Topical skin components

Abstract

To provide a topical composition for skin including a heparinoid, which moisturizes the skin more effectively than traditional ones and, preferably, reduces irritation for a sensitive skin.SOLUTION: A topical composition for skin contains a heparinoid, a Centella asiatica extract, and water. Preferably, a content of the heparinoid is 0.005 to 5 mass% relative to the topical composition for skin. Also preferably, a content of the Centella asiatica extract is 0.0000001 (1×10-7) to 5 mass% relative to the topical composition for skin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a composition for external use on the skin. [Background technology]

[0002] It is known that compositions containing heparin-like substances, when applied to the skin as topical agents, provide moisturizing, anti-inflammatory, and blood circulation-promoting effects on the skin (Non-Patent Document 1). For this reason, several topical compositions containing heparin-like substances have been proposed. For example, Patent Document 1 describes a topical composition containing heparin-like substances and amino acid components, and Patent Document 2 describes a topical skin preparation containing heparin-like substances, tocopherol, an anti-inflammatory agent, and an antipruritic agent.

[0003] Furthermore, compositions containing Centella asiatica extract, also known as CICA, are known to exhibit effects such as improving rough skin when applied to the skin as a topical agent. For example, Patent Document 3 describes a topical skin preparation containing Centella asiatica extract and vitamins. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2021-59524 [Patent Document 2] Japanese Patent Publication No. 2016-196419 [Patent Document 3] Japanese Patent Publication No. 63-79809 [Non-patent literature]

[0005] [Non-Patent Document 1] Product name: Hillmild Package insert URL: https: / / www.info.pmda.go.jp / downfiles / otc / PDF / J2001000156_02_A.pdf [Overview of the project] [Problems that the invention aims to solve]

[0006] As mentioned above, conventional topical skin compositions containing heparin-like substances have moisturizing, anti-inflammatory, and blood circulation-promoting effects on the skin. However, there has been a need for these topical compositions to have even higher effects, particularly higher moisturizing effects. Therefore, the present invention provides a topical skin composition containing heparin-like substances that has a high moisturizing effect on the skin and, preferably, is less irritating to sensitive skin. [Means for solving the problem]

[0007] In other words, the present invention relates to the following topical skin compositions. [1] A topical skin composition comprising a heparin-like substance, a centella asiatica extract, and a liquid carrier. [2] The topical skin composition according to [1], wherein the content of the heparin-like substance is 0.005% by mass to 5% by mass relative to the topical skin composition. [3] The content of the Centella asiatica extract is 0.0000001 (1 × 10) relative to the topical skin composition. -7 ) The topical skin composition according to [1] or [2], wherein the concentration is ~5% by mass. [4] A humectant, which is a dermatological composition according to any of [1] to [3] above.

[0008] Furthermore, the present invention relates to a method for enhancing the moisturizing effect described below. [5] A method for enhancing the moisturizing effect of a topical skin composition containing a heparin-like substance, comprising incorporating Centella asiatica extract into the topical skin composition. [Effects of the Invention]

[0009] The topical skin composition of the present invention, when applied to the skin, can enhance the moisturizing properties of the skin compared to conventional heparin-like substance-containing compositions. [Modes for carrying out the invention]

[0010] [1. External skin composition] The external skin composition of the present invention contains 1) a heparin-like substance, 2) a Centella asiatica extract, and a liquid carrier, and may further contain other additional components.

[0011] [1-1. Heparin-like substance] The heparin-like substance is a polysulfuric ester of mucopolysaccharide. Mucopolysaccharide is a complex polysaccharide containing amino sugars that is widely distributed in animal tissues and body fluids, for example, chondroitin sulfate. The heparin-like substance may be obtained by polysulfation of mucopolysaccharide, or may be obtained by extraction from tissues of edible animals (for example, lungs including bovine tracheal cartilage). Further, the heparin-like substance contained in the external skin composition of the present invention may be a heparin-like substance listed in the Japanese Non-Pharmacopoeia Drug Standards.

[0012] The external skin composition of the present invention contains the heparin-like substance in an amount of 0.005% by mass or more, preferably 0.01% by mass or more, more preferably 0.05% by mass or more, and still more preferably 0.1% by mass or more, relative to the total mass of the composition. Further, the external skin composition of the present invention contains the heparin-like substance in an amount of 5% by mass or less, preferably 3% by mass or less, more preferably 1% by mass or less, and still more preferably 0.5% by mass or less, relative to the total mass of the composition. The external skin composition of the present invention contains the heparin-like substance in, for example, 0.1% by mass or 0.3% by mass. The content of the heparin-like substance can be appropriately set so that the external skin composition has an appropriate moisturizing effect.

