topical skin preparations

Abstract

To provide a topical skin preparation that contains a combination of specific components for synergistically improved viscoelasticity of skin and has an excellent use feeling.SOLUTION: A topical skin preparation contains the following (A)-(C): (A) squalane, (B) one or more ester oil selected from the group consisting of isocetyl stearate, hexyldecyl isostearate, octyldodecyl myristate, isostearyl isostearate, isocetyl myristate, isotridecyl isononanoate, cetyl ethylhexanoate, ethylhexyl palmitate, isopropyl myristate, isononyl isononanoate, isodecyl neopentanoate, and isopropyl palmitate, and (C) polyglyceryl fatty acid ester with an HLB of less than 5.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an external preparation for skin. [Background technology]

[0002] Human skin develops wrinkles and sagging due to aging and external stresses such as ultraviolet rays, and these conditions can increase in severity. To improve these conditions, technological developments are being conducted, such as combining various ingredients (Patent Document 1). However, simply using ingredients in combination does not synergistically improve the effect, but rather the effect of such combinations is unpredictable, with some ingredients additively improving the effect and others canceling out the other effects. In particular, there is a great need for ingredients that can be incorporated into topical skin preparations in smaller amounts to achieve greater effects. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-235472 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide an external skin preparation that synergistically improves the viscoelasticity of the skin by using specific ingredients in combination, and that has a good feel when used. [Means for solving the problem]

[0005] The means for solving the problems of the present invention is to provide an external skin preparation containing the following (A) to (C): (A) Squalane (B) one or more ester oils selected from the group consisting of isocetyl stearate, hexyldecyl isostearate, octyldodecyl myristate, isostearyl isostearate, isocetyl myristate, isotridecyl isononanoate, cetyl ethylhexanoate, ethylhexyl palmitate, isopropyl myristate, isononyl isononanoate, isodecyl neopentanoate, and isopropyl palmitate; (C) Polyglycerol fatty acid ester with an HLB of less than 5 [Effects of the Invention]

[0006] The external skin preparation of the present invention exhibits the effect of synergistically improving the viscoelasticity of the skin and providing a good feeling when used in combination with specific ingredients. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, an embodiment of the present invention will be described.

[0008] [Squalane] The squalane used in the topical skin preparation of the present invention is 2,6,10,15,19,23-hexamethyltetracosane, and is available in animal-derived forms extracted from deep-sea shark liver, and plant-derived forms extracted from olive fruit or rice bran. In either case, hydrogenated squalane is preferred, and plant-derived squalane is particularly preferred in the present invention. Commercially available products such as NIKKOL Sugar Squalane (registered trademark) (manufactured by Nippon Surfactant Industries Co., Ltd.), Olive Squalane (manufactured by Kokyu Alcohol Kogyo Co., Ltd.), Oryza Squalane (manufactured by Oryza Oil & Fat Chemical Co., Ltd.), vegetable squalane, squalane (all manufactured by Kishimoto Tokushu Kanyu Kogyosho Co., Ltd.), super squalane, squalane (all manufactured by Maruha Nichiro Corporation), squalane, refined olive squalane (manufactured by Nikko Chemicals Co., Ltd.), phytosqualane (manufactured by Sophim Co., Ltd.), and Prepure 3759-LQ (manufactured by Uniqema Co., Ltd.) can also be used.

[0009] The amount of squalane in the present invention is not particularly limited to the total amount of the external skin preparation, but is preferably 0.00001 to 40% by mass, more preferably 0.0001 to 30% by mass.

[0010] [Ester oil] The one or more ester oils selected from the group consisting of isocetyl stearate, hexyldecyl isostearate, octyldodecyl myristate, isostearyl isostearate, isocetyl myristate, isotridecyl isononanoate, cetyl ethylhexanoate, ethylhexyl palmitate, isopropyl myristate, isononyl isononanoate, isodecyl neopentanoate, and isopropyl palmitate to be incorporated into the topical skin preparation of the present invention are not particularly limited in terms of raw materials, production method, purification method, etc., as long as they are those typically used in topical skin preparations, etc. Among these, hexyldecyl isostearate is particularly preferred.

[0011] Examples of commercially available hexyldecyl isostearate include EMALEX HIS-34 (manufactured by Nippon Emulsion Co., Ltd.) and ICIS (manufactured by Kokyu Alcohol Kogyo Co., Ltd.).

[0012] The amount of hexyldecyl isostearate in the present invention is not particularly limited, but is preferably 0.001 to 30% by mass, more preferably 0.001 to 20% by mass, based on the total amount of the external skin preparation.

