JP7301760B2 - Skin topical agent - Google Patents

Description

The present disclosure relates to topical skin preparations.

Ascorbic acid is known as an antioxidant having a strong reducing action. In addition, ascorbic acid is an important component involved in collagen synthesis in vivo, and is also known to be effective for whitening. However, since ascorbic acid has a strong reducing action, it itself is rapidly oxidized, making it unstable and difficult to handle. Therefore, ascorbic acid derivatives (also referred to as “provitamin C”), which are chemically modified ascorbic acid to make it easier to use, are often used in external preparations for skin such as cosmetics.
For example, Patent Document 1 discloses a lip balm using L-ascorbyl palmitate.

JP-A-2003-231628

When ascorbic acid is stabilized as a derivative, the handleability is improved, but the molecular weight increases, so even if the compounding amount is increased, the concentration of ascorbic acid becomes low. For example, in the case of L-ascorbyl palmitate contained in the lip balm described in Patent Document 1, the molecular weight is about three times that of ascorbic acid, so the concentration of the active ingredient ascorbic acid is about one-third. Become. In addition, in the case of ascorbic acid derivatives, in order to exert the effect of ascorbic acid, it is necessary to remove the chemically modified moiety and return to ascorbic acid. It may not perform as expected. Therefore, it is desirable to be able to mix ascorbic acid at a high concentration in an external preparation for skin without converting ascorbic acid into a derivative. However, as already mentioned, ascorbic acid is an unstable substance. According to the studies of the present inventors, in conventional formulations, when a high concentration of ascorbic acid is added to an external preparation for skin, the external preparation for skin is colored due to denaturation due to oxidation, hydrolysis, etc. of ascorbic acid. It was also found that problems such as offensive odors from external preparations for skin may occur.

An object to be solved by one embodiment of the present invention is to provide an external preparation for skin containing ascorbic acid at a high concentration and having excellent storage stability of ascorbic acid.

Specific means for solving the above problems include the following embodiments.
[1] ascorbic acid;
an oily gelling agent;
a polyhydric alcohol;
and
An external preparation for skin, wherein the content of ascorbic acid is 0.5% by mass or more relative to the total weight of the external preparation for skin.
[2] The external preparation for skin according to [1], which further contains an oil.
[3] Contains no water, or the content of water is in the range of more than 0% by mass and 10% by mass or less with respect to the total mass of the external skin preparation [1] or [2] topical skin preparation.
[4] A group in which the polyhydric alcohol consists of glycerin, 1,3-butylene glycol, diglycerin, propylene glycol, dipropylene glycol, ethoxydiglycol, pentylene glycol, hexanediol, polyethylene glycol, and polyoxyethylene methyl glucoside. The skin external preparation according to any one of [1] to [3], which is at least one selected from the above.
[5] The external preparation for skin according to any one of [1] to [4], wherein the oily gelling agent is an amino acid-based oily gelling agent.
[6] The external preparation for skin according to [5], wherein the amino acid-based oily gelling agent is at least one selected from the group consisting of L-glutamic acid derivatives, L-isoleucine derivatives, and L-valine derivatives.
[7] Any one of [1] to [6], wherein the polyhydric alcohol content is in the range of 20% by mass or more and 98.5% by mass or less with respect to the total mass of the external skin preparation. Skin external agent.
[8] The skin according to any one of [1] to [7], wherein the content of the oily gelling agent is in the range of 1% by mass or more and 20% by mass or less with respect to the total mass of the external skin preparation. External agent.
[9] The skin according to any one of [1] to [8], wherein the content of polyhydric alcohol is in the range of 3 to 197 times the content of ascorbic acid on a mass basis. External agents.
[10] Any one of [1] to [9], wherein the content of the polyhydric alcohol is in the range of 2 to 98.5 times the content of the oily gelling agent on a mass basis. The external preparation for skin according to .

According to one embodiment of the present invention, an external preparation for skin containing ascorbic acid at a high concentration and having excellent storage stability of ascorbic acid is provided.

An example of an embodiment of an external preparation for skin to which the present invention is applied will be described below. However, the present invention is by no means limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the purpose of the present invention.

In the present disclosure, a numerical range indicated using "to" means a range including the numerical values before and after "to" as the minimum and maximum values, respectively.
In the present disclosure, in the numerical ranges described in stages, the upper limit or lower limit described in a certain numerical range may be replaced with the upper limit or lower limit of another numerical range described in stages. Also, in the numerical ranges described in the present disclosure, the upper or lower limits of a certain numerical range may be replaced with the values shown in the examples.
In the present disclosure, a combination of two or more preferred aspects is a more preferred aspect.
In the present disclosure, when there are multiple substances corresponding to each component in the external skin preparation, the amount of each component in the external skin preparation is the amount of the multiple substances present in the external skin preparation unless otherwise specified. means total volume.

In the present disclosure, “containing ascorbic acid at a high concentration” means that the content of ascorbic acid is 0.5% by mass or more (preferably 1.0% by mass or more) relative to the total mass of the external skin preparation. It means that there is

[External preparation for skin]
The external preparation for skin of the present disclosure contains ascorbic acid, an oily gelling agent, and a polyhydric alcohol, and the content of ascorbic acid is 0.5% by mass with respect to the total weight of the external preparation for skin. That's it.

