JP2009269915A - Stabilizer to component such as external preparation for skin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stabilizer which controls the photolysis with lapse of time or the like of hydroquinone, astaxanthins, ubiquinone, and retinols blended with an external preparation for skin or the like, as an active ingredient, and can make these compounds stably exist over a long period of time in a formulation such as an external preparation for skin or the like, and to provide the external preparation for skin using the same. <P>SOLUTION: The stabilizer, that is, hydroquinone, astaxanthins, ubiquinone and retinols comprise fullerenes as an effective ingredient. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a stabilizer for hydroquinone, astaxanthins, ubiquinones, and retinols blended in a skin external preparation or the like.

  Hydroquinone is used in cosmetics and quasi-drugs as a whitening ingredient that inhibits tyrosinase activity, which is involved in the production of melanin in the skin.For example, it is caused by skin whitening, excessive exposure to ultraviolet rays, An external preparation for skin containing hydroquinone is known for preventing and improving freckles and liver spots.

  However, hydroquinone has a problem that it is relatively unstable and difficult to blend.

  Astaxanthins are carotenoid pigments widely distributed in the animal and plant kingdoms in nature, and are known to exhibit an antioxidant action, an action of eliminating active oxygen and singlet oxygen, and the like. Astaxanthin is conventionally blended in cosmetics, foods, etc., but pigments are generally easily decomposed by light, etc., and astaxanthin has a problem in blending into cosmetics, etc. Currently, a method such as covering with a sheet that does not transmit light is used. Furthermore, ascorbic acid, tocopherol, polyphenols and the like have been proposed as antioxidants for astaxanthins.

  Ubiquinone, represented by coenzyme Q10, is called a coenzyme and is a nutrient necessary for generating energy for the cells to work. For example, coenzyme Q10 is said to be effective for anti-oxidation, improvement of immunity, maintenance of cardiac function, prevention of arteriosclerosis, prevention of blood clot, reduction of bad cholesterol, recovery from fatigue, improvement of skin trouble, etc. Used in foods and health foods.

  However, coenzyme Q10 is easily decomposed by light or the like, and its stabilization is an issue, and various techniques for this purpose have been studied (see Patent Document 1).

  In addition, retinols are also called vitamin A and have an antioxidant ability and are known to be effective in the treatment and prevention of photoaging (wrinkles, etc.), night blindness, keratinous skin diseases, It is blended in cosmetics and pharmaceuticals, and is also included in foods.

  However, retinols have a problem that they are relatively unstable and difficult to mix.

Republished 2005-035477

  The present invention was made in view of the circumstances as described above, and suppresses photolysis over time of hydroquinone, astaxanthins, ubiquinones, and retinols blended as an active ingredient in a skin external preparation and the like, It is an object of the present invention to provide a stabilizer capable of allowing these compounds to exist stably over a long period of time in a composition such as a skin external preparation and a skin external preparation using the same.

  The present invention is characterized by the following in order to solve the above problems.

  1st: The stabilizer for photolysis suppression of hydroquinone characterized by including fullerene as an active ingredient.

  Second: A skin external preparation comprising hydroquinone blended in an effective amount for whitening the skin and the first hydroquinone photodegradation stabilizing stabilizer.

  Third: A stabilizer for inhibiting photolysis of ubiquinone, comprising fullerenes as an active ingredient.

  Fourth: The third stabilizer for photodegradation suppression of ubiquinone, wherein the ubiquinone is coenzyme Q10.

  5: An external preparation for skin comprising ubiquinone and a stabilizer for inhibiting photolysis of the third or fourth ubiquinone.

  6th: The stabilizer of astaxanthins characterized by containing fullerene as an active ingredient.

  Seventh: An external preparation for skin, comprising astaxanthins and a stabilizer for the sixth astaxanthin.

  Eighth: A stabilizer for retinol, which contains fullerenes as an active ingredient.

  Ninth: A skin external preparation characterized by containing a retinol and a stabilizer for the eighth retinol.

