WO2021104772A1

WO2021104772A1 - Active substance combinations of ubiquinol and carrageenan and cosmetic or dermatological preparations containing said active substance combinations

Info

Publication number: WO2021104772A1
Application number: PCT/EP2020/080011
Authority: WO
Inventors: Julia Maxi Weise; Andrea Krueger; Thomas Raschke; Alexandra Vogelsang
Original assignee: Beiersdorf Ag
Priority date: 2019-11-26
Filing date: 2020-10-26
Publication date: 2021-06-03
Also published as: DE102019218241A1

Abstract

The invention relates to active substance combinations comprising a) one or more ubiquinols and b) carrageenan.

Description

description

Active ingredient combinations of ubiquinol and carrageenan and cosmetic or dermatological preparations containing such active ingredient combinations

The present invention relates to cosmetic and dermatological preparations with an effective content of physiologically compatible combinations of active ingredients. In particular, the present invention relates to cosmetic preparations with effective protection against harmful oxidation processes in the skin, but also to protect cosmetic preparations themselves or to protect the constituents of cosmetic preparations from harmful oxidation processes.

The present invention also relates to antioxidants, preferably those which are used in skin-care cosmetic or dermatological preparations. In particular, the invention also relates to cosmetic and dermatological preparations containing such antioxidants. In a preferred embodiment, the present invention relates to cosmetic and dermatological preparations for the prophylaxis and treatment of cosmetic or dermatological skin changes such as skin aging, in particular skin aging caused by oxidative processes.

The present invention also relates to active ingredients and preparations containing such active ingredients for the cosmetic and dermatological treatment or prophylaxis of erythematous, inflammatory, allergic or autoimmune reactive phenomena, in particular dermatoses.

The present invention also relates to active ingredient combinations and preparations which are used for the prophylaxis and treatment of light-sensitive skin, in particular of photodermatoses. The damaging effect of the ultraviolet part of solar radiation on the skin is well known. While rays with a wavelength smaller than 290 nm (the so-called UVC range) are absorbed by the ozone layer in the earth's atmosphere, rays in the range between 290 nm and 320 nm, the so-called UVB range, cause erythema simple sunburn or even more or less severe burns.

The narrower range around 308 nm is given as a maximum of the erythema effectiveness of sunlight.

To protect against UVB radiation, numerous compounds are known which are derivatives of 3-benzylidene camphor, 4-aminobenzoic acid, cinnamic acid, salicylic acid, benzophenone and also 2-phenylbenzimidazole.

It is also important to have filter substances available for the range between about 320 nm and about 400 nm, the so-called UVA range, since its rays can cause reactions in photosensitive skin. It has been proven that UVA radiation leads to damage to the elastic and collagen fibers of the connective tissue, which causes the skin to age prematurely, and that it can be seen as the cause of numerous phototoxic and photoallergic reactions. The damaging influence of UVB radiation can be intensified by UVA radiation.

To protect against the rays of the UVA range, use is therefore made of certain derivatives of dibenzoyl methane, the photostability of which (Int. J. Cosm. Science 10, 53 (1988)) is insufficient.

However, UV radiation can also lead to photochemical reactions, in which case the photochemical reaction products intervene in the skin's metabolism.

Such photochemical reaction products are predominantly radical compounds, for example hydroxy radicals. Undefined free radical photo products, which arise in the skin itself, can display uncontrolled secondary reactions due to their high reactivity. But also singlet oxygen, a A non-radical excited state of the oxygen molecule can occur with UV irradiation, as can short-lived epoxides and many others. Singlet oxygen, for example, is distinguished from the normally present triplet oxygen (radical ground state) by increased reactivity. However, there are also excited, reactive (radical) triplet states of the oxygen molecule.

UV radiation also counts as ionizing radiation. There is therefore a risk that ionic species will also be formed when exposed to UV, which in turn are able to intervene oxidatively in the biochemical processes.

In order to prevent these reactions, additional antioxidants and / or radical scavengers can be incorporated into the cosmetic or dermatological formulations.

It has already been proposed to use vitamin E, a substance with a known antioxidant effect, in light protection formulations, but here too the effect achieved remains far below that which was hoped for.

