Aqueous transparent gel composition

Abstract

To provide an aqueous, transparent gel-like composition containing tranexamic acid, which exhibits excellent sustained moisturizing power and hardness stability. [Solution] An aqueous transparent gel composition containing a compound represented by the following formula (1), tranexamic acid, an amide bond-containing anionic surfactant, 10% to 50% by mass of a polyhydric alcohol relative to the total amount of the aqueous transparent gel composition, and water, wherein the content of the salt-forming compound is 0.3% to 10% by mass relative to the total amount of the aqueous transparent gel composition. 1 , R 2 , R 3 Details of n and m are given in the specification. JPEG2026046080000012.jpg24158

Description

[Technical Field]

[0001] This disclosure relates to an aqueous transparent gel-like composition. [Background technology]

[0002] Tranexamic acid is incorporated into cosmetics that are expected to have effects such as skin whitening. For example, Patent Document 1 discloses a skin cosmetic characterized by containing (a) a whitening agent selected from tranexamic acid and ascorbic acid glucoside; (b) polyethylene glycol with an average degree of polymerization of ethylene oxide of 4 to 20; (c) a water-soluble polymer of 0.15% by mass or more; (d) one or more selected from polyoxyethylene polyoxypropylene alkyl (C18 to C28) ethers and polyoxyethylene hydrogenated castor oil; and (e) water, with a viscosity at 30°C in the range of 3,000 to 10,000 mPa·s.

[0003] Transparent gel-like compositions are in demand in the cosmetics field because they have aesthetic features such as a sense of luxury and a beautiful appearance. For example, Patent Document 2 discloses a transparent gel-like composition containing an associative thickener, a whitening agent, a betaine compound, an amide bond-containing anionic surfactant, and water, wherein the content of the associative thickener is 1% to 3% by mass of the total amount of the transparent gel-like composition, the content of the betaine compound is 2% or more by mass of the total amount of the transparent gel-like composition, and the content of the amide bond-containing anionic surfactant is 0.0001% to 2% by mass of the total amount of the transparent gel-like composition. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2019 / 093254 [Patent Document 2] Japanese Patent Publication No. 2021-116262 [Overview of the project] [Problems that the invention aims to solve]

[0005] Incidentally, cosmetics are generally used twice a day, in the morning and evening. Therefore, when applying a cosmetic to the skin for its moisturizing effect, the moisturizing effect during the day or overnight (i.e., the long-term moisturizing effect) is required. On the other hand, in order to improve the moisturizing effect, it is conceivable to add a large amount of a humectant. However, a cosmetic containing a large amount of a humectant has problems such as a decrease in the feel of use and a decrease in stability. In addition, depending on the type of humectant, when a cosmetic is applied to the skin, the humectant may not remain in the stratum corneum for a long time, and the moisturizing effect tends to decrease over time.

[0006] Moreover, tranexamic acid is often incorporated into compositions for which effects such as whitening are desired. For example, there is a demand for incorporating tranexamic acid into a whitening cosmetic. However, when tranexamic acid is incorporated into a gel-like composition, the hardness stability of the gel-like composition may decrease.

[0007] One problem to be solved by an embodiment of the present disclosure is to provide an aqueous transparent gel-like composition containing tranexamic acid and excellent in the persistence of moisturizing effect and hardness stability. Means for Solving the Problems

[0008] The present disclosure includes the following embodiments. [1] A compound represented by the following formula (1), tranexamic acid, an anionic surfactant containing an amide bond, a polyhydric alcohol in an amount of 10% to 50% by mass based on the total amount of the aqueous transparent gel-like composition, water, and an aqueous transparent gel-like composition having a salt-forming compound content of 0.3% to -10% by mass based on the total amount of the aqueous transparent gel-like composition.

[0009]

Chemical formula

[0010] In formula (1), R 1 is, independently of each other, a group represented by R 11 -(O-R 12 )x-. R 11 is, independently of each other, a hydrocarbon group, and R 12 is, independently of each other, an alkylene group having 2 to 4 carbon atoms. x is an integer from 1 to 500. R 2 is, independently of each other, a hydrocarbon group which may have a urethane bond. R 3 is an alkylene group having 2 to 4 carbon atoms, and when there are a plurality of R 3 , the plurality of R 3 may be the same or different. n is an integer from 1 to 500, and m is an integer of 1 or more.

[0011] [2] The aqueous transparent gel composition according to [1], wherein the amide bond-containing anionic surfactant contains at least one anionic surfactant selected from the group consisting of sodium stearoyl glutamate, sodium stearoyl methyltaurine, surfactin Na, lysine dilauroyl glutamate Na, and sodium myristoyl glutamate. [3] The aqueous transparent gel composition according to [1] or [2], wherein the polyhydric alcohol contains at least one selected from the group consisting of glycerin and diglycerin. [4] The aqueous transparent gel composition according to any one of [1] to [3], wherein the content of tranexamic acid is 1% by mass to 5% by mass based on the total amount of the aqueous transparent gel composition. [5] The aqueous transparent gel composition according to any one of [1] to [4], which is a skin care cosmetic. [Advantages of the Invention]

[0012] According to one embodiment of the present disclosure, it is possible to provide an aqueous transparent gel composition containing tranexamic acid and excellent in the persistence of moisturizing power and hardness stability. [Modes for Carrying Out the Invention]

[0013] The aqueous transparent gel composition of this disclosure will be described below with reference to an example of an embodiment. However, the aqueous transparent gel composition of this disclosure is not limited in any way to the following embodiment, and can be implemented with appropriate modifications within the scope of the purpose of this disclosure.

[0014] In this disclosure, a numerical range indicated using "~" means a range that includes the numbers before and after "~" as the minimum and maximum values, respectively. In this disclosure, in numerical ranges described in stages, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Furthermore, in numerical ranges described in this disclosure, the upper or lower limit of that range may be replaced with the values ​​shown in the examples. In this disclosure, the amount of each component in the aqueous transparent gel composition means the total amount of multiple substances present in the aqueous transparent gel composition if multiple substances corresponding to each component are present in the aqueous transparent gel composition, unless otherwise specified. In this disclosure, a combination of two or more preferred embodiments is a more preferred embodiment.

[0015] In this disclosure, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes, as long as their intended purpose is achieved.

[0016] <Aqueous transparent gel composition> The aqueous transparent gel composition of this disclosure (hereinafter also simply referred to as "transparent gel composition") contains a compound represented by the following formula (1) (hereinafter also referred to as "specific compound"), tranexamic acid, an amide bond-containing anionic surfactant, and a polyhydric alcohol in an amount of 10% to 50% by mass relative to the total amount of the aqueous transparent gel composition, and water, wherein the content of the salt-forming compound is 0.3% to 10% by mass relative to the total amount of the transparent gel composition.

[0017] [ka]

[0018] In formula (1), R 1 Each of them is independent of R 11 -(OR 12 It is a group represented by )x-. 11 Each of these independently represents a hydrocarbon group, and R 12 Each of these independently represents an alkylene group with 2 to 4 carbon atoms. x is an integer from 1 to 500. 2 Each of these independently represents a hydrocarbon group which may have a urethane bond. 3 R represents an alkylene group with 2 to 4 carbon atoms. 3 If there are multiple R 3 They may be the same or different. n is an integer between 1 and 500, and m is an integer greater than or equal to 1.

