External preparation for skin

Abstract

Provided is an external preparation for the skin, which, after application, can achieve an effect of improving wrinkles early, and which can last for a long period of time. The external preparation for skin according to the present invention comprises (A) retinol, (B) castor seed oil, (C) bis-diglycerol polyacyl adipate-2 or dimeric pentaerythritol hexahydroxy stearate, and (D) water.

Description

Technical Field

[0001] The present invention relates to a topical skin preparation having a high effect of improving wrinkles when applied to the skin. Background Art

[0002] Retinol is known as an effective ingredient for preventing and treating skin keratosis and the like, and preventing and repairing skin aging, and has been used in cosmetics and the like expecting an effect of improving wrinkles. However, for the effect of improving wrinkles, it is desired to exhibit the effect earlier. In addition, retinol is liable to cause isomerization, decomposition, polymerization or the like due to light, air, heat or metal ions, etc., and from the viewpoint of the stability of retinol, it is desired to further improve the retinol compounding technique.

[0003] In addition, in order to achieve the effect of improving wrinkles, it is effective to soften the stratum corneum of the skin. There are also known topical skin preparations for softening the stratum corneum, but from the viewpoints of the effect of improving wrinkles and stability, further improvement is desired.

[0004] Based on this background, there is a need for a topical skin preparation that can obtain an effect of improving wrinkles at an early stage after application and can maintain the effect for a long time.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Laid-Open No. 6-024958 Summary of the Invention

[0008] The present invention has been made in view of the above problems, and an object thereof is to provide a topical skin preparation that can obtain an effect of improving wrinkles at an early stage and has excellent stability over time.

[0009] According to the present invention, the following inventions are provided. [1]

[0011] A topical skin preparation comprising:

[0012] (A) retinol,

[0013] (B) castor oil,

[0014] (C) bis-diglycerol polyacyl adipate-2 or dipentaerythritol hexahydroxystearate, and

[0015] (D) water. [2]

[0017] The topical skin preparation according to [1], which is an oil-in-water type emulsion preparation. [3]

[0019] The topical skin preparation according to [1] or [2], wherein the content of component (A) is 0.005 to 5% by mass based on the total mass of the topical skin preparation. [4]

[0021] The topical skin preparation according to any one of [1] to [3], wherein the content of component (B) is 0.2 to 30% by mass based on the total mass of the topical skin preparation. [5]

[0023] The topical skin preparation according to any one of [1] to [4], wherein the content of component (C) is 0.2 to 30% by mass based on the total mass of the topical skin preparation. [6]

[0025] The topical skin preparation according to any one of [1] to [5], wherein the total content of component (B) and component (C) is 0.5 to 40% by mass based on the total mass of the topical skin preparation. [7]

[0027] The topical skin preparation according to any one of [1] to [6], wherein the ratio of [total content of component (B) and component (C)] / [content of component (A)] is 10 to 500. [8]

[0029] The topical skin preparation according to any one of [1] to [7], wherein component (B) is an ester of a fatty acid having 14 to 20 carbon atoms and glycerol. [9]

[0031] The topical skin preparation according to any one of [1] to [8], which further contains (E) hydrogenated lecithin.

[10]

[0033] The topical skin preparation according to any one of [1] to [9], which further contains (F) higher alcohol.

[11]

[0035] The topical skin preparation according to any one of [1] to

[10] , which further contains (G) polyol.

[0036] Advantages of the Invention

[0037] According to the present invention, there is provided a topical skin preparation having excellent effect stability, which can obtain a wrinkle improvement effect at an early stage after application to the skin and further the effect can be sustained. Detailed Description

[0038] [Topical Skin Preparation]

[0039] The topical skin preparation of the present invention contains the following components as essential components:

[0040] (A) Retinol,

[0041] (B) Castor oil,

[0042] (C) Bis-diglycerol polyacyl adipate-2 or dipentaerythritol hexahydroxystearate, and

[0043] (D) Water.

[0044] Hereinafter, these essential components and additional components that can be used together will be described.

[0045] [(A) Retinol]

[0046] The topical skin preparation of the present invention contains retinol (hereinafter sometimes referred to as component (A)). Retinol is used in the fields of cosmetics, pharmaceuticals, quasi-drugs, etc., and the present invention can be arbitrarily selected from these.

[0047] Retinol (alias: vitamin A) has several stereoisomers such as all-trans, 13-cis, 9-cis, etc., and any of them can be used.

[0048] Regarding the blending amount of retinol ((A) component), as long as it is an effective amount capable of exerting the effect of improving wrinkles, there is no particular limitation. Usually, based on the total mass of the topical skin preparation, it is preferably 0.005 to 5% by mass, more preferably 0.01 to 1% by mass. By setting the content of retinol within this range, a sufficient effect of improving wrinkles can be obtained.