The object of the invention was therefore also to create cosmetic, dermatological and pharmaceutical active ingredients and preparations and light protection formulations which are used for the prophylaxis and treatment of light-sensitive skin, in particular photodermatoses, preferably PLD.

Further names for polymorphic light dermatosis are PLD, PLE, Mallorca acne and a large number of other names, as they are in the literature (e.g. A. Voelckel et al, Zentralblatt Skin and Sexual Diseases (1989), 156, p.2), are specified.

Erythematous skin symptoms also occur as side effects of certain skin diseases or irregularities. For example, the typical skin rash in the appearance of acne is regularly more or less reddened.

Mainly, antioxidants are used as protective substances against spoilage of the preparations containing them. Still, it is known that even in human and animal skin, undesirable oxidation processes can occur. Such processes play an essential role in skin aging.

In the article "Skin Diseases Associated with Oxidative Injury" in "Oxidative Stress in Dermatology", p. 323 ff. (Marcel Decker Inc., New York, Basel, Hong Kong, editors: Jürgen Fuchs, Frankfurt, and Lester Packer , Berkeley / California), oxidative damage to the skin and its more detailed causes are listed.

If human hair is to be colored permanently, only oxidizing hair coloring processes come into consideration in practice. In oxidative hair coloring, the dye chromophore is formed by the reaction of precursors (phenols, aminophenols, more rarely also diamines) and bases (mostly p-phenylenediamine) with the oxidizing agent, mostly hydrogen peroxide. Hydrogen peroxide concentrations around 6% are commonly used.

It is usually assumed that, in addition to the coloring effect, the hydrogen peroxide also has a bleaching effect. In oxidatively dyed human hair, similar to bleached hair, microscopic holes can be detected in the places where melanin granules are present.

The fact is that the oxidizing agent hydrogen peroxide not only reacts with the dye precursors, but also with the hair substance and can cause damage to the hair under certain circumstances.

Antioxidants are substances which prevent oxidation processes or which prevent the automation of fats containing unsaturated compounds. Antioxidants, which are also used in the fields of cosmetics and pharmacy, are, for example, α-tocopherol, in particular in the form of α-tocopheryl acetate, sesamol, gallic acid derivatives, butylhydroxyanisole and butylhydroxytoluene.

Antioxidants and / or radical scavengers can also be incorporated into cosmetic formulations for the purpose of preventing such reactions. Some antioxidants and radical scavengers are known. For example, US Patents 4,144,325 and 4,248,861, as well as numerous other documents, suggest using vitamin E, a substance with a known antioxidant effect, in light protection formulations, but here too the effect achieved remains far below the hoped-for effect.

One object of the present invention was to eliminate the disadvantages of the prior art. In particular, active ingredients or preparations containing such active ingredients should be made available, if they are used, damage to the skin and / or hair due to oxidative influence can at least be reduced, if not completely prevented.

Another object of the present invention was to provide cosmetic preparations which, before or after treatment of the hair with hair coloring preparations, even those with a content of strong oxidizing agents such as hydrogen peroxide, counteract their damaging oxidizing effect.

In particular, active ingredients and preparations containing such active ingredients should be made available for the cosmetic and dermatological treatment and / or prophylaxis of erythematous, inflammatory, allergic or autoimmune-reactive symptoms, in particular dermatoses, but also the appearance of "stinging".

It was surprising and could not be foreseen by the person skilled in the art that active ingredient combinations comprising a) one or more ubiquinols and b) carrageenan or cosmetic or dermatological preparations containing such active ingredient combinations or the use of such active ingredient combinations as an antioxidant and / or as a radical scavenger , especially in cosmetic or dermatological preparations, the solution to these problems and remedy the disadvantages of the prior art. Ubiquinols or their oxidized form, the ubiquinones, play an important role in the transport of electrons in the respiratory chain of living things. Ubiquinols are characterized by the following chemical structure and act as antioxidants:

In naturally occurring ubiquinols or their oxidized form, the ubiquinones, n can assume values from 0 to 50. In mammals, especially humans, n = 10 predominates (ubidecarenol), which according to the invention is the preferred ubiquinol. Due to the redox character of ubiquinone and ubiquinol, only the reduced form, ubiquinol, can act as an antioxidant (Fig. 1).

The cosmetic use of ubiquinols is known per se, for example from WO 2017/045034, DE 42 28 871 and other publications.

