Antidandruff agent and scalp composition containing the same

Abstract

The present invention aims to provide a scalp composition that has a practically sufficient effect on scalp roughness such as dandruff, despite having lower bactericidal and antibacterial properties than conventionally known zinc compounds. [Solution] A scalp composition characterized by containing zinc glycine as an anti-dandruff agent.

Description

[Technical Field]

[0001] The present invention relates to a technique for an anti-dandruff agent containing zinc glycine as an active ingredient, and a scalp composition containing the anti-dandruff agent. [Background technology]

[0002] Scalp roughness, such as dandruff, is known to be caused by various predisposing factors, including excessive washing, irritation from ultraviolet rays, oxidative stress, and lifestyle habits and physical constitution (Non-Patent Document 1). Furthermore, these predisposing factors, coupled with increased social stress, have led to a growing demand for scalp compositions (Non-Patent Document 1). Accordingly, various scalp compositions have been proposed, including medicated shampoos and rinses designed to prevent scalp roughness, such as dandruff, and scalp cosmetics designed to moisturize the scalp. These scalp compositions generally contain ingredients that improve or alleviate factors thought to cause scalp roughness. For example, active ingredients used in medicated shampoos and rinses used to cleanse hair and scalp include zinc pyrithione, piroctone olamine, miconazole nitrate, ketoconazole, and dipotassium glycyrrhizinate. As mentioned above, antibacterial and anti-inflammatory agents have traditionally been used to treat scalp roughness, such as dandruff, and scalp compositions with high functionality have also been proposed. However, previous surveys show that many consumers still have concerns about dandruff and itching.

[0003] Zinc is a trace metal essential for living organisms. Approximately 8% of the zinc in the body is found in skin and hair, and within the skin, it is particularly concentrated in the epidermis (Patent Document 1, Non-Patent Document 2). Zinc has also been reported to maintain epidermal homeostasis, and zinc compounds are widely used in skin care products as active ingredients for anti-aging, such as for preventing blemishes (Non-Patent Document 3). However, zinc compounds are rarely used in scalp compositions to prevent scalp roughness such as dandruff, and zinc pyrithione, which has been reported to have antibacterial properties against the bacteria that cause dandruff, is the main one (Non-Patent Document 4). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-247729 [Non-patent literature]

[0005] [Non-Patent Document 1] M.Takahashi etal.,COSME TECH JAPAN.2014,4:37-47. [Non-patent document 2] Japan Society of Clinical Nutrition, Guidelines for the Treatment of Zinc Deficiency 2018 [Non-patent document 3] H. MASAKI et al., J DERMATOL SCI. 2007, 1:73-75. [Non-patent document 4] MCGINLEY KJ, etal., ARCH DERMATOL RES. 34:339-342. 1982. Summary of the Invention [Problem to be solved by the invention]

[0006] The bactericidal properties of metal ions such as zinc are well known, and zinc pyrithione, based on its strong bactericidal properties against dandruff-causing bacteria, has long been used as an anti-dandruff agent. On the other hand, some bactericides and antibacterial agents have concerns about their safety to the human body, and in recent years, it has been pointed out that bactericides and antibacterial agents may disrupt the delicate balance of normal skin bacteria. For these reasons, it is considered desirable to avoid using large amounts of bactericides and antibacterial agents in scalp compositions. However, as mentioned above, zinc is an important trace metal for the body that maintains epidermal homeostasis, and it is thought that it should be used to prevent scalp roughness such as dandruff. However, zinc compounds have not been thoroughly studied as anti-dandruff agents that are not based on bactericidal or antibacterial properties.

[0007] The present invention aims to provide a scalp composition that has a practically sufficient effect on scalp roughness such as dandruff, despite having lower bactericidal and antibacterial properties than conventionally known zinc compounds. [Means for solving the problem]

[0008] The present inventors have conducted extensive research into active ingredients that have an improving effect on subjects suffering from scalp roughness such as dandruff, despite having lower bactericidal and antibacterial properties than conventionally known zinc compounds. As a result, they have discovered that zinc glycine has a significant anti-dandruff effect, leading to the completion of the present invention. [Effects of the Invention]

[0009] According to the present invention, there is provided a scalp composition which has a practically sufficient effect against scalp roughness such as dandruff, despite having lower bactericidal and antibacterial properties than conventionally known zinc compounds. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 shows the results of the amount of involucrin derived from epidermal cells in each sample, detected by dot blotting. DETAILED DESCRIPTION OF THE INVENTION

[0011] The scalp composition according to the present invention contains zinc glycine as an active ingredient, and exerts its effects when applied to the scalp as a scalp composition.

[0012] The amount of this scalp composition to be incorporated into scalp cosmetics varies depending on the application, formulation, purpose of incorporation, etc., and is not particularly limited, but generally, the amount of zinc glycine in the topical preparation is preferably 0.001 to 10.0 mass%, more preferably 0.01 to 5.0 mass%.