[0013] [1-2. Centella asiatica extract] The Centella asiatica extract may be a crude drug extract extracted from a part or whole plant of Centella asiatica (also known as gotu kola), a plant of the Apiaceae family. The Centella asiatica extract may contain triterpene derivative components such as asiaticoside and madecassoside. Centella asiatica is native to Asia, Africa, India and other regions, but its cultivation method and production area are not particularly limited.

[0014] The method for preparing Centella asiatica extract (extraction method) is not particularly limited, but it can be obtained by extracting a part of Centella asiatica (preferably leaves and stems) or the whole plant as is or dried, using a solvent. Examples of solvents used for extraction include lower monohydric alcohols (methyl alcohol, ethyl alcohol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, etc.), liquid polyhydric alcohols (glycerin, propylene glycol, 1,3-butylene glycol, etc.), lower esters (ethyl acetate, etc.), hydrocarbons (benzene, hexane, pentane, etc.), ketones (acetone, methyl ethyl ketone, etc.), ethers (diethyl ether, tetrahydrofuran, dipropyl ether, etc.), acetonitrile, etc., and one or more of these can be used. A preferred extraction method involves using 0-100 vol% aqueous ethyl alcohol, propylene glycol, or 1,3-butylene glycol, extracting at room temperature or with heating for 1-10 days, filtering, and then allowing the resulting filtrate to mature for another week before filtering again. The extract may be used as is, or it may be desolvent-removed and used as a dried solid.

[0015] Centella asiatica extract is registered as an additive for quasi-drugs under ingredient code 520774 in the Quasi-drug Raw Material Standards 2021. It is also available on the market as, for example, Centella asiatica extract BG70 (Maruzen Pharmaceutical), TECA (SEPPIC SA), Centellin CG (SAMI-SABINSA GROUP LIMITED), CENTELLA ASIATICA BT (Bio Component Research), CICA EX (BG) (Radiant, Inc), CICAegg (registered trademark) (Nanoegg Co., Ltd.), Neosome NE Dermapharm (Nexthia USA LLC), and VEGETOL HYDROCOTYL GR 040 HYDRO (Gattefosse SAS).

[0016] The present invention provides a Centella asiatica extract to the entire composition, with a dry solid content of 0.0000001 (1 × 10) units.-7 ) mass% or more, preferably 0.000001 (1×10 -6 ) mass% or more, more preferably 0.00001 (1×10 -5 ) mass% or more, further preferably 0.0001 (1×10 -4 ) mass% or more, particularly preferably 0.001 (1×10 -3 ) mass% or more. In addition, the external composition for skin of the present invention comprises, based on the total weight of the composition, Centella asiatica extract in an amount of 5 mass% or less, preferably 2 mass% or less, more preferably 1 mass% or less, further preferably 0.5 mass% or less, particularly preferably 0.1 mass% or less, calculated as dry solid content. When an extract liquid is used as the Centella asiatica extract, it may be formulated so as to fall within the above range when converted to dry solid content. Within this range, the extract can be stably formulated, and high effects (such as the effect of enhancing the moisturizing action of heparin-like substances) can be exhibited. The content of Centella asiatica extract as dry solid content is 0.0000001 (1×10 -7 ) mass% or more, the moisturizing action of the heparin-like substance can be enhanced, and even if it exceeds 5 mass%, the effect is unlikely to increase further.

[0017] An external composition for skin comprising Centella asiatica extract may exhibit a moisturizing effect even when a heparin-like substance is not co-formulated (that is, even when used alone); however, as in the present invention, an external composition for skin in which a heparin-like substance and a Centella asiatica extract are co-formulated can enhance the moisturizing action of the heparin-like substance even when the concentration of the Centella asiatica extract is a low concentration that does not exhibit a moisturizing action when used alone. In addition, in an external composition for skin in which a heparin-like substance and a Centella asiatica extract are co-formulated, the Centella asiatica extract enhances the moisturizing action of the heparin-like substance, and this enhancement of the moisturizing action can be greater than the moisturizing action exhibited by the Centella asiatica extract when used alone. As described above, the moisturizing action of a heparin-like substance can be synergistically enhanced by Centella asiatica extract. This synergistic effect is also demonstrated by the examples described later in the present specification.