  The present inventors suppress the photolysis and the like of hydroquinone, astaxanthin, ubiquinone, and retinol by blending fullerenes, and make these compounds stable in a composition such as a skin external preparation for a long period of time. The present inventors have found that it can be present and have completed the present invention.

  Fullerenes have antioxidant activity and have been proposed to be used as a component of an external preparation for skin (Japanese Patent Application Laid-Open No. 2004-269523). However, as far as the present inventors know, fullerenes are allowed to coexist with hydroquinone, astaxanthin, ubiquinone, and retinol, and thereby significantly suppress and stabilize the photolysis of these compounds. The present inventors have made it clear for the first time, and are not taught at all as conventional knowledge.

  According to the stabilizer of the present invention, hydroquinone, astaxanthin, ubiquinone, and retinol compounded as an active ingredient in a skin external preparation or the like is inhibited from being photodegraded over time, and in a composition such as a skin external preparation. These compounds can exist stably over a long period of time.

  According to the external preparation for skin of the present invention, since the above-mentioned stabilizer containing fullerenes is blended, the hydroquinone, astaxanthins, ubiquinones, and retinols blended as an active ingredient in the skin external preparation over time. Can be stably present for a long period of time in the external preparation for skin.

It is a graph which shows the time-dependent change (under ultraviolet irradiation) of the hydroquinone relative amount by HPLC analysis. 2 is a photograph of a solution in a quartz cell before and after ultraviolet irradiation in Example 2. FIG. It is a graph which shows the time-dependent change (under visible light irradiation) of the quantity of Coenzyme Q10 by HPLC analysis. It is a graph which shows the result of the comparative test by the fluorescent lamp (visible light) irradiation using the solution containing PVP corresponding to Radical Sponge 10% and 1, 3- butylene glycol. It is a graph which shows the time-dependent change (under ultraviolet light irradiation) of the quantity of Coenzyme Q10 by HPLC analysis. It is a graph which shows the result of an astaxanthin fading test using linoleic acid. It is a graph which shows the measurement result of AOA. It is a photograph which shows the fading degree of the solution in 2 hours after heating at 45 degreeC. It is a graph which shows the result of the astaxanthin fading test by UVB irradiation. It is a graph which shows the result of the astaxanthin fading test by UVB irradiation. It is a graph which shows the comparison result of the astaxanthin fading test by UVB irradiation using the solution containing PVP equivalent to Radical Sponge 1%, and 1, 3- butylene glycol. It is a graph which shows the time-dependent change (under ultraviolet light irradiation) of the amount of retinol by HPLC analysis.

  Hereinafter, the present invention will be described in detail.

The fullerenes used in the stabilizer of the present invention may be one or more of fullerenes, fullerene derivatives, fullerene inclusion compounds, fullerene complexes, or salts thereof. Among these, fullerenes include C ₃₂ , C ₄₄ , C ₅₀ , C ₆₀ , C ₅₈ , C ₆₀ , C ₇₀ , C ₇₆ , C ₇₈ , C ₈₂ , C ₈₄ , C ₉₀ , C _96, etc. ₆₀ alone _or, it is preferably 60 mass% or more content of _{C 60.}

  Examples of the fullerene derivative include those in which a modifying group such as a hydroxyl group is bonded to a carbon atom of the fullerene skeleton.

  Examples of the compound that includes or complexs fullerene include organic oligomers, organic polymers, cyclodextrins that can form inclusion compounds and inclusion complexes, crown ethers, and similar compounds thereof. Specifically, for example, polyvinylpyrrolidone inclusion fullerene, γ-cyclodextrin inclusion fullerene, polyethylene glycol-modified fullerene can be used.

  The organic polymer that includes or complexs fullerene has a weight average molecular weight of, for example, 1200 to 100,000, and in the case of polyvinylpyrrolidone, it is usually 8000 to 100,000, preferably 10,000 to 100,000, more preferably 4000 to 100,000.

  The stabilizer of the present invention can be in various forms blended with the above fullerene, for example, liquid, solid, etc., but can be blended into a composition blended with hydroquinone, ubiquinone, astaxanthins, or retinols. From the viewpoint of ease, it is preferable to use an aqueous solution of fullerene that has been water-solubilized by inclusion or complexation, or an oil-based solution in which fullerenes are dissolved in squalanes or the like. Examples of the squalane include squalane, squalene, a mixture thereof, and the like, and those derived from plants or animals and fish are exemplified.