Well-known and proven polymers in cosmetics and pharmaceutical galenics that are used to thicken the formula are e.g. xanthan gum, sclerotium gum and PAS80. Unfortunately, the antioxidant effect of ubiquinol is weakened or canceled by interaction with these 3 polymers (Fig. 2-4).

A well-known and proven hydrocolloid in cosmetics and pharmaceutical galenics is carrageenan.

Carrageenan is the polysaccharide extract from carrageenan (Irish moss, Chondrus crispus L, solids content approx. 1%) obtained with dilute, alkaline, almost boiling aqueous solutions. The resulting crude extract is filtered in the presence of adsorbents and im Thickened in a vacuum and finally dried in a suitable manner, residual water is usually removed by treatment with hydrophilic organic solvents.

Carrageenan consists essentially of 2 components, which are referred to as k-carrageenan and l-carrageenan and are chemically largely identical. k-carrageenan contains less ester sulfate (23-28%) than l-carrageenan (24-33%) and also has a different optical twist. In k-carrageenan, 3,6-anhydro-D-galactopyranose units are linked via C4 to D-galactopyranose-4-sulfate units with a glucosidic bond at the C3 atom. In contrast, l-carrageenan probably consists of α-D-galactopyranose-4-sulfate units. l-carrageenan has a larger molecular weight than l-carrageenan and probably also a larger molecular size.

Carrageenan is an anionic polyelectrolyte with a high electrical charge. In addition to heparin, carrageenan is the natural inorganic polyelectrolyte with the highest electrical charge. Carrageenan is therefore capable of various reactions with other molecules.

The molecular weights determined are between 100,000 and 800,000. The main solvent for carrageenan is water; the solubility is influenced by the presence of hydrophilic, organic liquids, salts delay or prevent the dissolution, e.g. B.

0.25 mol KCl or 0.75 mol NaCl. The viscosity of the carrageenan solutions is logarithmic as a function of the concentration. Depending on the quality of the carrageenan, a 2% solution has a viscosity (40 °) of 50-3000 m Pa s.

Surprisingly, it has been shown that when ubiquinol (Qh2) is combined with the polymer carrageenan, the antioxidant effect of ubiquinol is largely retained (FIG. 5).

However, the person skilled in the art could not have foreseen that the physiologically compatible active ingredient combinations used according to the invention or cosmetic or dermatological preparations containing those would have a better effect as an antioxidant better than radical scavengers better prevent the binding of harmful photo products to lipids, DNA and proteins better prevent skin aging better protect the skin against photoreactions better prevent inflammatory reactions than the active ingredients, active ingredient combinations and preparations of the prior art would. Furthermore, it could not have been foreseen that the active ingredient combinations in cosmetic or dermatological preparations would have a higher stability than comparable active ingredients, for example as vitamin C.

According to the invention, therefore, the use of physiologically compatible active ingredient combinations as antioxidants and their use for combating and / or prophylaxis of skin aging and inflammatory reactions caused by oxidative stress.

It is advantageous according to the invention to choose the molar ratio of one or more ubiquinols to carrageenan from the range from 1000: 1 to 1: 1000, preferably 100: 1 to 1: 100, particularly preferably 50: 1 to 1:20.

According to the invention, the preparations are particularly advantageously characterized in that one or more ubiquinols, in particular ubidecarenol, in concentrations of 0.001-10.00% by weight, preferably 0.005-5.00% by weight, particularly preferably 0.01-3 , 00% by weight, based in each case on the total weight of the composition, is or are present.

According to the invention, the preparations are particularly advantageously characterized in that carrageenan in concentrations of 0.001-10.00% by weight, preferably 0.005-5.00% by weight, particularly preferably 0.01-3.00% by weight, in each case based on the total weight of the composition, is or are present.

The cosmetic or dermatological formulations according to the invention can be composed as usual and for the treatment, care and cleaning of the skin and / or the hair and serve as a make-up product in decorative cosmetics. They contain preferably 0.001% by weight to 10% by weight, preferably 0.05% by weight to 5% by weight, in particular 0.1-2.0% by weight, based on the total weight of the agent, one or more active ingredient combinations according to the invention.

For use, the cosmetic and dermatological preparations according to the invention are applied to the skin and / or hair in a sufficient amount in the manner customary for cosmetics.