[0018] [1-3. Liquid Carrier] The topical skin composition of the present invention may contain an appropriate liquid carrier depending on the properties of the composition. For example, if the topical skin composition of the present invention is an aqueous solution (e.g., lotion or serum) or a gel, the main carrier can be water; if it is a lotion, the main carrier can be water along with an oil (e.g., petrolatum); and if it is an ointment or an oily cream, the main carrier can be an oil.

[0019] The topical skin composition of the present invention may contain polyhydric alcohols such as glycerin, propylene glycol, and 1,3-butylene glycol as a liquid carrier. Furthermore, the topical skin composition of the present invention may also contain lower alcohols such as ethanol and propanol as a liquid carrier. However, if it is desired to reduce skin irritation when the topical skin composition of the present invention is applied to sensitive skin, it is preferable that the topical skin composition does not contain lower alcohols, particularly ethanol, or is substantially free of them.

[0020] [1-4. Other ingredients] In addition to heparinoid, centella asiatica extract, and liquid carrier, the topical skin composition of the present invention may contain other components depending on the desired effects of the topical skin composition or the desired dosage form of the formulation.

[0021] The topical skin composition of the present invention may also contain other active ingredients, such as anti-aging agents, anti-inflammatory agents, acne care agents, and antihistamines. Examples of anti-aging agents include niacinamide (also called nicotinamide), arbutin, tranexamic acid, vitamins (e.g., tocopherol derivatives, vitamin C derivatives, retinol palmitate, etc.), ellagic acid, and linoleic acid; examples of anti-inflammatory agents include allantoin, glycyrrhizic acid or its salts (e.g., dipotassium glycyrrhizate), and ε-aminocaproic acid; examples of acne care agents include isopropylmethylphenol and salicylic acid; and examples of antihistamines include diphenhydramine or its salts.

[0022] The topical skin composition of the present invention may further contain a humectant. The aforementioned Centella asiatica extract may also function as a humectant; however, it may also contain 1) ceramide or ceramide-like components, 2) phospholipid polymers, 3) aloe extract, 4) amino acid-based humectants, 5) squalane, or 6) polyhydric alcohols. The amount of these components can be determined according to the moisturizing effect required of the topical skin composition.

[0023] 1) Ceramide is a type of sphingolipid, a compound in which a fatty acid is amide-bonded to a sphingoid. Ceramide-like components may be glycoceramides such as glucosylceramide and galactosylceramide, or synthetic ceramides such as Sofcare® Ceramide SL-E (manufactured by Kao Corporation, N-(hexadecyloxyhydroxypropyl)-N-(hydroxyethylhexadecanamide)) and CERACUTE®-L (manufactured by NOF Corporation, glyceryl-N-(2-methacryloyloxyethyl)carbamate / stearyl methacrylate copolymer). The content of ceramide and / or ceramide-like components in the topical skin composition of the present invention may be set according to the purpose and is not particularly limited.

[0024] 2) Phospholipid polymers are methacryloyloxyethyl phosphorylcholine polymers, which are biocompatible polymers similar to phospholipids, a major component of biological membranes. Examples of phospholipid polymers include Lipidure (registered trademark) (NOF Corporation, 2-methacryloyloxyethyl phosphorylcholine / butyl methacrylate copolymer) and NIKKOL (registered trademark) Resinol S-10 (Nikko Chemicals Co., Ltd., hydrogenated soybean phospholipid). The content of phospholipid polymers in the topical skin composition of the present invention may be set according to the purpose and is not particularly limited.

[0025] 3) Aloe extract is an extract from the leaf pulp of aloe (such as Cape aloe, aloe vera, and tree aloe), a medicinal plant belonging to the lily family. Aloe extract is said to contain uronic acid, lipids, proteins, amino acids, and anthraquinone compounds (such as aloin and aloe-emodin). The amount of aloe extract in the topical skin composition of the present invention may be set according to the purpose and is not particularly limited.

[0026] 4) Amino acid-based humectants are humectants derived from amino acids such as glutamic acid. Examples of amino acid-based humectants include pyrrolidone carboxylic acid or its salts (e.g., sodium salt), pyrrolidine carboxylic acid or its salts, acylpyrrolidine carboxylic acid or its salts, etc. The amino acids in the amino acid-based humectants may be racemic or optically active. Amino acid-based humectants are available on the market as AJIDEW (registered trademark) (Ajinomoto Co., Inc.), PRODEW (registered trademark) (Ajinomoto Co., Inc.), AquaDew (registered trademark) (Ajinomoto Co., Inc.), etc. The content of the amino acid-based humectant in the topical skin composition of the present invention may be set according to the purpose and is not particularly limited.