Since ascorbic acid is an unstable substance, it is difficult to contain ascorbic acid in a stable state in external preparations for skin. Ascorbic acid derivatives, which are chemically modified ascorbic acid to make it easier to use, are often used in conventional skin preparations for external use. However, when ascorbic acid is stabilized as a derivative, the handling property is improved, but the molecular weight increases, so even if the compounding amount is increased, the concentration of ascorbic acid becomes low. In addition, many ascorbic acid derivatives penetrate the skin, are decomposed by enzymes present in the skin, and are metabolized to become ascorbic acid. It may not work as expected. Therefore, it is desirable to be able to mix ascorbic acid at a high concentration in an external preparation for skin without converting ascorbic acid into a derivative. However, in conventional formulations, when a high concentration of ascorbic acid is added to an external preparation for skin, the external preparation for skin is colored or has a foul odor due to denaturation due to oxidation or hydrolysis of ascorbic acid. There are cases where problems such as

In contrast, the external preparation for skin of the present disclosure contains ascorbic acid, an oily gelling agent, and a polyhydric alcohol in combination, so that it is possible to contain ascorbic acid at a high concentration and ascorbic acid by oxidation, hydrolysis, or the like. Since the denaturation of acid is suppressed, the storage stability of ascorbic acid is excellent.

In addition, when the external preparation for skin of the present disclosure is in the form of a liquid, it is possible to obtain an effect that dripping is less likely to occur when applied to the skin.
In addition, the external preparation for skin of the present disclosure can have the effect of being less sticky when applied to the skin.
In addition, the external preparation for skin of the present disclosure can exhibit an effect of excellent moisturizing feeling.

Each component of the external preparation for skin of the present disclosure will be described in detail below.

[Ascorbic acid]
The external skin preparation of the present disclosure contains ascorbic acid.
In addition, the content of ascorbic acid in the external skin preparation of the present disclosure is 0.5% by mass or more with respect to the total mass of the external skin preparation.

Ascorbic acid may be any of D-, L-, and DL-forms, but preferably L-form (so-called L-ascorbic acid).

A commercial item can be used as ascorbic acid.
Examples of commercial products of ascorbic acid include L(+)-ascorbic acid [trade name, ingredient name: L-ascorbic acid, Fuji Film Wako Pure Chemical Industries, Ltd.].

The content of ascorbic acid in the external skin preparation of the present disclosure is 0.5% by mass or more, and is in the range of 0.5% by mass or more and 10.0% by mass or less with respect to the total mass of the external skin preparation. Is preferably in the range of 0.5% by mass or more and 8.0% by mass or less, more preferably in the range of 1.0% by mass or more and 8.0% by mass or less, 1.0% by mass It is particularly preferable to be in the range of 5.0% by mass or more.

[Oil-based gelling agent]
The topical skin preparation of the present disclosure contains an oily gelling agent.
In the present disclosure, "oily gelling agent" means a gelling agent having a solubility in water of less than 0.1% by mass (less than 1 g/L) at 25°C.
In the present disclosure, "gelling agent" refers to a compound having gelling ability. Specific mechanisms for expressing the gelling ability include, for example, the formation of an oregano gel that creates a network-like higher-order structure, and the formation of a card house in which plate-like molecular crystals physically mesh with each other. is included.

The oily gelling agent is not particularly limited as long as it is a component that can be applied to the skin. It is preferably the component used. In the fields of cosmetics and quasi-drugs, oily gelling agents are also called oil gelling agents or oil gelling agents.
The oily gelling agent is preferably solid, more preferably solid at 25°C. Here, the expression that the oily gelling agent is "solid at 25°C" means that the melting point or softening point of the oily gelling agent is 25°C or higher.

Oily gelling agents include amino acid derivatives, metal soaps, sugar fatty acid esters and the like. Oily gelling agents include waxes such as petroleum wax, vegetable wax, animal wax, mineral wax and synthetic wax.
Among these, the oily gelling agent is preferably at least one selected from the group consisting of amino acid derivatives, sugar fatty acid esters, petroleum waxes, vegetable waxes, and mineral waxes, and is preferably selected from the group consisting of amino acid derivatives and sugar fatty acid esters. is more preferred, and an amino acid derivative is even more preferred.
In the present disclosure, an amino acid derivative that is an oily gelling agent, that is, an "amino acid-based oily gelling agent" means an oily gelling agent that is an amide, ester, or amine salt of an amino acid. and long-chain fatty acids, the molecules self-associate through non-covalent bonds such as hydrogen bonds to form fibrous aggregates, which ultimately form a network structure and incorporate solvent molecules into the gel. A compound that undergoes chemical transformation.

Amino acid derivatives (that is, amino acid-based oily gelling agents) that are oily gelling agents include L-glutamic acid derivatives, L-isoleucine derivatives, L-valine derivatives and the like.
Among these, L-glutamic acid derivatives are preferred as amino acid-based oily gelling agents.
Specific examples of L-glutamic acid derivatives include N-lauroyl-L-glutamic acid dibutylamide (cosmetic ingredient label name: dibutyl lauroyl glutamide), N-2-ethylhexanoyl-L-glutamic acid dibutylamide (cosmetics ingredient label name: dibutylethylhexanoyl glutamide), lauroyl glutamic acid stearylamide, N-lauroyl-L-glutamic acid-α, γ-bis-n-butylamide and the like.
Specific examples of L-isoleucine derivatives include N-octadecyl-L-isoleucinamide and the like.
Specific examples of L-valine derivatives include N-octadecyl-L-valineamide and the like.

Examples of amino acid-based oily gelling agents include lauroylphenylalanine laurylamide, dicaproyllysine laurylamide, dicaproyllysine laurylamine salt, dicaproyllysine lauryl ester, and the like.

