comparative Example 2)

[0264] Repeat the preparation steps of Example 2, with the limitation that phytic acid and sodium hydroxide are not used.

[0265] (Comparative Example 3)

[0266] Repeat the preparation steps of Example 2, with the limitation that the molecular weight of chitosan is changed from 3,000 to 5,000 and phytic acid and sodium hydroxide are not used.

[0267] (Comparative Example 4)

[0268] Repeat the preparation steps of Example 2, with the limitation that the molecular weight of chitosan is changed from 3,000 to 7,000 and phytic acid and sodium hydroxide are not used.

[0269] (Comparative Example 5)

[0270] Repeat the preparation steps of Example 1, with the limitation that the amount of polycation is changed and poly-ε-lysine is used instead of chitosan with a molecular weight of 3,000.

[0271]

[0272] Table 2

[0273]

[0274] M.W.: Molecular weight

[0275] [Evaluation]

[0276] (Stability)

[0277] Visual observations were made on the compositions according to Examples 1-9 and the compositions according to Comparative Examples 1-5 immediately after preparation and evaluated according to the following criteria.

[0278] Good: Uniform and no precipitation

[0279] Fair: Uniform and no precipitation, but slow precipitation after several days

[0280] Poor: Non-uniform, with precipitation

[0281] The results are shown in Tables 1 and 2.

[0282] (Sensory evaluation)

[0283] Three panelists evaluated each of the compositions according to Example 1 and the compositions according to Examples 5-9 and the composition according to Comparative Example 5 at time points during and after the application of the compositions. Specifically, each panelist applied each composition to his or her hand and spread it, then dried it in order to evaluate spreadability, stickiness when dry, moisturizing feeling after drying, softness after drying, and smoothness after drying, and graded them from 1 (low) to 5 (high) in view of a control of 1 wt% aqueous solution of sodium hyaluronate (HA) or carboxymethyl cellulose (CMC). Then they were classified into the following three categories based on the average grade:

[0284] Much better: Much better than the control

[0285] Better: Better than the control

[0286] Same: The same as the control

[0287] The results are shown in Tables 3 and 4.

[0288] Table 3

[0289] Example 1 Example 6 Example 7 Comparative Example 5 HA 1% solution Spreading property Better Better Better Same Control Viscosity Much better Much better Much better Better Control Moisturizing feeling Better Better Better Better Control Softness Better Better Better Better Control Smoothness Better Better Better Better Control

[0290] Table 4

[0291] Example 5 Example 8 Example 9 CMC 1% solution Spreading property Better Better Better Control Viscosity Better Better Better Control Moisturizing feeling Better Better Better Control Softness Better Better Better Control Smoothness Better Better Better Control

[0292] (Summary)

[0293] The compositions according to Examples 1-9 are stable (see Table 1).

[0294] Compared with the composition containing only an anionic polymer (control), the spreadability of the composition according to Example 1 and the compositions according to Examples 5-9, and the texture provided by the composition according to Example 1 and the compositions according to Examples 5-9 are improved (see Tables 3 and 4), because a polyion complex is formed by the combination of a cationic polymer (chitosan having a molecular weight of 20,000 or less) and an anionic polymer (sodium hyaluronate or carboxymethyl cellulose).

[0295] The sensory evaluation results for Example 1 are also applicable to Examples 2-4, because the composition according to Example 1 is similar to the compositions according to Examples 2-4.

[0296] The composition according to Comparative Example 1 (which contains chitosan having a higher molecular weight) is unstable (see Table 2).

[0297] The composition according to Comparative Example 2 (which does not contain phytic acid) is unstable (see Table 2).

[0298] The composition according to Comparative Example 3 (which does not contain phytic acid) is unstable (see Table 2).

[0299] The composition according to Comparative Example 4 (which does not contain phytic acid) is unstable (see Table 2).

[0300] The composition according to Comparative Example 5 (which contains poly-ε-lysine instead of chitosan) is stable, but compared with the composition according to the present invention, it has less spreadability during application and is stickier after application (see Tables 2 and 3). Therefore, compared with the composition according to Comparative Example 5, the composition according to the present invention has greater spreadability during application and less stickiness after application due to the use of chitosan having a molecular weight of 20,000 or less instead of poly-ε-lysine (see Table 3).