  The stabilizer containing the fullerenes of the present invention as an active ingredient can be used as a stabilizer for suppressing photolysis of hydroquinone. In particular, it is suitable for suppressing photodecomposition of hydroquinone by ultraviolet rays such as UVA and UVB, and as a fullerene, polyvinylpyrrolidone inclusion fullerene and the like are suitable. Hydroquinone is used for the treatment of stains, freckles, etc. Hydroquinone as a quasi-drug is prescribed in dermatology as a whitening agent due to its strong bleaching action, and hydroquinone in pharmacies etc. Ointments, creams, and the like that are formulated with are commercially available. When hydroquinone is blended in the external preparation for skin, the blending amount is preferably 0.01 to 10% by mass in consideration of whitening action and other points. Further, the blending amount of fullerenes is preferably 0.00002 to 0.01% by mass with respect to the blending amount of hydroquinone in consideration of the photodegradation inhibitory effect and use as a skin external preparation.

  Moreover, the stabilizer which uses the fullerene of this invention as an active ingredient can be used as a stabilizer for photolysis suppression of ubiquinone. In order to suppress the photolysis of ubiquinone by ultraviolet rays such as UVA and UVB, polyvinylpyrrolidone inclusion fullerene and the like are suitable as fullerenes. In order to suppress the photolysis of ubiquinone by visible light, fullerene or the like dissolved in squalanes is suitable. Examples of the ubiquinone include those having an isoprenoid chain consisting of 1 to 12 isoprene units as side chains, and a typical example is coenzyme Q10. Coenzyme Q10 has the following formula having an isoprenoid chain consisting of 10 isoprene units as a side chain:

And is widely distributed in nature. In animals and plants, it is involved in the electron transport system of oxidative phosphorylation in mitochondria.

  Coenzyme Q10 used in the present invention is not particularly limited as long as it can be ingested and applied by a living body, for example, a mammal, especially a human. For example, commonly used industrial synthetic products, fungal extracts such as yeast extract obtained by fermentation, extraction from animals and plants such as sardines, pigs, cows, chickens, broccoli, eggplant, garlic, cabbage Goods can be used.

  When ubiquinone is blended in the external preparation for skin, the blending amount is preferably 0.001 to 5% by mass. In addition, the blending amount of fullerenes is preferably 0.00002 to 3.3% by mass with respect to the blending amount of ubiquinone in consideration of the photodegradation inhibitory effect and use as a skin external preparation.

  Moreover, the stabilizer which uses the fullerene of this invention as an active ingredient can be mix | blended with the foodstuff etc. which contain coenzyme Q10 other than that.

Further, the stabilizer of the present invention can be used as a stabilizer for astaxanthins containing fullerenes as an active ingredient. In particular, it is suitable for suppressing photodegradation of astaxanthins by ultraviolet rays such as UVA and UVB, and as a fullerene, polyvinylpyrrolidone inclusion fullerene and the like are suitable. Astaxanthins have antioxidant ability, active oxygen scavenging, singlet oxygen scavenging, and the like, and are blended in cosmetics and foods. Astaxanthin is a red pigment and belongs to a kind of carotenoid xanthophylls, and its chemical structure is 3,3'-dihydroxy-β, β-carotene-4,4'-dione (C ₄ 0H ₅₂ 0 ₄ , molecular weight 596.82) The chemical formula is represented by the following formula.

  Astaxanthins are widely distributed in nature, and are known to exist as astaxanthin fatty acid esters and astaxanthin proteins bound to proteins in crustaceans and the like. Astaxanthin is a 3S, 3S'-form, 3S, 3R'-form (meso-form), 3R in which isomers exist due to the configuration of the hydroxyl group at the 3 (3 ')-position of the ring structure present at both ends of the molecule. , 3R'- isomers, and cis- and trans- isomers of conjugated double bonds at the center of the molecule. For example, all cis-, 9-cis and 13-cis isomers.

