JP2552298B2 - Beautiful skin cosmetics - Google Patents

Description

TECHNICAL FIELD The present invention relates to cosmetics containing 4-hydroxy-3-ethoxycinnamic acid and / or a derivative thereof.

More specifically, the present invention, by the action of 4-hydroxy-3-ethoxycinnamic acid or a derivative thereof, prevents sunburn due to ultraviolet rays, has a whitening effect by inhibiting tyrosinase activity and an effect of reducing spots and freckles, and further An object of the present invention is to provide a novel cosmetic for beautiful skin, which can suppress acceleration of skin aging due to

(Problems to be Solved by Prior Art and Invention) Generally, when the skin is exposed to excessive ultraviolet rays outdoors, sunburn occurs in several hours after exposure to sunlight,
When it gets worse, it causes blisters. Furthermore, pigmentation subsequently occurs. Thus, excessive UV exposure is extremely harmful from both an aesthetic perspective and the health of the skin.

So far, the main cause of the above-mentioned symptoms is 290 to 320 nm of medium-wavelength ultraviolet rays (hereinafter UV-
It is called B. ), Especially the most involved in "erythema induction" 305-3
Ultraviolet rays in the vicinity of 10 nm has been emphasized, and discussions have been made on how to prevent this.

However, recently, the harmful effect of long-wavelength ultraviolet rays of 320 to 400 nm (hereinafter referred to as UV-A) is becoming clear. For example, if UV-A is irradiated before and after UV-B irradiation, UV-
Since the erythema-inducing ability of B is promoted and UV-A reaches the inside of the dermis, it is known that skin aging is caused by the long-term effects on the intradermal components (collagen, glycosaminoglycan, etc.). Came to be.

Many ultraviolet absorbers have been developed in order to prevent the ultraviolet rays, but in reality, few of them have the effects and safety as well as the stability and solubility as a cosmetic raw material. That is, the ultraviolet absorbers that have been used before in Japan are roughly classified into benzophenone type, urocanic acid type, p-aminobenzoic acid type, cinnamic acid type, and others (salicylic acid type, benzotriazole type, etc.). However, for example, the benzophenone series is 280 to 290 nm and 320 to 3
It has an absorption maximum around 30 nm and is one of the widely used raw materials, but on the other hand, it has a characteristic that the absorption capacity around 305 to 310 nm, which is most involved in erythema induction, is relatively low. Also, urocanic acid type is a biological component and is highly safe,
Since the absorption maximum is around 280 to 290 nm, the practical effect is low particularly for UV-A. It is said that p-aminobenzoic acid type and cinnamic acid type have a maximum absorption around 300 to 310 nm and a high absorption effect, but have a safety problem such as contact photosensitivity. Further, the benzotriazole type has a drawback that it is not allowed to be incorporated into cosmetics from the viewpoint of safety, and the salicylic acid type has a weak absorption effect, and it is difficult to maintain the function as a sunscreen unless a large amount is incorporated.

In Japan, since the safety of ultraviolet absorbers is emphasized, the actual amount of the ultraviolet absorbers used is regulated to 4 to 5% or less.

Therefore, for high SPF products desired by consumers, inorganic powder such as titanium oxide that physically reflects / scatters ultraviolet rays is often used in combination, but in this case, the formulation that can be blended is limited, In addition, it may be unsuitable for lotion type or oil type products because the feeling of use during application may deteriorate.

(Means for Solving Problems) In view of the above-mentioned conventional problems, the present inventors have made various searches in order to find a material that is truly safe and excellent in effect, and has both safety and solubility as a cosmetic raw material. As a result of repeated experimental studies, a 4-hydroxy-3-ethoxycinnamic acid-based compound, which had never been used practically in cosmetics and was not known to have an effect on the skin, was found to be 290-330 nm. It has been found that it has a large UV absorption effect in the vicinity and is optimal as a UV absorption agent for cosmetics, and that it has a large thyrodinase activity inhibitory effect in the skin and has a great whitening effect, and thus completed the present invention. I arrived.

That is, the present invention, as an active ingredient, the general formula (In the formula, R represents hydrogen or a linear, branched, cyclic, or polycyclic alkyl group, alkenyl group, aryl group, and alkali metal, alkaline earth metal, and fourth chain amine.) 4 TECHNICAL FIELD The present invention relates to a cosmetic for beautiful skin, characterized by comprising hydroxy-3-ethoxycinnamic acid and / or a derivative thereof as an active ingredient.

 The present invention will be described in detail below.

