JP2024138105A - Cosmetics - Google Patents

Abstract

To provide a cosmetic having a high preservative effect against both fungi and bacteria and further to provide a preservative-free cosmetic.SOLUTION: There is provided a cosmetic containing (A) a fatty acid glyceryl ester having 8 to 12 carbon atoms and (B) a specific acetophenone derivative and there is provided a method for enhancing preservative ability against fungi and bacteria, which comprises blending the component (A) and the component (B) in an object to be preserved such as a cosmetic.SELECTED DRAWING: None

Description

The present invention relates to a cosmetic product that has a high preservative effect.

Because cosmetics are used for long periods after opening, it is essential that they have a preservative effect to inhibit the growth and proliferation of microorganisms. For this reason, cosmetics generally contain preservatives such as parabens, such as methylparaben and ethylparaben, and phenoxyethanol. However, due to the increasing focus on safety in recent years, there is a trend toward additive-free cosmetics, and cosmetics that do not contain preservatives as one of the additives are in demand. Therefore, technology has been developed to impart a preservative effect to cosmetics in place of conventional cosmetic preservatives.

Medium-chain fatty acid glycerin esters and sucrose fatty acid esters have been proposed as safe substances with bacteriostatic properties. However, adding large amounts of these substances in an attempt to achieve a high bacteriostatic effect can cause skin irritation. In addition, while these substances have bacteriostatic properties against yeast and bacteria, they are weak against molds, making it difficult to provide a broad antibacterial spectrum to cosmetics.

Patent Document 1 describes that a skin topical agent having antiseptic and antibacterial effects can be obtained by combining (A) 0.2% by mass or more of n-hexyl 2,2-bis(hydroxymethyl)propionate with (B) one or more selected from polyhydric alcohols having 3 to 9 carbon atoms, alkyl glyceryl ethers having 6 to 8 carbon atoms, and fatty acid glyceryl esters having 8 to 12 carbon atoms in a specific ratio.

In addition, dihydric glycols such as dipropylene glycol and 1,3-butylene glycol are highly safe moisturizing agents that are widely used in cosmetics, and are also known to have antibacterial properties. However, in order to obtain a high preservative effect using such dihydric glycols, it is necessary to incorporate them in large amounts in the cosmetics, which can cause the cosmetics to become sticky.

Therefore, a substance that imparts preservative properties to cosmetics needs to have a broad antibacterial spectrum without impairing the usability of the cosmetics.

JP 2011-46747 A

The present invention aims to provide a cosmetic product that has a high preservative effect against fungi and bacteria.

As a result of intensive research into solving the above problems, the inventors discovered that a combination of a certain type of fatty acid glyceryl ester and a specific acetophenone derivative exhibits a high preservative effect against both fungi and bacteria, leading to the completion of the present invention.

That is, the present invention provides
(A) a fatty acid glyceryl ester having 8 to 12 carbon atoms, and (B) an acetophenone derivative represented by the following formula (1):

(In the formula, ^R1 and ^R2 each independently represent a hydrogen atom, a hydroxyl group, or a methoxy group.)
A cosmetic preparation comprising the above is provided.

The cosmetic of the present invention, by being configured as described above, can provide a cosmetic having a high preservative effect against fungi and bacteria. Since sufficient preservative effect can be obtained by the components (A) and (B), it is not necessary to incorporate a large amount of dihydric glycol or lower alcohol to obtain the preservative effect, and a cosmetic having a good feel when used can be obtained without stickiness or irritation to the skin. In addition, it is possible to realize a cosmetic that does not contain preservatives that are normally used in cosmetics, i.e., a "preservative-free" cosmetic.

The cosmetic of the present invention is characterized by containing (A) a fatty acid glyceryl ester having 8 to 12 carbon atoms, and (B) a specific acetophenone derivative. The blending of components (A) and (B) provides the cosmetic with a preservative effect. Each component constituting the cosmetic of the present invention is described in detail below.

