JP2007277119A - Skin care preparation for external use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a skin care preparation for external use remarkably effective for preventing/improving skin darkening after sunburn and pigmentation such as stains, freckles and the like, having excellent bleaching effect together with preventing/improving dry skin and rough skin and imparting integrated cosmetic effect to the skin. <P>SOLUTION: The skin care preparation for external use contains one or more species selected from a group consisting of L-ascorbic acid, L-ascorbic acid derivatives and salts thereof, a hydrolyzed silk protein and has 5-8 pH values. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an external preparation for skin. Specifically, the present invention relates to an external preparation for skin that is excellent in the effect of preventing and / or improving pigmentation, drying, and rough skin, and can impart a comprehensive cosmetic effect to the skin.

  Skin darkening after sunburn, pigmentation such as stains and freckles, triggered by hormonal abnormalities and stimulation of ultraviolet rays, increase melanin production in epidermal pigment cells, excessive deposition of melanin in the epidermis This phenomenon is considered to occur. In addition, it is considered that pigmentation is markedly caused by a decrease in the metabolic function of the skin due to aging, a slow turnover speed, and a long stratum corneum cell containing melanin remaining in the epidermis.

  In order to prevent and / or improve such skin pigmentation, various whitening agents, for example, substances that suppress the production of melanin, substances that reduce the produced melanin, substances that promote the excretion of the produced melanin, Etc. have been screened and have been blended into topical skin preparations such as cosmetics. Specifically, ascorbic acid, cysteine, hydroquinone, placenta extract, 2-hydroxy acid and derivatives thereof, extracts from plants and algae, and the like are used. Among them, ascorbic acid is considered to be an effective whitening agent because it exhibits an excellent inhibitory action on melanin production and a reducing action on the produced melanin, and is excellent in safety, and has been widely used as a compounding ingredient for skin external preparations (non- Patent Document 1).

  However, many of these already reported have problems in terms of stability, safety, odor, etc., and the expected effects are weak and still not satisfactory.

  In addition, skin external preparations such as cosmetics are required to have not only a whitening effect but also an effect of preventing and / or improving dryness and rough skin, and contribute to the overall health and health of the skin. . Dryness and rough skin caused by disturbance of physiological functions become more prominent with aging. This is because natural moisturizing factor (NMF) decreases due to aging and the stratum corneum moisture content decreases, resulting in a decrease in moisturizing function and a slow turnover rate due to aging, resulting in a thicker stratum corneum. Is considered to be the cause. Conventional skin external preparations cannot sufficiently cope with such problems.

  The present applicant has so far described the action of hydrolyzed silk protein on skin as an antioxidant action (Patent Document 1), an anti-skin inflammation action (Patent Document 2), a tyrosinase activity inhibitory action (Patent Document 3), and a surface activity. (Patent document 4), collagen production promoting action (patent document 5), improvement of moisture retention by using in combination with monosaccharides and / or oligosaccharides (patent document 6), cell protecting action after ultraviolet irradiation, erythema inhibiting action, pigment The inventors have found and applied for a patent for an inhibitory action on deposition, an inhibitory action on wrinkle formation, and a therapeutic action against skin disorders (Patent Document 7). There has also been reported an attempt to contain a hydrolyzed silk protein in a skin external preparation as a cell activator (Patent Document 8). Although the external preparation for skin containing hydrolyzed silk protein exhibits a temporary effect on symptoms such as pigmentation, dryness, and rough skin, there is a demand for a better external preparation for skin.

Japanese Patent Laid-Open No. 10-14154 Japanese Patent Laid-Open No. 10-245345 JP-A-10-265403 JP-A-11-276876 JP-A-10-226653 Japanese Patent Laid-Open No. 2001-64148 JP 2003-252744 A JP 2003-335619 A Directed by Katsuyuki Takeda et al. “Usefulness of Cosmetics” issued by Yakuji Nippo Inc. March 31, 2001

  The present invention has been made in view of such a current situation, and the object of the present invention is extremely effective in preventing and / or improving pigmentation such as skin darkening / stain / freckle after sunburn. It is intended to provide an external preparation for skin which has a whitening effect and also has an effect of preventing and / or improving dryness and rough skin, and can give a comprehensive cosmetic effect to the skin.