4-Hydroxy-3-ethoxycinnamic acid used in the skin cosmetic of the present invention is a substance represented by the above general formula (I) (R is hydrogen).

4-Hydroxy-3-ethoxycinnamic acid has never been practically used in cosmetics until now, but as shown in the ultraviolet absorption spectrum (see FIG. 1) described later,
It has absorption maxima near 5 nm and 324 nm (in ethanol) and shows an absorption pattern similar to that of benzophenone-based UV absorbers, and it also absorbs in the "erythema-inducing" region (305-310 nm) like benzophenone-based UV absorbers. From the fact that there is almost no decrease in the activity, it was revealed by the experiments of the present inventor that the erythema-suppressing effect and the increase in the number of melanocytes at the time of irradiating the skin with ultraviolet rays are excellent.

Similarly, according to the inventors' experiments, 4-hydroxy-3
-Ethoxycinnamic acid was also revealed to have a thyrodinase activity inhibitory action, and it was also demonstrated to be useful for a whitening effect and a reduction of spots and freckles.

4-Hydroxy-3-ethoxycinnamic acid is generally a pale yellow to white needle-like or powdery crystal, is easy to handle, has no odor, and is hardly soluble in cold water. Olive oil, soybean oil It is slightly soluble in vegetable oils and esters such as but is soluble in alcohol and polyhydric alcohols,
When used as a cosmetic ingredient, it can be applied to a wide range of dosage forms.

On the other hand, in the cosmetic for beautiful skin of the present invention, 4-hydroxy-3-ethoxycinnamic acid may be used as its salt. When used as a salt, the solubility in water is increased, which is particularly preferable for use in lotion and the like. When 4-hydroxy-3-ethoxycinnamic acid is used as a salt, basic substances for forming the salt include lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, ammonium hydroxide and the like. Inorganic base, arginine, lysine, histidine,
Basic amino acids such as ornithine and organic bases such as monoethanolamine, diethanolamine and triethanolamine are used. The above-mentioned salt may be prepared in advance and then added, or the salt-forming components may be added separately and reacted in the formulation system to form a salt.

Furthermore, 4-hydroxy-3-ethoxycinnamic acid can also be used as its ester. By using it as an ester, the solubility in oily components is improved, and it becomes suitable for use in cosmetic oils and the like.
The method itself for esterifying 4-hydroxy-3-ethoxycinnamic acid can be produced by a known method, for example, an acid halide method, an acid anhydride method, a direct method, a DCC method or the like. The properties of the 4-hydroxy-3-ethoxycinnamic acid ester derivative vary widely from crystalline to viscous oily to oily depending on the type of alcohol used for esterification. In addition, the ultraviolet absorption characteristics of these 4-hydroxy-3-ethoxycinnamic acid ester derivatives are generally 3 to 4 nm longer than that of 4-hydroxy-3-ethoxycinnamic acid in the absorption maximum toward the long wavelength side ( Red shift).

Specific examples of the 4-hydroxy-3-ethoxycinnamic acid ester derivative include ethyl 4-hydroxy-3-ethoxycinnamate, 2-ethylhexyl 4-hydroxy-3-ethoxycinnamate, and 4-hydroxy-3-ethoxycinnamate. Allyl acid, cetyl 4-hydroxy-3-ethoxycinnamate, oleyl 4-hydroxy-3-ethoxycinnamate, phenyl 4-hydroxy-3-ethoxycinnamate, menthyl 4-hydroxy-3-ethoxycinnamate,
4-hydroxy-3-ethoxycinnamic acid such as cholesteryl 4-hydroxy-3-ethoxycinnamate and straight-chain,
Examples thereof include branched, cyclic and polycyclic ester compounds with alkyl, alkenyl and aryl alcohols.

In the cosmetic for beautiful skin of the present invention, any one kind or two or more kinds can be selected and used from the group consisting of the 4-hydroxy-3-ethoxycinnamic acid and its derivative. The blending ratio is 0.01% by weight with respect to the entire cosmetic.
Above, 0.5 wt% or more is selected as a particularly preferable amount. Even if the amount exceeds 10% by weight, there is almost no change in the effect.
There is no need to exceed.

The cosmetic base used in the skin-care cosmetic of the present invention may be any base as long as it is a base normally used in skin-care cosmetics, and is not particularly limited. Specific dosage forms include cream, ointment, emulsion, lotion, oil, pack and the like. For example, as a cream base, beeswax, cetyl alcohol, stearic acid, glycerin, propylene glycol, propylene glycol monostearate, polyoxyethylene cetyl ether, etc., and as a lotion base, oleyl alcohol, ethanol, propylene glycol, glycerin. , Lauryl ether,
Examples thereof include sorbitan monolaurate.