[0019] The transparent gel-like composition of this disclosure contains tranexamic acid and exhibits excellent sustained moisturizing power and hardness stability. Specifically, the transparent gel-like composition according to this disclosure is obtained by selecting a specific compound, tranexamic acid, an amide bond-containing anionic surfactant, a predetermined amount of polyhydric alcohol, and water as components of the transparent gel-like composition, and by controlling the content of the salt-forming compound in the transparent gel-like composition within a certain range, thereby exhibiting excellent sustained moisturizing power and hardness stability despite being a composition containing tranexamic acid.

[0020] On the other hand, Patent Document 1 (International Publication No. 2019 / 093254) discloses a skin cosmetic containing tranexamic acid as a whitening agent, but according to the inventors' findings, this skin cosmetic has poor sustained moisturizing power. Furthermore, the transparent gel-like composition disclosed in Patent Document 2 (Japanese Patent Application Publication No. 2021-116262) is a transparent gel-like composition that focuses on achieving both the suppression of stickiness and the persistence of transparency, and does not focus on achieving both sustained moisturizing power and hardness stability in a transparent gel-like composition containing tranexamic acid.

[0021] In this disclosure, a transparent gel-like composition is considered "aqueous" if it contains water, the total content of water and water-soluble liquid components is 80% by mass or more of the total amount of the composition, and the content of components with a solubility of less than 1% by mass in water at 25°C is less than 5% by mass of the total amount of the composition. Here, "water-soluble liquid component" refers to a liquid component whose solubility in water at 25°C is 1% by mass or more.

[0022] In this disclosure, a transparent gel-like composition is considered "gel-like" if 100g of the object to be measured is placed in a glass container measuring 47mm in diameter and 90mm in height, sealed, stored at 25°C for 24 hours, and then measured using a hardness tester to show a hardness of 7g or more and less than 50g. In other words, in this disclosure, if the composition to be measured has a hardness within the above range, the composition is determined to be "gel-like." If the hardness is less than 7g, the composition is determined to be "liquid," and if the hardness is 50g or more, the composition is determined to be "solid."

[0023] In this disclosure, "transparency" in a transparent gel-like composition is determined by "transparency" using turbidity as an indicator. In this disclosure, turbidity is measured by absorbance using light at a wavelength of 625 nm with a spectrophotometer and a cell with an optical path length of 0.5 cm. In this disclosure, a transparent gel-like composition is said to have "transparency" if its turbidity (absorbance) is 0.04 or less (preferably 0.035 or less, more preferably 0.03 or less, and even more preferably 0.025 or less). Details of the specific evaluation method for evaluating the "transparency" of a transparent gel-like composition are shown in the examples described later.

[0024] In this disclosure, the term "salt-forming compound" is used to refer collectively to compounds that form a salt structure in the transparent gel composition, among all compounds incorporated into the transparent gel composition. Salt-forming compounds include raw material components used in the preparation of the transparent gel composition that have a salt structure, and compounds that dissociate in the transparent gel composition and form a salt structure with other ions present in the system. The salt structures of salt-forming compounds include intramolecular salts. Intramolecular salts have positive and negative charges at non-adjacent positions within the same molecule, and the positively charged atom does not have any dissociable hydrogen atoms bonded to it. Examples include cation structures such as those found in quaternary ammonium compounds, sulfonium compounds, and phosphonium compounds.

[0025] Examples of compounds that qualify as salt-forming compounds in this disclosure include amino acids such as tranexamic acid, glycine, and lysine; carboxylic acids such as citric acid, phosphoric acid, and malic acid; fatty acids such as isostearic acid, oleic acid, and myristic acid; betaine compounds; carnitine; sodium chloride; alkali metal hydroxides such as sodium pyrosulfite, sodium hydroxide, and potassium hydroxide; and anionic surfactants containing amide bonds.

[0026] In this disclosure, the "hardness stability" of a transparent gel-like composition is determined by the separation temperature of the transparent gel-like composition. A higher separation temperature of the transparent gel-like composition indicates superior "hardness stability." A transparent gel-like composition is said to have superior "hardness stability" if its separation temperature is preferably 60°C or higher (more preferably 70°C or higher, even more preferably 80°C or higher, and particularly preferably 90°C or higher). In this disclosure, the separation temperature of the transparent gel-like composition is confirmed by visual observation of whether or not the transparent gel-like composition has separated. Specific evaluation methods for assessing the "hardness stability" of the transparent gel-like composition are shown in the examples described later.

[0027] In this disclosure, the "sustained moisturizing power" of a transparent gel composition is determined by the increase in skin moisture content measured 6 hours after application, based on the skin moisture content measured before application of the transparent gel composition. Skin moisture content is measured using a stratum corneum moisture meter (Corneometer CM825, Courage+Khazaka). A transparent gel composition is said to have excellent "sustained moisturizing power" if the increase in skin moisture content measured using the above stratum corneum moisture meter is preferably greater than 10 (more preferably greater than 15, and even more preferably greater than 20). Details of the specific evaluation method and criteria for evaluating the "sustained moisturizing power" of a transparent gel composition are shown in the examples described later.

[0028] The components of the transparent gel-like composition of this disclosure will be described in detail below.

[0029] [(A) Compound represented by formula (1) (specific compound)] The transparent gel-like composition of this disclosure contains a compound represented by formula (1) (specific compound). In the transparent gel-like composition of this disclosure, a specific compound contributes to the formation of the gel. The gel-forming properties of certain compounds can be inhibited by the salt concentration in the composition. However, in the transparent gel-like composition of this disclosure, the salt-forming compound content is 0.3% to 10% by mass relative to the total amount of the transparent gel-like composition, thus enabling good gel formation.

[0030] The transparent gel-like composition of this disclosure may contain only one compound represented by formula (1), or it may contain two or more compounds.

[0031] [ka]

[0032] In formula (1), R 1 Each of them is independent of R 11 -(OR 12 It is a group represented by )x-. 11 Each of these independently represents a hydrocarbon group, and R 12Each of these independently represents an alkylene group with 2 to 4 carbon atoms. x is an integer from 1 to 500. 2 Each of these independently represents a hydrocarbon group which may have a urethane bond. 3 R represents an alkylene group with 2 to 4 carbon atoms. 3 If there are multiple R 3 They may be the same or different. n is an integer between 1 and 500, and m is an integer greater than or equal to 1.

[0033] As is clear from formula (1), the specific compound is a hydrophobic modified urethane copolymer having urethane bonds and hydrophilic alkylene oxy groups in its main chain, and hydrophobic hydrocarbon groups at its terminals.

[0034] In equation (1), R 1 R 11 -(OR 12 It is a group represented by )x-. There are two R 1 They may be the same or different. R 11 This represents a hydrocarbon group. R 11 Examples of hydrocarbon groups represented by this symbol include aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups consisting of combinations thereof. The aliphatic hydrocarbon group may be linear, branched, or cyclic, and is preferably a branched aliphatic hydrocarbon group. R 11 The hydrocarbon group represented is preferably an aliphatic hydrocarbon group such as an alkyl group, an alkenyl group, a cycloalkyl group, or a cycloalkenyl group.

[0035] Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tertiary butyl, pentyl, isopentyl, neopentyl, tertiary pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, undecyl, dodecyl, tridecyl, isotridecyl, myristyl, palmityl, stearyl, isostearyl, icosyl, docosyl, tetracosyl, triacontyl, 2-octyldodecyl, 2-dodecylhexadecyl, 2-tetradecyloctadecyl, monomethyl branched-isostearyl, and decyltetradeceth.

[0036] Examples of alkenyl groups include vinyl, allyl, propenyl, isopropenyl, butenyl, pentenyl, isopentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, dodecenyl, tetradecenyl, and oleyl.

[0037] Examples of cycloalkyl groups include cyclopentyl, cyclohexyl, and cycloheptyl groups. Examples of cycloalkenyl groups include cyclopentenyl, cyclohexenyl, and cycloheptenyl.