Specific examples of sugar fatty acid esters include dextrin palmitate, dextrin myristate, (palmitate/ethylhexanoate) dextrin, (palmitate/hexyldecanoate) dextrin, and inulin stearate.
Specific examples of petroleum wax include paraffin wax and microcrystalline wax.
Specific examples of plant waxes include carnauba wax, candelilla wax, rice bran wax, sunflower seed wax, jojoba seed oil, 12-hydroxystearic acid and the like.
Specific examples of mineral waxes include ceresin, montan wax, ozokerite, and the like.

A commercially available product can be used as the oily gelling agent.
Examples of commercially available oily gelling agents include amino acid-based oil gelling agent GP-1 [trade name, N-lauroyl-L-glutamic acid dibutylamide (cosmetics ingredient display name: dibutyl lauroyl glutamide), Ajinomoto Co., Inc. ], amino acid-based oil gelling agent EB-21 [trade name, N-2-ethylhexanoyl-L-glutamic acid dibutylamide (cosmetic ingredient display name: dibutylethylhexanoyl glutamide), Ajinomoto Co.], AJK- IS3613 [trade name, a mixture of dibutyl lauroyl glutamide (27.0% by mass), dibutylethylhexanoyl glutamide (9.0% by mass), and isostearic acid (64.0% by mass), Kokyu Alcohol Kogyo Co., Ltd. ], AJK-OD2046 [trade name, mixture of dibutyl lauroyl glutamide (12.0% by mass), dibutylethylhexanoyl glutamide (8.0% by mass), and octyldodecanol (80.0% by mass), high grade Alcohol Kogyo Co., Ltd.], Rheopal KL2 [trade name, dextrin palmitate, Chiba Flour Milling Co., Ltd.], Rheopal MKL2 [trade name, dextrin myristate, Chiba Flour Milling Co., Ltd.], Rheopal WX [trade name, (palmitic acid / hexyl decanoic acid) dextrin, Chiba Flour Milling Co., Ltd.], Rheopearl ISL2 [trade name, inulin stearate, Chiba Flour Milling Co., Ltd.], purified microcrystalline wax [trade name, microcrystalline wax, Nikko Rika Co., Ltd.], purified Paraffin wax [trade name, paraffin wax (cosmetics ingredient label name: paraffin), Nikko Rika Co., Ltd.], Candelilla wax MK-4 [trade name, candelilla wax (cosmetics ingredient label name: candelilla wax), Yokozeki oils and fats Kogyo Co., Ltd.], refined carnauba wax R-100 [trade name, carnauba wax (cosmetic ingredient display name: carnauba wax), Yokozeki Yushi Kogyo Co., Ltd.], castor hardened fatty acid [trade name, 12-hydroxystearic acid ( Cosmetic Ingredient Name: Hydroxystearic Acid, NOF Corporation], Refined Ceresin N [Trade Name, Ceresin, Nikko Rica Corporation], CERESIN #820 [Trade Name, Synthetic Wax (Cosmetics Ingredient Name: Ceresin), Nikko Rica Co., Ltd.] and the like.

The external preparation for skin of the present disclosure may contain only one type of oily gelling agent, or may contain two or more types.

The content of the oily gelling agent in the external skin preparation of the present disclosure is not particularly limited, but for example, it is preferably in the range of 1% by mass or more and 20% by mass or less with respect to the total mass of the external skin preparation. It is more preferably in the range of 1% by mass or more and 15% by mass or less, even more preferably in the range of 1% by mass or more and 10% by mass or less, and particularly preferably in the range of 1% by mass or more and 8% by mass or less.
When the content of the oily gelling agent in the topical skin preparation of the present disclosure is within the above range with respect to the total weight of the topical skin preparation, the topical skin preparation gels better, and the storage stability of ascorbic acid increases. can improve. Further, if the external preparation for skin is gelled better, for example, when the external preparation for skin is liquid, dripping tends to be less likely to occur when the external preparation for skin is applied to the skin. In addition, when the topical skin preparation gels better, for example, stickiness tends to be less likely to occur when the topical skin preparation is applied to the skin.

[Polyhydric alcohol]
The external preparation for skin of the present disclosure contains a polyhydric alcohol.
In the external preparation for skin of the present disclosure, the polyhydric alcohol contributes to improving the storage stability of ascorbic acid in combination with the oily gelling agent described above. In addition, in the external preparation for skin of the present disclosure, the polyhydric alcohol contributes to improving the solubility of ascorbic acid.

In the present disclosure, "polyhydric alcohol" means an alcohol having two or more hydroxyl groups in the molecule and being liquid at 60°C. Here, the polyhydric alcohol being "liquid at 60°C" means that the polyhydric alcohol has a melting point or softening point of less than 60°C.

Specific examples of polyhydric alcohols include glycerin, 1,3-butylene glycol (cosmetic ingredient display name: BG), diglycerin, propylene glycol, dipropylene glycol, ethoxydiglycol, pentylene glycol, hexanediol, polyethylene glycol, Examples include polyoxyethylene methyl glucoside (cosmetic ingredient display name: methyl gluceth), ethylene glycol, and diethylene glycol.
Among these, polyhydric alcohols include glycerin, 1,3-butylene glycol, diglycerin, propylene glycol, dipropylene glycol, ethoxydiglycol, pentylene glycol, hexanediol, polyethylene glycol, and polyoxyethylene methyl glucoside. At least one selected from the group consisting of glycerin, 1,3-butylene glycol, diglycerin, propylene glycol, dipropylene glycol, and ethoxydiglycol is more preferred.

The external preparation for skin of the present disclosure may contain only one type of polyhydric alcohol, or may contain two or more types.