The skin-care cosmetic of the present invention is prepared as a cosmetic in a suitable form such as cream, milky lotion, and lotion by a conventional method by appropriately using these principles. In addition, in the cosmetic for beautiful skin of the present invention, in addition to the above-mentioned usual cosmetic bases, UV absorbers other than 4-hydroxy-3-ethoxycinnamic acid and its derivatives and fine particle titanium oxide are used as needed. Various medicinal ingredients such as ultraviolet light scattering agents, allantoin, placenta extract, etc., other thickening agents, plasticizers, calamines, pigments, antioxidants, chelating agents, fragrances and the like can be added.

Next, in order to explain the usefulness of the skin-care cosmetic of the present invention in more detail, with respect to the melanin-suppressing action of 4-hydroxy-3-ethoxycinnamic acid, the action of inhibiting tyrosinase activity, which is known as the mechanism, and ultraviolet rays. The results of experimental examples of the inhibitory effect on the increase in the number of melanocytes and the inhibitory effect on erythema due to are shown below.

Experimental Example 1. Tyrosinase activity inhibitory effect The tyrosinase activity inhibitory effect of 4-hydroxy-3-ethoxycinnamic acid was examined using an enzyme tyrosinase extracted from Harding-Passay mouse melanoma. The enzyme activity was determined by a photometric method in which the amount of dopachrome produced was measured by the absorbance at an absorption maximum of 475 nm using dopa as a substrate. The results are shown in Table 1 showing the thyrodinase activity inhibition rate after 10 minutes of reaction.

(Sample solution concentration) 5 × 10 ^-3 M, 1 × 10 ^-3 M, 5 × 10 ^-4 M (Reaction solution composition) Enzyme solution 0.2 ml 5 mM Dopa 1.0 0.1 M phosphate buffer (pH 6.8) 1.74 Sample Solution 0.06 (total) 3.0 ml As shown in the results of Table-1, 4-hydroxy-3-
It was revealed that ethoxycinnamic acid has a remarkable thyrodinase activity inhibitory action, and it has a whitening effect and a stain,
It has been demonstrated to be useful in reducing freckles.

Experimental Example 2. Inhibitory effect on increase in melanocyte number due to ultraviolet rays A group of 6 C57BL mice was used as a test solution in the right auricle, that is, propylene glycol: ethanol = 1: 1.
In a vehicle consisting of 0.1 W / V%, 0.5 W / V% at 4-
10 μm of each solution of hydroxy-3-ethoxycinnamic acid and 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid was applied, and the same amount of vehicle was applied to the left auricle of the mouse.

Next, using the FL20SE30 lamp as a light source, the auricle was placed directly under the light source, and ultraviolet rays of 33 μw / cm ² were irradiated for 20 seconds (about 0.07 joule). The sample was applied to the auricle of the mouse once a day, and the ultraviolet irradiation was repeated once for three consecutive days after the application. After leaving it for 1 week, collect the left and right auricles,
Subsequently, NaBr treatment was performed to separate the epidermis. The epidermis was stained with Dopa to prepare a tissue sample, and the number of melanocytes was counted under a microscope. The results are shown in Table-2 (4-hydroxy-3
-Ethoxycinnamic acid) and Table-3 (2-hydroxy-4)
-Methoxybenzophenone-5-sulfonic acid).

As shown in the comparison of Table-2 and Table-3, 4-
Hydroxy-3-ethoxycinnamic acid is a conventionally used 2-hydroxy-4-methoxybenzophenone-5.
-Has the effect of suppressing the increase in the number of melanocytes due to ultraviolet rays equivalent to or higher than sulfonic acid, and especially 0.5 W / v
It was found that when the ratio was more than 100%, the increase in the number of melanocytes was completely suppressed.

