JP7750656B2 - Vesicle dispersion and cosmetic - Google Patents

Description

The present invention relates to a vesicle dispersion and a cosmetic preparation containing the vesicle dispersion.

Vesicles are small reticulum bodies consisting of bilayer membranes formed by amphiphilic lipids, surfactants, etc. A distinctive feature of vesicles is their ability to encapsulate both water-soluble and oil-soluble substances, and they have been used as drug carriers in drug delivery systems, etc.

Cosmetics and other products often contain oil-soluble agents such as astaxanthin and tocopherol for their beneficial effects on the skin. However, when these oil-soluble substances are added to lotions and other products, they can cause cloudiness, impairing the aesthetic appearance, and have poor dispersion stability, resulting in separation over time, posing stability issues.

To solve these problems, Patent Document 1 discloses the development of a translucent or transparent cosmetic product that has excellent stability and provides noticeable effects such as a feeling of penetration, no stickiness, and softness to the skin after application.

However, even with the embodiment proposed in Patent Document 1, it was difficult to obtain a vesicle dispersion that contained oily components, including functional oils, and that had excellent stability and usability.

JP 2011-136934 A

The present invention provides a vesicle dispersion and a cosmetic preparation containing the vesicle dispersion that are excellent in stability and feel when used, while still containing oily components including functional oils.

The vesicle dispersion according to the present invention comprises:
(A) water,
(B) 3% by weight or more of pentylene glycol;
(C) a compound containing 0.55% by weight or more and 0.9% by weight or less of lecithin and phytosterols;
(D) a functional oil, and (E) polyoxyethylene hydrogenated castor oil or polyglyceryl isostearate may be included.

In the vesicle dispersion according to the present invention,
Component (E) may contain hydrophilic polyoxyethylene hydrogenated castor oil or polyglyceryl isostearate having an HLB of 10 or more.

In the vesicle dispersion according to the present invention,
When polyoxyethylene hydrogenated castor oil is used as component (E), the polyoxyethylene hydrogenated castor oil may be PEG-60 hydrogenated castor oil.

In the vesicle dispersion according to the present invention,
When polyglyceryl isostearate is used as component (E), the polyglyceryl isostearate may be polyglyceryl-10 isostearate.

In the vesicle dispersion according to the present invention,
The oil is a compound containing astaxanthin and caprylic/capric triglyceride,
The compound containing astaxanthin and caprylic/capric triglyceride may be included at 0.4% by weight or less.

In the vesicle dispersion according to the present invention,
Polyoxyethylene hydrogenated castor oil or polyglyceryl isostearate may be contained in an amount of 0.75% by weight or more and 2.5% by weight or less.

The cosmetic composition according to the present invention comprises:
The cosmetic composition may contain the above-mentioned vesicle dispersion.

The present invention provides a vesicle dispersion that contains oily components, including functional oils, yet has excellent stability and a pleasant feel when used, as well as a cosmetic preparation containing the vesicle dispersion.

The vesicle dispersion of this embodiment may contain water, pentylene glycol, a compound containing lecithin and phytosterols as an amphiphilic substance, an oil, and polyoxyethylene hydrogenated castor oil or polyglyceryl isostearate as a surfactant.

The vesicle dispersion may contain pentylene glycol at 3% by weight or more, preferably 4% by weight or more, and more preferably 5% by weight or more. A lower pentylene glycol content can cause problems with transparency and stability over time after formulation. The upper limit of pentylene glycol can be 60% by weight, and more specifically, 50% by weight. Note that fine particles increase transparency, while larger particles decrease transparency. This embodiment is superior in that it maintains transparency despite containing a large amount of oil and achieves fine particles. Achieving such fine particles enables high skin permeability.

The vesicle dispersion may contain 0.55% by weight or more of the compound containing lecithin and phytosterols, and preferably 0.6% by weight or more. The vesicle dispersion may contain 0.9% by weight or less of the compound containing lecithin and phytosterols, and preferably 0.8% by weight or less. If the content of the compound containing lecithin and phytosterols is too low or too high, problems with stability over time may occur. Furthermore, if the content of the compound containing lecithin and phytosterols is too high, transparency may be poor.

