JP2008115162A - Emulsifier for liquid crystal formation, liquid crystal forming emulsion composition containing the same and cosmetic containing liquid crystal forming emulsion composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new emulsifier for forming a liquid crystal which forms a liquid crystal structure resembling to lipid between horney cells, stably maintaining the crystal structure even while it is spreaded on a skin, which is easily prepared into a pharmaceutical formulation and exhibits high skin-care effect, and a liquid crystal forming emulsified composition and a cosmetic. <P>SOLUTION: The liquid crystal forming composition and cosmetic contain the new liquid crystal forming emulsifier essentially containing sterol, polyoxyethylene sterols and lecithin, form liquid crystal structure resembling to lipid between horny cells and inhibit vaporization of moisture when spread on the skin with the composition, and exhibition of excellent skin-care effect and an improving effect of skin condition are found, which have resulted in the solution of the task. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an emulsifier for forming a liquid crystal, a liquid crystal forming emulsion composition containing the same, and a cosmetic, and further relates to a cosmetic that is stable and excellent in skin care effect.

  In order to protect the skin from harsh external environments such as overdrying, to prevent or improve rough skin, dry skin, etc., and to prevent aging of the skin due to aging, various oily raw materials are surfactants Cosmetics that have been emulsified and added with humectants such as glycerin, hyaluronic acid or amino acids, and skin nutrients such as vitamin E have been widely used.

  These cosmetics are coated with an emulsified layer containing oil and water on the skin to protect the skin from external irritation, prevent transpiration of moisture from the inside of the skin, and provide a certain amount of moisture to the skin. By giving, it contributes to the improvement of rough skin and dry skin.

However, these conventional cosmetics are insufficient in the following points.
(1) Conventional cosmetics mainly have an oil-in-water structure (hereinafter referred to as O / W type) in which oil forms emulsified micelles with a surfactant and is dispersed in a continuous aqueous phase. When applied to the skin, the water that is the continuous phase evaporates and scatters in a short time, and cannot provide a sufficient moisturizing effect to the skin.
(2) Since the emulsion is destroyed due to the evaporation and scattering of moisture, the contained humectant and skin nutrient cannot be sufficiently penetrated into the skin, and the desired effect cannot be exhibited.
(3) The emulsifier used in conventional O / W type cosmetics has high hydrophilicity, and the resulting emulsion is easily dissolved in water (poor water resistance). Therefore, when a cosmetic prepared with these highly hydrophilic emulsifiers is applied to the skin, it tends to flow with sweat or the like, and the effect persistence is poor.
(4) On the other hand, cosmetics also have a water-in-oil type (hereinafter referred to as W / O type) structure in which water is dispersed in an oil phase that is a continuous phase, but this is oily when applied to the skin. There is a problem with the usability.

  In recent years, for the purpose of solving these problems, liquid crystal type cosmetics having a liquid crystal structure similar to keratinocyte lipids, which have a high affinity for skin and excellent moisturizing effect and rough skin improving effect have been proposed. Specifically, there is disclosed a technique for forming a liquid crystal structure close to keratinocyte lipids by combining natural or synthetic ceramides with amphiphilic substances such as higher fatty acids, higher alcohols, glycolipids, and cholesterols (patents). Reference 1).

  In this technology, ceramide forms a layered liquid crystal structure (lamellar liquid crystal structure) and retains moisture as bound water, thereby utilizing the properties that contribute to the adhesion and moisture retention of keratinocytes (non-patent) References 1 and 2).

However, this technique has the following problems, and satisfactory results have not been obtained.
(1) Ceramide is easily crystallized including natural products and synthetic products, and is hardly soluble in oily raw materials and solvents generally used in cosmetics. Therefore, it is difficult to formulate, and further, there arises problems such as crystallization in the formulation over time and loss of quality.
(2) Ceramide itself has no emulsifying power, and it is feared that it precipitates as crystals in the emulsion. In order to solve this, it is necessary to use various hydrophilic surfactants. There is concern about skin irritation.
(3) Furthermore, it is very expensive.