The active ingredient combinations according to the invention can advantageously be incorporated into customary cosmetic and dermatological preparations, which can be in various forms. So you can z. B. a solution, an emulsion of the water-in-oil (W / O) type or of the oil-in-water (O / W) type, or a multiple emulsions, for example of the water-in-oil-in-water type (W / O / W) or oil-in-water-in-oil (O / W / O), a hydrodispersion or lipodispersion, a Pickering emulsion, a gel, a solid stick or an aerosol.

Emulsions according to the invention for the purposes of the present invention, e.g. B. in the form of a cream, a lotion, a cosmetic milk are advantageous and contain z. B. fats, oils, waxes and / or other fatty substances, as well as water and one or more emulsifiers, as they are usually used for such a type of formulation.

It is also possible and advantageous for the purposes of the present invention to incorporate the active compound combinations according to the invention into aqueous systems or surfactant preparations for cleaning the skin and hair.

It is of course known to the person skilled in the art that sophisticated cosmetic compositions are mostly inconceivable without the customary auxiliaries and additives. These include, for example, consistency enhancers, fillers, perfumes, dyes, emulsifiers, additional active ingredients such as vitamins or proteins, sunscreens, stabilizers, insect repellants, alcohol, water, salts, antimicrobial, proteolytic or keratolytic substances, etc. Mutatis mutandis, corresponding requirements apply to the formulation of medical preparations.

Medical topical compositions for the purposes of the present invention generally contain one or more medicaments in effective concentrations. For the sake of simplicity, reference is made to the statutory provisions of the Federal Republic of Germany (e.g. Cosmetics Ordinance, Food and Drug Act) to clearly distinguish between cosmetic and medical applications and corresponding products.

It is also advantageous to add the active ingredient combinations according to the invention as an additive to preparations which already contain other active ingredients for other purposes.

Accordingly, cosmetic or topical dermatological compositions for the purposes of the present invention, depending on their structure, can be used, for example, as skin protection cream, cleansing milk, sun protection lotion, nutritional cream, day or night cream, etc. It is optionally possible and advantageous to use the compositions according to the invention as a basis for to use pharmaceutical formulations.

For use, the cosmetic and dermatological preparations are applied according to the invention to the skin and / or hair in a sufficient amount in the manner customary for cosmetics.

Those cosmetic and dermatological preparations which are in the form of a sunscreen agent are particularly preferred. These can advantageously also contain at least one further UVA filter and / or at least one further UVB filter and / or at least one inorganic pigment, preferably an inorganic micropigment.

According to the invention, the cosmetic and dermatological preparations can contain cosmetic auxiliaries such as are customarily used in such preparations, for example preservatives, bactericides, perfumes, substances for preventing the Foaming, dyes, pigments that have a coloring effect, thickeners, moisturizing and / or moisturizing substances, fats, oils, waxes or other common components of a cosmetic or dermatological formulation such as alcohols, polyols, polymers, foam stabilizers, electrolytes, organic solvents or Silicone derivatives.

An additional content of customary antioxidants is generally preferred. According to the invention, all antioxidants suitable or customary for cosmetic and / or dermatological applications can be used as favorable antioxidants.

The amount of the aforementioned antioxidants (one or more compounds) in the preparations is preferably 0.001 to 30% by weight, particularly preferably 0.005-20% by weight, in particular 0.01-10% by weight, based on the total weight the preparation.

If the cosmetic or dermatological preparation in the sense of the present invention is a solution or emulsion or dispersion, the following solvents can be used:

Water or aqueous solutions

Oils, such as triglycerides of capric or caprylic acid, but preferably castor oil; Fats, waxes and other natural and synthetic fatty substances, preferably esters of fatty acids with alcohols of low carbon number, e.g. with isopropanol, propylene glycol or glycerine, or esters of fatty alcohols with alkanoic acids of low carbon number or with fatty acids;

Alcohols, diols or polyols with a low carbon number and their ethers, preferably ethanol, isopropanol, propylene glycol, glycerol, ethylene glycol, ethylene glycol monoethyl or monobutyl ether, propylene glycol monomethyl, monoethyl or monobutyl ether, diethylene glycol monomethyl ether or analogues Products.