[0049] [(B) Castor oil]

[0050] The topical skin preparation of the present invention contains castor oil (hereinafter sometimes referred to as component (B)). Castor oil, as a natural oil, is an ester of fatty acids and glycerol extracted from the seeds of Ricinus communis of the Euphorbiaceae family. The fatty acids constituting castor oil are composed of about 90% ricinoleic acid and palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, etc.

[0051] Castor oil is usually extracted from natural components, and its water content, coloring, acid value, etc. may vary slightly depending on its purification conditions, etc. From the viewpoint of the quality stability of cosmetics, those with high purity are preferred. In addition, from the viewpoint of storage stability, those with a low acid value are preferred, for example, those with an acid value of 0.5 mg KOH / g or less.

[0052] It should be noted that as castor oil, a synthetic compound equivalent to natural castor oil can also be used. Specifically, an ester of a fatty acid having 14 to 20 carbon atoms and glycerol can also be used as component (B).

[0053] Based on the total mass of the topical skin preparation, the content rate of castor oil ((B) component) is preferably 0.2 to 30% by mass, more preferably 0.5 to 20% by mass. By setting the content of castor oil within this range, the effects of the present invention can be better demonstrated.

[0054] [(C) Bis-diglycerol polyacyl adipate-2 / Dipentaerythritol hexahydroxystearate]

[0055] The topical skin preparation of the present invention contains bis-diglycerol polyacyl adipate-2 or dipentaerythritol hexahydroxystearate (hereinafter sometimes referred to as (C) component). By combining with the (B) component, the (C) component can exert a horny layer softening effect earlier after the topical skin preparation is applied to the skin, and further enhance the wrinkle improvement effect brought by the (A) component. It is considered that the oxidation of the (A) component is effectively inhibited by the combination of the (B) component and the (C) component, thus showing this effect.

[0056] Based on the total mass of the topical skin preparation, the content rate of the (C) component is preferably 0.2 to 30% by mass, more preferably 0.5 to 20% by mass. In addition, the total content rate of the (B) component and the (C) component is preferably 0.5 to 40% by mass, more preferably 0.5 to 30% by mass, and further preferably 1 to 20% by mass. By making the total content rate of the (B) component and the (C) component 0.5% by mass or more, a sufficient wrinkle improvement effect can be achieved. In addition, by making it 40% by mass or less, stickiness can be suppressed, thereby improving the usability.

[0057] Furthermore, the ratio of [(total content of (B) component and (C) component)] / [(content of (A) component)] is preferably 10 to 500, more preferably 10 to 300.

[0058] By adjusting the content of the (B) component and the content of the (C) component to meet this condition, a horny layer softening effect can be exerted earlier after the topical skin preparation is applied to the skin, and a wrinkle improvement effect can be obtained for a long time.

[0059] [(D) Water]

[0060] In addition to the above components, the topical skin preparation of the present invention further contains water. As the water, the water used in cosmetics, quasi-drugs, etc. can be used. For example, purified water, ion-exchanged water, tap water, etc. can be used.

[0061] [Other components]

[0062] In addition to the above (A) to (D) components, the topical skin preparation of the present invention can also be formulated with other components as needed within the range that does not impair the effects of the present invention.

[0063] As one of such other components, hydrogenated lecithin (hereinafter sometimes referred to as component (E)) can be mentioned. Hydrogenated lecithin is a lecithin derivative obtained by hydrogenating lecithin mainly composed of phospholipids. Lecithin has: a hydrophilic group including an anionic active group of the phosphate ester salt type and a cationic active group of the quaternary ammonium salt type; and a hydrophobic group having saturated aliphatic carboxylic acid residues such as palmitic acid and stearic acid, and unsaturated aliphatic carboxylic acid residues such as oleic acid and linoleic acid. Hydrogenated lecithin is hydrogenated to improve the saturation degree, and the oxidation stability is improved.

[0064] When the skin external preparation of the present invention is made into an emulsion such as an oil-in-water emulsion preparation, component (E) can be effectively used as a dispersant. When component (E) is formulated, its content is preferably 0.1 to 3% by mass, more preferably 0.5 to 3% by mass, based on the total mass of the skin external preparation.

[0065] As other examples of other components, higher alcohols (hereinafter sometimes referred to as component (F)) can be mentioned. In the present invention, the higher alcohol is not particularly limited as long as it can be used in the fields of cosmetics, pharmaceuticals, quasi-drugs, etc. Specifically, stearyl alcohol, behenyl alcohol, lauryl alcohol, myristyl alcohol, and cetyl alcohol can be mentioned. In addition, a mixture of these is preferred, for example, a combination of stearyl alcohol and behenyl alcohol.

[0066] When component (F) is formulated, its content is preferably 0.1 to 20% by mass, more preferably 0.5 to 10% by mass, based on the total mass of the skin external preparation.