  As a result of intensive research to solve the above-mentioned problems, the present inventor is to combine a known whitening agent and a hydrolyzed silk protein in a skin external preparation, and set the pH within a range of 5-8. As a result, the whitening effect is synergistically enhanced compared to when each is used alone, and also has the effect of preventing and / or improving dryness and rough skin, and is stable, skin irritant, skin sensitization, etc. The present inventors have found that an external preparation for skin having no safety problems can be obtained, and have completed the present invention based on this finding.

That is, the present invention firstly contains one or more selected from the group consisting of L-ascorbic acid, L-ascorbic acid derivatives and salts thereof, and a hydrolyzed silk protein, and has a pH of 5 It is -8, It is a skin external preparation characterized by the above-mentioned.
A second aspect of the present invention is the above-mentioned external preparation for skin, wherein the hydrolyzed silk protein is hydrolyzed sericin.
Thirdly, the present invention is characterized in that the average molecular weight of hydrolyzed sericin is 5,000 to 100,000, and hydrolyzed sericin contains 20 to 40 mol% of serine as an amino acid composition, It is a skin external preparation.
4thly this invention is said skin external preparation characterized by content of hydrolyzed silk protein being 0.0001-20 weight% with respect to the skin external preparation whole quantity.
Fifthly, the present invention is characterized in that at least one selected from the group consisting of L-ascorbic acid, L-ascorbic acid derivatives and salts thereof is L-ascorbic acid derivatives or salts thereof. The above-mentioned external preparation for skin.
Sixthly, the L-ascorbic acid derivative or a salt thereof is the above-mentioned external preparation for skin, wherein the L-ascorbic acid derivative or a salt thereof is L-ascorbic acid-2-glucoside or a salt thereof.
Seventh, the present invention has a content of one or more selected from the group consisting of L-ascorbic acid, L-ascorbic acid derivatives, and salts thereof in the range of 0.001 to 0.001 based on the total amount of the external preparation for skin. The skin external preparation described above, characterized by being 20% by weight.

  L-ascorbic acid, L-ascorbic acid derivatives and salts thereof have long been used in skin external preparations to prevent and / or improve pigmentation such as skin darkening, spots and freckles after sunburn. The effect of the present invention obtained by using in combination with a hydrolyzed silk protein has not been known so far.

  According to the present invention, skin having both an excellent whitening effect and an effect of preventing and / or improving dryness and rough skin, and has no problem in terms of stability and safety, and can impart a comprehensive cosmetic effect to the skin. An external preparation can be provided.

Hereinafter, the present invention will be described in detail.
The L-ascorbic acid, L-ascorbic acid derivative and salts thereof used in the present invention are not particularly limited as long as they are used as components of a skin external preparation in the cosmetics, quasi-drugs or pharmaceutical fields.

  L-ascorbic acid is generally referred to as vitamin C, and in the tyrosinase reaction that generates melanin from tyrosine, it suppresses melanin production by reducing dopaquinone, an intermediate of melanin, and reduces dark-colored oxidized melanin. It has two actions, the action of making light reduced melanin.

  Examples of L-ascorbic acid derivatives include L-ascorbic acid monostearate, L-ascorbic acid monopalmitate, L-ascorbic acid monooleate, L-ascorbic acid distearate, L-ascorbic acid dipalmitate, L-ascorbic acid. L-ascorbic acid alkyl ester derivatives such as diolate, L-ascorbic acid tristearate, L-ascorbic acid tripalmitate, L-ascorbic acid trioleate; L-ascorbic acid monophosphate, L-ascorbic acid diphosphate, L-ascorbic acid phosphate derivatives such as L-ascorbic acid triphosphate; L-ascorbic acid sulfate derivatives such as L-ascorbic acid-2-sulfate; L-ascorbic acid-2-glucoside , And the like Bruno L- ascorbic acid glucoside derivatives.

  Examples of salts of L-ascorbic acid and L-ascorbic acid derivatives include alkali metal salts such as sodium salts and potassium salts; alkaline earth metal salts such as magnesium salts and calcium salts; ammonium salts and tricyclohexylammonium salts. Examples include ammonium salts; organic amine salts such as triethanolamine salt and triethylamine salt; and basic amino acid salts such as arginine salt and lysine salt.