In the vesicle dispersion, the oil containing a functional substance (functional oil) may be contained in an amount less than 0.5% by weight. As long as it functions as a functional substance, there is no problem, so there is no particular lower limit. However, as an example, the oil containing a functional substance (functional oil) may be contained in an amount of 0.01% by weight or more. Examples of oils include ester oils, hydrocarbon oils, silicone oils, and animal and vegetable oils and fats. Examples of ester oils include fatty acid esters such as caprylic/capric triglyceride, cetyl ethylhexanoate, isotridecyl isononanoate, isopropyl myristate, isocetyl myristate, octyldodecyl myristate, isopropyl palmitate, ethylhexyl palmitate, butyl stearate, ethylhexyl stearate, isotridecyl stearate, methyl oleate, ethyl oleate, isobutyl oleate, triethylhexanoin, diisopropyl adipate, and diethyl sebacate. Examples of hydrocarbon oils include squalane, liquid paraffin, isoparaffin, petrolatum, paraffin wax, ceresin, and microcrystalline wax.

When the oil containing a functional substance (functional oil) is a compound containing astaxanthin and caprylic/capric triglyceride, it is preferably contained at 0.4% by weight or less, and even more preferably at 0.3% by weight or less. Excessive oil content can cause problems with stability over time. Astaxanthin is one example of a functional substance and is not particularly limited. Functional substances may also be used, such as tocopherol and ceramide, instead of astaxanthin. Other functional substances that may be used include carotenoids such as β-carotene, zeaxanthin, lycopene, and lutein; oil-soluble vitamins and their derivatives such as retinol and tocotrienol; ubiquinones such as coenzyme Q10; UV protection agents such as 2-ethylhexyl paramethoxycinnamate; isoflavones, anthocyanins; polyphenols such as chlorogenic acid, ferulic acid, gallic acid, and proanthocyanidin; fragrances; plant extracts; proteins; and sphingolipids such as ceramide.

When polyoxyethylene hydrogenated castor oil is included, the vesicle dispersion preferably contains 0.75% by weight or more of polyoxyethylene hydrogenated castor oil, and more preferably 1.0% by weight or more. Furthermore, the vesicle dispersion preferably contains 2.5% by weight or less of polyoxyethylene hydrogenated castor oil, and more preferably 2.3% by weight or less, and even more preferably 2.0% by weight or less.

When polyglyceryl isostearate is contained, the vesicle dispersion preferably contains 0.75% by weight or more of polyglyceryl isostearate, and more preferably 1.0% by weight or more. Furthermore, the vesicle dispersion preferably contains 2.5% by weight or less of polyglyceryl isostearate, and more preferably 2.3% by weight or less, and even more preferably 2.0% by weight or less.

If the content of polyoxyethylene hydrogenated castor oil or polyglyceryl isostearate is too low, problems with stability over time may arise. On the other hand, if the content of polyoxyethylene hydrogenated castor oil or polyglyceryl isostearate is too high, problems with stability over time may arise and transparency may also be impaired.

As polyoxyethylene hydrogenated castor oil, it is preferable to use hydrophilic polyoxyethylene hydrogenated castor oil with an HLB of 10 or higher. Hydrogenated castor oil may also be used as polyoxyethylene hydrogenated castor oil, and PEG-30 hydrogenated castor oil, PEG-40 hydrogenated castor oil, PEG-60 hydrogenated castor oil, PEG-70 hydrogenated castor oil, PEG-80 hydrogenated castor oil, PEG-100 hydrogenated castor oil, etc. may also be used. However, it is preferable to use PEG-60 hydrogenated castor oil. As polyglyceryl isostearate, it is also possible to use hydrophilic polyglyceryl isostearate with an HLB of 10 or higher. Examples of polyglyceryl isostearate that may be used include polyglyceryl-5 isostearate, polyglyceryl-6 isostearate, polyglyceryl-7 isostearate, polyglyceryl-8 isostearate, polyglyceryl-9 isostearate, polyglyceryl-10 isostearate, and polyglyceryl-20 isostearate. However, it is preferable to use polyglyceryl-10 isostearate.

The cosmetic composition according to this embodiment may contain ingredients such as additives. Examples of such additives include thickeners, surfactants, preservatives, pH adjusters, chelating agents, stabilizers, irritation reducers, antiseptics, colorants, dispersants, fragrances, antioxidants, plant extracts, vitamins, and amino acids.

[Examples and Comparative Examples]
Next, examples and comparative examples will be described.

The vesicle dispersions in the examples and comparative examples were prepared as follows.