<(A) Fatty acid glyceryl ester>
The fatty acid glyceryl ester (A) blended in the cosmetic preparation of the present invention (hereinafter, may be simply referred to as "component (A)") is a fatty acid glyceryl ester typically blended in cosmetics and has 8 to 12 carbon atoms. Examples include glyceryl caprylate, glyceryl 2-ethylhexanoate, glyceryl caprate, glyceryl undecylenate, glyceryl laurate, etc. In the cosmetic preparation of the present invention, one or a combination of two or more of the above fatty acid glyceryl esters may be used as component (A). In the present invention, it is preferable to use glyceryl caprate, and it is even more preferable to use glyceryl monocaprate.

The amount of component (A) in the total cosmetic is preferably such that the lower limit is 0.01% by mass or more or 0.05% by mass or more, and the upper limit is 0.4% by mass or less or 0.3% by mass or less. Thus, preferred ranges of the amount include 0.01-0.4% by mass, 0.01-0.3% by mass, 0.05-0.4% by mass, 0.05-0.3% by mass, etc. If the amount is less than 0.01% by mass, sufficient antiseptic and antibacterial effects may not be obtained, and if the amount is more than 0.4% by mass, irritation to the skin may be felt.

<(B) Acetophenone Derivative>
The acetophenone derivative (B) incorporated in the cosmetic preparation of the present invention (hereinafter, may be simply referred to as "component (B)") is an acetophenone derivative that is typically incorporated in cosmetics, and is a compound represented by the following formula (1) or a salt thereof.

In the above formula, R ¹ and R ² each independently represent a hydrogen atom, a hydroxyl group, or a methoxy group, and R ¹ and R ² are located at the ortho, meta, or para position relative to the acetyl group.

In the present invention, it is preferable that the compound is one or more selected from the group consisting of the compounds listed below.

Acetophenone

2-Hydroxyacetophenone

3-Hydroxyacetophenone

4-Hydroxyacetophenone

Of these, 4-hydroxyacetophenone is more preferred in the present invention.

The salt of the compound represented by the above formula (1) may be any cosmetically acceptable salt or pharma- ceutically acceptable salt, and examples thereof include sodium salts, potassium salts, ammonium salts, etc.

The amount of component (B) in the cosmetic is preferably such that the lower limit is 0.06% by mass or more or 0.1% by mass or more, and the upper limit is 2.0% by mass or less or 1.0% by mass or less, based on the total amount of the cosmetic. Thus, preferred ranges of the amount include 0.06 to 2.0% by mass, 0.06 to 1.0% by mass, 0.1 to 2.0% by mass, and 0.1 to 1.0% by mass. If the amount is less than 0.06% by mass, sufficient antiseptic and antibacterial effects may not be obtained, and if the amount is more than 2.0% by mass, irritation may be felt on the skin.

In this specification, "antibacterial" means inhibiting the growth of bacteria on the surface of an object, and "preservative" means inhibiting the invasion, growth, and proliferation of microorganisms, and preventing spoilage and fermentation. Therefore, in this invention, "preservative effect" or "preservative action" refers to effects that include both "antibacterial" and "preservative", and in the case of a cosmetic product, it means the effect of inhibiting the growth of bacteria, yeast, mold, and other fungi in the cosmetic product, preventing the cosmetic product from deteriorating due to bacteria, and enhancing the shelf life of the cosmetic product.

In the course of research into the present invention, it became clear that fatty acid glyceryl esters have a strong preservative effect against yeast and bacteria, but a weak preservative effect against mold, and that acetophenone derivatives have a strong preservative effect against mold, but a weak preservative effect against yeast and bacteria. On the other hand, phenoxyethanol, which is commonly used as a preservative in cosmetics, has a strong preservative effect against Pseudomonas aeruginosa, but a weak preservative effect against other bacteria, yeast, and mold. It became clear that when phenoxyethanol and fatty acid glyceryl esters are combined, the preservative effect against many microorganisms is improved, but the rate at which mold is killed is significantly slowed, thereby negating part of the preservative effect that each of them had when used alone.

In the present invention, by combining a fatty acid glyceryl ester with an acetophenone derivative, a new combination with a broad antibacterial spectrum was realized that provides a high preservative effect against mold, yeast, and bacteria without canceling out the advantages of each other.