  In addition, as a patent for blending a liquid crystal composition into a cosmetic, a technology of a color forming liquid crystal composition formed by a hydrophilic surfactant, a sterol and an α-glyceryl alkyl ether is disclosed (see Patent Documents 2 to 5). . However, they are characterized by color development, and the skin care effect is questionable.

  In general, in a technique for enhancing the skin care effect using a liquid crystal structure, it is necessary to stably hold the liquid crystal structure while the preparation is applied to and applied to the skin. When the liquid crystal structure disappears on the skin, the functions expected of the liquid crystal cosmetics such as the continuous moisturizing effect by crystal water are lost.

In the conventional technique, when applied to the skin, the liquid crystal structure disappears due to the temperature of the skin or moisture evaporation during application. No technique has been found to keep the liquid crystal structure stable on the skin during application. Therefore, cosmetics that protect skin from harsh external environments such as overdrying and prevent or improve rough or dry skin without the use of expensive and difficult-to-form ingredients such as ceramide ( Skin condition improving cosmetics) are desired.
The journal of investigative dermatology, vol. 96 (6), 845-851 (1991) International journal of cosmetic science, 19, 143-156 (1997) JP 06-345633 A Japanese Patent No. 2929318 Japanese Patent No. 3133399 Patent 2949451 Patent No. 2964272

  The present invention provides a novel liquid crystal forming emulsifier that forms a liquid crystal structure similar to keratinocyte lipids, stably maintains the liquid crystal structure even when applied to the skin, exhibits a high skin care effect, and is easily formulated. An object of the present invention is to provide a liquid crystal-forming emulsion composition and a cosmetic containing the same.

  As a result of diligent research to find a new cosmetic for this problem, a composition containing an emulsifier containing sterol, polyoxyethylene sterols, and lecithin as essential components, and the cosmetic, It was found that the above-mentioned problems can be solved by forming a similar liquid crystal structure.

  When the liquid crystal forming emulsion composition or cosmetic containing the liquid crystal forming emulsifier of the present invention was applied to the skin, the liquid crystal suppressed the transpiration of water, and thus showed excellent skin care effect and skin condition improving effect.

  The sterol of the component (A) used in the present invention includes animal sterols such as cholesterol, cholestanol, lanosterol and dehydrocholesterol, plant sterols such as β-sitosterol, stigmasterol, campesterol and ergosterol, mycostol, Examples include sterols derived from microorganisms such as timosterol. These may be used as they are or may be subjected to chemical treatment such as hydrogenation for stabilization. Moreover, these 1 type (s) or 2 or more types can be used in combination. Among these, cholesterol, cholestanol, plant sterol, and plant stanol are particularly preferable.

  As the component (B) used in the present invention, ethylene oxide is added to the above sterol to form polyoxyethylene sterol ether. Specifically, plant sterol and its hydrogenated product (plant stanol) ), Animal cholesterol and its hydrogenated product (animal stanol), and the like. The number of moles of ethylene oxide added to sterols is n = 3 to 100, preferably n = 5 to 50, and more preferably n = 10 to 30.

  As the component (C) used in the present invention, lecithins such as soybean lecithin, egg yolk lecithin, hydrogenated soybean lecithin, hydrogenated egg yolk lecithin, lysolecithin and / or hydrogenated by converting these lecithins into monoacyl bodies by enzymatic treatment Examples include lysolecithin and hydroxylated hydroxylecithin. In addition, phospholipid fractions in lecithin such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, phosphatidic acid, and phosphatidylserine can be used individually or in combination.

  In the present invention, the ratio (mass ratio) of the components (A) to (C) is preferably (A) / (B) = 10/90 to 90/10, more preferably (A) / (B) = 20/80 to 80/20, and more preferably (A) / (B) = 20/80 to 40/60.

  Further, the ratio (mass ratio) of the sum of the components (A) and (B) and the component (C) is preferably [(A) + (B)] / (C) = 98/2 to 70/30, More preferably, [(A) + (B)] / (C) = 95/5 to 70/30, and even more preferably, [(A) + (B)] / (C) = 90/10 to 75 / 25. Within this range, the liquid crystal-forming emulsion composition and the cosmetic can be prepared more stably.