  Among the above L-ascorbic acid, L-ascorbic acid derivatives and salts thereof, L-ascorbic acid derivatives and salts thereof are preferable in terms of stability, and L-ascorbic acid-2-glucoside and salts thereof are particularly preferable. L-ascorbic acid-2-glucoside and its salt are excellent in stability because they do not exhibit direct reducing properties, and are excellent in safety because they are produced and metabolized in vivo. L-ascorbic acid-2-glucoside and its salt are gradually hydrolyzed to L-ascorbic acid and glucose by α-glucosidase in the epidermis and dermis, and exert the efficacy of L-ascorbic acid for a long time. Sustained effect is expected.

  The L-ascorbic acid, L-ascorbic acid derivatives and salts thereof used in the present invention are mainly obtained by known synthetic techniques, but of course, those obtained by other methods can also be used. Commercially available products can be used.

  In the present invention, L-ascorbic acid, L-ascorbic acid derivatives and salts thereof can be used singly or in combination of two or more. The content of one or more selected from the group consisting of L-ascorbic acid, L-ascorbic acid derivatives and salts thereof is not particularly limited, but is 0.001 to 20 relative to the total amount of the external preparation for skin. It is preferable that it is weight%. If the content is less than 0.001% by weight, the whitening effect of the external preparation for skin tends to be poor, and conversely, even if the content exceeds 20% by weight, an increase in the effect cannot be substantially expected, and the external preparation for skin It tends to be difficult to add to the composition. A more preferred content is 0.01 to 10% by weight, and even more preferred is 0.1 to 7% by weight.

  The hydrolyzed silk protein used in the present invention is obtained by hydrolyzing silk protein by acid, alkali, or enzyme treatment. The silk protein is a mixture of proteins mainly composed of fibroin and sericin. In the present invention, fibroin and sericin can be used alone or in a mixture and hydrolyzed, but tyrosinase activity inhibitory action and cell It is preferable to use a product obtained by hydrolyzing sericin from the viewpoints of high activation, antioxidant and moisturizing effects and preventing and / or improving dryness and rough skin.

  The amino acid composition of sericin is similar to the amino acid composition of the natural moisturizing factor involved in the moisture regulation of the skin stratum corneum, and particularly contains a large amount of serine rich in hydrophilicity. Compared to natural proteins such as fibroin and collagen used as a humectant, sericin containing a large amount of serine has a high hydrophilicity and is superior as a humectant. Moreover, since it is excellent in moisture release property, stickiness does not arise. Furthermore, antioxidant action, skin inflammation prevention action, tyrosinase activity inhibition action, surface activity ability, collagen production promotion action, UV damage protection action (cell protection action, erythema inhibition action, pigmentation inhibition action, wrinkle formation inhibition action and skin damage) As described above, it has a number of excellent actions, such as a therapeutic action on cells and a cell activation action. And since it is excellent in adhesiveness and a film formation effect | action, the effect is exhibited over a long time, and the effect with respect to skin becomes very remarkable.

  Such sericin is easily available as a hydrolyzate from silkworms or raw silk. That is, the hydrolyzed sericin used in the present invention can be eluted by partially hydrolyzing sericin contained in silkworms or raw silk in acid or alkaline aqueous solution or by enzymatic treatment. The eluate was adjusted to pH 3-5 with an organic acid or inorganic acid, or mixed with a water-soluble organic solvent such as methanol, ethanol, dioxane, etc. to precipitate hydrolyzed sericin, dried after filtration, and powdered. Things can also be used.

  The molecular weight of the hydrolyzed sericin thus obtained is usually distributed in the range of 500 to 200,000, and any of them can be used, but preferably hydrolyzed sericin having an average molecular weight of 5,000 to 100,000. is there. When the average molecular weight is less than 5,000, various effects of sericin tend to decrease. When the average molecular weight exceeds 100,000, the familiarity with the skin tends to deteriorate.