Experimental Example 3. Inhibitory effect on erythema and edema due to ultraviolet rays A group of 8 guinea pigs was shaved on the back, and a bandage with two small holes (circle of 1.5 cm in diameter) was applied to the shaved part and fixed. 30μ of test solution on one site of guinea pig
30 μl of the vehicle alone (control) was applied to the other site. About 0.8 J / cm ^{2 which} is four times the minimum amount of erythema after 1 hour (using the FL20SE30 lamp as the light source, 300
(irradiation with μW / cm ² for 28 minutes), and allowed to stand for a certain period of time for judgment. The method of judgment was to observe with the naked eye 2, 4, 6, 24, 48, 72 hours after irradiation according to the following judgment criteria.
The test solution was 4 W / V% in a vehicle consisting of propylene glycol: isopropyl alcohol = 3: 7 (W / W).
It was prepared by dissolving 4-hydroxy-3-ethoxycinnamic acid at a ratio of 10 W / V% and 2-hydroxy-4-methoxybenzophenone at a ratio of 10 W / V%. The obtained results (n = 8 for each test solution) were averaged and the final results are shown in FIG.

(Criteria) Mild erythema 0.5 (±) Clear erythema 1.0 (+) Erythema and weak swelling 1.5 (+ to ++) Erythema and clear swelling 2.0 (++) Small blister / blister 3.0 (+++) Fig. 2 As shown in Fig. 4, 4-hydroxy-3-ethoxycinnamic acid is already used in the conventional 2-
Hydroxy-4-methoxybenzophenone (10W / V%)
It was clear that it had an effect of significantly suppressing erythema and swelling caused by ultraviolet rays.

As described above in detail, the skin-care cosmetic of the present invention containing 4-hydroxy-3-ethoxycinnamic acid and a derivative thereof reduces the whitening effect and stains / freckles, and prevents various harmful effects caused by ultraviolet rays. It has become an excellent one.

Examples of the skin-care cosmetic of the present invention are shown below. The mixing ratio is parts by weight.

Example 1. Lotion Propylene glycol 10.0 Ethyl alcohol 20.0 Liquid paraffin 2.0 Polyoxyethylene (30) hydrogenated castor oil 1.0 Sodium 4-hydroxy-3-ethoxycinnamate 8.0 Polyethylene glycol 5.0 Citric acid 0.2 Sodium phosphate 0.3 Allantoin 0.05 EDTA-2Na 0.05 Antioxidant 0.02 Perfume 0.2 Purified water 53.18 Example 2. Cream Solid paraffin 2.0 Stearyl alcohol 4.0 Squalane 2.0 Liquid paraffin 6.0 Glyceryl monostearate 2.5 Polyoxyethylene sorbitan monostearate 2.5 Ethyl alcohol 9.0 Propylene glycol 8.0 4-Hydroxy-3 Ethyl ethoxycinnamate 4.0 2-Hydroxy-4-methoxybenzophenone 3.0 Hydrophobized particulate titanium oxide 5.0 Purified water 52.0 Example 3. Foundation Hydrophobized particulate titanium oxide 7 .0 triglyceride isostearate 2.0 2-octyldodecyl oleate 8.0 liquid paraffin 3.0 cetyl alcohol 5.0 candelilla wax 2.0 4-hydroxy-3-ethoxy cetyl cinnamate 5.0 polyoxyethylene (25) monostearate 2.0 sorbitan monostearate 1.0 yellow oxide Iron 1.3 Rouge 0.8 Polyethylene glycol 4.0 Methylparaben 0.2 Perfume 0.2 Purified water 58.5 Example 4. Powder talc 80.0 Crystalline cellulose 5.0 Ultramarine blue 1.0 Spherical calcium silicate 3.0 Fine particle titanium oxide 3.5 4-Hydroxy-3-ethoxycinnamic acid 3.0 Squalane 4.5

[Brief description of drawings]

FIG. 1 is an ultraviolet absorption spectrum (in 0.001% ethanol) of 4-hydroxy-3-ethoxycinnamic acid. FIG. 2 shows the relationship between erythema intensity (n = 8 average value) and time course after UV irradiation on guinea pigs. In the figure, (a) is control and (b) is 10 W / V. %
Of 2-hydroxy-4-methoxybenzophenone solution, (c) of 4W / V% 4-hydroxy-3-ethoxycinnamic acid solution, (d) of 10W / V% 4-hydroxy-3- An ethoxycinnamic acid solution was applied.

Claims (2)

(57) [Claims] 1. A formula (I) based on a cosmetic base. (In the formula, R represents hydrogen or a linear, branched, cyclic, or polycyclic alkyl group, alkenyl group, aryl group, and alkali metal, alkaline earth metal, or quaternary amine.) 4 -Hydroxy-3-ethoxycinnamic acid and / or its derivative as an active ingredient. 2. The cosmetic for beautiful skin according to claim 1, wherein the compounding amount of the 4-hydroxy-3-ethoxycinnamic acid and / or its derivative is 0.01 to 10% by weight with respect to the total amount of the cosmetic. .