  The liquid crystal forming emulsifier of the present invention may be composed only of the components (A) to (C), or an oily raw material may be used in combination. It is preferable that content of (A)-(C) component contains 0.1-30 mass% with respect to liquid crystal forming emulsion composition whole quantity or cosmetics whole quantity. More preferably, it is 0.3-20 mass%, More preferably, it is 0.5-10 mass%. Within this range, preferred lamellar liquid crystals and hexagonal liquid crystals are formed in the liquid crystal forming emulsifier / squalane / water system.

  When the emulsifier for liquid crystal formation of the present invention uses the components (A) to (C) and the oily raw material in combination, the preferred mixing ratio (mass ratio) of both is the sum of oily raw materials / [(A) to (C) components. Amount] = 10 / 0.1 to 0.1 / 10, more preferably 10 / 0.5 to 0.5 / 10, still more preferably 10/1 to 1/10.

  As the oily raw material, any oily raw material generally used in cosmetics can be suitably used. Specifically, hydrocarbons such as squalane and liquid paraffin, vegetable oils such as olive oil, macadamian nut oil, jojoba oil, animal oils such as beef tallow, glyceryl triisooctanoate, isopropyl myristate, cetyl isooctanoate, isooctyl palmitate, etc. And esters such as dimethylsilicone, phenylmethylsilicone, and cyclomethicone.

  The presence or absence of the liquid crystal structure in the liquid crystal forming emulsion composition and the cosmetic containing the liquid crystal forming emulsifier of the present invention can be confirmed by observing the liquid crystal composition with a polarizing microscope. The liquid crystal composition can confirm a maltase cross image having a shape unique to a lamellar liquid crystal by observation with a polarizing microscope. In addition, the liquid crystal structure can be confirmed with a transmission electron microscope (TEM) using a resin foam-embedded ultra-thin cutting method or a frozen section method.

  The liquid crystal forming emulsion composition and the cosmetic containing the liquid crystal forming emulsifier of the present invention are characterized in that a large amount of bound water is retained in the structure, and the amount of bound water is determined by thermal analysis (DSC analysis). ). Specifically, the moisture content in the sample was changed, and the total heat of fusion (endothermic enthalpy ΔH) obtained by DSC analysis from each frozen state was plotted on the vertical axis, and the actual water content (Karl Fischer method, etc.) ) Is plotted on the horizontal axis, the intersection of the vertical axis and the horizontal axis is obtained, and the value is defined as the amount of bound water.

  In the liquid crystal forming emulsion composition and cosmetics of the present invention, surfactants generally used in cosmetics, higher alcohols, fatty acids, active ingredients, moisturizing ingredients, antibacterial ingredients, viscosity modifiers, dyes, fragrances, etc. should be used in combination. Can do.

  Illustrative of these are surfactants such as POE sorbitan monooleate, POE sorbitan fatty acid esters such as POE sorbitan monostearate, POE sorbite fatty acid esters such as POE sorbite monolaurate and POE sorbite monooleate, and POE glycerin monoester. POE glycerin fatty acid esters such as stearate, POE glycerin monoisostearate, POE glycerin triisostearate, POE fatty acid esters such as POE monooleate and POE monoisostearate, POE lauryl ether, POE oleyl ether, POE isostearyl POE alkyl ethers such as ether and POE stearyl ether, POE / POP cetyl ether, POE / POP decyl tetradecyl ether Non-ionic surfactants such as POE / POP alkyl ethers such as sucrose, sucrose fatty acid esters, polyglycerin fatty acid esters, fatty acid soaps such as sodium laurate and sodium palmitate, sodium lauryl sulfate, sodium POE lauryl sulfate, etc. Sulfates, sodium lauroyl sarcosine sodium, cocoyl-N-methyltaurine sodium, acylated amino acid salts such as sodium lauryl glutamate, anionic surfactants such as monobasyl phosphate sodium phosphate, quaternary ammonium salts Such as cationic surfactants.

  Examples of higher alcohols include lauryl alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, behenyl alcohol, myristyl alcohol, oleyl alcohol, and cetostearyl alcohol.

  Examples of fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, 12-hydroxystearic acid, and isostearic acid.