  Hydrolyzed sericin preferably contains 20 to 40 mol% of serine as an amino acid composition. When the serine content is less than 20 mol%, various functions and effects of sericin, particularly moisture retention, tend to be lowered. Further, since the hydrolyzed sericin is derived from the natural protein sericin (serine content around 32 mol%), the serine content is at most 40 mol%.

  Hydrolyzed sericin used in the present invention is readily water-soluble, excellent in miscibility with normal skin external preparation components, and maintains stable properties as an aqueous solution, and has no irritation or sensitization to the skin. Excellent safety.

  The content of the hydrolyzed silk protein in the present invention is not particularly limited and can be adjusted according to the dosage form and purpose of the external preparation for skin, but preferably 0.0001 to 20% by weight based on the total amount of the external preparation for skin. is there. If the content is less than 0.0001% by weight, the skin cosmetic effect tends to be poor. Even if the content exceeds 20% by weight, an increase in the effect cannot be substantially expected, which is uneconomical. A more preferable content is 0.001 to 10% by weight, and still more preferably 0.01 to 10% by weight.

  The external preparation for skin of the present invention comprises one or more selected from the group consisting of L-ascorbic acid, L-ascorbic acid derivatives and their salts, and hydrolyzed silk protein, as described above, as essential components. In addition, as an optional component, other components usually used in skin preparations such as cosmetics, quasi-drugs, and pharmaceuticals, such as oils, wetting agents, antioxidants, surfactants, Preservatives, moisturizers, pigments, ultraviolet absorbers, antioxidants, fragrances, antibacterial / antifungal water, alcohol, thickeners and the like can be appropriately blended as necessary.

  The pH of the external preparation for skin of the present invention is preferably 5-8. When the pH is less than 5 or exceeds 8, the stability is inferior and the durability of the effect is lowered. There is also a risk of irritation to the skin. In the present invention, the pH can be adjusted using a commonly used pH adjuster, for example, hydrochloric acid, citric acid, lactic acid, malic acid, and salts thereof as the acid, sodium hydroxide as the base, Examples thereof include potassium hydroxide, sodium citrate, sodium lactate, potassium chloride, triethanolamine, and aminomethylpropanol. From these, one kind is used alone, or two or more kinds are used in combination.

  The dosage form of the external preparation for skin of the present invention is arbitrary, and can be provided in various dosage forms such as a lotion, emulsion, gel, cream, ointment, powder, granule and the like.

  The external preparation for skin of the present invention refers to an external preparation applied to the outer skin as a cosmetic, quasi-drug, or pharmaceutical product. For example, an ointment, cream, emulsion, lotion, essence, jelly, gel, pack, mask, bath It is used as an agent.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to a following example.

First, the usage test method of a skin external preparation is demonstrated.
[Use test]
The group consists of 20 female panelists aged 30 to 60 years with skin aging symptoms such as stains, freckles and other pigmentation, dryness, and rough skin. Each sample is blinded twice a day for 2 months. Used continuously. The skin pigmentation state (whitening effect), water content (moisturizing effect), and turnover improvement were evaluated and determined by the following methods.

The skin pigmentation state before and after the start of the whitening effect use test was observed with the naked eye, and evaluated and determined according to the following criteria.
(Evaluation criteria)
Improvement: Pigmentation is almost unnoticeable Slightly improved: Pigmentation is slightly thinner No change: Little change (Criteria)
◎: When the number of panelists evaluated as improved or slightly improved is 15 or more ○: When the number of panelists evaluated as improved or slightly improved is 10 to 14 △: Panelists evaluated as improved or slightly improved When the number is 5 to 9 ×: When the number of panelists evaluated as improved or slightly improved is 4 or less

The moisture content of the skin before and after the start of the moisturizing effect use test was measured using a skin moisture meter (SKICON-200, manufactured by IBS) in a constant temperature and humidity room at a room temperature of 23 ° C. and a humidity of 55%. The rate of change was determined by the following formula. Furthermore, it evaluated and determined in accordance with the following criteria.
Rate of change in water content (%) = (water content after end of use test−water content before start of use test) / water content before start of use test × 100
(Evaluation criteria)
Improvement: When water content change rate is 80% or more Slightly improved: Water content change rate is 40% or more and less than 80% No change: Water content change rate is less than 40% (Criteria)
◎: When the number of panelists evaluated as improved or slightly improved is 15 or more ○: When the number of panelists evaluated as improved or slightly improved is 10 to 14 △: Panelists evaluated as improved or slightly improved When the number is 5 to 9 ×: When the number of panelists evaluated as improved or slightly improved is 4 or less