In particular, mixtures of the abovementioned solvents are used. In the case of alcoholic solvents, water can be another component. If the cosmetic or dermatological preparation in the sense of the present invention is a solution or emulsion or dispersion, the following solvents can be used:

Water or aqueous solutions

In particular, mixtures of the abovementioned solvents are used. In the case of alcoholic solvents, water can be another component.

Suitable propellants for cosmetic and / or dermatological preparations that can be sprayed from aerosol containers in the context of the present invention are the customary, highly volatile, liquefied propellants, for example hydrocarbons (propane, butane, isobutane), which can be used alone or in a mixture with one another. It is also advantageous to use compressed air.

Of course, the person skilled in the art knows that there are propellant gases which are nontoxic per se, which would be suitable in principle for the implementation of the present invention in the form of aerosol preparations, but which should nevertheless be avoided because of their harmful effects on the environment or other accompanying circumstances, in particular fluorocarbons and Chlorofluorocarbons (CFCs).

Cosmetic preparations within the meaning of the present invention can also be in the form of gels which, in addition to an effective content of active ingredient combinations according to the invention and solvents usually used for this, preferably water, also organic thickeners, for example gum arabic, xanthan gum, sodium alginate, cellulose Derivatives, preferably methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose or inorganic thickeners, e.g. B. aluminum silicates such as bentonite, or a mixture of polyethylene glycol and polyethylene glycol stearate or distearate contain. The thickening agent is contained in the gel, for example, in an amount between 0.1 and 30% by weight, preferably between 0.5 and 15% by weight.

Furthermore, it is advantageous if the emulsion of the present invention has further active ingredients selected from the group consisting of glycyrrhetinic acid, arctic acid (also as a component of burdock fruit extracts), folic acid, alpha-glucosyl rutin, carnitine, carnosine, caffeine, natural and / or synthetic isoflavonoids, glyceryl glucose , Taurine, tocopherol, tocopherol acetate, vitamin C, vitamin C phosphate, vitamin C palmitate, niacinamide, vitamin A palmitate, retinol, panthenol, glycyrrhiza inflata root extract, arctiin, licochalcone A, 4-butylresocinol, N - [(2,4-dihydroxyphenyl ) thiazol-2-yl] isobutyramide, honociol and magnolol (also as a component of magnolia extracts) and / or silymarin (milk thistle extract).

It is advantageous according to the invention, in addition to the combinations according to the invention, to use further oil-soluble UVA filters and / or UVB filters in the lipid phase and / or further water-soluble UVA filters and / or UVB filters in the aqueous phase.

According to the invention, the light protection formulations can advantageously contain further substances which absorb UV radiation in the UVB range, the total amount of the filter substances being, for example, 0.1% by weight to 30% by weight, preferably 0.5 to 10% by weight. %, in particular 1 to 6% by weight, based on the total weight of the preparations, in order to provide cosmetic preparations which protect the skin from the entire range of ultraviolet radiation. They can also serve as sunscreens.

Particularly advantageous UV filter substances that are liquid at room temperature within the meaning of the present invention are homomenthyl salicylate (INCI: Homosalate), 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate (INCI: Octocrylene), 2-ethylhexyl-2-hydroxybenzoate (2 -Ethylhexylsalicy- lat, Octylsalicylat, INCI: Octyl Salicylate) and esters of cinnamic acid, preferably 4-methoxy- cinnamic acid (2-ethylhexyl) ester (2-ethylhexyl-4-methoxycinnamate, INCI: Octyl Methoxycinnamate).

Advantageous UV-A filter substances for the purposes of the present invention are dibenzoyl methane derivatives, in particular 4- (tert-butyl) -4'-methoxydibenzoylmethane (CAS No. 70356-09-1), which is available from Givaudan under the Parsol brand ® 1789 and sold by Merck under the trade name Eusolex ® 9020.