Patent Document 1 describes that the fatty acid glyceryl ester according to the present invention exhibits a preservative antibacterial effect when combined with n-hexyl 2,2-bis(hydroxymethyl)propionate. In addition, Patent Document 2 (JP 2018-90579 A) describes that the acetophenone derivative according to the present invention exhibits a preservative effect against bacteria and fungi when combined with an acylamino acid such as acylproline (e.g., decanoylproline) or acylglycine (e.g., octanoylglycine, undecylenoylglycine) and a polyhydric alcohol.

In contrast, in the present invention, the preservative effect is achieved by combining (A) a fatty acid glyceryl ester with (B) a specific acetophenone derivative, so it is not necessary to incorporate n-hexyl 2,2-bis(hydroxymethyl)propionate or acyl amino acids such as acyl proline (e.g., decanoyl proline) and acyl glycine (e.g., octanoyl glycine and undecylenoyl glycine) described in the above patent document. Thus, embodiments of the present invention include embodiments that do not contain n-hexyl 2,2-bis(hydroxymethyl)propionate and/or acyl amino acids.

The cosmetic of the present invention may contain various ingredients that are usually used in cosmetics. For example, it may contain oils such as hydrocarbon oils, higher fatty acids, higher alcohols, synthetic ester oils, silicone oils, liquid oils, solid oils, and waxes that are usually used in cosmetics, UV protection agents, oil phase thickeners, surfactants, water, lower alcohols, polyhydric alcohols, water-soluble polymers, moisturizers, powders, coloring materials, fragrances, neutralizing agents, chelating agents, pH adjusters, vitamins, antioxidants, medicines, etc., as needed.

In the present invention, since a sufficient preservative effect is obtained by the (A) fatty acid glyceryl ester and the (B) acetophenone derivative, it is not necessary to blend phenoxyethanol and parabens, which are normally used as preservatives in cosmetics. Therefore, embodiments of the present invention include embodiments that do not contain phenoxyethanol and/or parabens. According to the present invention, it is possible to realize a cosmetic that does not contain preservatives, that is, a "preservative-free" cosmetic.

Conventionally, in order to impart a preservative effect to cosmetics, divalent glycols such as dipropylene glycol and 1,3-butylene glycol may be blended in an amount exceeding 10% by mass relative to the total amount of the cosmetic. According to the present invention, a sufficient preservative effect is obtained by the (A) fatty acid glyceryl ester and the (B) acetophenone derivative, so that it is possible to reduce the blending amount of the divalent glycol to 10% by mass or less. Thus, embodiments of the present invention include embodiments in which the blending amount of the divalent glycol is 10% by mass or less. By reducing the blending amount of the divalent glycol, it is possible to obtain a cosmetic that has a non-sticky feel when used.

Conventionally, antibacterial effects have sometimes been obtained by increasing the amount of lower alcohol such as ethanol. According to the present invention, sufficient preservative effects are obtained by the (A) fatty acid glyceryl ester and the (B) acetophenone derivative, so the amount of lower alcohol can be reduced to 3% by mass or less. Thus, aspects of the present invention include aspects in which the amount of lower alcohol such as ethanol is 10% by mass or less, and aspects in which no lower alcohol is used. By reducing the amount of lower alcohol, it is possible to obtain a cosmetic product in which irritation to the skin is sufficiently suppressed.

When the fatty acid glyceryl ester (A) and the specific acetophenone derivative (B) according to the present invention are blended with an object, the blended object exhibits excellent preservative activity against bacteria and fungi such as yeast and mold. Therefore, according to the present invention, by blending the components (A) and (B) according to the present invention with an object to be preserved, the preservative activity of the object to be preserved against bacteria and fungi can be increased. Here, the object to be preserved is not limited to cosmetics, and examples include topical skin preparations such as ointments, fragrance products such as perfumes and colognes, daily hygiene products such as sweat wipes, and hygiene products for babies such as baby wipes.

That is, the present invention relates to (A) a fatty acid glyceryl ester having 8 to 12 carbon atoms, and (B) an acetophenone derivative represented by the following formula (1):

(In the formula, ^R1 and ^R2 each independently represent a hydrogen atom, a hydroxyl group, or a methoxy group.)
In the present invention, the object to be preserved is preferably a cosmetic material.