[0027] 5) Squalane is a saturated hydrocarbon obtained by reducing (hydrogenating) squalene, a hydrocarbon obtained from the liver oil of deep-sea sharks such as dogfish, and is a colorless liquid. The content of the amino acid-based humectant in the skin external composition of the present invention may be set according to the purpose and is not particularly limited.

[0028] 6) Examples of polyhydric alcohols used as wetting agents include glycerin, propylene glycol, 1,3-butylene glycol, and polyethylene glycol.

[0029] The topical skin composition of the present invention may contain a viscosity agent. The viscosity agent is not particularly limited to the extent that it is pharmaceutically acceptable, but examples include water-soluble polymers such as carboxyvinyl polymer, polyvinylpyrrolidone, polyethylene glycol, polyvinyl alcohol, xanthan gum, sodium chondroitin sulfate, and sodium hyaluronate; and celluloses such as hydroxyethylcellulose, methylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, and sodium carboxymethylcellulose. These viscosity agents may be used individually or in combination of two or more.

[0030] The topical skin composition of the present invention may contain a pH adjusting agent for adjusting the pH of the composition to a desired value. Examples of pH adjusters include inorganic acids (phosphoric acid, pyrophosphoric acid, metaphosphoric acid, polyphosphoric acid, sulfuric acid, nitric acid, hydrochloric acid, etc.) and their salts; organic acids (monocarboxylic acids (e.g., acetic acid, sorbic acid), polycarboxylic acids (e.g., oxalic acid, succinic acid, maleic acid, fumaric acid), oxycarboxylic acids [e.g., hydroxymonocarboxylic acids (e.g., glycolic acid, lactic acid, gluconic acid), hydroxypolycarboxylic acids (e.g., tartaric acid, malic acid, citric acid, etc.)] and their salts; inorganic bases (metal hydroxides (e.g., sodium hydroxide, potassium hydroxide, calcium hydroxide, etc.)); organic bases (amines [e.g., alkanolamines (e.g., monoethanolamine, diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, N-methylethanolamine, N-aminoethylethanolamine, N-methyldiethanolamine, etc.)], amino acids (e.g., glycine, etc.)). The topical skin composition of the present invention may contain a combination of multiple pH adjusters.

[0031] The topical skin composition of the present invention may contain a preservative. Examples of preservatives include para-hydroxybenzoic acid esters, commonly known as "parabens." Specifically, methylparaben (methyl parahydroxybenzoate), ethylparaben (ethyl parahydroxybenzoate), propylparaben, isopropylparaben, butylparaben, isobutylparaben, etc., and their salts are exemplified as preservatives. The topical skin composition of the present invention may contain a combination of multiple types of parabens; for example, methylparaben may be combined with ethylparaben or propylparaben. When the topical skin composition of the present invention contains parabens, the paraben content in the composition may be 1 w / v% or less, preferably 0.5 w / v% or less, and more preferably 0.25 w / v% or less.

[0032] The topical skin composition of the present invention includes an emulsifier when the dosage form is an emulsion. The emulsifier may be an anionic, cationic, amphoteric, or nonionic surfactant. Examples of emulsifiers include, but are not limited to, glyceryl monostearate, polyoxyl stearate, glycol distearate, lecithin, sorbitan sesquioleate, sorbitan trioleate, steareth-2, and PEG-7 glyceryl cocoate.

[0033] The topical skin composition of the present invention may contain softening agents, colorants, fragrances, and the like.

[0034] [1-5. Dosage Forms of Topical Skin Compositions] The topical skin composition of the present invention is preferably a liquid formulation, but the dosage form is not particularly limited and may include aqueous formulations, oily formulations, emulsion formulations (either oil-in-water emulsion or water-in-oil emulsion), suspension formulations, aerosol formulations, gel formulations, etc. Furthermore, the topical skin composition of the present invention may be in the form of a cosmetic, such as solid, pressed, oil, liquid, gel, balm, mud, cream, emulsion, lotion, foam (bubble), film, powder, water, pencil, spray (mist), stick, sheet, etc.