  When the astaxanthin is blended with the external preparation for skin, the blending amount is preferably 0.00001 to 5% by mass. Further, the blending amount of fullerenes is preferably 0.00002 to 0.001% by mass with respect to the blending amount of astaxanthins in consideration of the stabilizing action of astaxanthins and use as a skin external preparation.

  The stabilizer for astaxanthins according to the present invention can be added to foods containing astaxanthins.

  The stabilizer of the present invention can be used as a stabilizer for retinols containing fullerenes as an active ingredient. In particular, it is suitable for suppressing the photolysis of retinols by ultraviolet rays such as UVA and UVB, and as a fullerene, polyvinylpyrrolidone inclusion fullerene and the like are suitable.

  Examples of retinols include retinol and derivatives thereof. Examples of retinol derivatives include retinol acetate, retinol propionate, retinol butyrate, retinol octylate, retinol laurate, retinol palmitate, retinol stearate, and myristic acid. Retinol fatty acid esters such as retinol, retinoic oleate, retinol linolenic acid, retinol linoleate; retinol oxides such as retinal and retinoic acid; retinoic acid esters such as retinoic acid methyl, retinoic acid ethyl, retinoic acid retinol, and retinoic acid tocopherol In retinoic acid, a salt such as sodium retinoic acid may be used.

  When retinols are blended in a skin external preparation, the blending amount is preferably 0.001 to 10% by mass in consideration of anti-wrinkle action and the like. Further, the blending amount of fullerenes is preferably 0.05 to 5% by mass with respect to the blending amount of retinols in consideration of the photodegradation inhibitory effect and use as a skin external preparation.

  In the present invention, the external preparation for skin includes various components generally used in cosmetics, quasi drugs, pharmaceuticals, etc., such as water, fats and oils, hydrocarbons, higher fatty acids, higher alcohols, silicones, anionic surfactants, cations Surfactants, amphoteric surfactants, nonionic surfactants, preservatives, sugars, sequestering agents, polymers such as water-soluble polymers, thickeners, powder components, UV absorbers, UV screening agents, A humectant, a fragrance, a pH adjuster, and the like can be blended. In addition, vitamins, skin activators, blood circulation promoters, active oxygen scavengers, anti-inflammatory agents, whitening agents, other medicinal components such as bactericides, bioactive components, and the like can be blended.

  The external preparation for skin of the present invention can be made into various dosage forms such as lotions, emulsions, gels, creams, ointments, plasters, haptics, aerosols, etc. It can be applied by application, sticking, spraying, etc.

  When the external preparation for skin of the present invention is used as a cosmetic, it should be in the form of lotion, emulsion, cream, pack, makeup base lotion, makeup cream, foundation, hand cream, leg cream, body lotion, etc. Can do.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples at all. In the following, “%” represents “% by mass” unless otherwise specified.
<Example 1>
Tests were conducted on the action of fullerene to inhibit the photolysis of hydroquinone. As a fullerene sample, Radical Sponge (Vitamin C60 Bioresearch Corp., registered trademark) was used. Radical Sponge is a mixture of mixed fullerenes (C ₆₀ , C ₇₀ ) in PVP and then dissolved in 1,3-butylene glycol and water. The composition is 10% PVP, 75% 1,3-butylene glycol. , Water 15%, C ₆₀ 200 ppm or more. Radical Sponge1% is contained _{C 60} of about 2 ppm.

  Hydroquinone (manufactured by Nacalai Tesque) was dissolved in distilled water, and a 2% hydroquinone solution adjusted to pH 5.3 to 5.8 with NaOH was prepared.

  Two samples of Radial Sponge 0.1% and 1% added to 2% hydroquinone solution and 2% Hydroquinone solution to which Radical Sponge is not added are each stored in 3 mL in a quartz cell with an optical path length of 1 cm and irradiated with ultraviolet light for 120 minutes. Went.

Ultraviolet irradiation was performed by irradiating UVA / B (irradiation intensity 50 mW / cm ² : 365 nm) using a large mask alignment apparatus M-2L type (Mikasa Co., Ltd.).