First, component D (caprylic/capric triglyceride) and component E (PEG-60 hydrogenated castor oil, polyglyceryl-10 isostearate, PEG-20 sorbitan cocoate, or polyglyceryl-10 stearate) were heated and mixed at 75°C to 85°C to prepare a homogeneous first solution.

Furthermore, component B (pentylene glycol or BG) and component C (a compound containing hydrogenated lecithin and phytosterols or a compound containing hydrogenated lecithin and cholesterol) were heated and mixed at 75°C to 85°C to prepare a homogeneous second solution.

Next, the first solution was added to the second solution while stirring, and the mixture was heated and mixed at 75-85°C to prepare a homogeneous third solution.

Next, the third solution was added to purified water heated to 75-85°C while stirring, and the mixture was heated and mixed at 75-85°C. The solution was then cooled to room temperature while stirring to obtain a vesicle dispersion.

Components D and E were added to a solution containing components B and C, and mixed at 75-85°C until uniform. Then, the mixture was cooled to room temperature.

The evaluation methods used in the examples and comparative examples are as follows: Usually, when preparing a vesicle dispersion, special equipment capable of applying high energy, such as a high-pressure homogenizer or an ultrasonic disperser, is used, but in the vesicle dispersion according to the examples of the present invention, it is possible to obtain fine vesicles even with a homomixer, which is a very beneficial result.
(Method for evaluating transparency immediately after preparation)
The container was sealed in a 70 mL transparent glass container and left to stand at room temperature of 20 to 25°C. A piece of paper with letters printed on it was placed behind the container, and when the container was viewed from a horizontal direction, the container was evaluated based on whether the letters were clearly visible.
3: The characters are clearly readable 2: The characters are slightly blurred 1: The characters are blurred and difficult to read

(Method for evaluating stability over time)
The samples were sealed in transparent glass containers and left to stand at a constant temperature. The degree of change from the initial state was evaluated by visual observation.
⊚: There is almost no change in transparency from the initial stage, and no separation or precipitation is observed.
○: A slight decrease in transparency is observed, or slight separation or precipitation is observed, or both.
△: A clear decrease in transparency is observed, or there is a lot of separation or precipitation, or both.
×: Significant decrease in transparency is observed, or the degree of separation or precipitation is large, or both.

(Method for evaluating penetration sensation)
Five expert panelists applied the prescribed amount of 1.5 mL to the face and rated the penetration sensation on a 5-point scale (5: very noticeable, 4: somewhat noticeable, 3: average, 2: not noticeable, 1: not noticeable). The scores were averaged and evaluated on a 4-point scale.
◎: 4.5 or more ○: 3.5 or more but less than 4.5 △: 2.5 or more but less than 3.5 ×: Less than 2.5

As shown in Table 1 below, it was confirmed that when pentylene glycol was contained at 5% by weight or more, there were no problems with transparency, stability over time, and penetration sensation. In particular, it was confirmed that when pentylene glycol was contained at 5% by weight or more and 10% by weight or less, excellent stability over time was also exhibited at a low temperature of 5°C. It is also beneficial that stability can be maintained even in low-temperature conditions such as a bathroom in winter. It is also beneficial that stability can be maintained even in thick conditions in summer.

As shown in Table 2 below, BG was unable to provide the same effects as when pentylene glycol was used. It was confirmed that the stability over time and transparency at a low temperature of 5°C were inferior to those when pentylene glycol was used. It was also confirmed that even when BG was included, excellent effects could be obtained by using pentylene glycol (see Example 6).

As shown in Table 3 below, it was confirmed that there were no problems with transparency, stability over time, and penetration sensation when the compound containing hydrogenated lecithin and phytosterols was contained in an amount of 0.6% by weight or more and 0.8% by weight or less. On the other hand, it was confirmed that when the content of the compound containing hydrogenated lecithin and phytosterols was 0.5% by weight or less, problems arose in stability over time at low temperatures, and when the content of the compound containing lecithin and phytosterols was 1% by weight or more, problems arose in stability over time at room temperature (25°C) and at low temperatures.

As shown in Table 4 below, it was confirmed that problems with stability over time at low temperatures occur when a compound containing astaxanthin and caprylic/capric triglyceride, an example of an oil, is contained at 0.5% by weight or more. Furthermore, it was confirmed that problems with stability over time at low temperatures occur when a compound containing hydrogenated lecithin and cholesterol is used instead of a compound containing hydrogenated lecithin and phytosterols, even when the content of the compound containing astaxanthin and caprylic/capric triglyceride is 0.2% by weight.