Turnover turnover was estimated by stratum corneum cell area. The stratum corneum was collected from the skin before and after the use test by tape stripping, dyed and observed with a microscope to measure the stratum corneum cell area, and the rate of change was determined by the following equation. Furthermore, it evaluated and determined in accordance with the following criteria.
Change rate of stratum corneum cell area (%) = difference of stratum corneum area before start of trial test and end of trial / corneocyte area before start of use test × 100
(Evaluation criteria)
Improvement: When change rate of stratum corneum cell area is 50% or more Slight improvement: When change rate of stratum corneum cell area is 20% or more and less than 50% No change: Change rate of stratum corneum cell area is less than 20% Case (Criteria)
◎: When the number of panelists evaluated as improved or slightly improved is 15 or more ○: When the number of panelists evaluated as improved or slightly improved is 10 to 14 △: Panelists evaluated as improved or slightly improved When the number is 5 to 9 ×: When the number of panelists evaluated as improved or slightly improved is 4 or less

  Next, the preparation method of the hydrolyzed silk protein aqueous solution contained in the skin external preparation of this invention is demonstrated.

[Hydrolyzed silk protein aqueous solution 1 (average molecular weight 12,000)]
Silk fabric made of raw silk was treated with 0.3% sodium carbonate (pH 11-12) at 95 ° C. for 2 hours to extract hydrolyzed sericin. The obtained extract was filtered through a filter having an average pore size of 0.2 μm to remove aggregates, and then the filtrate was desalted with a reverse osmosis membrane to obtain a colorless and transparent hydrolyzed sericin extract having a concentration of 0.2%. It was. The extract was concentrated to about 2% using an evaporator and then freeze-dried to obtain a hydrolyzed silk protein powder containing hydrolyzed sericin as a main component. This hydrolyzed silk protein had a molecular weight distribution of 500 to 50,000, an average molecular weight of 12,000, and contained 35 mol% of serine as an amino acid composition.
A hydrolyzed silk protein aqueous solution was prepared by dissolving 5 g of hydrolyzed silk protein powder in 95 g of purified water.

[Hydrolyzed silk protein aqueous solution 2 (average molecular weight 30,000)]
A silk fabric made of raw silk was treated with 0.2% sodium carbonate (pH 11-12) at 95 ° C. for 2 hours to extract hydrolyzed sericin. The obtained extract was filtered through a filter having an average pore size of 0.2 μm to remove aggregates, and then the filtrate was desalted with a reverse osmosis membrane to obtain a colorless and transparent hydrolyzed sericin extract having a concentration of 0.2%. It was. The extract was concentrated to about 2% using an evaporator and then freeze-dried to obtain a hydrolyzed silk protein powder containing hydrolyzed sericin as a main component. This hydrolyzed silk protein had a molecular weight distribution of 3,000 to 70,000, an average molecular weight of 30,000, and contained 35 mol% of serine as an amino acid composition.
A hydrolyzed silk protein aqueous solution was prepared by dissolving 5 g of hydrolyzed silk protein powder in 95 g of purified water.

[Hydrolyzed silk protein aqueous solution 3 (average molecular weight 50,000)]
A silk fabric made of raw silk was treated with 0.1% sodium carbonate (pH 11-12) at 95 ° C. for 2 hours to extract hydrolyzed sericin. The obtained extract was filtered through a filter having an average pore size of 0.2 μm to remove aggregates, and then the filtrate was desalted with a reverse osmosis membrane to obtain a colorless and transparent hydrolyzed sericin extract having a concentration of 0.2%. It was. The extract was concentrated to about 2% using an evaporator and then freeze-dried to obtain a hydrolyzed silk protein powder containing hydrolyzed sericin as a main component. The hydrolyzed silk protein had a molecular weight distribution of 5,000 to 100,000, an average molecular weight of 50,000, and contained 35 mol% of serine as an amino acid composition.
A hydrolyzed silk protein aqueous solution was prepared by dissolving 5 g of hydrolyzed silk protein powder in 95 g of purified water.