Advantageous further UV filter substances for the purposes of the present invention are sulfonated, water-soluble UV filters, such as. B .:

Phenylene-1,4-bis (2-benzimidazyl) -3,3'-5,5'-tetrasulfonic acid and its salts, especially the corresponding sodium, potassium or triethanolammonium salts, especially phenylene-1, 4-bis- (2-benzimidazyl) -3,3'-5,5'-tetrasulfonic acid-bis-sodium salt with the INCI name Bisimidazylate (CAS-No .: 180898-37-7), which, for example, under the The trade name Neo Heliopan AP is available from Symrise;

1,4-di (2-oxo-10-sulfo-3-bornylidenemethyl) benzene (also: 3,3 '- (1,4-phenylenedimethylene) -bis- (7,7-dimethyl-2-oxo-bicyclo- [ 2.2.1] hept-1-ylmethane sulfonic acid) and its salts (especially the corresponding 10-sulfato compounds, especially the corresponding sodium, potassium or triethanolammonium salt), which is also known as benzene-1,4-di (2-oxo-3-bornylidenemethyl-10-sulfonic acid). Benzene-1,4-di (2-oxo-3-bornylidenemethyl-10-sulfonic acid) has the INCI name Terephtalidene Dicampher Sulfonic Acid (CAS . No .: 90457-82-2) and is available, for example, under the trade name Mexoryl SX from Chimex;

Advantageous broadband filters are, for example, triazine derivatives, such as. B.

2.4-bis - {[4- (2-ethylhexyloxy) -2-hydroxy] -phenyl} -6- (4-methoxyphenyl) -1,3,5-triazine INCI: Aniso Triazine), which is sold under the trade name Tinosorb ® S is available from BASF. Proof of effectiveness:

The increased antioxidant effect of the active ingredient combinations according to the invention was determined as follows:

2,2-Diphenyl-1-picrylhydrazyl (DPPH ·) is a stable, commercially available radical with an absorption maximum at 524 nm. In the presence of antioxidants, DPPH · is reduced to the corresponding hydrazine derivative. Depending on the antioxidative capacity and the concentration of the examined antioxidant, this reaction leads to a discoloration of the DPPH ·. The resulting change in absorption can be followed spectrophotometrically. "Trolox" - a vitamin E derivative - is included as a high standard. The respective solvent control was defined as 100%. The lower the percentage result of the measurement, the better the antioxidant effect of the substance tested.

The following test solutions were created:

Final concentrations in the DPPH assay:

25 mM Trolox

25 pM (0.002%) or 50 pM (0.004%) ubiquinone

25 pM (0.002%) or 50 pM (0.004%) ubiquinol

0.01% xanthan gum

0.2% sclerotium gum

0.2% PAS80

0.01% carrageenan

The results are shown graphically in Figures 1-5.

FIG. 1 shows that only the reduced form of Q10, ubiquinol (Qh2), has an antioxidant effect.

FIG. 2 shows that the antioxidant effect of ubiquinol is weakened or canceled by interaction with xanthan gum. FIG. 3: shows that the antioxidant effect of ubiquinol is weakened or canceled by interaction with sclerotium gum.

FIG. 4 shows that the antioxidant effect of ubiquinol is weakened or canceled by interaction with PAS 80.

FIG. 5 shows that when ubiquinol (Qh2) is combined with the polymer carrageenan, the antioxidant effect of ubiquinol is largely retained.

The following examples are intended to illustrate the present invention without restricting it. Unless otherwise stated, all quantities, proportions and percentages are based on the weight and the total amount or the total weight of the preparations.

Taqe cream

O / W cream

Claims

1. Active ingredient combinations comprising a) one or more ubiquinols and b) carrageenan

2. Cosmetic or dermatological preparations with a content of such active substance combinations according to claim 1.

3. Active ingredient combinations according to claim 1 or preparations according to claim 2, in which the molar ratio of one or more ubiquinols to carrageenan is in the range from 1000: 1 to 1: 1000, preferably 100: 1 to 1: 100, especially preferably 50: 1 to 1:20 is selected.

4. Preparations according to claim 2 or 3, characterized in that one or more ubiquinols, in particular ubidecarenol, in concentrations of 0.001-10.00% by weight, preferably 0.005-5.00% by weight, particularly preferably 0 , 01 -

3.00% by weight, based in each case on the total weight of the composition, is or are present.

5. Preparations according to one of the preceding claims, characterized in that carrageenan in concentrations of 0.001-10.00% by weight, preferably 0.005-5.00% by weight, particularly preferably 0.01-3.00% by weight %, in each case based on the total weight of the composition, is or are present.

6. Use of active ingredient combinations according to claim 1 or 3 as antioxidants and / or as radical scavengers, in particular in cosmetic or dermatological preparations.