[0013] In addition, to improve the solubility of zinc glycinate in the scalp composition, it is desirable to incorporate an organic acid and / or its salt, or an amino acid and / or its salt. Examples of organic acids include alkanoic acids, saturated dibasic acids, and hydroxycarboxylic acids. Examples of alkanoic acids include methanoic acid, ethanoic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, and heptanoic acid. Examples of saturated dibasic acids include oxalic acid, malonic acid, succinic acid, and glutaric acid. Examples of hydroxycarboxylic acids include citric acid, glycolic acid, tartaric acid, and lactic acid. Other examples include vitamins such as ascorbic acid. Examples of water-soluble organic acid salts include alkali metal salts of the organic acids, such as trisodium citrate and sodium lactate. The amino acid may be any of neutral amino acids, basic amino acids, and acidic amino acids, such as glycine, alanine, valine, leucine, isoleucine, serine, threonine, phenylalanine, tyrosine, tryptophan, cystine, cysteine, methionine, proline, hydroxyproline, aspartic acid, asparagine, glutamic acid, glutamine, arginine, histidine, lysine, γ-aminobutyric acid, DL-pyrrolidonecarboxylic acid, and ε-aminocaproic acid, which may be in the D-, L-, or DL-form. Furthermore, the amino acid salt may be an alkali metal salt or hydrochloride of an amino acid.

[0014] The scalp cosmetic of the present scalp composition can be blended with existing anti-inflammatory agents and agents for preventing / ameliorating rough skin. The combined use of these ingredients produces a synergistic effect of the present effect and does not impair the present effect.

[0015] Furthermore, the scalp cosmetic of the present scalp composition can contain any ingredients that can be incorporated into cosmetics, quasi-drugs, etc., as long as the effects of the present invention are not impaired. Examples of such ingredients include hydrocarbons such as liquid paraffin, vegetable oils and fats, waxes, synthetic ester oils, silicone-based oil phase components, fluorine-based oil phase components, higher alcohols, fatty acids, thickeners, ultraviolet absorbers, powders, pigments, colorants, anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, polyhydric alcohols, sugars, polymeric compounds, physiologically active ingredients, transdermal absorption enhancers, solvents, antioxidants, fragrances, preservatives, etc.

[0016] The scalp cosmetic containing the antidandruff agent may be in any form, such as a skin lotion, lotion, emulsion, cream, pack, ointment, dispersion, solid, mousse, spray, etc. In addition to scalp cosmetics, the agent can also be suitably used in medicinal ointments, etc.

[0017] The present invention will be specifically described below with reference to examples, but the technical scope of the present invention is not limited to these examples. [Example]

[0018] <Evaluation of antibacterial activity against dandruff-causing bacteria> 1-1. Experimental Method The bacterial solution and the 0.5% sample solution shown in Table 1 were added to a mixed solution of YM Broth and PEG400 (25% PEG400) containing 1% olive oil and 0.2% Tween 80, and then subjected to osmotic culture at 37°C. The number of bacteria was counted after 24 hours and used as an index of antibacterial effect.

[0019] [1-2. Experimental Results] Malassezia furfur is known to be a causative fungus of dandruff, and its proliferation leads to dandruff and itching. Therefore, the usefulness of samples for preventing dandruff was investigated by evaluating their effect on the proliferation of Malassezia furfur. As shown in Table 1, zinc pyrithione (0.5% solution), known as a zinc-based antibacterial agent against Malassezia furfur, showed strong antibacterial activity after 24 hours. On the other hand, zinc glycine (0.5% solution), an example of the present invention, slightly inhibited the proliferation of Malassezia furfur, but did not show strong antibacterial activity.

[0020] [Table 1] TIFF2026043663000001.tif2897 [Example]

[0021] <Evaluation of the promoting effect on barrier components produced by epidermal cells> 2-1. Experimental Method The samples shown in Figure 1 were added to human epidermal cells and cultured for 6 days. After 6 days of culture, involucrin, which is used as an index of keratinization of epidermal cells, was detected in the epidermal cells by dot blotting.

[0022] [2-2. Test Results] A weakening of the epidermal barrier is observed in areas of rough scalp caused by dandruff. Therefore, we evaluated the epidermal barrier-promoting effect of zinc glycine using involucrin, a component that increases with epidermal keratinization, as an indicator. In this evaluation method, dot blots, the more intense the black dots, the greater the amount of involucrin. As shown in Figure 1, a significant increase in the degree of keratinization in human epidermal cells after 6 days of culture was observed with zinc glycine. On the other hand, no significant increase in involucrin was observed with zinc pyrithione. [Example]

[0023] <Evaluation of dandruff improvement effect in human trials> [3-1. Test Overview] This study was conducted with the approval of the ethical committee and involved 24 men and women with scalp dryness symptoms who had given their consent. They were divided into two groups of 12 people, one receiving a placebo lotion and the other receiving a lotion containing 1% glycine zinc, and a 4-week continuous use test was conducted. Regarding scalp dryness symptoms, a comprehensive scalp dryness scale consisting of a 16-point score was calculated using the following indicators: Dandruff score (experts assessed dandruff scores on a scale of 0 to 10) Redness score (experts assessed scalp redness on a scale of 0 to 3 points) Itch score (subjects rated the degree of scalp itching on a scale of 0 to 3 points.)