The content of the polyhydric alcohol in the external skin preparation of the present disclosure is not particularly limited, but is preferably in the range of 10% by mass or more and 98.5% by mass or less with respect to the total mass of the external skin preparation, It is more preferably in the range of 20% by mass or more and 98.5% by mass or less, even more preferably in the range of 20% by mass or more and 95% by mass or less, and is in the range of 20% by mass or more and 90% by mass or less. Especially preferred.
When the content of the polyhydric alcohol in the external skin preparation of the present disclosure is within the above range with respect to the total mass of the external skin preparation, there is a tendency to achieve an external skin preparation containing ascorbic acid at a higher concentration.

In addition, the content of the polyhydric alcohol in the external preparation for skin of the present disclosure is preferably in the range of 3 times or more and 197 times or less, and 5 times or more and 150 times or less, relative to the content of ascorbic acid on a mass basis. , more preferably 10 times or more and 125 times or less, and particularly preferably 20 times or more and 100 times or less.
When the content of the polyhydric alcohol in the topical skin preparation of the present disclosure is within the above range on a mass basis with respect to the content of ascorbic acid, there is a tendency to achieve a topical skin preparation containing ascorbic acid at a higher concentration. There is

In addition, the content of the polyhydric alcohol in the external preparation for skin of the present disclosure is preferably in the range of 2 to 98.5 times the content of the oily gelling agent on a mass basis. The range is more preferably 90 times or less, more preferably 3 times or more and 70 times or less, and particularly preferably 4 times or more and 50 times or less.
When the content of the polyhydric alcohol in the external skin preparation of the present disclosure is within the above range on a mass basis with respect to the content of the oily gelling agent, the storage stability of ascorbic acid tends to be further improved. .
In addition, if the content of the polyhydric alcohol in the topical skin preparation of the present disclosure is at least twice the content of the oily gelling agent on a mass basis, the topical skin preparation will cause stickiness when applied to the skin. tend to be less likely to occur.
In addition, when the content of the polyhydric alcohol in the topical skin preparation of the present disclosure is 98.5 times or less on a mass basis with respect to the content of the oily gelling agent, the form of the topical skin preparation is liquid. In some cases, dripping tends to be less likely to occur when the external preparation for skin is applied to the skin.

In the topical skin preparation of the present disclosure, the viscosity, hardness, etc. of the topical skin preparation can be controlled by adjusting the ratio between the content of the oily gelling agent and the content of the polyhydric alcohol. For example, viscosity, hardness, etc. can be increased by increasing the ratio of the oily gelling agent. Therefore, by adjusting the ratio between the content of the oily gelling agent and the content of the polyhydric alcohol, it is possible to control the form (so-called dosage form) of the external preparation for skin.

[Oil agent]
The external preparation for skin of the present disclosure preferably further contains an oil.
In the external preparation for skin of the present disclosure, the oil contributes to improving the moisturizing feeling.

In the present disclosure, the term “oil agent” means that the solubility in water at 25° C. is less than 0.1% by mass (less than 1 g/L), and the field of skin external preparations (specifically, cosmetics and quasi-drugs product field), it means a component that is generally used as an oil agent. However, the oil agent in the present disclosure does not include a component corresponding to the oily gelling agent described above.

The oil is preferably liquid, more preferably liquid at 25°C. Here, the expression that the oil is "liquid at 25°C" means that the oil has a melting point or softening point of less than 25°C.

Oil agents include ester oils, hydrocarbon oils, silicone oils, higher fatty acids, higher alcohols, and the like.
In the present disclosure, "higher fatty acid" means a fatty acid having 12-24 carbon atoms.
In the present disclosure, "higher alcohol" means an alcohol having a hydrocarbon group with 12-24 carbon atoms.

Specific examples of ester oils include isopropyl myristate, cetyl ethylhexanoate, hexyldecyl ethylhexanoate, isostearyl neopentanoate, isodecyl neopentanoate, octyldodecyl neopentanoate, isotridecyl isononanoate, isononyl isononanoate, isopropyl isostearate, and myristine. Isocetyl acid, octyldodecyl myristate, isopropyl palmitate, ethylhexyl palmitate, neopentyl glycol dicaprate, neopentyl glycol diethylhexanoate, PG dicaprate, PG dicaprylate, diisostearyl malate, tri(caprylic acid/capric acid) ) glyceryl, trimethylolpropane triethylhexanoate, pentaerythrityl tetraethylhexanoate, triethylhexanoin, hexyldecyl isostearate and the like. The above "PG" is an abbreviation for propylene glycol.
Specific examples of hydrocarbon oils include liquid paraffin and squalane.
Specific examples of silicone oils include dimethicone, cyclopentasiloxane, phenyldimethicone, and the like.
Specific examples of higher fatty acids include isostearic acid, oleic acid, linoleic acid and the like.
Specific examples of higher alcohols include isostearyl alcohol, hexyldecanol, octyldecanol, decyltetradecanol, and oleyl alcohol.

When the external preparation for skin of the present disclosure contains an oil agent, it may contain only one oil agent, or may contain two or more oil agents.

When the topical skin preparation of the present disclosure contains an oil, the content of the oil is not particularly limited. , 3 to 70 mass %, more preferably 5 to 60 mass %.
When the content of the oil agent in the external skin preparation of the present disclosure is 1% by mass or more with respect to the total mass of the external skin preparation, the moisturizing feeling tends to be further improved.
Depending on the type of oil, if the content is too high, stickiness may occur when the external preparation for skin is applied to the skin.
When the content of the oil in the external skin preparation of the present disclosure is 80% by mass or less with respect to the total mass of the external skin preparation, stickiness tends to be less likely to occur when the external skin preparation is applied to the skin.