[0038] R 11 The number of carbon atoms in the hydrocarbon group represented is preferably 8 to 36, and more preferably 12 to 30. R 12 This represents an alkylene group having 2 to 4 carbon atoms, with a 2-carbon alkylene group (i.e., an ethylene group) being preferred. x is an integer between 1 and 500, preferably between 1 and 300, more preferably between 1 and 100, even more preferably between 5 and 50, and particularly preferably between 10 and 40.

[0039] In equation (1), R 2 Each of these independently represents a hydrocarbon group which may have a urethane bond. R 2Examples of hydrocarbon groups represented by this symbol include aliphatic hydrocarbon groups, aromatic hydrocarbon groups, and groups consisting of combinations thereof. The aliphatic hydrocarbon group may be linear, branched, or cyclic, and is preferably a linear aliphatic hydrocarbon group. R 2 Examples of hydrocarbon groups represented by are the previously mentioned R 11 Examples of hydrocarbon groups represented by the symbol include divalent groups obtained by removing one hydrogen atom from aliphatic hydrocarbon groups such as alkyl groups, alkenyl groups, cycloalkyl groups, and cycloalkenyl groups.

[0040] R 2 The number of carbon atoms in the hydrocarbon group represented is preferably 1 to 10, more preferably 2 to 8, even more preferably 4 to 8, and particularly preferably 6.

[0041] In equation (1), R 3 This represents an alkylene group having 2 to 4 carbon atoms, with a 2-carbon alkylene group (i.e., an ethylene group) being preferred. In equation (1), R 3 If there are multiple R 3 They may be the same or different.

[0042] In equation (1), n ​​is an integer between 1 and 500, preferably between 1 and 400, more preferably between 10 and 400, and even more preferably between 100 and 300. In formula (1), m is an integer greater than or equal to 1, preferably between 1 and 20, more preferably between 1 and 10, and even more preferably between 1 and 5.

[0043] A specific compound can be obtained, for example, by heating a compound represented by formula (2) below, a compound represented by formula (3) below, and a compound represented by formula (4) below at 80°C to 90°C for 1 to 3 hours and allowing them to react. In the above reaction, one compound represented by formula (2), one compound represented by formula (3), and one compound represented by formula (4) may be used as raw materials, or two or more compounds may be used for each compound.

[0044] [ka]

[0045] [ka]

[0046] [ka]

[0047] R in equation (2) 1 R in equation (1) 1 It corresponds to. R in equation (3) 2 R in equation (1) 2 It corresponds to. R in equation (4) 3 And n are R in equation (1). 3 And corresponds to n.

[0048] The charging ratios of the compound represented by formula (2), the compound represented by formula (3), and the compound represented by formula (4) are not particularly limited and can be set appropriately depending on the specific compound to be used.

[0049] <Compound represented by formula (1-1)> The compound represented by formula (1) is preferably the compound represented by formula (1-1) below (hereinafter referred to as "specific compound (1-1)" as appropriate).

[0050] [ka]

[0051] In equation (1-1), n1 is an integer between 1 and 500, m1 is an integer greater than or equal to 1, and x1 is an integer between 1 and 500.

[0052] In equation (1-1), n1 is an integer between 1 and 500, preferably between 1 and 400, more preferably between 10 and 400, even more preferably between 100 and 300, and particularly preferably 240. In formula (1-1), m1 is an integer greater than or equal to 1, preferably an integer between 1 and 20, more preferably an integer between 1 and 10, even more preferably an integer between 1 and 5, and particularly preferably an integer between 1 and 3. In equation (1-1), x1 is an integer between 1 and 500, preferably between 1 and 300, more preferably between 1 and 100, even more preferably between 5 and 50, particularly preferably between 10 and 40, and most preferably 20.

[0053] As specific compounds (1-1), compounds described in Japanese Patent Publication No. 9-71766, International Publication No. 2014 / 084174, etc., are preferred examples. As the specific compound (1-1), polyethylene glycol (PEG)-240 / decyltetradeceth-20 / hexamethylene diisocyanate (HDI) copolymer is particularly preferred.

[0054] The specific compound may be a synthetic product or may be available commercially. Examples of commercially available products include Adekanol GT-700, Adekanol GT-730, and Adekanol GT-930, which can be obtained from ADEKA Corporation.

[0055] The specific compound preferably has a viscosity of 2000 mPa·s to 5000 mPa·s, and more preferably 2500 mPa·s to 4600 mPa·s, when diluted to 1% by mass in an aqueous solution at 25°C. Viscosity can be measured using a Type B viscometer. An example of a Type B viscometer is the "TV-10M" manufactured by Toki Sangyo Co., Ltd.

[0056] The content of the specific compound is preferably 1% to 3% by mass relative to the total amount of the transparent gel-like composition. When the content of a specific compound is 1% to 3% by mass relative to the total amount of the transparent gel-like composition, transparency and appropriate hardness can be achieved in the transparent gel-like composition. The content of the specific compound is more preferably 1% to 2.5% by mass, and even more preferably 1% to 2% by mass, relative to the total amount of the transparent gel-like composition.

[0057] ((B) Tranexamic acid) The transparent gel-like composition of this disclosure contains tranexamic acid. Tranexamic acid is a compound that can exhibit a whitening effect (i.e., an effect that suppresses melanin production and prevents blemishes, freckles, etc.) and can be included in a transparent gel-like composition as a whitening agent.

[0058] Tranexamic acid is included in one embodiment of the salt-forming compound in the transparent gel-like composition of this disclosure.

[0059] Tranexamic acid can be used in the form of tranexamic acid or tranexamic acid salt in the preparation of transparent gel-like compositions. Examples of tranexamic acid salts include metal salts such as magnesium salts, calcium salts, sodium salts, and potassium salts, as well as inorganic salts such as phosphates, hydrochlorides, hydrobroms, and sulfates.

[0060] The content of tranexamic acid in the transparent gel composition of this disclosure is not limited as long as the effects expected from the inclusion of tranexamic acid are obtained, but it is preferably 1% to 5% by mass, more preferably 1.5% to 3% by mass, and even more preferably 1.8% to 2.2% by mass, based on the total amount of the transparent gel composition.

[0061] [(C) Amide bond-containing anionic surfactant] The transparent gel-like composition of this disclosure contains an anionic surfactant containing an amide bond. In this disclosure, the amide bond-containing anionic surfactant is not particularly limited as long as it is an anionic surfactant and contains an amide bond in its molecular structure. In the following, anionic surfactants containing amide bonds will also be referred to as "specific surfactants" as appropriate.

[0062] An amide bond-containing anionic surfactant is included in one embodiment of the salt-forming compound in the transparent gel-like composition of this disclosure.

[0063] The specific surfactant is preferably an anionic surfactant having at least one amide bond and at least one hydrocarbon chain. The hydrocarbon chain may be a straight chain or a branched chain. The hydrocarbon chain is preferably a saturated hydrocarbon chain. The amide bond may also be introduced into a specific surfactant using an amino acid. The specific surfactant is preferably an amide bond-containing anionic surfactant having at least one hydrocarbon chain with 2 to 20 carbon atoms per molecule, and more preferably an amide bond-containing anionic surfactant having one hydrocarbon chain with 2 to 20 carbon atoms.