The analysis of the oxidized substance before and after the ultraviolet irradiation was performed using high performance liquid chromatography (Hitachi HPLC). The analysis conditions are as follows.
HPLC column: Cosmosil 5C18MSII (4.6 mm × 150 mm)
Developing solvent: 20% → 100% Methanol flow rate: 0.5 mL / min
Detection: UV 280nm
FIG. 1 shows the change over time in the relative amount by HPLC analysis when the 2% hydroquinone solution is taken as 100%. The decomposition of hydroquinone (HQ) was observed with the irradiation time of ultraviolet rays. The decomposition was delayed when 0.1% radical sponge was added, and the decomposition was suppressed when 1% radical sponge was added.

A test similar to the above was performed by irradiation with a fluorescent lamp (visible light), but the amount of hydroquinone was constant regardless of whether fullerene was added or not.
<Example 2>
The mechanism of the action of fullerene confirmed in Example 1 to suppress the photolysis of hydroquinone by fullerene was examined. Using the quartz cell used in Example 1, the quartz cell containing 4% hydroquinone solution and the quartz cell containing distilled water were overlapped, and ultraviolet irradiation was performed for 15 minutes from the quartz cell side containing distilled water. (Condition 1). On the other hand, a quartz cell separately containing a 4% hydroquinone solution and a quartz cell containing a 5% radical sponge solution were overlapped, and ultraviolet irradiation was performed for 15 minutes from the quartz cell side containing the fullerene solution (condition 2).

The solution in the cell before and after the ultraviolet irradiation is shown in FIG. Under condition 1, it was confirmed that hydroquinone was oxidized by ultraviolet irradiation and a large amount of brown benzoquinone polymer was produced via benzoquinone. From this result, it became clear that not only the antioxidant power of fullerene but also the ultraviolet absorption ability of fullerene contributes to the stabilization of hydroquinone.
<Example 3>
A test was conducted on the photodegradation inhibitory effect of coenzyme Q10 by fullerene. Radical Sponge was used as the fullerene sample. Two samples of Coenzyme Q10 (Sigma C9538) in 0.03% ethanol solution with Radical Sponge 0.1% and 1% added, and each of Coenzyme Q10 0.03% ethanol solution without Radical Sponge added with an optical path length of 1 cm 3 mL was accommodated in a quartz cell, and fluorescent lamp (visible light) irradiation was performed for 5 days.

  Paruk (National Parook FL15EX-N, 15 Watt) was used as a fluorescent lamp, and the quartz cell was irradiated with visible light from a position 40 cm apart.

The analysis of the oxidized substance before and after irradiation with visible light was performed using high performance liquid chromatography (Hitachi HPLC). The analysis conditions are as follows.
HPLC column: Cosmosil 5C18MSII (4.6 mm × 150 mm)
Developing solvent: acetonitrile 70%-chloroform 30%
Flow rate: 1 mL / min
Detection: UV 275nm
The time course of the amount of coenzyme Q10 by HPLC analysis is shown in FIG. By adding 0.1% Radical Sponge, the effect of suppressing photolysis of Coenzyme Q10 was recognized, and by adding 1% Radical Sponge, the photolysis of Coenzyme Q10 was further suppressed.

  A test similar to the above was performed by ultraviolet irradiation, but the photodegradation amount of coenzyme Q10 was almost the same regardless of whether fullerene was added or not.

Next, as a comparative test, a solution containing PVP corresponding to Radical Sponge 10% and 1,3-butylene glycol was added to a 0.03% ethanol solution of coenzyme Q10, and a fluorescent lamp for 5 days ( (Visible light) irradiation was performed. The result is shown in FIG. Even when PVP corresponding to Radical Sponge 10% and 1,3-butylene glycol were added, the photodegradation inhibitory effect of coenzyme Q10 was not seen compared to the 0.03% ethanol solution of coenzyme Q10, and fullerene was photodegraded by coenzyme Q10. It became clear that it was suppressing.
<Example 4>
Next, as a fullerene sample, an oil-soluble fullerene, Lipo Fullerne (LF: Vitamin C60 Bioresearch Co., Ltd., registered trademark) was used to test the photodegradation inhibitory action of coenzyme Q10. Lipo Fullerne is obtained by dissolving mixed fullerene (C ₆₀ , C ₇₀ ) in a plant squalane and containing 200 ppm or more of C ₆₀ .