〔water〕
The external preparation for skin of the present disclosure may contain water.
Water is not particularly limited as long as it can be used for external skin preparations.
Specific examples of water include natural water, purified water, distilled water, ion-exchanged water, pure water, and ultrapure water (eg, Milli-Q water).
Among these, purified water, distilled water, ion-exchanged water, pure water, or ultrapure water is preferable as water from the viewpoint of less impurities.

The water content in the external preparation for skin of the present disclosure is not particularly limited.
For example, from the viewpoint of further suppressing denaturation due to hydrolysis of ascorbic acid, the external preparation for skin of the present disclosure does not contain water, or the water content is 0 mass with respect to the total weight of the external skin preparation. % and 10% by mass or less, and does not contain water, or the water content is more than 0% by mass and 5% by mass or less with respect to the total mass of the external skin preparation. More preferably, it does not contain water, or the water content is in the range of more than 0% by mass and 1% by mass or less with respect to the total mass of the external skin preparation. Preferably, it is particularly preferably free of water.
In the present disclosure, "free of water" means that the content of water is 0% by mass with respect to the total mass of the external skin preparation, or that it is substantially free of water. The expression "substantially free of water" means that the presence of water that is unavoidably mixed is allowed, but the presence of intentionally added water is not allowed.

[Other ingredients]
The external preparation for skin of the present disclosure may optionally contain components other than the components described above (so-called other components) as long as the effects of the present disclosure are not impaired.
Other components include additive components commonly used in external preparations for skin (hereinafter also simply referred to as “additive components”).

<Additional ingredients>
The external preparation for skin of the present disclosure may contain additional ingredients.
Examples of additive components include functional components that exhibit useful cosmetic effects (moisturizing effect, whitening effect, skin conditioning effect, etc.) when used in external skin preparations that are cosmetics (so-called cosmetics and medicinal cosmetics). be done.
Examples of such functional ingredients include ascorbic acid derivatives such as L-ascorbyl palmitate; carotenoids such as β-carotene, astaxanthin, zeaxanthin, lycopene and lutein; vitamin E such as tocopherol and tocotrienol; ubiquinone such as coenzyme Q10; acids; glycosphingolipids such as glucosylceramide and galactosylceramide; collagens such as hydrolyzed collagen and water-soluble collagen; amino acids such as acetylhydroxyproline;
Other additives include preservatives, ultraviolet absorbers, anti-inflammatory agents, colorants, perfumes, and the like.
One of these additive components may serve two or more functions.

[Uses of topical skin preparations]
Since the external preparation for skin of the present disclosure contains ascorbic acid at a high concentration and has excellent storage stability, the useful effects of ascorbic acid are maintained for a long period of time. Here, the "useful effect attributed to ascorbic acid" includes pigmentation suppression effect due to tyrosinase activity inhibition and melanin production suppression, anti-aging effect due to fibroblast proliferation and collagen synthesis promotion, and the like. Therefore, the external preparation for skin of the present disclosure can be suitably used as, for example, cosmetics, quasi-drugs (eg, medicinal cosmetics), and the like.

[Form of topical skin preparation]
The form (so-called dosage form) of the external skin preparation of the present disclosure is not particularly limited.
Forms of the external preparation for skin of the present disclosure include, for example, forms such as sticks, balms (so-called pastes), creams, milky lotions, and essences.

[Container for external skin preparation]
The container for the external skin preparation of the present disclosure is not particularly limited.
Containers for the external preparation for skin of the present disclosure include stick type, compact type, jar type, tube type, pump type and the like containers.

[Method for producing external preparation for skin]
The method for producing the external preparation for skin of the present disclosure is not particularly limited, and known production methods can be applied.
An example of a suitable method for producing the external skin preparation of the present disclosure will be described below. However, descriptions of items common to the external preparation for skin described above, such as components and amounts of the external preparation for skin, will be omitted.

First, an oily gelling agent, a polyhydric alcohol, and, if necessary, an oil agent are mixed with heating to obtain a first solution. The first solution is then cooled. Next, a predetermined amount of ascorbic acid is added to the first solution after cooling and then mixed to obtain a second solution. Then, the second solution is cooled to room temperature (that is, 25°C ± 5°C; hereinafter the same) to obtain an external preparation for skin.
When the external preparation for skin is filled in a container, the second solution may be filled in the container and then cooled to room temperature, or the second solution may be cooled to room temperature and then filled in the container. It can be appropriately selected depending on the form (that is, dosage form) of the external preparation for skin.

The components contained in the first solution may be mixed all at once, or may be divided into several components and mixed.
The mixing means is not particularly limited, and known mixing means can be applied.
Specific examples of mixing means include mechanical stirring using a stirrer and manual stirring using a stirring rod.

The heating temperature for mixing the components contained in the first solution is preferably 100° C. or higher. Although the upper limit of the heating temperature is not particularly limited, it is preferably 150° C. or less from the viewpoint of production suitability.
The time for mixing the components contained in the first solution is not particularly limited as long as each component can be sufficiently mixed. For example, it can be set as appropriate according to the mixing means, the type of each component, etc. .

The cooling temperature of the first solution is, for example, preferably 80° C. or lower, more preferably 70° C. or lower, and further preferably 60° C. or lower, from the viewpoint of suppressing thermal decomposition of ascorbic acid. preferable. Although the lower limit of the cooling temperature is not particularly limited, it is preferably 50° C. or higher from the viewpoint of production suitability.
The cooling means is not particularly limited, and known cooling means can be applied.
A specific example of the cooling means is a cooling means using a cooler.

The external preparation for skin of the present disclosure will be described in more detail below with reference to examples. However, the topical skin preparation of the present disclosure is not limited to the following examples unless it exceeds the gist thereof.