[0064] Specific examples of specific surfactants include disodium stearoyl glutamate, sodium stearoyl glutamate, sodium stearoyl methyl taurate, sodium surfactant, sodium dilauroyl glutamate lysine, and sodium myristoyl glutamate. From the viewpoint of hardness stability of the transparent gel-like composition of this disclosure, at least one selected from sodium stearoyl glutamate, sodium stearoyl methyl taurate, sodium surfactant, sodium dilauroyl glutamate lysine, and sodium myristoyl glutamate is preferred, and at least one selected from sodium stearoyl glutamate and sodium stearoyl methyl taurate is more preferred.

[0065] Certain surfactants are also available as commercially produced products. Examples of commercially available specific surfactants are listed below, but are not limited to these. One example of a commercially available product containing sodium stearoyl glutamate is Amisoft HS-11P (Ajinomoto Healthy Supply Co., Ltd.). A commercially available product containing sodium stearoyl methyl taurate is NIKKOL® SMT (Nikko Chemicals Co., Ltd.). One example of a commercially available product containing sodium surfactant is Kaneka Surfactin (Kaneka Corporation). A commercially available product containing dilauroyl glutamate lysine sodium is Pellicea® L-30 (Asahi Kasei Finechem Co., Ltd.). A commercially available product containing sodium myristoyl glutamate is AminoSurfact® AMMS-P1 (Asahi Kasei Finechem Co., Ltd.).

[0066] The transparent gel-like composition of this disclosure may contain only one specific surfactant or may contain two or more specific surfactants.

[0067] The content of the specific surfactant is preferably 0.05% to 0.20% by mass, and more preferably 0.1% to 0.15% by mass, relative to the total amount of the transparent gel-like composition, from the viewpoint of hardness stability and usability.

[0068] [(D) Polyhydric alcohols] The transparent gel-like composition of this disclosure contains a polyhydric alcohol in an amount of 10% to 50% by mass relative to the total amount of the transparent gel-like composition.

[0069] The transparent gel-like composition of this disclosure contains polyhydric alcohols in an amount of 10% to 50% by mass relative to the total amount of the transparent gel-like composition, thereby exhibiting excellent sustained moisturizing power and hardness stability.

[0070] In this disclosure, polyhydric alcohols are not included in the water-miscible solvents described later.

[0071] The transparent gel-like composition of this disclosure may contain only one polyhydric alcohol or two or more polyhydric alcohols.

[0072] The polyhydric alcohol is preferably a dihydric or trihydric lower alcohol, such as glycerin, 1,3-butanediol (cosmetic ingredient name: BG), 1,2-butanediol, pentylene glycol, and dipropylene glycol (cosmetic ingredient name: DPG). Note that "lower alcohol" refers to an alcohol with 5 or fewer carbon atoms.

[0073] From the viewpoint of sustained moisturizing effect, the polyhydric alcohol preferably contains at least one selected from the group consisting of glycerin and diglycerin.

[0074] The polyhydric alcohol content in the transparent gel-like composition is 10% to 50% by mass relative to the total amount of the transparent gel-like composition. From the viewpoint of sustained moisturizing power, the polyhydric alcohol content is 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more, based on the total amount of the transparent gel-like composition. From the viewpoint of hardness stability and usability, the polyhydric alcohol content is 50% by mass or less, preferably 30% by mass or less, and more preferably 25% by mass or less, relative to the total amount of the transparent gel-like composition.

[0075] [(E)Water] The transparent gel-like composition of this disclosure contains water. There are no particular restrictions on the type of water used; natural water, purified water, distilled water, ion-exchanged water, pure water, and ultrapure water (such as Milli-Q water) can be used. Milli-Q water is ultrapure water obtained using Merck KGaA's Millipore Milli-Q water production system. From the viewpoint of having fewer impurities, purified water, distilled water, ion-exchanged water, pure water, or ultrapure water is preferred as the water contained in the transparent gel-like composition.

[0076] The water content in the transparent gel-like composition is not particularly limited, but is preferably 50% by mass or more and 95% by mass or less, more preferably 55% by mass or more and 90% by mass or less, and even more preferably 60% by mass or more and 85% by mass or less, based on the total amount of the transparent gel-like composition.

[0077] The transparent gel-like composition may contain, in addition to water, at least one aqueous solvent that is miscible with water. Examples of water-miscible aqueous solvents include water-miscible organic solvents, and alcohol-based solvents (specifically, monohydric alcohols such as ethanol) can be used. The content of the water-miscible aqueous solvent can be, for example, 10% by mass or less based on the total amount of the transparent gel-like composition.

[0078] [Content of salt-forming compounds] The transparent gel-like composition of this disclosure has a salt-forming compound content of 0.3% to 10% by mass relative to the total amount of the transparent gel-like composition.

[0079] The transparent gel-like composition disclosed herein provides the expected effects of tranexamic acid and the hardness stability effect of a transparent gel-like composition containing tranexamic acid when the salt-forming compound content is 0.3% by mass or more of the total amount of the transparent gel-like composition, and exhibits excellent hardness stability when the salt-forming compound content is 10% by mass or less, even though it is a transparent gel-like composition containing tranexamic acid.

[0080] The lower limit of the salt-forming compound content is 0.3% by mass, and from the viewpoint of the effects expected from the inclusion of tranexamic acid, it is preferable that it be 1% by mass or more relative to the total amount of the transparent gel-like composition. The upper limit of the salt-forming compound content is 10% by mass. From the viewpoint of hardness stability, it is preferably less than 10% by mass, more preferably less than 7.5% by mass, and even more preferably less than 5% by mass, relative to the total amount of the transparent gel-like composition.

[0081] [Other ingredients] The transparent gel-like composition of this disclosure may contain, as necessary, components other than those described above (hereinafter referred to as "other components"), to the extent that it does not impair the effect.

[0082] If the other component is a compound that corresponds to a salt-forming compound, the other component will be included within the range of salt-forming compound content in the transparent gel-like composition of this disclosure.

[0083] Other components may be those that perform two or more functions. Other ingredients include, for example, ceramides, fatty acids, astaxanthin, antioxidants, betaine compounds, and other additives.

[0084] (Ceramide) The transparent gel-like composition of this disclosure may contain ceramide. The ceramide is preferably a natural type of ceramide. In this disclosure, "natural-type ceramide" means ceramide that has the same structure as ceramide found in the stratum corneum of human skin (so-called human-type ceramide).

[0085] Ceramides with a common structure, referred to as "natural type," may be natural products (extracts), ceramides obtained by microbial fermentation, ceramides derived from animals, or synthetic products. The ceramide may be a naturally occurring (D(-)) optically active form, a non-natural (L(+)) optically active form, or a mixture of a naturally occurring optically active form and a non-natural optically active form. The relative stereoconfiguration of ceramide may be that of the natural type, the unnatural type, or a mixture of the natural and unnatural types.

[0086] Specific examples of naturally occurring ceramides include ceramide 1, ceramide 2, ceramide 3, ceramide 4, ceramide 5, ceramide 6, ceramide 7, ceramide 8, and ceramide 9.

[0087] Natural ceramides are also available as commercially produced products. Examples of commercially available natural ceramides include Ceramide I, Ceramide EOP27, Ceramide EOS27, Ceramide III, Ceramide IIIA, Ceramide IIIB, Ceramide IIIC, Ceramide VI (all brand names, Evonik), Ceramide TIC-001 (brand name, Takasago International Corporation), CERAMIDE II (brand name, Quest International), DS-Ceramide VI, DS-CLA-Phytoceramide, C6-Phytoceramide, DS-ceramide Y3S (all brand names, Doosan), and CERAMIDE 2 (brand name, Sederma).

[0088] If the transparent gel-like composition of this disclosure contains ceramide, it may contain only one type of ceramide or two or more types.