[0035] The pH of the topical skin composition of the present invention is preferably adjusted to a range of 5 to 7. This is because it facilitates the penetration of the topical skin composition into the skin.

[0036] The viscosity of the topical skin composition of the present invention can be appropriately adjusted according to the dosage form of the formulation and the desired feel when the composition is applied to the skin. For example, a lower viscosity composition tends to have a greater tendency to wet and spread when applied to the skin; a higher viscosity composition tends to have a greater tendency to blend into the skin when applied. As a guideline, for example, if the topical skin composition of the present invention is an aqueous solution, the viscosity may be in the range of 400 to 1300 mPa·s, and if it is an emulsion, the viscosity may be in the range of 2000 to 12000 mPa·s. Viscosity is measured as the viscosity after 90 seconds at 0.33 rpm under rheometer conditions: 25°C.

[0037] The topical skin composition of the present invention is filled in a container, for example, a light-shielding container. Furthermore, the topical skin composition of the present invention can be easily applied to the skin by being filled in a pump or spray-type container.

[0038] [2. Uses of topical skin compositions] The topical skin composition of the present invention is used by being applied to the skin, for example, by being applied to the skin. For example, the topical skin composition can be rubbed directly into the skin, or gauze or the like soaked in the topical skin composition can be applied to the skin. The area to which the topical skin composition of the present invention is applied is not particularly limited as long as it is skin, and examples include, but are not particularly limited, areas where moisturizing is particularly required, such as the face, flaky knees and heels, and the back. The frequency of application to the skin is not particularly limited, but may be once to several times a day.

[0039] The topical skin composition of the present invention is expected to exhibit moisturizing, anti-inflammatory, and blood circulation-promoting effects when applied to the skin; thereby, it may provide effects such as improving rough and chapped skin, preventing heat rash, chilblains, cracks, chapped skin, and acne, conditioning the skin to keep it healthy, moisturizing the skin, protecting the skin, and preventing skin dryness.

[0040] The topical skin composition of the present invention is particularly preferred for use as a skin moisturizer due to its high moisturizing effect on the skin.

[0041] [3. Method for producing topical skin compositions] The method for producing the topical skin composition of the present invention is not particularly limited and can be produced according to conventional methods depending on the dosage form. For example, it can be obtained by sequentially adding and mixing predetermined amounts of each component (including at least a heparin-like substance and Centella asiatica extract) to a liquid carrier. The methods for producing each dosage form of the composition are described in, for example, "Collection of Examples of Emulsion Preparation Techniques" (Publisher: Technical Information Association, Authors: Asako Mizuno, Chiharu Terada, Planning and Editing), which can be referred to. [Examples]

[0042] The present invention will be described in more detail below with reference to examples, but the present invention is not limited by these examples.

[0043] [Example 1] and [Example 2]: Purified water was mixed with heparinoid (product listed in the Japanese Pharmacopoeia) in the amounts shown in Table 1 and Centella asiatica extract (Centella asiatica extract BG70 (Maruzen Pharmaceutical), 1% solution) and dissolved at room temperature. [Comparative Example 1]: Heparin-like substances (products listed in the Japanese Pharmacopoeia) were added to purified water in the amounts shown in Table 1 and dissolved at room temperature. [Comparative Example 2] and [Comparative Example 3]: Purified water was mixed with the Centella asiatica extract (Centella asiatica extract BG70 (Maruzen Pharmaceutical), 1% solution) in the amounts shown in Table 1 and dissolved at room temperature.

[0044] The moisturizing effect on the skin of two human subjects was confirmed for the samples prepared in Examples 1 and 2 and Comparative Examples 1-3, as well as water (control sample). First, before applying each sample, the skin moisture content of the application site (inner forearm) of the subjects was measured five times, and the average of the moisture increase rate of the three measurements excluding the maximum and minimum values ​​was defined as the pre-application moisture content X. Then, 5 μL of each sample was applied to a circular area with a diameter of approximately 0.8 cm in the said area. Thirty minutes after application, the skin moisture content of the application site was measured five times, and the average of the moisture increase rate of the three measurements excluding the maximum and minimum values ​​was defined as the post-application moisture content Y.

[0045] For each sample, the moisture increase rate Z (%) was calculated using the formula "(Moisture content after application Y - Moisture content before application X) / Moisture content before application X × 100". The moisture increase rate Z (%) for each sample was then subtracted from the moisture increase rate (%) for the control sample, water, and the result is shown in Table 1.