[Manufacturing of external preparation for skin]
(Example 1)
Dibutyl lauroyl glutamide, an oily gelling agent (cosmetic ingredient display name) [trade name: amino acid-based oil gelling agent GP-1, ingredient name: N-lauroyl-L-glutamic acid dibutylamide, Ajinomoto Co., Inc.]2. 0 parts by mass and 97.0 parts by mass of polyhydric alcohol propylene glycol (Fuji Film Wako Pure Chemical Industries, Ltd.) were mixed by stirring while heating to 120°C to obtain a first solution. . The first solution was then cooled to a liquid temperature of 60° C. while stirring was continued. Next, 1.0 parts by mass of ascorbic acid [trade name: L(+)-ascorbic acid, component name: L-ascorbic acid, Fuji Film Wako Pure Chemical Industries, Ltd.] was added to the cooled first solution. After that, they were mixed by stirring to obtain a second solution. Then, after pouring the second solution into a glass container, it was cooled to room temperature to obtain an external preparation for skin of Example 1.

(Examples 2 to 11)
In Example 1, except that the composition of the external skin preparation was changed to the composition shown in Table 1, the same operation as in Example 1 was performed to obtain each of the external skin preparations of Examples 2 to 11.

(Examples 12 to 24)
In Example 1, except for changing the composition of the external skin preparation to that shown in Table 2, the same operation as in Example 1 was performed to obtain each of the external skin preparations of Examples 12 to 24.

(Examples 25 to 29)
In Example 1, except for changing the composition of the external skin preparation to the composition shown in Table 3, the same operation as in Example 1 was performed to obtain each of the external skin preparations of Examples 25 to 29.

(Comparative Examples 1 to 6)
In Example 1, except for changing the composition of the external skin preparation to the composition shown in Table 4, the same operation as in Example 1 was performed to obtain each of the external skin preparations of Comparative Examples 1 to 6.

〔evaluation〕
Each external preparation for skin of Examples 1 to 29 and Comparative Example 1 was evaluated as follows. The results are shown in Tables 1-4.
Ascorbic acid was not dissolved in each of the external skin preparations of Comparative Examples 2 to 6, so the following evaluation was not performed.

1. Storage Stability The present inventors have found that an external preparation for skin containing ascorbic acid at a high concentration develops coloration and odor due to denaturation of ascorbic acid such as oxidation and hydrolysis of ascorbic acid. there is An external preparation for skin in which ascorbic acid is not denatured is colorless, transparent, and odorless. Therefore, in this evaluation, the storage stability of ascorbic acid was evaluated based on the coloring and odor of the external preparation for skin. The skin external preparations of Examples 1 to 29 and Comparative Example 1 are all colorless, transparent, and odorless.

The external preparation for skin in a glass container was placed in a thermostat set at a temperature of 50° C. and allowed to stand for one month. Next, the coloration and odor of the external preparation for skin after being left were checked by one expert panelist. The coloration of the external preparation for skin was confirmed visually.
Then, based on the determination results, the storage stability of ascorbic acid was evaluated according to the following evaluation criteria. If the evaluation results of "coloring" and "smell" were both "A" or "B", it was determined that the external preparation for skin had excellent storage stability of ascorbic acid. In addition, in the following evaluation criteria, "A" is the most excellent.

-Evaluation criteria for coloring-
A: Not colored at all.
B: Slightly colored.
C: Remarkably colored.

- Odor Evaluation Criteria -
A: No odor is felt at all.
B: A slight odor is sensed.
C: Remarkable odor is sensed.

2. Dripping Each external preparation for skin was evaluated for dripping when applied to the skin.
One panelist specializing in cosmetics evaluation was asked to use the external preparation for skin. Specifically, 0.1 g of the external preparation for skin was applied to the skin of the forearm, and the presence or absence and degree of dripping upon application was determined. Based on the determination results, dripping was evaluated according to the following evaluation criteria. If the evaluation result was "A" or "B", it was judged to be an external preparation for skin that does not easily drip. In addition, in the following evaluation criteria, "A" is the most excellent.

-Evaluation criteria-
A: No dripping occurs at all.
B: Slight dripping occurs, but it is not noticeable.
C: Remarkable dripping occurs.

3. Stickiness Each topical skin preparation was evaluated for stickiness when applied to the skin.
One panelist specializing in cosmetics evaluation was asked to use the external preparation for skin. Specifically, 0.1 g of the external preparation for skin was applied to the skin of the forearm, and the presence or absence and degree of stickiness upon application was determined. Then, based on the determination results, stickiness was evaluated according to the following evaluation criteria. If the evaluation result was "A" or "B", it was determined that the skin preparation for external use was less sticky. In addition, in the following evaluation criteria, "A" is the most excellent.

-Evaluation criteria-
A: No stickiness is felt at all.
B: Slight stickiness is felt, but it is not noticeable.
C: Remarkable stickiness is felt.

4. Moisturizing Feeling Moisturizing feeling was evaluated for each topical skin preparation.
One panelist specializing in cosmetics evaluation was asked to use the external preparation for skin. Specifically, 0.1 g of the external preparation for skin was applied to the inner side of the forearm in an area of about 25 cm ² . After 1 minute from spreading, the degree of moist feeling (so-called moisturizing feeling) remaining on the surface of the skin was evaluated. Then, based on the determination results, the moisturizing feeling was evaluated according to the following evaluation criteria. If the evaluation result was "A" or "B", it was judged to be an external preparation for skin with excellent moisturizing feeling. In addition, in the following evaluation criteria, "A" is the most excellent.

-Evaluation criteria-
A: Very strong moist feel remaining on the surface of the skin.
B: Strong moist feel remaining on the surface of the skin.
C: Weak moist feel remaining on the surface of the skin.