  For L-ascorbic acid, L-ascorbic acid derivatives and salts thereof, and other components, those commercially available for pharmaceuticals, quasi drugs or cosmetics were used.

[Examples 1 to 5, Comparative Examples 1 to 4]
With the formulation shown in Table 1, skin lotions according to Examples 1 to 5 of the present invention were prepared. At the same time, Comparative Examples 1 to 4 containing no hydrolyzed silk protein or L-ascorbic acid derivative were prepared according to the formulation shown in Table 2. The skin lotion was prepared by sequentially adding all components to purified water, mixing and homogenizing.

  A use test was conducted on the skin lotions of Examples 1 to 5 and Comparative Examples 1 to 4, and the effects of the present invention were confirmed. The results are shown in Table 3.

  As is clear from Table 3, in Examples 1 to 5 of the present invention containing both the L-ascorbic acid derivative and the hydrolyzed silk protein, all the items of pigmentation state, water content and turnover were improved. Was recognized. In particular, the effect of improving the pigmentation state is synergistically enhanced. On the other hand, in Comparative Examples 1 to 3 containing only the L-ascorbic acid derivative or the hydrolyzed silk protein, although an improvement tendency was observed, the degree was lower than those in Examples 1 to 5.

  Another embodiment of the present invention will be described.

[Example 6] Lotion (1) 1,3-butylene glycol 8 (% by weight)
(2) Concentrated glycerin 6
(3) Ethanol 3
(4) L-ascorbic acid-2-glucoside 2
(5) Hydrolyzed silk protein aqueous solution 2 (average molecular weight 30,000) 2
(6) Aloe extract 0.2
(7) Chlorella extract 0.2
(8) Cuckoo extract 0.01
(9) Yeast extract 0.2
(10) Sodium hydroxide appropriate amount (11) Sodium citrate appropriate amount (12) citric acid appropriate amount (13) paraoxybenzoic acid ester appropriate amount (14) purified water remaining pH: 6.7
Manufacturing method: All components are added to purified water sequentially, and mixed and homogenized.

[Example 7] Cosmetic liquid (1) 1,3-butylene glycol 12 (% by weight)
(2) Ethanol 5
(3) L-ascorbic acid-2-glucoside 2
(4) Hydrolyzed silk protein aqueous solution 2 (average molecular weight 30,000) 2
(5) Hydrogenated soybean phospholipid 0.5
(6) Aloe extract 0.2
(7) Chlorella extract 0.2
(8) Cuckoo extract 0.01
(9) Mulberry extract 0.1
(10) Marronie extract 0.1
(11) Walnut extract 0.1
(12) Yeast extract 0.2
(13) Daylily powder 0.1
(14) Sodium alginate Appropriate amount (15) Carrageenan Appropriate amount (16) Sodium citrate Appropriate amount (17) Sodium hydroxide Appropriate amount (18) Citric acid Appropriate amount (19) Paraoxybenzoic acid ester Appropriate amount (20) Purified water Residual pH: 7. 3
Production method: The components are mixed and homogenized, heated to 80 ° C., and cooled with stirring.

[Example 8] Milk (1) Concentrated glycerin 10 (% by weight)
(2) Ethanol 8
(3) Glyceryl tri-2-ethylhexanoate 6
(4) 1,3-butylene glycol 5
(5) Polyglyceryl distearate 2
(6) Batyl alcohol 2
(7) L-ascorbic acid-2-glucoside 2
(8) Hydrolyzed silk protein aqueous solution 3 (average molecular weight 50,000) 2
(9) Hydrogenated soybean phospholipid 0.5
(10) Aloe extract 0.2
(11) Chlorella extract 0.2
(12) Cuckoo extract 0.01
(13) Yeast extract 0.2
(14) Daylily powder 0.1
(15) d-δ-tocopherol 0.1
(16) Diethylenetriaminepentaacetic acid pentasodium appropriate amount (17) Carboxyvinyl polymer appropriate amount (18) Hydroxyethyl cellulose appropriate amount (19) Sodium citrate appropriate amount (20) Sodium hydroxide appropriate amount (21) Paraoxybenzoic acid ester appropriate amount (22) Purified water remaining Amount pH: 7.0
Production method: The oil component and the aqueous component are mixed and homogenized and heated to 80 ° C. The oil component is added to the aqueous component to emulsify, and the mixture is cooled with stirring.