  Three samples of Coenzyme Q10 (Sigma C9538) in 0.03% squalane solution with Lipo Fullerne 0.1%, 1%, 5%, tartrazine 0.003% and polyoxyethylene polyoxypropylene glycol 0.006 3 mL of each of the sample to which% was added and the 0.03% squalane solution of coenzyme Q10 to which these were not added were accommodated in a quartz cell having an optical path length of 1 cm and irradiated with ultraviolet rays for 30 minutes. In addition, it is known that tartrazine improves light stability (Japanese Patent No. 3091913), and was used as a control.

Ultraviolet irradiation was performed by irradiating UVA / B (irradiation intensity 50 mW / cm ² : 365 nm) using a large mask alignment apparatus M-2L type (Mikasa Co., Ltd.). About the reagent used for experiment, it confirmed beforehand that the stabilizer (antioxidant) was not contained in the reagent.

The analysis of the oxidized substance before and after the ultraviolet irradiation was performed using high performance liquid chromatography (Hitachi HPLC). The analysis conditions are as follows.
HPLC column: Cosmosil 5C18MSII (4.6 mm × 150 mm)
Developing solvent: 65% methanol / 35% ethanol Flow rate: 1 mL / min
Detection: UV 254nm
The time course of the amount of coenzyme Q10 by HPLC analysis is shown in FIG. By adding 1% and 5% Lipo Fullerne, the photodegradation inhibitory effect of coenzyme Q10 was observed.

A test similar to the above was performed by irradiation with visible light, but the photodegradation amount of coenzyme Q10 was almost the same regardless of whether fullerene was added or not.
<Example 5>
The astaxanthin stabilizing action by fullerene was tested by the astaxanthin fading method. Prepare a mixture of astaxanthin in chloroform (1 mg / mL) 1.1 mL, Tween 40 in chloroform (0.2 mg / mL) 2.2 mL, linoleic acid in chloroform (0.1 mg / mL) 440 μL, then chloroform Was removed with an evaporator and then diluted with 72 mL of a phosphate buffer (pH 7.0) to prepare an astaxanthin solution.

  On the other hand, Radial Sponge (final concentration 14 μM), APPF lotion (containing ITO, APPS and fullerene, final concentration 14 μM), γ-cyclodextrin inclusion fullerene (final concentration 12 μM), vitamin E (final concentration 15 μM) ), Ascorbic acid (final concentration 15 μM) was used, 10 μl of each test solution was added to the wells, and then 190 μl of the astaxanthin solution was added to each well to make a total of 200 μl.

The solution in each well was heated to 45 ° C., and the absorbance over time (450 nm) was measured with a plate reader. The result is shown in FIG. Also in Figure 7 the results of measurement of _{AOA (100 (k control -k sample} ) / k control), it shows the discoloration degree of the solution at 45 ° C. warm after 2 hours Figure 8.

Astaxanthin fading means a decrease in antioxidant power, and linoleic acid is added to generate lipid radicals on the test. Astaxanthin fades due to the oxidation of linoleic acid, but all fullerene-containing samples suppressed the fading of astaxanthin.
<Example 6>
The effect of fullerene on the photodegradation of astaxanthin was tested by the astaxanthin fading method. Prepare a mixed solution of 275 μL of astaxanthin in chloroform (1 mg / mL) and 550 μL of Tween 40 in chloroform (0.2 mg / mL), then remove the chloroform with an evaporator, and then with 18 mL of phosphate buffer (pH 7.0). Diluted to prepare an astaxanthin solution.

  On the other hand, as a test solution, Radial Sponge (final concentration 5%, 1%, 0.5%), APPF lotion (containing ITO, APPS and fullerene, final concentration 1%, 14 μM), ascorbic acid (final concentration 14 μM) , Vitamin E (final concentration 14 μM), green tea catechin (final concentration 14 μM), Pt colloid (final concentration 1 ppm), 10 μl of each test solution was added to each well, and 190 μl of the above astaxanthin solution was added to each well. The total volume was 200 μl.