[0089] The ceramide content in the transparent gel composition of this disclosure is preferably 0.0001% to 1% by mass, more preferably 0.0001% to 0.1% by mass, and even more preferably 0.0001% to 0.01% by mass, based on the total amount of the transparent gel composition. A ceramide content of 0.0001% by mass or more relative to the total amount of the transparent gel-like composition is preferable because it allows the transparent gel-like composition to exhibit the effects obtained by containing ceramide (e.g., moisturizing effect). Furthermore, it is preferable that the ceramide content is 1% by mass or less relative to the total amount of the transparent gel-like composition, as this results in a transparent gel-like composition with excellent transparency.

[0090] (fatty acid) The transparent gel-like composition of this disclosure may contain fatty acids. Among fatty acids, fatty acids with a melting point of 25°C or lower (hereinafter referred to as "specific fatty acids") are particularly preferred. The specific fatty acid contributes to the transparency and its stability over time in the transparent gel-like composition of this disclosure. Furthermore, the specific fatty acid also contributes to the hardness stability of the transparent gel-like composition. The specific fatty acid may also be used as an emulsifier, solubilizer, or for other purposes. Furthermore, "fatty acids with a melting point of 25°C or lower" refers to fatty acids that are liquid at 25°C.

[0091] As for specific fatty acids, there are no particular restrictions as long as they have a melting point of 25°C or lower. The specific fatty acids may be derived from natural sources or may be synthetic products. As for the specific fatty acid, from the viewpoint of ease of application to the human body, at least one fatty acid selected from the group consisting of isostearic acid, oleic acid, and linoleic acid is preferred, and from the viewpoint of transparency of the transparent gel-like composition, the stability of transparency over time, and the stability of hardness over time, at least one fatty acid selected from isostearic acid and oleic acid is more preferred, and isostearic acid is even more preferred.

[0092] If the transparent gel-like composition of this disclosure contains fatty acids (preferably specific fatty acids), it may contain only one type of fatty acid or two or more types.

[0093] The fatty acid content (preferably specific fatty acids) in the transparent gel composition of this disclosure is preferably 0.01% to 5% by mass, more preferably 0.1% to 1% by mass, and even more preferably 0.1% to 0.5% by mass, based on the total amount of the transparent gel composition, from the viewpoint of transparency, its stability over time, stability of hardness over time, and skin irritation.

[0094] (Astaxanthin) The transparent gel-like composition of this disclosure may contain astaxanthin. Astaxanthin has excellent whitening and antioxidant effects, and by further including astaxanthin in the transparent gel-like composition disclosed herein, these effects can be expected. Astaxanthin encompasses at least one of astaxanthin and its derivatives (e.g., astaxanthin esters). In this disclosure, unless otherwise specified, astaxanthin and its derivatives are collectively referred to as "astaxanthin."

[0095] Astaxanthin can be derived from natural sources such as plants, algae, crustaceans, and bacteria, or it can be synthesized astaxanthin obtained by conventional methods. Astaxanthin can be extracted from cultures of, for example, the red yeast Phaffia, the green alga Haematococcus, marine bacteria, and krill. In the transparent gel-like composition of this disclosure, astaxanthin may be included as an astaxanthin-containing oil obtained as an isolate or extract from a natural product or culture thereof containing astaxanthin. As for astaxanthin or astaxanthin-containing oil, from the viewpoint of quality and productivity, astaxanthin derived from an extract of Haematococcus algae (hereinafter referred to as "Haematococcus algae extract") or an extract of krill (hereinafter referred to as "krill extract") is preferred, and astaxanthin derived from krill extract is particularly preferred. Astaxanthin derived from krill extract (so-called krill-derived astaxanthin) can be used not only in cosmetics but also in quasi-drugs, for example.

[0096] Commercially available astaxanthin can be used. Examples of commercially available Haematococcus algae extracts include FUJIFILM Astaxanthin SS, FUJIFILM Astaxanthin S, FUJIFILM Astaxanthin 10OS, FUJIFILM Astaxanthin 5OS, FUJIFILM Astaxanthin 10O, and FUJIFILM Astaxanthin 5O from Fujifilm Corporation, as well as Astareal® Oil 50F and Astareal® Oil 5F from Fuji Chemical Industry Co., Ltd., and BioAstin® SCE7 from Toyo Enzyme Chemical Co., Ltd. Examples of commercially available krill extracts include Astax-ST (product name) from Marine Daioh Co., Ltd.

[0097] The aqueous gel composition of this disclosure may also contain astaxanthin as an astaxanthin-containing paste.

[0098] The astaxanthin content in the transparent gel-like composition of this disclosure can be appropriately set from viewpoints such as the expression of singlet oxygen scavenging ability (so-called antioxidant effect) and good appearance (e.g., transparency). The astaxanthin content in the transparent gel composition of this disclosure is preferably, for example, 0.000001% by mass to 0.01% by mass (0.01 ppm to 100 ppm) relative to the total amount of the transparent gel composition, more preferably 0.000005% by mass to 0.0075% by mass (0.05 ppm to 75 ppm), and even more preferably 0.0001% by mass to 0.005% by mass (1 ppm to 50 ppm).

[0099] The form in which astaxanthin is contained in the transparent gel-like composition of this disclosure is not particularly limited, but for example, astaxanthin is preferably contained in emulsion particles dispersed in the aqueous phase, as this allows for the incorporation of astaxanthin at a high concentration, astaxanthin can be stably contained in the transparent gel-like composition, and transparency of the transparent gel-like composition can be easily obtained. In particular, from the viewpoint of ease of manufacture, the transparent gel-like composition of this disclosure is preferably contained in the form of an emulsion in which an oil phase containing astaxanthin is dispersed in an aqueous phase (i.e., an astaxanthin emulsion). For details regarding the components contained in the astaxanthin emulsion, please refer to paragraphs

[0037] to

[0061] of Japanese Patent Publication No. 2017-088604. For details regarding the method for preparing the astaxanthin emulsion, please refer to paragraphs

[0089] to

[0093] of Japanese Patent Publication No. 2017-088604.

[0100] (Antioxidant) The transparent gel-like composition of this disclosure preferably contains an antioxidant. There are no particular restrictions on the antioxidant used; for example, any antioxidant commonly used in the field of cosmetics can be appropriately selected. Examples of antioxidants include compounds having phenolic hydroxyl groups (also called phenolic antioxidants), ascorbic acids, and inorganic salts of sulfites or pyrosulfites such as sodium bisulfite, potassium bisulfite, sodium sulfite, potassium sulfite, sodium pyrosulfite, and potassium pyrosulfite.

[0101] Examples of compounds having a phenolic hydroxyl group include flavonoids such as catechin, anthocyanin, flavone, isoflavone, flavan, flavanone, rutin, and glucosylrutin; phenolic acids such as ferulic acid, chlorogenic acid, ellagic acid, gallic acid, and propyl gallate; and dibutylhydroxytoluene (BHT).

[0102] Examples of ascorbic acid derivatives include ascorbic acid, ascorbic acid derivatives, and salts thereof. Here, "ascorbic acid derivative" refers to a compound produced from ascorbic acid through decomposition caused by pH, heat, light, oxidation, enzymes, etc.

[0103] Examples of ascorbic acid derivatives include L-ascorbic acid, sodium L-ascorbate, potassium L-ascorbate, calcium L-ascorbate, L-ascorbic acid phosphate, magnesium salt of L-ascorbic acid phosphate, sodium salt of L-ascorbic acid phosphate, L-ascorbic acid sulfate, disodium salt of L-ascorbic acid sulfate, L-ascorbic acid stearate, L-ascorbic acid 2-glucoside, L-ascorbic acid palmitate, and L-ascorbyl tetraisopalmitate.