In Tables 1 to 4, "-" described in the composition column means that the corresponding component is not included.
In Tables 1 to 4, for convenience, components corresponding to ascorbic acid, oily gelling agents, polyhydric alcohols, and oils are classified into (A), (B), (C), and (D), respectively. Notated.

Details of each component listed in Tables 1 to 4 are as follows.
<(A): Ascorbic acid>
・Ascorbic acid [trade name: L(+)-ascorbic acid, component name: L-ascorbic acid, FUJIFILM Wako Pure Chemical Industries, Ltd.]

<(B): oily gelling agent>
- Amino acid-based oily gelling agent -
・Dibutyl lauroyl glutamide (cosmetic ingredient labeling name) [Product name: amino acid-based oil gelling agent GP-1, ingredient name: N-lauroyl-L-glutamic acid dibutylamide, Ajinomoto Co., Inc.]
・Dibutylethylhexanoyl glutamide (cosmetic ingredient labeling name) [Product name: amino acid-based oil gelling agent EB-21, ingredient name: N-2-ethylhexanoyl-L-glutamic acid dibutylamide, Ajinomoto Co., Inc.]
-sugar fatty acid ester-
・Dextrin palmitate [trade name: Rheopearl KL2, Chiba Flour Mills Co., Ltd.]
・Dextrin myristate [trade name: Rheopearl MKL2, Chiba Flour Mills Co., Ltd.]
・Inulin stearate [trade name: Leopal ISL2, Chiba Flour Mills Co., Ltd.]
-Petroleum wax-
・Paraffin (Cosmetics Ingredient Labeling Name) [Product Name: Refined Paraffin Wax, Ingredient Name: Paraffin Wax, Nikko Rica Co., Ltd.]
・Microcrystalline wax [Product name: Refined Microcrystalline Wax, Nikko Rica Co., Ltd.]
-Vegetable Wax-
・ Candelilla wax (cosmetic ingredient display name) [Product name: Candelilla wax MK-4, ingredient name: Candelilla wax, Yokozeki Yushi Kogyo Co., Ltd.]
・ Carnauba wax (cosmetics ingredient display name) [Product name: refined carnauba wax R-100, ingredient name: carnauba wax, Yokozeki Yushi Kogyo Co., Ltd.]
－Mineral wax－
・Ceresin (Cosmetic Ingredient Display Name) [Product name: CERESIN #820, Nikko Rica Co., Ltd.]
All of the above "(B) oily gelling agents" are solid at 25°C.

<(C) Polyhydric alcohol>
・Propylene glycol [FUJIFILM Wako Pure Chemical Industries, Ltd.]
・ BG (Cosmetics Ingredient Labeling Name) [ingredient name: 1,3-butylene glycol, Daicel Corporation]
・Ethoxydiglycol [Product name: Transquitol CG, Ikeda Bussan Co., Ltd.]
・Pentylene glycol [trade name: Hydrolite (registered trademark)-5, Symrise]
・Hexanediol [trade name: Hydrolite (registered trademark)-6, Symrise]
・Dipropylene glycol [Koyo Fine Chemicals Co., Ltd.]
・Glycerin [Product name: Concentrated glycerin for cosmetics, Kao Corporation]
・Diglycerin [trade name: diglycerin 801, Sakamoto Yakuhin Kogyo Co., Ltd.]
・Methyl Gluceth-10 (Cosmetic Ingredient Labeling Name) [Product Name: Macbiobride (registered trademark) MG-10E, Quasi-drug Ingredient Labeling Name: Polyoxyethylene Methyl Glucoside, NOF Corporation]
・Methyl Gluceth-20 (Cosmetic Ingredient Labeling Name) [Product Name: Macbiobride (registered trademark) MG-20E, Quasi-drug Ingredient Labeling Name: Polyoxyethylene Methyl Glucoside, NOF Corporation]
・ PEG-6 (Cosmetics Ingredient Labeling Name) [Product Name: PEG#300, Quasi-drug Ingredient Labeling Name: Polyethylene Glycol 300, NOF Corporation]
・ PEG-12 (Cosmetics Ingredient Labeling Name) [Product Name: PEG#600, Quasi-drug Ingredient Labeling Name: Polyethylene Glycol 600, NOF Corporation]

<(D) Oil>
-Ester oil-
・Isostearic acid (Kokyu Alcohol Industry Co., Ltd.)
・Isopropyl myristate [trade name: NIKKOL (registered trademark) IPM-100, Nikko Chemicals Co., Ltd.]
・ Diisopropyl sebacate [trade name: FineNeo (registered trademark)-iPSE, Nippon Fine Chemical Co., Ltd.]
－Hydrocarbon oil－
・ Squalane [trade name: NIKKOL (registered trademark) refined olive squalane, Nikko Chemicals Co., Ltd.]
-Silicone oil-
・Cyclopentasiloxane [trade name: KF-995, Shin-Etsu Chemical Co., Ltd.]
All of the above "(D) oils" are liquid or paste at 25°C.