Each well was irradiated with UV light from a UVB lamp for 30 minutes, and the absorbance difference ΔABS (450 nm) before and after UV irradiation was measured with a plate reader. From the obtained ΔABS,% lnh (= ΔABS _control− ΔABS _sample ) / ΔABS _control was calculated using water as a control.

  The results are shown in FIGS. The vertical axis of each graph represents% lnh. 9 and 10, all the fullerene-containing samples suppressed photolysis of astaxanthin.

Next, as a comparative test, a test solution containing Radical Sponge (final concentration 1%) and a solution containing PVP corresponding to Radical Sponge 1% and 1,3-butylene glycol were used, A test similar to the above was performed. The result is shown in FIG. Even when PVP corresponding to Radical Sponge 1% and 1,3-butylene glycol were added, no significant fading suppression was observed due to the addition of Radical Sponge 1%, and it became clear that fullerenes act on the fading suppression of astaxanthin. It was.
<Example 7>
Next, as a fullerene sample, oil-soluble fullerene Lipo Fullerne (LF: Vitamin C60 Bioresearch Co., Ltd., registered trademark) was used to test the photolysis-inhibiting action of retinol.

  Three samples obtained by adding Lipo Fullerne 0.1%, 1%, 5% to a 0.04% polyoxyethylene polyoxypropylene glycol solution of retinol (Sigma RO271), bentonite (manufactured by Hojun Co., Ltd., Sven N- 400) Each sample containing 0.016% and a 0.04% polyoxyethylene polyoxypropylene glycol solution of retinol to which these are not added are accommodated in a quartz cell having an optical path length of 1 cm and irradiated with ultraviolet rays for 60 minutes. went. Bentonite is known to improve light stability (Japanese Patent Laid-Open No. 2008-106041), and was used as a control.

Ultraviolet irradiation was performed by irradiating UVA / B (irradiation intensity 50 mW / cm ² : 365 nm) using a large mask alignment apparatus M-2L type (Mikasa Co., Ltd.). About the reagent used for experiment, it confirmed beforehand that the stabilizer (antioxidant) was not contained in the reagent.

The analysis of the oxidized substance before and after the ultraviolet irradiation was performed using high performance liquid chromatography (Hitachi HPLC). The analysis conditions are as follows.
HPLC column: Cosmosil 5C18MSII (4.6 mm × 150 mm)
Developing solvent: 100% methanol Flow rate: 0.5 mL / min
Detection: UV 254nm
FIG. 12 shows the change over time in the amount of retinol by HPLC analysis. Retinol decomposition was observed in the sample to which no Lipo Fullerne had been added with the passage of ultraviolet irradiation time. In contrast, the addition of Lipo Fullerne inhibited retinol degradation in a concentration-dependent manner.

  A test similar to that described above was performed with visible light irradiation, but the amount of retinol photodegraded was the same regardless of whether fullerene was added or not.

Claims (9)

  A stabilizer for inhibiting photolysis of hydroquinone, comprising fullerenes as an active ingredient.   An external preparation for skin, comprising hydroquinone blended in an effective amount for skin whitening and the hydroquinone photodegradation stabilizing stabilizer according to claim 1.   A stabilizer for suppressing photolysis of ubiquinone, comprising fullerenes as an active ingredient.   The stabilizer for ubiquinone photodegradation according to claim 3, wherein the ubiquinone is coenzyme Q10.   An external preparation for skin comprising ubiquinone and the stabilizer for inhibiting photolysis of ubiquinone according to claim 3 or 4.   A stabilizer for astaxanthins, comprising fullerenes as an active ingredient.   An external preparation for skin, comprising astaxanthins and the stabilizer for astaxanthins according to claim 6.   A stabilizer for retinol, comprising fullerenes as an active ingredient.   An external preparation for skin comprising retinols and the retinol stabilizer according to claim 8.