  As active ingredients, ascorbic acid, magnesium ascorbate phosphate ester, ascorbyl palmitate, ascorbyl stearate, ascorbyl tetraisopalmitate, ascorbic acid glucoside, arbutin, ellagic acid, lucinol and other NMF components such as amino acids, Anti-aging agents such as water-soluble collagen, elastin, glycyrrhizic acid, glycyrrhetinic acid and ceramide, anti-aging agents such as retinol and vitamin A acid, various vitamins and their derivatives.

  Examples of the moisturizing component include polyethylene glycol, propylene glycol, 1,3-butylene glycol, dipropylene glycol, glycerin, sorbitol, xylitol, maltitol, chondroitin sulfate, hyaluronic acid, sodium pyrrolidone carboxylate and the like.

  When preparing the liquid crystal-forming emulsion composition and cosmetics of the present invention, ordinary emulsification devices such as paddle mixers and homomixers can be used. In the preparation method, the oily raw material and the components (A) to (C) are previously melt-mixed at 50 to 120 ° C. and hot water at 50 to 80 ° C. is added under stirring with a homomixer or the like, or A method in which an oily raw material and components (A) to (C) previously melted and mixed at 50 to 120 ° C. are poured into warm water at 50 to 80 ° C. while stirring with a homomixer or the like. It is done.

  The liquid crystal forming emulsion composition and cosmetics of the present invention are suitably used for skin care cosmetics such as moisturizing creams, emollient creams, massage creams, moisturizing cosmetics, moisturizing lotions, emollient milks, or skin treatments such as ointments. it can.

  The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto.

(1) Preparation of liquid crystal forming emulsifier Liquid crystal forming emulsifiers shown in Table 1 below were prepared. That is, in a stainless steel mixing vessel equipped with a heater and a temperature controller, the components listed in Table 1 were mixed and dissolved while stirring at 70 to 75 ° C., and then cooled to room temperature to obtain an emulsifier for liquid crystal formation.

(2) Preparation of Liquid Crystal Forming Emulsion Composition Using the liquid crystal forming emulsifier shown in Table 1 below, the liquid crystal forming emulsion composition shown in Table 2 below was prepared. That is, in a stainless steel homomixer with 10 liter scraping and stirring equipped with a decompression device, a heater and a temperature controller, components other than water are mixed and dissolved at 85 to 90 ° C., and stirred under reduced pressure (30 mmHg or less). While stirring (stirring speed: 5000 rpm), water at the same temperature was gradually added thereto. Furthermore, it stirred for 30 minutes on the same conditions, and cooled to room temperature, and obtained the liquid crystal forming emulsion composition. The preparation scale of the liquid crystal forming emulsion composition was 5 kg.

(3) Confirmation of liquid crystal structure A sample obtained by thinly extending the liquid crystal forming emulsion composition on a slide glass was observed at 25 ° C. and 32 ° C. near the skin temperature using a polarizing microscope with a hot stage (magnification 200 times). ). The maltase cross image of the sample was observed.

(4) Confirmation of the liquid crystal structure on the skin The liquid crystal forming emulsion composition was applied to the inner side of the forearm of a 40-year-old man (20 μg / cm ² ), left at room temperature for 6 hours, and then transferred onto a slide glass. A sample was used. This was observed with a polarizing microscope by the method (3) (25 ° C.), and the presence or absence of a liquid crystal structure was confirmed.

  As a result, as shown in Table 2, the liquid crystal-forming emulsion composition of the present invention had a liquid crystal structure having optical anisotropy near the skin temperature of 32 ° C. Moreover, the liquid crystal forming emulsion composition of the present invention kept the liquid crystal structure stable even after 6 hours from application to the skin.

  Liquid crystal forming emulsion compositions shown in Table 3 were prepared and the amount of bound water was measured. The preparation of the liquid crystal forming emulsion composition was in accordance with the method for preparing the liquid crystal forming emulsion composition in Example 1 (2). As shown in Table 3, the amount of bound water was measured by measuring the endothermic enthalpy at the time of melting of samples (moisture amounts 20, 30, 40, 50 and 60%) in which the amount of moisture in the composition was changed, using a differential thermal analyzer (DSC). And was estimated from the value of the y-intercept obtained from the regression line between the value and the total amount of water contained in the sample (measured by the Karl Fischer method).