[0104] If the transparent gel-like composition of this disclosure contains an antioxidant, it may contain only one antioxidant or two or more antioxidants.

[0105] If the transparent gel-like composition of this disclosure contains an antioxidant, the content of the antioxidant in the transparent gel-like composition is preferably 0.01% to 2% by mass, and more preferably 0.1% to 1% by mass, based on the total amount of the transparent gel-like composition, from the viewpoint of the transparency of the transparent gel-like composition.

[0106] (Betaine compound) The transparent gel-like composition of this disclosure may contain a betaine compound. In this disclosure, "betaine compound" refers to an electrolyte compound having both a cationic and anionic site in its molecule. In the transparent gel-like composition of this disclosure, the betaine compound contributes to suppressing stickiness caused by associative thickeners, such as specific compounds.

[0107] There are no particular restrictions on the betaine compound used. One preferred embodiment of the betaine compound is a betaine compound having a molecular weight of 200 or less. That is, it is preferable that at least one of the betaine compounds in the transparent gel-like composition of this disclosure is a betaine compound with a molecular weight of 200 or less. Confirmation that the betaine compound has a molecular weight of 200 or less can be calculated from the molecular structure of the betaine compound determined by known means.

[0108] Specifically, preferred betaine compounds include lauryl propyl betaine, cocamidopropyl betaine, trimethylglycine, carnitine, proline betaine, trigonelline, and lecithin. From the viewpoint of their track record in use in cosmetics, trimethylglycine, carnitine, and proline betaine are more preferred.

[0109] In particular, as the betaine compound, at least one selected from trimethylglycine and carnitine is preferred from the viewpoint of suppressing stickiness when applying the transparent gel-like composition and maintaining transparency. Trimethylglycine is especially preferred from the viewpoint of suppressing stickiness when applying the transparent gel-like composition.

[0110] Trimethylglycine is a compound having the structure shown below. Trimethylglycine is sometimes referred to as glycine betaine, anhydrous betaine, or simply betaine. Note that the cosmetic ingredient name for trimethylglycine is betaine.

[0111] [ka]

[0112] (Other additives) The transparent gel-like composition of this disclosure may appropriately contain additives commonly used in cosmetics, quasi-drugs, etc. Examples of additives include functional ingredients that exhibit useful cosmetic effects (e.g., moisturizing effect, skin conditioning effect, etc.) when used in cosmetics. Other additives include, for example, solubilizers such as polyoxyethylene polyoxypropylene decyltetradecyl ether (cosmetic ingredient name: PPG-6 decyltetradeceth-20), surfactants other than specific surfactants, phenoxyethanol, carotenoids other than astaxanthin (e.g., lycopene), preservatives such as ethylhexylglycerin, vitamin E derivatives such as tocopherol, colorants, thickeners, pH adjusters such as sodium hydroxide and hydrochloric acid, buffers, fragrances, antibacterial agents, UV absorbers, free radical scavengers, antimicrobial agents, anti-inflammatory agents, and minerals.

[0113] [Uses of transparent gel-like compositions] Applications of the transparent gel-like composition of this disclosure include, for example, cosmetics (e.g., skincare cosmetics such as lotions and serums), quasi-drugs, and pharmaceuticals. However, the applications of the transparent gel-like composition of this disclosure are not limited to these. The transparent gel-like composition disclosed herein has aesthetic features such as a sense of luxury and a beautiful appearance, and also exhibits excellent transparency retention and hardness stability. Therefore, it is preferably a cosmetic, i.e., a transparent gel-like cosmetic, and particularly preferably a transparent gel-like skincare cosmetic. The skincare cosmetic can be a whitening skincare cosmetic.

[0114] [Method for producing a transparent gel-like composition] The method for producing the transparent gel-like composition of this disclosure is not particularly limited. The transparent gel-like composition of this disclosure can be obtained using a specific compound, tranexamic acid, a specific amount of polyhydric alcohol, a specific surfactant, water, and other components as needed, according to a known method for producing transparent gel-like compositions. One preferred method for producing the transparent gel-like composition of this disclosure is a method that includes mixing a specific compound, tranexamic acid, a specific amount of polyhydric alcohol, a specific surfactant, and water (hereinafter referred to as the "mixing step" as appropriate). The following describes an example of a preferred method for producing the transparent gel-like composition of this disclosure. However, matters common to the previously described transparent gel-like composition, such as the components and their amounts, will not be explained.

[0115] [Mixing process] In the mixing process, a specific compound, a specific amount of polyhydric alcohol, a specific surfactant, tranexamic acid, and water are mixed. The method of mixing these components is not particularly limited. For example, a specific compound, a polyhydric alcohol, a specific surfactant, tranexamic acid, and water may be mixed together, or the specific compound, polyhydric alcohol, specific surfactant, and tranexamic acid may be added to the water while stirring and then mixed.

[0116] The mixing method is not particularly limited, and any commercially available mixing method may be used. Mixing means include stirrers, paddle mixers, impeller mixers, homomixers, disperser mixers, ultramixers, high-pressure homogenizers, ultrasonic homogenizers, and the like. Among these, at least one selected from the group consisting of homomixers and disperser mixers is preferred as the mixing means.

[0117] The temperature at which each component is mixed is not particularly limited and can be set as appropriate. It is generally preferable to set it to 4°C to 85°C, and more preferably to 60°C to 85°C. The stirring conditions when mixing each component are not particularly limited as long as the components are thoroughly mixed, and can be set appropriately depending on the mixing method. For example, when using a homomixer as the mixing method, the components can usually be stirred at 500 rpm (revolutions per minute; the same applies hereafter) to 8000 rpm for 5 to 60 minutes.

[0118] The method for producing the transparent gel-like composition of this disclosure may include steps other than the mixing step (so-called other steps) as necessary. Other processes include, for example, defoaming, heat sterilization, cooling, and removal. Methods known in the industry may be used for the defoaming, heat sterilization, cooling, and removal processes. [Examples]

[0119] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the spirit of the invention.

[0120] [Example 1] [Preparation of gel-like composition] The specific compound is PEG-240 / decyltetradeceth-20 / HDI copolymer (product name: Adekanol GT-700, ADEKA Corporation) in 1.2 parts by mass, and as a whitening agent, tranexamic acid (product name: Japanese Pharmacopoeia Tranexamic Acid, Maruzen Pharmaceutical Co., Ltd.) in 2 parts by mass and isostearic acid (product name: Isostearic Acid). A mixture of 0.25 parts by mass of EX (Higher Alcohol Industry Co., Ltd.), 0.125 parts by mass of sodium stearoyl glutamate as an amide bond-containing anionic surfactant, 20 parts by mass of glycerin (product name: Cosmetic-grade concentrated glycerin, Kao Corporation), 0.5 parts by mass of phenoxyethanol, 0.2 parts by mass of ethylhexylglycerin (product name: Adekanol GE-RF, ADEKA), 0.05 parts by mass of sodium pyrosulfite, 0.1 parts by mass of glucosylrutin, 0.05 parts by mass of dibutylhydroxytoluene (BHT), and 0.5 parts by mass of PPG-6 decyltetradeceth-20 (product name: NIKKOL SG-DTD620, Nikko Chemicals Co., Ltd.) was mixed with 50 parts by mass of pure water, and then an appropriate amount of 1 mol / L aqueous sodium hydroxide solution was added to adjust the pH to 8. The resulting mixture was heated to 70°C, stirred at 2000 rpm for 20 minutes using a homogenizer (model name: Homomixer HM-310, AS ONE Corporation), and then cooled to 40°C. Next, to the cooled mixture, 0.37 parts by mass of astaxanthin-containing dispersion and 6.1 parts by mass of ceramide-containing dispersion were added, and pure water was added until the total volume reached 100 parts by mass. The mixture was then stirred at 2000 rpm for 20 minutes using a homogenizer (model name: Homomixer HM-310, AS ONE Corporation). The stirred mixture was then degassed under vacuum to obtain the gel-like composition of Example 1.