Claims

1. A composition comprising: (a) at least one cationic polymer; (b) at least one anionic polymer; (c) at least one non-polymeric acid or its salt having two or more pKa values; and (d) water, wherein the (a) cationic polymer is selected from chitosan having a molecular weight of 20,000 or less.

2. The composition according to claim 1, wherein, based on the total weight of the composition, the amount of the (a) cationic polymer in the composition is 0.01% to 15% by weight, preferably 0.05% to 10% by weight, and more preferably 0.1% to 5% by weight.

3. The composition according to claim 1 or 2, wherein the (b) anionic polymer has at least one negatively chargeable and / or negatively charged moiety selected from sulfate group, sulfate radical, sulfonic acid group, sulfonate radical, phosphoric acid group, phosphate radical, phosphonic acid group, phosphonate radical, carboxylic acid group and carboxylate radical, and is preferably selected from carboxylic acid group and carboxylate radical.

4. The composition according to any one of claims 1 to 3, wherein the (b) anionic polymer is selected from polysaccharides such as alginic acid, hyaluronic acid and cellulose polymers; anionic (co)polyamino acids such as (co)polyglutamic acid; (co)poly(meth)acrylic acid; (co)polyamic acid; (co)polystyrene sulfonate; (co)poly(vinyl sulfate); dextran sulfate; chondroitin sulfate; (co)polymaleic acid; (co)polyfumaric acid; maleic acid (co)polymers; and their salts.

5. The composition according to any one of claims 1 to 4, wherein the (b) anionic polymer is selected from polysaccharides, preferably hyaluronic acid and its derivatives, cellulose polymers and their salts, and mixtures thereof, and more preferably hyaluronic acid and its salts, carboxymethyl cellulose and its salts, and mixtures thereof.

6. The composition according to any one of claims 1 to 5, wherein, based on the total weight of the composition, the amount of the (b) anionic polymer in the composition is 0.01% to 15% by weight, preferably 0.05% to 10% by weight, and more preferably 0.1% to 5% by weight.

7. The composition according to any one of claims 1 to 6, wherein the (c) non-polymeric acid or its salt having two or more pKa values is an organic acid or its salt, preferably a hydrophilic organic acid or its salt or a water-soluble organic acid or its salt, and more preferably phytic acid or its salt, terephthalylidene dicamphor sulfonic acid or its salt, or a mixture thereof.

8. The composition according to any one of claims 1 to 7, wherein, based on the total weight of the composition, the amount of the (c) non-polymeric acid or its salt having two or more pKa values in the composition is 0.001% to 10% by weight, preferably 0.005% to 5% by weight, and more preferably 0.01% to 1% by weight.

9. The composition according to any one of claims 1 to 8, wherein the amount of the (d) water in the composition is 50% to 99% by weight, preferably 60% to 98% by weight, and more preferably 70% to 97% by weight, based on the total weight of the composition.

10. The composition according to any one of claims 1 to 9, wherein the pH of the composition is 3 to 9, preferably 3.5 to 8.5, and more preferably 4 to 8.

11. The composition according to any one of claims 1 to 10, wherein the composition is a cosmetic composition, preferably a skin cosmetic composition, and more preferably a skin care cosmetic composition.

12. A cosmetic method for keratinous substances such as the skin, comprising: applying the composition according to any one of claims 1 to 11 to the keratinous substance; and drying the composition to form a cosmetic film on the keratinous substance.

13. Use of (a) at least one cationic polymer in a composition comprising (b) at least one anionic polymer; (c) at least one non-polymeric acid or its salt having two or more pKa values; and (d) water, for stabilizing the composition and / or improving the spreadability of the composition, wherein the (a) cationic polymer is selected from chitosan having a molecular weight of 20,000 or less.

14. A film, preferably a cosmetic film, comprising: (a) at least one cationic polymer; (b) at least one anionic polymer; and (c) at least one non-polymeric acid or its salt having two or more pKa values, wherein the (a) cationic polymer is selected from chitosan having a molecular weight of 20,000 or less.

15. Use of (a) at least one cationic polymer in a film comprising (b) at least one anionic polymer; and (c) at least one non-polymeric acid or its salt having two or more pKa values, for improving the texture of the film, preferably for enhancing the moisturizing feeling, softness and smoothness provided by the film and / or reducing the tackiness of the film, and more preferably for reducing the tackiness of the film, wherein the (a) cationic polymer is selected from chitosan having a molecular weight of 20,000 or less.

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