As a result, as shown in Table 3, the liquid crystal forming emulsion composition of the present invention contained about twice the amount of bound water as that of the comparative example.

Using the liquid crystal forming emulsion composition of the present invention product 12 and the comparative product (emulsion composition) 8 shown in Table 2, a moisture retention test was conducted. The method consists of 2.5 mg / day of the product of the present invention and the comparative product on the inner side of the forearm of 6 volunteer men and women (25-45 years old) who waited for 15 minutes in a constant temperature / humidity chamber adjusted to 22% relative humidity 45%. cm ^{2 was} applied. After application, the moisturizing effect was evaluated by measuring skin conductance of the application site after 15, 30, 45 and 60 minutes under the same conditions by SKICON 200.

As a result, as shown in FIG. 1, the skin conductance 1 hour after the sample application was 100.0 μS ± 9.6 for the product of the present invention 12 and 61.2 μS ± 8.2 for Comparative Example 8. It was. The product of the present invention was found to significantly increase the skin conductance relative to the comparative product. Therefore, the moisturizing effect of the product of the present invention was confirmed.

  Using the liquid crystal forming emulsion composition of the present invention product 12 shown in Table 2 and the comparative product (emulsion composition) 8, a keratin moisture transpiration (TEWL) measurement test was conducted. Twelve male volunteers (28-55 years old) were used to evaluate the effect of TEWL reduction by long-term continuous use (21 days) of the inventive product 12 and the comparative product 8. The application site of the sample was the inside of the thigh, and the application frequency was 2 times / day. The TEWL at the application site before application start and after 1, 2, and 3 weeks after application start was measured with a cut meter. The measurement was performed in a constant temperature / humidity chamber adjusted to 22 ° C. and a relative humidity of 45%.

As a result, as shown in FIG. 2, in the continuous use for 2 weeks and 3 weeks, the TEWL of the site where the product 12 of the present invention was applied was significantly decreased compared to the comparative product. A skin improvement effect was confirmed.

Moist cream A soy sterol 1.0% by mass
POE (20) Soybean Sterol 2.0
Hydrogenated soybean lecithin 1.0
Tri (caprylic / capric) glyceryl 5.0
Squalane 4.0
Triethylhexanoin 3.0
Cetyl alcohol 6.0
Cyclopentasiloxane 4.0
Dimethicone (6mm ² / s) 2.0
B Carbopol 980 (2% aqueous solution) 10.0
1,3-butylene glycol 5.0
Glycerin 3.0
L-hydroxyproline 0.1
EDTA-2Na 0.05
Preservative appropriate amount Purified water Remainder C Arginine 0.2
Purified water 3.0
D Sodium hyaluronate (1% aqueous solution) 2.0
Purified water 2.0
(Preparation method)
A and B are each heated to 80 ° C. to be uniform. While stirring B with a homomixer at 80 ° C., A is gradually added to emulsify. Then, it cools, stirring with a paddle, C and D are added at 50 degreeC, and preparation is complete | finished at 35 degreeC.

Moist Essence A Soybean Sterol 0.5% by mass
POE (20) soybean sterol 0.7
POE (10) soybean sterol 0.3
Hydrogenated soybean lecithin 0.5
Tri (caprylic / capric) glyceryl 2.0
Squalane 1.0
Triethylhexanoin 0.5
Cetyl ethylhexanoate 0.5
Cetyl alcohol 2.0
Cyclopentasiloxane 1.0
Dimethicone (6mm ² / s) 0.5
B Carbopol 981 (2% aqueous solution) 10.0
Quince Seed 0.1
1,3-butylene glycol 3.0
Pentylene glycol 1.5
Glycerin 1.0
EDTA-2Na 0.05
Preservative appropriate amount Purified water Remainder C Arginine 0.2
Purified water 3.0
D Sodium hyaluronate (1% aqueous solution) 2.0
Purified water 2.0
(Preparation method)
A and B are each heated to 80 ° C. to be uniform. While stirring B with a homomixer at 80 ° C., A is gradually added to emulsify. Then, it cools, stirring with a paddle, C and D are added at 50 degreeC, and preparation is complete | finished at 35 degreeC.