[Example 9] Cream (1) Concentrated glycerin 15 (% by weight)
(2) 1,3-butylene glycol 10
(3) Squalane 10
(4) Hardened oil 5
(5) Batyl alcohol 5
(6) Ethanol 5
(7) Behenyl alcohol 2
(8) Cetyl palmitate 2
(9) Lipophilic glyceryl monostearate 2
(10) Polyoxyethylene glyceryl isostearate 1
(11) Methyl polysiloxane 1
(12) L-ascorbic acid-2-glucoside 2
(13) Hydrolyzed silk protein aqueous solution 3 (average molecular weight 50,000) 2
(14) Aloe extract 0.2
(15) Chlorella extract 0.2
(16) Cuckoo extract 0.01
(17) Mulberry extract 0.1
(18) Marronie extract 0.1
(19) Walnut extract 0.1
(20) Yeast extract 0.2
(21) Centella extract 0.1
(22) Terminaria extract 0.01
(23) Licorice extract powder 0.1
(24) Batyl alcohol 0.1
(25) Diethylenetriaminepentaacetic acid pentasodium appropriate amount (26) Hydroxyethylcellulose appropriate amount (27) Sodium citrate appropriate amount (28) Sodium hydroxide appropriate amount (29) Paraoxybenzoic acid ester appropriate amount (30) Purified water Remaining pH: 6.5
Production method: The oil component and the aqueous component are mixed and homogenized and heated to 80 ° C. The oil component is added to the aqueous component to emulsify, and the mixture is cooled with stirring.

  A use test was performed on the external preparations for skin of Examples 6 to 9, and the effects of the present invention were confirmed. At that time, the hydrolyzed silk protein aqueous solution contained in each of Examples 6 to 9 was replaced with purified water to give Comparative Examples 5 to 8, which were simultaneously evaluated. The results are shown in Table 4.

  As is clear from Table 4, in Examples 6 to 9 of the present invention containing both the L-ascorbic acid derivative and the hydrolyzed silk protein, improvement was made in any of the items of pigmentation state, water content, and turnover. Was recognized. In particular, the effect of improving the pigmentation state is synergistically enhanced. On the other hand, although the improvement tendency was seen in Comparative Examples 5-8 containing only an L-ascorbic acid derivative, the grade was lower than Examples 6-9.

In addition, about Examples 1-9, there was no panel which complained of skin irritation during the said use test period. In addition, no change in state such as separation or aggregation was observed, indicating that safety and stability were good.

Claims (7)

  It contains one or two or more selected from the group consisting of L-ascorbic acid, L-ascorbic acid derivatives and salts thereof, and a hydrolyzed silk protein, and has a pH of 5-8. Skin external preparation.   The skin external preparation according to claim 1, wherein the hydrolyzed silk protein is hydrolyzed sericin.   The skin external preparation according to claim 2, wherein the average molecular weight of hydrolyzed sericin is 5,000 to 100,000, and hydrolyzed sericin contains 20 to 40 mol% of serine as an amino acid composition. .   The skin external preparation according to any one of claims 1 to 3, wherein the content of the hydrolyzed silk protein is 0.0001 to 20% by weight based on the total amount of the skin external preparation.   The L-ascorbic acid, the L-ascorbic acid derivative, and at least one selected from the group thereof is an L-ascorbic acid derivative or a salt thereof. The external preparation for skin according to one item.   The skin external preparation according to claim 5, wherein the L-ascorbic acid derivative or a salt thereof is L-ascorbic acid-2-glucoside or a salt thereof.   The content of one or more selected from the group consisting of L-ascorbic acid, L-ascorbic acid derivatives and salts thereof is 0.001 to 20% by weight based on the total amount of the external preparation for skin. The skin external preparation as described in any one of Claims 1-6.