[0121] [Examples 2 to 12 and Comparative Examples 1 to 10] Except for appropriately changing the components and their amounts in the gel-like composition of Example 1 so that the compositions shown in Tables 1 and 2 below were obtained, the gel-like compositions of Examples 2 to 12 and Comparative Examples 1 to 10 were obtained in the same manner as in Example 1.

[0122] The astaxanthin-containing dispersion and ceramide-containing dispersion used in the examples and comparative examples were the dispersions prepared as follows.

[0123] <Preparation of an astaxanthin-containing emulsified composition> Aqueous phase composition A was obtained by heating the following components at 70°C for 1 hour to dissolve them. -Composition of aqueous composition A- Sucrose stearate (HLB=16): 3.1g Decaglyceryl monooleate (HLB=12): 6.4g Glycerin: 42.0g ·Pure water: 27.9g

[0124] Oil phase composition A was obtained by heating the following components at 70°C for 1 hour to dissolve them. -Composition of oil phase composition A- • Krill extract: 14.3g (Product name: Astax-ST, contains 5% by mass of astaxanthin, manufactured by Marine Daioh Co., Ltd.) Mixed tocopherols: 4.4g (Product name: Riken E-Oil 800, Riken Vitamin Co., Ltd.) • Lecithin: 1.9g (Product name: SLP Paste, Tsuji Oil Co., Ltd.)

[0125] In the composition of oil phase composition A, krill extract, mixed tocopherols, and lecithin are components corresponding to the oily components in this disclosure.

[0126] The obtained aqueous phase composition A was stirred at 10,000 rpm using an ultrasonic homogenizer (model: HP93, SMT Corporation) while maintaining the temperature at 70°C. Oil phase composition A was then added to the stirred aqueous phase composition A to obtain a crude emulsion. Next, the obtained crude emulsion was cooled to approximately 40°C, and high-pressure emulsification was performed at a pressure of 200 MPa using an ultra-high-pressure emulsifier (model name: Starburst, Sugino Machine Co., Ltd.). After that, the mixture was filtered using a microfilter with an average pore size of 1 μm to obtain an astaxanthin-containing emulsion composition (astaxanthin content: 0.715% by mass).

[0127] The obtained astaxanthin-containing emulsified composition was diluted with Milli-Q water to a concentration of 1% by mass, and the particle size of the dispersed particles was measured using a particle size analyzer (model: FPAR-1000, Otsuka Electronics Co., Ltd.), which was found to be 58 nm (median diameter (d50)).

[0128] <Preparation of ceramide-containing dispersion composition> The following components were stirred at room temperature for 1 hour to obtain oil phase composition B. -Composition of oil phase composition B- • Ceramide 3: 4.8g • Ceramide 6: 5.9g • Oleic acid: 1.1g Ethanol: 412.0g

[0129] In the composition of oil phase composition B, ceramide 3, ceramide 6, and oleic acid are components corresponding to the oily components in this disclosure.

[0130] The following components were stirred at room temperature for 1 hour to obtain aqueous phase composition B. -Composition of aqueous phase composition B- • Polyglyceryl-10 myristate: 10.7g Glycerin: 53.4g • 1,3-Butylene glycol: 53.4g • 4% by mass sodium hydroxide solution: 3.2 g ·Pure water: 865.3g

[0131] The obtained oil phase composition B (oil phase) and aqueous phase composition B (aqueous phase) were micromixed in a ratio of 1:7 (mass ratio) using a KM-type 100 / 100 impact-type micromixer to obtain a dispersion. The operating conditions of the micromixer are as follows.

[0132] Micromixer Usage Conditions -Microchannel- • Oil phase microchannel Cross-sectional shape / width / depth / length = rectangle / 70μm / 100μm / 10mm • Water phase microchannel Cross-sectional shape / width / depth / length = rectangle / 490μm / 100μm / 10mm -Flow rate- The aqueous phase is introduced into the outer ring at a flow rate of 21.0 ml / min, and the oil phase is introduced into the inner ring at a flow rate of 3.0 ml / min, and then micro-mixed.

[0133] The obtained dispersion was desolvated using a centrifugal thin-film vacuum evaporator (model name: Evapol CEP-lab, Okawara Manufacturing Co., Ltd.) until the ethanol concentration was 0.1% by mass or less, and then concentrated and adjusted to a total ceramide concentration of 1.0% by mass to obtain a ceramide-containing dispersion composition.

[0134] [evaluation] The following evaluations were performed using the gel compositions from Examples 1 to 12 and Comparative Examples 1 to 10. The results are shown in Tables 1 and 2. Note that the units for the amounts of each component in Tables 1 and 2 are "mass percent," and the amount of water used is adjusted so that the total amount of each gel-like composition equals 100 mass percent. In Tables 1 and 2, blank spaces in the composition column indicate that the corresponding ingredient is not included. In Table 2, a "-" in the evaluation column indicates that the corresponding evaluation could not be conducted. In Tables 1 and 2, the "*" in the ingredient column indicates that it is a salt-forming compound.

[0135] 1. Evaluation of bulk properties 1-1. Measurement of hardness (confirmation of the properties of the composition) The composition obtained in Examples 1 to 12 and Comparative Examples 1 to 10 was confirmed to be a gel-like composition by measuring its hardness. The measurement method and criteria are as follows. As a result, the compositions prepared in Examples 1 to 12 and Comparative Examples 1 to 6, and Comparative Examples 8 to 9 all had hardness measurements within the range of 10 g to less than 50 g, confirming that they were "gel-like" as defined in this disclosure.

[0136] <Method for measuring hardness> 100g of each gel-like composition, immediately after preparation, was placed in a glass container measuring 47mm in diameter and 90mm in height, capped, and stored at 25°C for 24 hours. The hardness of each gel-like composition after 24 hours of storage at 25°C was measured using a rheometer (model name: FUDOH REHOMETER, Rheotec Co., Ltd.). Specifically, for each aqueous composition, the peak stress value measured when the tip of a 20mm diameter adapter was inserted 20mm with a load of 2kg at a speed of 60mm / min under the measurement temperature of 25°C was defined as the hardness measurement value (unit: g). Details of the measurement conditions are shown below.

[0137] Measurement conditions Adapter: No. 3 (Diameter: 20mm) Load capacity: 2kg Speed: 60mm / min Measurement temperature: 25℃ Unloaded basis: 0.1% Sampling interval: 0.02 seconds X-axis table movement distance: 20mm (forced termination: 20mm)

[0138] ~Standards~ Gel-like: Hardness between 7g and less than 50g Liquid: Hardness less than 7g Solid: Hardness of 50g or more

[0139] 1-2. Transparency (turbidity immediately after preparation) 100g of each gel-like composition immediately after preparation was placed in a glass container measuring 47mm in diameter and 90mm in height, capped, and stored at 25°C for 24 hours. After 24 hours at 25°C, each gel-like composition was placed in a quartz cell with a path length of 0.5cm, and the cell was centrifuged at 4000rpm for 2 minutes using a small refrigerated centrifuge (model: CF5RX, Hitachi Koki Co., Ltd., swing rotor: T4SS31) to remove air bubbles. The absorbance of each gel-like composition after degassing was measured for light at a wavelength of 625 nm using a spectrophotometer (model: U-3310, Hitachi, Ltd.). The obtained absorbance measurements were used as an index to evaluate the transparency of the gel-like composition. The evaluation criteria are shown below. A lower absorbance measurement indicates better transparency of the gel-like composition. Evaluation results of "A," "B," and "C" were considered within the acceptable range for transparency. "A" is the most preferable.