Moisture whitening cream A soy sterol 1.0% by mass
POE (20) Soybean Sterol 2.0
Hydrogenated soybean lecithin 0.5
Tri (caprylic / capric) glyceryl 3.0
Squalane 3.0
Ascorbyl tetrahexyldecanoate 3.0
Triethylhexanoin 1.0
Cetyl ethylhexanoate 1.0
Cetyl alcohol 3.0
Behenyl alcohol 3.5
Microcrystalline wax 0.3
Cyclopentasiloxane 3.0
Dimethicone (6mm ² / s) 1.0
B Carbopol 980 (2% aqueous solution) 12.0
Xanthan gum (2% aqueous solution) 3.0
1,3-butylene glycol 5.0
Glycerin 1.0
PEG-30 0.3
EDTA-2Na 0.05
Preservative appropriate amount Purified water Remainder C Arginine 0.2
Purified water 3.0
D Sodium hyaluronate (1% aqueous solution) 2.0
Purified water 2.0
(Preparation method)
A and B are each heated to 80 ° C. to be uniform. While stirring B with a homomixer at 80 ° C., A is gradually added to emulsify. Then, it cools with stirring with a paddle, C and D are added at 50 degreeC, and preparation is complete | finished at 35 degreeC.

Anti-aging cream (light type)
A 5.0% by mass of the emulsifier for liquid crystal formation of the present invention product
Cetearyl alcohol 2.5
Microcrystalline wax 0.3
Tri (caprylic / capric) glyceryl 5.0
Meadow Foam Oil 3.0
Squalane 3.0
Triethylhexanoin 2.0
Macadamia nut oil 1.0
Hydrogenated retinol and tri (caprylic acid / capric acid)
Glyceryl) mixture 1.0
Cyclopentasiloxane 3.0
Dimethicone (6mm ² / s) 2.0
B Carbopol 980 (2% aqueous solution) 12.0
Xanthan gum (2% aqueous solution) 3.0
Glycerin 4.0
1,3-butylene glycol 3.0
Pentylene glycol 2.0
EDTA-2Na 0.05
Preservative appropriate amount Purified water Remainder C Arginine 0.2
Purified water 3.0
D Sodium hyaluronate (1% aqueous solution) 2.0
Purified water 2.0
(Preparation method)
A and B are each heated to 80 ° C. to be uniform. While stirring B with a homomixer at 80 ° C., A is gradually added to emulsify. Then, it cools, stirring with a paddle, C and D are added at 50 degreeC, and preparation is complete | finished at 35 degreeC.

  The cosmetics of Examples 5 to 8 were confirmed to form a liquid crystal when measured using the liquid crystal confirmation method of Example 1, and to have a skin care effect by performing the test of Example 4. confirmed.

  By using an emulsifier for liquid crystal formation comprising sterols, polyoxyethylene sterols and lecithin as essential components of the present invention, a liquid crystal structure similar to keratinocyte lipids is formed, and moisture when the composition is applied to the skin By suppressing the transpiration of the liquid crystal, it was possible to obtain a liquid crystal forming emulsion composition and a cosmetic that exhibit excellent skin care effect and skin improvement effect.

Claims (5)

An emulsifier for forming a liquid crystal containing the following (A) to (C) as essential components.
(A) Sterol (B) Polyoxyethylene sterol (C) Lecithin The ratio (mass ratio) of the components (A) to (C) is
(A) / (B) = 10/90 to 90/10
And [(A) + (B)] / (C) = 98/2 to 70/30
The emulsifier for liquid crystal formation according to claim 1. A liquid crystal forming emulsion composition containing the liquid crystal forming emulsifier, wherein the liquid crystal forming emulsion composition contains 0.1 to 30% by mass of the total amount of the components (A) to (C). The ratio (mass ratio) of the components (A) to (C) is
(A) / (B) = 10/90 to 90/10
And [(A) + (B)] / (C) = 98/2 to 70/30
The liquid crystal forming emulsion composition according to claim 3. Cosmetics containing the emulsifier for liquid crystal formation of Claim 1 or 2.