[0046] Skin moisture content was measured using the SKICON®-200EX skin surface stratum corneum moisture content measuring device (Yayoi Co., Ltd.). This device can measure the moisture content of the "surface" stratum corneum by measuring the conductivity (conductance μS) to alternating current using high frequency. This is because high frequency current flows easily through the surface of materials, and there is a close correlation between conductivity and moisture content. In this embodiment, the softness and smoothness of the skin are appropriately evaluated by measuring the moisture content of the "surface" stratum corneum.

[0047] [Table 1]

[0048] As shown in Table 1, the sample of Comparative Example 1 containing 0.1% heparinoid showed a moisture content increase of 5.0%, and 0.000001(1×10 -6 In the sample of Comparative Example 2, which contained 0.000001% (1 × 10¹⁶) Centella asiatica extract (solid content), no increase in moisture content was observed (-0.5%). Based on the results of Comparative Example 1 and Comparative Example 2, 0.1% heparinoid and 0.000001 (1 × 10¹⁶)-6 )% Centella asiatica extract-containing sample has a theoretical moisture increase rate of 4.5% as an additive effect. However, 0.1% of heparin-like substance and 0.000001 (1×10 -6 )% Centella asiatica extract-containing sample of Example 1 shows a moisture increase rate (9.5%) that greatly exceeds 4.5%, which demonstrates that the Centella asiatica extract synergistically enhances the moisturizing effect of the heparin-like substance.

[0049] In addition, as shown in Table 1, the sample of Comparative Example 1 containing 0.1% heparin-like substance has a moisture content increase rate of 5.0%, and 0.001 (1×10 -3 )% Centella asiatica extract-containing sample of Comparative Example 3 has a moisture content increase rate of 9.5%. Based on the results of Comparative Example 1 and Comparative Example 3, 0.1% of heparin-like substance and 0.001 (1×10 -3 )% Centella asiatica extract-containing sample has a theoretical moisture increase rate of 14.5% as an additive effect. However, 0.1% of heparin-like substance and 0.001 (1×10 -3 )% Centella asiatica extract-containing sample of Example 2 shows a moisture increase rate (24.0%) that greatly exceeds 14.5%, which demonstrates that the Centella asiatica extract synergistically enhances the moisturizing effect of the heparin-like substance.

[0050] As described above, the results shown in Table 1 demonstrate that the Centella asiatica extract synergistically enhances the moisturizing effect of the heparin-like substance depending on its concentration.

[0051] [Example 3] Preparation of Toner A viscous agent was added to the aqueous solvent described in Table 2 and dispersed. All the remaining components described in Table 2 (active ingredients, pH adjusters, preservatives, Centella asiatica extract) were added to the solution obtained through dispersion, and the mixture was mixed at room temperature. Thereafter, the mixture was stirred while heating to 70°C, then stirred while cooling to 30°C, and then returned to room temperature to obtain a composition. In the obtained composition, the components were in a dissolved state.

[0052] [Table 2]

[0053] In Table 2, % indicates mass %. KELTROL (registered trademark) CG-SFT (manufactured by CP Kelco Inc.) was used as xanthan gum, NTC-CARBOMER 381 (manufactured by Guangzhou Tinci Materials Technology) as carboxyvinyl polymer, and Centella asiatica extract BG70 (manufactured by Maruzen Pharmaceutical Co., Ltd.) as centella asiatica extract (BG70).

[0054] [Example 4] Preparation of emulsion A viscosity-enhancing agent was added to the aqueous solvent listed in Table 3 and dispersed. The active ingredient, pH adjuster, and Centella asiatica extract were added to the resulting solution and the temperature was raised to 80°C (Solution A). Separately, an oily component, surfactant (emulsifier), and preservative were stirred while the temperature was raised to 80°C (Solution B). While stirring Solution B at 80°C, it was mixed with Solution A at 80°C, and then stirred while cooling to 30°C. After that, it was returned to room temperature to obtain the composition. The obtained composition had its components in an emulsified state.

[0055] [Table 3]

[0056] In Table 3, % indicates mass %. Furthermore, NTC-CARBOMER 381 (manufactured by Guangzhou Tinci Materials Technology) was used as the carboxyvinyl polymer, NIKKOL MYS-40MV (manufactured by Nikko Chemicals Co., Ltd.) as the polyoxyl stearate 40, NIKKOL MGS-BMV (manufactured by Nikko Chemicals Co., Ltd.) as the glyceryl monostearate, and Centella asiatica extract (BG70) was Centella asiatica extract BG70 (manufactured by Maruzen Pharmaceutical Co., Ltd.).