In the above method, the components (A) and (B) of the present invention may be added to the finished product to be preserved, or may be mixed during the manufacturing process of the object to be preserved. The components (A) and (B) may be mixed simultaneously or separately. When mixed separately, either the component (A) or the component (B) may be added first.

The formulation of the cosmetic of the present invention is not particularly limited, and any ordinary cosmetic formulation can be used. That is, liquid, gel, paste, emulsion, cream, spray, etc. can be used.

The cosmetic composition according to the present invention is not particularly limited, and can be blended into skin care cosmetics such as lotion and moisturizing cream, makeup cosmetics such as foundation, BB cream, eye shadow, and lipstick, sunscreen cosmetics, packs, etc.

In addition, the present invention provides a preservative effect against fungi and bacteria by combining the (A) fatty acid glyceryl ester and the (B) acetophenone derivative, so that the present invention can provide a preservative composition with a broad antibacterial spectrum including fungi and bacteria. That is, the present invention provides a preservative composition comprising (A) a fatty acid glyceryl ester having 8 to 12 carbon atoms and (B) an acetophenone derivative represented by the following formula (1):

(In the formula, ^R1 and ^R2 each independently represent a hydrogen atom, a hydroxyl group, or a methoxy group.)
The present invention relates to a preservative composition comprising:

The present invention will be described in more detail below with reference to examples, but the present invention is in no way limited by these. Unless otherwise specified, the blending amount is indicated as mass % relative to the system in which the component is blended. Before describing each example in detail, the test and evaluation methods employed will be explained.

The lotions of Test Examples 1 to 5 having the compositions shown in Table 1 were prepared in the usual manner, and antiseptic effect tests and usage tests were carried out.

<Anti-corrosion effect test>
1. Test fungus Ps: Pseudomonas aeruginosa (strain name: Pseudomonas aeruginosa, ATCC15442)
E: Escherichia coli (strain name: Escherichia coli, ATCC8739)
S: Staphylococcus aureus (strain name: Staphylococcus aureus, ATCC6538)
Can: Candida (yeast) standard strain (strain name: Candida albicans, ATCC10231)
Asp: black mold (strain name: Aspergillus brasiliensis, ATCC16404)

2. Test Method for evaluating preservative activity The test was carried out according to ISO 11930, and the preservative activity against bacteria, fungi and mold was evaluated from the log reduction value (LRV) obtained by the following formula.
LRV = log10 (viable bacteria concentration on day 0/viable bacteria concentration at time of sampling)

3. Evaluation The preservative effect was evaluated according to the following criteria, and only those that were rated A were judged to have sufficient preservative power.
Evaluation criteria for preservative effect against Ps, E, and S: A: LRV was 3 or more after 7 days.
B: It took 8 to 14 days for the LRV to reach 3 or more.
C: LRV was less than 3 even after 14 days or more.
Evaluation criteria for preservative effect against Can: A: LRV was 1 or more after 7 days.
B: It took 8 to 14 days for the LRV to reach 1 or more.
C: LRV was less than 1 even after 14 days or more.
Evaluation criteria for antiseptic effect against Asp: A: LRV was 1 or more after 14 days.
B: It took 15 to 28 days for the LRV to reach 1 or more.
C: LRV was less than 1 even after 28 days or more.

<Usability test>
Ten panelists were asked to use the product twice a day for one week, and were asked to report on their satisfaction with the product and whether or not they experienced any skin irritation. The evaluation of the product's usability was classified into the following four-level scale, and the number of people who reported any skin irritation was also counted.
A: Eight or more panelists recognized that the product had no skin irritation and was pleasant to use. B: Five to fewer than eight panelists recognized that the product had no skin irritation and was pleasant to use. C: Three to fewer than five panelists recognized that the product had no skin irritation and was pleasant to use. D: Less than three panelists recognized that the product had no skin irritation and was pleasant to use.

The lotions (Test Examples 1 to 5) having the compositions shown in Table 1 below were prepared by conventional methods. The preservative effects against each fungus were evaluated according to the above test and evaluation methods.