As shown in Table 5 below, it was confirmed that problems with stability over time at low temperatures occurred when the content of PEG-60 hydrogenated castor oil was 0.5% by weight or less or 3% by weight or more. It was also confirmed that no problems occurred when polyglyceryl-10 isostearate was used instead of PEG-60 hydrogenated castor oil. On the other hand, it was confirmed that problems with stability over time occurred at room temperature and low temperatures when PEG-20 sorbitan cocoate or polyglyceryl-10 stearate was used instead of PEG-60 hydrogenated castor oil.

The raw materials used in the examples and comparative examples are as follows:
(Regarding component B)
Pentylene glycol Raw material name: Hydrolite (registered trademark) 5 green (Symrise Co., Ltd.)
BG Raw material name: 1,3-butylene glycol (13BGUK) (Daicel Corporation)
(Regarding Component C)
Hydrogenated lecithin: Phytosterols Raw material name: Phytopresome (Nippon Fine Chemical Co., Ltd.)
The ratio of hydrogenated lecithin to phytosterols is 85.7:14.3.
Hydrogenated lecithin: cholesterol Raw material name: Presome CS2-101 (Nippon Fine Chemical Co., Ltd.)
The ratio of hydrogenated lecithin to cholesterol is 80:20.
The hydrogenated lecithin and the sterols may be mixed separately, or may be mixed uniformly in advance before use.
(Regarding Component D)
Astaxanthin: Tri(caprylic/capric acid)glyceryl Ingredient name: Astax-ST (Marine Daioh Co., Ltd.)
The ratio of astaxanthin to tri(caprylic/capric acid)glyceryl is 5:95.
Astaxanthin and caprylic/capric triglyceride may be blended separately, or may be mixed uniformly in advance before use.
(Regarding component E)
PEG-60 hydrogenated castor oil Raw material name: Emanon CH-60(K) (Kao Corporation)
Polyglyceryl-10 Isostearate Ingredient name: S Face 10G-IS (Sakamoto Pharmaceutical Co., Ltd.)
PEG-20 sorbitan cocoate Raw material name: Leodor Super TW-L120 (Kao Corporation)
Polyglyceryl-10 stearate Raw material name: Decaglyn 1-SV (Nippon Surfactant Industry Co., Ltd.)

The vesicle dispersion according to this embodiment can be used by being contained in cosmetics. The content may be 100% by weight, and cosmetics consisting of the vesicle dispersion can also be provided. The lower limit is not particularly limited, but may be, for example, 0.01% by weight, or 0.1% by weight or more, or 1% by weight or more. As an example, an example cosmetic formulation is shown below. For example, the vesicle dispersion according to Example 1 can be used.

(lotion)

(Beauty serum)

(cream)

The above-mentioned embodiments and examples are merely examples intended to explain the invention described in the claims. Furthermore, the claims as originally filed may be modified as appropriate within the scope of the patent specification, and the scope may also be expanded and modified.

Claims (7)

(A) water,
(B) 3% by weight or more of pentylene glycol;
(C) lecithin and phytosterols ,
(D) less than 0.5 wt. % of a functional oil; and
(E) containing 0.75% by weight or more and less than 3% by weight of polyoxyethylene hydrogenated castor oil or polyglyceryl isostearate,
A vesicle dispersion having a total content of lecithin and phytosterols of 0.55% by weight or more and 0.9% by weight or less . The vesicle dispersion according to claim 1, comprising, as component (E), hydrophilic polyoxyethylene hydrogenated castor oil or polyglyceryl isostearate having an HLB of 10 or more. The vesicle dispersion according to claim 1 or 2, wherein when polyoxyethylene hydrogenated castor oil is used as component (E), the polyoxyethylene hydrogenated castor oil is PEG-60 hydrogenated castor oil. 3. The vesicle dispersion according to claim 1, wherein when polyglyceryl isostearate is used as component (E), the polyglyceryl isostearate is polyglyceryl-10 isostearate. The functional oil contains astaxanthin and caprylic/capric triglyceride;
5. The vesicle dispersion according to claim 1, wherein the total content of astaxanthin and caprylic/capric triglyceride is 0.4% by weight or less. 6. The vesicle dispersion according to claim 1, wherein the polyoxyethylene hydrogenated castor oil or polyglyceryl isostearate is contained in an amount of 2.5% by weight or less . A cosmetic preparation containing the vesicle dispersion described in any one of claims 1 to 6.