[0067] As other examples of other components, polyhydric alcohols (hereinafter sometimes referred to as component (G)) can be mentioned. Within the range not impairing the effects of the present invention, such polyhydric alcohols can be arbitrarily selected. Specifically, the polyhydric alcohol is preferably one or more selected from the group consisting of glycerin, diglycerin, polyglycerin, 1,3-butanediol, ethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polyethylene glycol, polypropylene glycol, trimethylolethane, trimethylolpropane, erythritol, pentaerythritol, sorbitan, glucose, sorbitol, maltitol, sucrose, raffinose, hexylene glycol, 1,2-pentanediol, and trehalose.

[0068] Component (G) exerts a moisturizing function and a function of imparting a warm feeling, and its content can be adjusted according to its purpose. Generally, the content of component (G) is preferably 5 to 40% by mass, more preferably 10 to 30% by mass, based on the total mass of the skin external preparation.

[0069] The topical skin preparation of the present invention may contain components commonly used in topical skin preparations other than those described above. Examples of such other components include: powder components, liquid oils, solid oils, waxes, hydrocarbon oils, higher fatty acids, ester oils, silicone oils, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, humectants, water-soluble polymers, film-forming agents, ultraviolet absorbers, masking agents, lower alcohols, sugars, amino acids, organic amines, polymer emulsions, pH regulators, skin nutrients, vitamins, antioxidants, antioxidant aids, food flavorings, etc.

[0070] The dosage form of the topical skin preparation of the present invention is preferably an emulsified preparation, and can be either an oil-in-water emulsified preparation or a water-in-oil emulsified preparation. However, an oil-in-water emulsified preparation with excellent usability is preferably prepared. In addition, any dosage form such as a liquid preparation, an emulsion preparation, or a paste preparation can also be used.

[0071] Examples

[0072] The present invention will be described as follows using each example. It should be noted that the present invention is not limited by any of these examples. In addition, unless otherwise specified, the content rate is mass% relative to the total amount.

[0073] [Examples 1 to 4 and Comparative Examples 1 to 2]

[0074] Each component was formulated at the content rates shown in Table 1 to prepare a topical skin preparation. For the obtained topical skin preparation, the residual rate of retinol and the stratum corneum softening effect were evaluated.

[0075] The residual rate of retinol was evaluated as follows: The obtained topical skin preparation was divided into two parts, and after storing at 0 °C and 40 °C for 2 months respectively, the retinol content rate was measured. Based on the retinol content rate of the sample stored at 0 °C, the retinol residual rate of the sample stored at 40 °C was evaluated.

[0076] In addition, the stratum corneum softening effect was measured as follows: The stratum corneum peeled from human skin was cut into a size of 20 mm × 3 mm, placed on a stratum corneum viscoelasticity measuring device, 3 μL of the topical skin preparation was applied, and then the storage modulus was measured at a temperature of 32 °C and a humidity of 50%. The measurement conditions were set as follows.

[0077] Measurement frequency: 1 Hz

[0078] Strain: 0.2%

[0079] For the evaluation criterion of the stratum corneum softening effect, based on the measured value of the storage modulus, the value of Comparative Example 1 using hydrogenated polydecene as the oil component was set to 100, and was set as follows.

[0080] S: Less than 50

[0081] A: 50 or more and less than 60

[0082] B: 60 or more and less than 80

[0083] C: 80 or more and 100 or less

[0084] [Table 1]

[0085] Table 1

[0086]

[0087] Next, other formulation examples of the skin external preparation of the present invention are given.

[0088] [Formulation Example 1]

[0089]

[0090]

[0091] [Formulation Example 2]

[0092]

[0093]

Claims

1. A topical skin agent, which comprises: (A) Retinol, (B) Castor oil, (C) Bis-diglycerol polyacyl adipate-2 or dipentaerythritol hexahydroxystearate, and (D) Water.

2. The topical skin agent according to claim 1, which is an oil-in-water emulsion preparation.

3. The topical skin agent according to claim 1 or 2, wherein, Based on the total mass of the topical skin preparation, the content rate of component (A) is 0.005 to 5% by mass.

4. The topical skin agent according to claim 1 or 2, wherein, Based on the total mass of the topical skin preparation, the content rate of component (B) is 0.2 to 30% by mass.

5. The topical skin agent according to claim 1 or 2, wherein, Based on the total mass of the topical skin preparation, the content rate of component (C) is 0.2 to 30% by mass.

6. The topical skin agent according to claim 1 or 2, wherein, Based on the total mass of the topical skin preparation, the total content rate of component (B) and component (C) is 0.5 to 40% by mass.

7. The topical skin agent according to claim 1 or 2, wherein, The ratio of [(total content of component (B) and component (C))] / [(content of component (A))] is 10 to 500.

8. The topical skin agent according to claim 1 or 2, wherein, Component (B) is an ester of a fatty acid having 14 to 20 carbon atoms and glycerol.

9. The topical skin agent according to claim 1 or 2, which further comprises (E) hydrogenated lecithin.

10. The topical skin agent according to claim 1 or 2, which further comprises (F) higher alcohols.

11. The topical skin agent according to claim 1 or 2, which further comprises (G) polyols.

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