As shown in Table 1, the lotion containing phenoxyethanol, which has been used as a preservative, (Test Example 1) had a high preservative effect against Pseudomonas aeruginosa (Ps), a moderate preservative effect against Escherichia coli (E), Candida albicans (Can) and black mold (Asp), and a weak preservative effect against Staphylococcus aureus (S). The lotion containing hydroxyacetophenone, an acetophenone derivative, (Test Example 2) had a strong preservative effect against Ps, E and Asp, a moderate preservative effect against Can, and a weak preservative effect against S. Furthermore, the lotion containing a combination of glyceryl caprate, a fatty acid glyceryl ester, and phenoxyethanol (Test Examples 3 and 4) had an improved preservative effect against E, S and Can, but a slower death rate for Asp and a significantly reduced preservative effect against mold, compared with the case of phenoxyethanol alone (Test Example 1). This suggests that combining fatty acid glyceryl esters with phenoxyethanol negates some of the preservative effects of phenoxyethanol.
On the other hand, the lotion (Test Example 5) containing a combination of the fatty acid glyceryl ester of the present invention and an acetophenone derivative exhibited a sufficient preservative effect against all of Ps, E, S, Can, and Asp.

The present invention includes the following aspects.
[Clause 1]
(A) a fatty acid glyceryl ester having 8 to 12 carbon atoms, and (B) an acetophenone derivative represented by the following formula (1):
(In the formula, ^R1 and ^R2 each independently represent a hydrogen atom, a hydroxyl group, or a methoxy group.)
A cosmetic comprising:
[Clause 2]
2. The cosmetic preparation according to claim 1, wherein the component (A) is glyceryl caprate.
[Clause 3]
3. The cosmetic preparation according to item 1 or 2, wherein the component (B) is 4-hydroxyacetophenone.
[Clause 4]
4. The cosmetic preparation according to any one of items 1 to 3, which is free of phenoxyethanol and parabens.
[Clause 5]
5. The cosmetic according to any one of items 1 to 4, wherein the blending amount of the component (A) is 0.3 mass% or less based on the total amount of the cosmetic.
[Clause 6]
(A) a fatty acid glyceryl ester having 8 to 12 carbon atoms, and (B) an acetophenone derivative represented by the following formula (I):
(In the formula, ^R1 and ^R2 each independently represent a hydrogen atom, a hydroxyl group, or a methoxy group.)
A method for enhancing antiseptic activity against fungi and bacteria, comprising blending the above-mentioned compound with a cosmetic.
[Clause 7]
(A) a fatty acid glyceryl ester having 8 to 12 carbon atoms, and (B) an acetophenone derivative represented by the following formula (I):
(In the formula, ^R1 and ^R2 each independently represent a hydrogen atom, a hydroxyl group, or a methoxy group.)
A preservative composition comprising:

Claims (6)

(A) a fatty acid glyceryl ester having 8 to 12 carbon atoms, and (B) an acetophenone derivative represented by the following formula (1):
(In the formula, ^R1 and ^R2 each independently represent a hydrogen atom, a hydroxyl group, or a methoxy group.)
Contains
A cosmetic preparation containing no acylproline or paraben,
When the cosmetic contains a dihydric glycol, the amount of the dihydric glycol contained therein is 10 mass % or less. The cosmetic preparation according to claim 1, wherein the component (A) is glyceryl caprate. The cosmetic preparation according to claim 1 or 2, wherein the component (B) is 4-hydroxyacetophenone. The cosmetic preparation according to claim 1 does not contain phenoxyethanol. The cosmetic according to claim 1, wherein the amount of component (A) is 0.4% by mass or less based on the total amount of the cosmetic. A cosmetic preparation containing no acylproline or paraben,
In the case where the cosmetic contains a divalent glycol, the amount of the divalent glycol contained in the cosmetic is 10% by mass or less.
(A) a fatty acid glyceryl ester having 8 to 12 carbon atoms, and (B) an acetophenone derivative represented by the following formula (I):
(In the formula, ^R1 and ^R2 each independently represent a hydrogen atom, a hydroxyl group, or a methoxy group.)
A method for enhancing the preservative activity of the cosmetic against fungi and bacteria, comprising blending said cosmetic with