[0013] [Polyglycerol fatty acid ester with HLB less than 5] The polyglycerol fatty acid ester to be incorporated into the topical skin preparation of the present invention can be one typically used in topical skin preparations, etc., as long as it has an HLB value of less than 5. Examples of polyglycerol fatty acid esters with an HLB value of less than 5 include polyglyceryl-2 triisostearate (HLB value: 1.3), polyglyceryl-2 isostearate (HLB value: 4.6), and polyglyceryl-10 pentaoleate (HLB value: 3.5). Among these, it is preferable to use polyglyceryl-2 triisostearate.

[0014] Commercially available polyglyceryl-2 triisostearate includes Cosmol 43V and Cosmol 43N (both manufactured by Nisshin Oillio Group, Ltd.), EMALEX TISG-2 (manufactured by Nippon Emulsion Co., Ltd.), Lysolex PGIS23 (manufactured by Kokyu Alcohol Kogyo Co., Ltd.), and NIKKOL DGTIS (manufactured by Nikko Chemicals Co., Ltd.).

[0015] The amount of the polyglycerol fatty acid ester having an HLB of less than 5 in the present invention is not particularly limited, but is preferably 0.001 to 30% by mass, more preferably 0.01 to 10% by mass, based on the total amount of the external skin preparation.

[0016] In addition to the above-mentioned components, the topical skin preparation of the present invention may contain optional components used in ordinary cosmetics and quasi-drugs to the extent that the effects of the present invention are not impaired. Specific examples include oils, surfactants, thickeners, preservatives, fragrances, moisturizers, antioxidants, anti-inflammatory agents, antibacterial agents, etc.

[0017] The formulation of the external skin preparation of the present invention is not particularly limited, and may be any formulation such as an oil-based formulation or an emulsion-based formulation.

[0018] The topical skin preparation of the present invention can be prepared by a conventional method.

[0019] The external skin preparation of the present invention can be used in the dosage form of, for example, a lotion, emulsion, or ointment. [Example]

[0020] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited thereto. The blending amounts are in mass % unless otherwise specified.

[0021] [Viscoelasticity test method] The samples shown in Tables 1 and 2 were prepared and subjected to viscoelasticity measurements.

[0022] [Measurement method] (1) Acclimation After washing the inside of the left and right forearms of the subjects, they wiped off the moisture and then rested for 15 minutes in a room adjusted to a temperature of 21±0.5°C and humidity of 50±5% to allow for acclimation. (2) Application A 3 cm x 3 cm area was marked on the inside of each forearm, and 9 μL was dropped onto it using a pipette and applied evenly with a finger wearing a finger cot. (3) Measurement Viscoelasticity was measured before and 15 minutes after application using a Cutometer MPA580. Skin viscoelasticity was measured using a Cutometer probe with a 2mm suction port, applying 150mb suction pressure for 1 second, and then analyzing the skin displacement when the suction was released. In this study, the parameter (R1) used as an index of skin viscoelasticity was analyzed. This value indicates how much the skin returns to its original shape within a set time after being sucked for a certain period of time. The lower the viscoelasticity, the worse the skin's return, resulting in a higher value. The relative values, with the value before application set to 1, were calculated and are shown in Tables 1 and 2.

[0023] [Usability evaluation] Twenty-one sensory evaluators independently used the topical skin preparations of the Examples and Comparative Examples, and rated them on a scale of 1 to 7 for film texture, skin softness, firmness, thickness, luxurious feel, and palatability. The average scores were calculated and the results were judged according to the following four-level rating scale. The results are shown in Table 2. 5 points or more: Very good "◎" 4.25 points or more but less than 5 points: Good "〇" 3.5 points or more but less than 4.25 points: slightly bad "△" Less than 3.5 points: Poor "X"

[0024] [Table 1]

[0025] As shown in Table 1, the viscoelasticity value was reduced in Example 1 compared to Comparative Examples 1 to 3, in which each component was applied alone. In addition, since the amount of each component in Example 1 was one-third that of Comparative Examples 1 to 3, it can be seen that the viscoelasticity value was reduced synergistically.

[0026] [Table 2]

[0027] As shown in Table 2, Example 2 had a reduced viscoelasticity value and a good feel when used, compared with Comparative Examples 4 to 7. Therefore, the topical skin preparation of the present invention improved the viscoelasticity of the skin and had a good feel when used.

Claims

[Claim 1] A topical skin preparation containing the following (A) to (C): (A) Squalane 1.2 to 3% by mass (B) Hexyldecyl isostearate 1.2 to 3 mass% (C) Polyglyceryl-2 triisostearate 0.6 to 3 mass%

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