[0024] [3-2. Test Results] As shown in Table 2, a significant reduction in the number of flakes of dandruff was observed after four weeks of continuous use in the group that used the 1% glycine zinc lotion compared to before use, and its dandruff improvement effect was stronger than that of the placebo group. At the same time, as shown in Table 3, in a comparison between groups using a comprehensive scale of scalp roughness, which was indexed by dandruff score, redness score, and itchiness score after four weeks of continuous use, the 1% glycine zinc lotion showed a greater scalp roughness improvement effect than the placebo lotion.

[0025] [Table 2]

[0026] [Table 3]

[0027] The scalp composition described below was prepared using the present invention. The obtained scalp composition improves scalp roughness such as dandruff. The blending amount is expressed as % by mass.

[0028] Example 4. Scalp lotion A Purified water remainder Ethanol 10.00 Glycerin 10.00 Propanediol 5.00 Phenoxyethanol 0.40 EDTA-disodium 0.05 B NIKKOL Glycine Zinc Complex* 1.00 Citric acid 0.30 Sodium citrate 1.00 Purified water 10.00 (Total) 100.00 (Preparation method) After heating A and dissolving it uniformly, add B to complete the preparation. *NIKKOL Glycine Zinc Complex: Glycine Zinc

[0029] Example 5. Scalp care shampoo A NIKKOL Glycine Zinc Complex 0.50 1,3-butylene glycol 4.00 Sorbitol 1.40 Ascorbic acid 0.20 Glutamic acid 0.20 Sodium benzoate 0.20 EDTA-2Na 0.10 Guar Hydroxypropyltrimonium Chloride 1.00 Purified water remainder B NIKKOL CMT-30* 20.00 NIKKOL Alaninate LN-30* 15.00 NIKKOL AM-3130N* 15.00 PG Lauryl 2.00 Caprylyl / Capryl Glucoside 5.00 NIKKOL Decaglyn 1-L 3.00 (Total) 100.00 (Preparation method) Heat A and B separately and stir until uniform. Once thoroughly mixed, gradually add B to A and stir until uniform. After mixing, cool while stirring to complete the preparation. *NIKKOL CMT-30: Water, Sodium Methyl Cocoyl Taurate *NIKKOL Alaninate LN-30: Water, Sodium Lauroyl Methylalanine *NIKKOL AM-3130N: Water, Cocamidopropyl Betaine

[0030] Example 6. Scalp care serum A Xanthan gum 0.40 Hydroxyethyl cellulose 0.40 1,3-butylene glycol 3.00 Glycerin 3.00 Hyaluronic acid (1% aqueous solution) 1.00 Dipotassium glycyrrhizinate 0.10 Phenoxyethanol 0.40 Purified water remainder B NIKKOL Glycine Zinc Complex 0.10 Citric acid 0.10 Malic acid 0.10 Purified water 10.00 (Total) 100.00 (Preparation method) Heat A and B separately and stir until uniform. Once thoroughly mixed, gradually add B to A and stir until uniform. After mixing, cool while stirring to complete the preparation.

[0031] Example 7. Scalp care emulsion A NIKKOL Resinol S-10* 0.80 Behenyl Alcohol 1.00 Cetyl palmitate 0.80 Ethylhexyl palmitate 4.00 Dimethicone (6cs) 2.60 NIKKOL Nicoguard 88* 0.30 B Propanediol 6.00 Xanthan gum 0.20 Gellan gum 0.10 Purified water remainder C NIKKOL Glycine Zinc Complex 2.00 Sodium citrate 1.00 Aspartic acid 0.50 Purified water 10.00 (Total) 100.00 (Preparation method) Mix phases A, B, and C uniformly at room temperature. After heating and dissolving A and B, add A to B and emulsify at 80°C using a homomixer. After emulsification, cool while stirring, and add phase C when it is around 35°C. Stir until uniform and preparation is complete. *NIKKOL Lecithin S-10: Hydrogenated lecithin *NIKKOL Nicoguard 88: Ethylhexylglycerin, glyceryl caprylate [Industrial Applicability]

[0032] It has been demonstrated that the scalp composition of the present invention has a sufficiently high practical effect against scalp roughness such as dandruff, despite having lower bactericidal and antibacterial properties than conventionally known zinc compounds. The scalp composition of the present invention is highly effective for users suffering from scalp roughness such as dandruff.

Claims

1. An anti-dandruff agent with zinc glycine as its active ingredient.

2. A scalp composition comprising zinc glycine as an anti-dandruff agent.

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