[0057] The moisturizing effect on the skin of eight human subjects was confirmed for the lotion prepared in Example 3, a commercially available lotion (NALC® Medicated Moist Lotion) as Comparative Example 4, and the emulsion prepared in Example 4, as well as a commercially available emulsion (NALC® Medicated Milk Lotion) as Comparative Example 5. First, before applying each sample, the skin moisture content of the application site (inner forearm) of the subjects was measured five times, and the average of the moisture increase rate of the three measurements excluding the maximum and minimum values ​​was defined as the pre-application moisture content X. Then, 5 μL of each sample was applied to a circular area with a diameter of approximately 0.8 cm in the said area. At 1 hour, 2 hours, 4 hours, and 6 hours after application, the skin moisture content of the application site was measured five times, and the average of the moisture increase rate of the three measurements excluding the maximum and minimum values ​​was defined as the post-application moisture content Y.

[0058] For each sample, the value calculated as "(Moisture content after application Y - Moisture content before application X) / Moisture content before application X × 100" is shown as the moisture increase rate (%) in Table 4 (Example 3 and Comparative Example 4) and Table 5 (Example 4 and Comparative Example 5). Skin moisture content was measured using the SKICON-200EX skin surface stratum corneum moisture content measuring device (Yayoi Co., Ltd.).

[0059] [Table 4]

[0060] [Table 5]

[0061] The NALC Medicated Moist Lotion used in Comparative Example 4 is a lotion containing heparinoid and dipotassium glycyrrhizate as active ingredients. Other ingredients include purified water, 2-methacryloyloxyethyl phosphorylcholine / butyl methacrylate copolymer solution, sodium hyaluronate (2), magnesium L-ascorbyl phosphate, yuzu ceramide, 1,3-butylene glycol, concentrated glycerin, glycosyl trehalose / hydrogenated starch hydrolysate mixture solution, citric acid, sodium citrate, and phenoxyethanol, but does not contain centella asiatica extract. As shown in Table 4, the lotion prepared in Example 3 increased the rate of skin moisture increase more than the commercially available lotion in Comparative Example 4, indicating superior moisturizing performance.

[0062] The NALC medicated milk lotion used in Comparative Example 5 is a lotion containing heparinoid and dipotassium glycyrrhizate as active ingredients, and other ingredients include purified water, dipropylene glycol, 1,3-butylene glycol, concentrated glycerin, sorbitol solution, sodium hyaluronate (2), 2-methacryloyloxyethyl phosphorylcholine / butyl methacrylate copolymer solution, squalane, glyceryl tri-2-ethylhexanoate, cetyl 2-ethylhexanoate, meadowfoam oil, light liquid isoparaffin, polyoxyethylene sorbitan monostearate (20 E.O.), self-emulsifying glyceryl monostearate, polyoxyethylene lauryl ether (7 E.O.), polyacrylamide, acrylic acid / alkyl methacrylate copolymer, xanthan gum, potassium hydroxide, natural vitamin E, disodium edetate, phenoxyethanol, and methyl parahydroxybenzoate, but does not contain Centella asiatica extract. As shown in Table 5, the emulsion prepared in Example 4 increased the rate of skin moisture increase more than the commercially available emulsion in Comparative Example 4, indicating superior moisturizing performance. [Industrial applicability]

[0063] According to the present invention, it is possible to provide a topical skin composition with enhanced moisturizing properties, and therefore the present invention can be used as a cosmetic or the like for moisturizing the skin, protecting the skin, and preventing skin dryness.

Claims

1. A topical skin composition comprising a heparin-like substance, a centella asiatica extract, and a liquid carrier, The content of the heparin-like substance is 0.1% to 0.3% by mass relative to the composition. A composition for topical use on the skin, wherein the content of the Centella asiatica extract is 1 × 10⁻⁶% by mass to 1 × 10⁻³% by mass as dry solid content relative to the composition.

2. A humectant, a topical skin composition according to claim 1.

3. A method for enhancing the moisturizing effect of a topical skin composition containing a heparin-like substance, A method for enhancing moisturizing effect, comprising adding to the aforementioned topical skin composition 1 × 10⁻⁶% by mass to 1 × 10⁻³% by mass of Centella asiatica extract as a dry solid content relative to the composition.

Images