As shown in Tables 1 to 3, all of the external preparations for skin of Examples 1 to 29 have little or no coloring and odor, and are excellent in the storage stability of ascorbic acid. was confirmed. In addition, it was confirmed that any of the external skin preparations of Examples 1 to 29 did not drip when applied to the skin, or if it did drip, it hardly dripped. was done. In addition, all of the external skin preparations of Examples 1 to 29 did not feel sticky when applied to the skin, or felt only a slight stickiness, confirming that stickiness was suppressed. was done. In addition, it was confirmed that all of the external preparations for skin of Examples 1 to 29 are excellent in moisturizing feeling.
On the other hand, as shown in Table 4, the external preparation for skin of Comparative Example 1 containing ascorbic acid and a polyhydric alcohol and not containing an oily gelling agent had significant coloration and odor, and the storage stability of ascorbic acid was high. was confirmed to be inferior to In addition, the external preparation for skin of Comparative Example 1 caused conspicuous dripping when applied to the skin. In addition, the external preparation for skin of Comparative Example 1 felt remarkably sticky when applied to the skin. In addition, it was confirmed that the external preparation for skin of Comparative Example 1 was inferior in moisturizing feeling.
It was confirmed that none of the external preparations for skin of Comparative Examples 2 to 6, which contained an oil agent instead of the polyhydric alcohol, dissolved ascorbic acid and could not contain ascorbic acid at a high concentration.

[Manufacturing of external preparation for skin]
[Example 30] Stick Of the following (1) to (10), (2) to (8) were mixed by stirring while heating to 100°C to obtain a first solution. The first solution was then cooled to a liquid temperature of 60° C. while stirring was continued. Next, (1), (9), and (10) were added to the cooled first solution, and then mixed by stirring to obtain a second solution. Then, after filling the stick container with the second solution, the container was cooled to room temperature to produce an external preparation for skin in the form of a stick.

-Composition of the stick-
(1) Ascorbic acid 3.0% by mass
(2) Dibutyl lauroyl glutamide 4.0% by mass
(3) Dibutylethylhexanoyl glutamide 1.4% by mass
(4) Propylene glycol 29.49% by mass
(5) 1,3-butylene glycol 5.0% by mass
(6) Ethoxydiglycol 42.0% by mass
(7) Glycerin 5.0% by mass
(8) isostearic acid 9.6% by mass
(9) Astaxanthin 0.01% by mass
(10) Tocopherol 0.5% by mass

[Example 31] Balm Of the following (1) to (9), (2) to (7) were mixed by stirring while heating to 100°C to obtain a first solution. The first solution was then cooled to a liquid temperature of 60° C. while stirring was continued. Next, (1), (8), and (9) were added to the cooled first solution, and then mixed by stirring to obtain a second solution. Next, after filling the second solution in a jar, the mixture was cooled to room temperature to produce an external skin preparation having a balm (so-called kneading) dosage form.

-Balm composition-
(1) Ascorbic acid 3.0% by mass
(2) Dibutyl lauroyl glutamide 2.0% by mass
(3) Propylene glycol 39.49% by mass
(4) 1,3-butylene glycol 5.0% by mass
(5) Ethoxydiglycol 40.0% by mass
(6) Glycerin 5.0% by mass
(7) Dimethicone 5.0% by mass
(8) Astaxanthin 0.01% by mass
(9) Tocopherol 0.5% by mass

[Example 32] Cream Of the following (1) to (9), (2) to (7) were mixed by stirring while heating to 100°C to obtain a first solution. The first solution was then cooled to a liquid temperature of 60° C. while stirring was continued. Next, (1), (8), and (9) were added to the cooled first solution, and then mixed by stirring to obtain a second solution. Next, after the second solution was cooled to room temperature, it was filled in a tube container to produce an external skin preparation having a cream dosage form.

-Composition of cream-
(1) Ascorbic acid 3.0% by mass
(2) Dibutyl lauroyl glutamide 1.0% by mass
(3) Propylene glycol 40.49% by mass
(4) 1,3-butylene glycol 5.0% by mass
(5) Ethoxydiglycol 30.0% by mass
(6) Glycerin 10.0% by mass
(7) Squalane 10.0% by mass
(8) Astaxanthin 0.01% by mass
(9) Tocopherol 0.5% by mass

Claims (8)

ascorbic acid and
an oily gelling agent;
a polyhydric alcohol;
and
The content of ascorbic acid is 0.5% by mass or more with respect to the total mass of the external skin preparation,
the oily gelling agent is an amino acid-based oily gelling agent,
the amino acid-based oily gelling agent is an L-glutamic acid derivative,
L-glutamic acid derivatives include N-lauroyl-L-glutamic acid dibutylamide, N-2-ethylhexanoyl-L-glutamic acid dibutylamide, lauroyl glutamic acid stearylamide, and N-lauroyl-L-glutamic acid-α,γ-bis- An external preparation for skin which is at least one selected from the group consisting of n-butylamide . The external preparation for skin according to claim 1, further comprising an oil. 3. The external skin preparation according to claim 1 or 2, which does not contain water or has a water content in the range of more than 0% by mass and 10% by mass or less with respect to the total mass of the external skin preparation. agent. The polyhydric alcohol is selected from the group consisting of glycerin, 1,3-butylene glycol, diglycerin, propylene glycol, dipropylene glycol, ethoxydiglycol, pentylene glycol, hexanediol, polyethylene glycol, and polyoxyethylene methyl glucoside. 4. The skin external preparation according to any one of claims 1 to 3, which contains at least one. The external preparation for skin according to any one of claims 1 to 4, wherein the content of the polyhydric alcohol is in the range of 20% by weight or more and 98.5% by weight or less with respect to the total weight of the external preparation for skin. . 6. The external skin preparation according to any one of claims 1 to 5, wherein the content of the oily gelling agent is in the range of 1% by mass or more and 20% by mass or less with respect to the total mass of the external skin preparation. 7. The external preparation for skin according to any one of claims 1 to 6, wherein the content of the polyhydric alcohol is in the range of 3 to 197 times the content of ascorbic acid on a mass basis. 8. The content of the polyhydric alcohol is in the range of 2 to 98.5 times the content of the oily gelling agent on a mass basis. Skin external agent.