[0140] ~Standards~ A: The absorbance measurement is 0.025 or less. B: The absorbance measurement is greater than 0.025 and less than or equal to 0.03. C: The absorbance measurement is greater than 0.03 and less than or equal to 0.035. D: The absorbance measurement is greater than 0.035 and less than or equal to 0.04. E: The absorbance measurement exceeds 0.04.

[0141] 1-3.Hardness stability 100g of each gel-like composition, immediately after preparation, was placed in a glass container measuring 47mm in diameter and 90mm in height, capped, and stored in a 40°C constant temperature bath for 30 minutes. After storage, the gel-like compositions were visually observed to evaluate whether gel separation was observed. If the gel appeared cloudy but it was unclear whether it was clearly separated, the next evaluation (+5°C) was performed. If clear separation was observed, the temperature at which the gel began to appear was defined as the separation temperature. For gel-like compositions where separation was not observed, the compositions were stored in a constant temperature bath at +5°C (45°C) for 30 minutes, and the separation of the gel-like compositions after storage was visually evaluated. Subsequently, the same procedure was repeated in increments of +5°C for gel-like compositions where separation was not observed, and the temperature at which the gel-like composition separated was determined. A higher temperature at which the gel-like composition separated was evaluated as indicating superior hardness stability. Specifically, the following evaluation criteria were used as indicators, and if the evaluation result was "A," "B," or "C," it was evaluated as having an acceptable rank for hardness stability. "A" is the most preferable.

[0142] ~Standards~ A: 90℃ or higher B: 80℃ or higher, but less than 90℃ C: 70℃ or higher, but less than 80℃ D: 60℃ or higher but less than 70℃ E: Below 60℃

[0143] 1-4. Amount of salt-forming compounds In Tables 1 and 2, the total content (mass%) of the salt-forming compounds indicated by "*" in the ingredient column was calculated in the gel-like composition. Specifically, the following evaluation criteria were used as indicators, and if the evaluation result was "A," "B," or "C," it was evaluated as being within an acceptable rank for the amount of salt-forming compounds. "A" is the most preferable.

[0144] ~Standards~ A: 0.3% by mass or more and less than 5% by mass B: 5% by mass or more and less than 7.5% by mass C: 7.5% by mass or more and less than 10% by mass D: Less than 0.3% by mass, or 10% or more by mass.

[0145] 2. Durability of moisturizing effect (evaluation of moisturizing effect after 6 hours) (1) The inner side of the subject's upper arm was washed with Biore Marshmallow Whip (registered trademark) (cleansing agent, Kao Corporation), rinsed with water, and wiped dry. The subject was then placed in a constant temperature and humidity chamber at 23°C and 50% for 15 minutes. (2) A 5cm x 7.5cm area was marked on the inner side of the washed upper arm, and the moisture content of five points within that area was measured using a Corneometer CM825. The average value of the obtained measurements from the five points was calculated and used as the initial value of skin moisture content. (3) Take 50 μL from each of the gel compositions prepared in the examples and comparative examples, Subjects I spread it with my finger so that it would fit within the marked area. (4) subject The device was left in a constant temperature and humidity room at 23°C and 50% humidity for 6 hours. (5) Similarly to (2) above, the skin moisture content was measured at five locations after application. The average value of the measurements obtained from the five locations was calculated and used as the skin moisture content after 6 hours. (6) The increase obtained by dividing the skin moisture content calculated in (5) by the skin moisture content calculated in (2), i.e., the value of "(skin moisture content after 6 hours) - (initial skin moisture content)", was calculated. A larger calculated increase was considered indicative of superior long-lasting moisturizing power. Specifically, the following evaluation criteria were used as indicators, and if the evaluation result was "A," "B," or "C," it was evaluated as having an acceptable level of moisturizing persistence. "A" is the most preferable.

[0146] ~Standards~ A: Over 20 B: Over 15 and under 20 C: Over 10 and under 15 D: Over 5 and under 10 E:5 or less

[0147] [Table 1]

[0148] [Table 2]

[0149] Details of the components other than those described above in Tables 1 and 2 are as follows: • Sodium stearoyl glutamate (Ajinomoto Healthy Supply Co., Ltd., product name: Amisoft HS-11P) • Sodium stearoyl methyl taurate (Nikko Chemicals Co., Ltd., product name: NIKKOL® SMT) • Surfactin Na (Kaneka Corporation, product name: Kaneka Surfactin) • Dilauroyl glutamate lysine sodium (Asahi Kasei Finechem Corporation, product name: Pellicea (registered trademark) L-30) • Isostearic acid (Product name: Isostearic acid EX, manufactured by Higher Alcohol Industry Co., Ltd.) • Carnitine (ILS Corporation, product name: L-carnitine) • PEG-6 (Product name: PEG#300, NOF Corporation) • PEG-60 glyceryl isostearate (product name: EMALEX GWIS-160EX, Nippon Emulsion Co., Ltd.) • Behenes-20 (Product name: NIKKOL BB-20, Nikko Chemicals Co., Ltd.) • Sodium pyrosulfite (product name: Sodium pyrosulfite "For manufacturing use only", Fujifilm Wako Pure Chemical Industries) • Glucosylrutin (Product name: αG-rutin PS-C, Toyo Sugar Refining Co., Ltd.) BG: Butylene glycol

[0150] As shown in Tables 1 and 2, each gel-like composition in the examples was confirmed to contain tranexamic acid and be an aqueous, transparent gel-like composition with excellent sustained moisturizing power and hardness stability.

Claims

1. The compound represented by the following formula (1), Tranexamic acid and Anionic surfactants containing amide bonds, A polyhydric alcohol in an amount of 10% to 50% by mass relative to the total volume of the aqueous transparent gel composition, It contains water, An aqueous transparent gel composition in which the salt-forming compound content is 0.3% to 10% by mass relative to the total amount of the aqueous transparent gel composition. 【Chemistry 1】 In formula (1), R １ each independently represents a group represented by R １１ -(O-R １２ ). R １１ each independently represents a hydrocarbon group, and R １２ each independently represents an alkylene group having 2 to 4 carbon atoms. x is an integer of 1 to 500. R ２ each independently represents a hydrocarbon group which may have a urethane bond. R ３ represents an alkylene group having 2 to 4 carbon atoms. When there are a plurality of R ３ , the plurality of R ３ may be the same or different. n is an integer of 1 to 500, and m is an integer of 1 or more.

2. The aqueous transparent gel composition according to claim 1, wherein the amide bond-containing anionic surfactant comprises at least one anionic surfactant selected from the group consisting of sodium stearoyl glutamate, sodium stearoyl methyl taurate, sodium surfactant, sodium dilauroyl glutamate lysine, and sodium myristoyl glutamate.

3. The aqueous transparent gel-like composition according to claim 1, wherein the polyhydric alcohol comprises at least one selected from the group consisting of glycerin and diglycerin.

4. The aqueous transparent gel composition according to claim 1, wherein the content of tranexamic acid is 1% by mass to 5% by mass based on the total amount of the aqueous transparent gel composition.

5. The aqueous transparent gel composition according to claim 1, which is a skincare cosmetic.

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