JP7750695B2 - topical skin preparations - Google Patents

Description

The present invention relates to an external skin preparation.

Human skin develops wrinkles and sagging due to aging and external stresses such as ultraviolet rays, and these conditions 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 provide greater effects in smaller amounts in topical skin preparations.

JP 2010-235472 A

The objective of the present invention is to provide a topical skin preparation that synergistically improves skin viscoelasticity and has a pleasant feel when used in combination with specific ingredients.

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; and (C) a polyglycerin fatty acid ester having an HLB of less than 5.

By combining specific ingredients, the topical skin preparation of the present invention synergistically improves the viscoelasticity of the skin, providing a pleasant feel when used.

The following describes how to implement the present invention.

[Squalane]
The squalane incorporated into 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, rice bran, etc. In either case, hydrogenated squalane is preferably used, 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.

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

[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.

Commercially available hexyldecyl isostearate includes EMALEX HIS-34 (manufactured by Nippon Emulsion Co., Ltd.) and I.C.I.S (manufactured by Kokyu Alcohol Kogyo Co., Ltd.).

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

[Polyglycerol fatty acid ester having an HLB of 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 of less than 5. Examples of polyglycerol fatty acid esters having an HLB 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). Of these, it is preferable to use polyglyceryl-2 triisostearate.

Commercially available polyglyceryl-2 triisostearate includes Cosmol 43V and Cosmol 43N (both manufactured by The 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.).

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

In addition to the above-mentioned ingredients, the topical skin preparation of the present invention can contain optional ingredients commonly used in cosmetics and quasi-drugs to the extent that they do not impair the effects of the present invention. Specific examples include oils, surfactants, thickeners, preservatives, fragrances, moisturizers, antioxidants, anti-inflammatory agents, and antibacterial agents.

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

The topical skin preparation of the present invention can be prepared by standard methods.

The topical skin preparation of the present invention can be used in the form of, for example, a lotion, emulsion, or ointment.

The present invention will be explained in more detail below using examples, but the scope of the present invention is not limited by these examples. Unless otherwise specified, blend amounts are in mass %.

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

[Measurement method]
(1) Acclimatization After washing the inside of the left and right forearms of each subject, the subject wiped off the moisture and rested for 15 minutes in a room adjusted to a temperature of 21±0.5° C. and a humidity of 50±5% for acclimation.
(2) Application A 3 cm x 3 cm area was marked on the inside of each forearm, and 9 μL of the solution was dropped onto the area using a pipette, which was then evenly applied using a finger wearing a finger cot.
(3) Measurement The viscoelasticity was measured before application and 15 minutes after application using a Cutometer MPA580. The measurement of skin viscoelasticity using a Cutometer involved using a probe with a 2 mm suction port, suction at 150 mb suction pressure for 1 second, and then analyzing the displacement of the skin when released. In this test, a parameter (R1) used as an index of skin viscoelasticity was analyzed. This is a value indicating "how much the skin returns within a specified time after suctioning the skin for a certain period of time." The lower the viscoelasticity, the worse the skin's return, and the larger the value. The relative value was calculated, with the value before application set to 1, and is shown in Tables 1 and 2.

[Usage evaluation]
Twenty-one sensory evaluators independently used the topical skin preparations of the Examples and Comparative Examples, and rated the film-like feel, skin softness, firmness, thickness, luxurious feel, and palatability on a scale of 1 to 7. 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"

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

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

Claims (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%