Aqueous cosmetic preparations containing alkylamidothiazoles

Abstract

The present invention relates to aqueous cosmetic preparations containing alkylamidothiazoles and Cellulose Gum and / or Hydroxypropyl Guar.

Description

[0001] Beiersdorf Aktiengesellschaft

[0002] Hamburg

[0003] Aqueous cosmetic preparations containing alkylamidothiazoles

[0004] The present invention relates to aqueous cosmetic and / or dermatological preparations containing alkylamidothiazoles.

[0005] A person's outward appearance can be influenced and enhanced through the use of cosmetic products. Regular use of cleansing and care products ensures that people feel attractive, beautiful, and comfortable in their surroundings, and radiate this outwards.

[0006] People use cosmetic care products for various reasons. One problem customers want to address is unwanted skin pigmentation, which is caused by melanocytes. These pigment-producing cells are located in the stratum basale, the lowest layer of the epidermis, and appear individually or in greater or lesser numbers, depending on skin type.

[0007] Melanocytes can produce the pigment melanin via their melanosomes. Melanin production can be stimulated by UV radiation, among other factors. Melanin is the product of an oxidative process. Here, tyrosine is converted by the enzyme tyrosinase, through various intermediate steps, into the brown to brownish-black eumelanins (DHICA and DHI melanin), or, when sulfur-containing compounds are involved, into the reddish pheomelanin. The melanin produced is then transported into the stratum corneum (corneocytes) of the epidermis, thus giving the skin its brownish to brownish-black color.

[0008] The two eumelanins, DHICA- and DHI-melanin, share the two intermediates donaquinone and donachrome. These two intermediates are also important in the formation of pheomelanin. The expression of melanin-synthesized enzymes is fundamentally controlled by a specific transcription factor (microphthalmia-associated transcription factor, MITF). In addition to the described enzymatic processes of melanin synthesis, other proteins are also important for melagnosis. The p-protein, among others, is thought to play a significant role, although its exact function is not yet fully understood. Besides melanin synthesis, the transfer of melanosomes, their retention in the epidermis, their degradation, and the breakdown of melanin are also crucial for skin pigmentation. The PAR-2 ​​receptor has been shown to play a fundamental role in the transport of melanosomes into keratinocytes (M. Seiberg et al., 2000, J. Cell. Sei)., 113:3093-101). Nevertheless, the appearance of the skin is also influenced by the size and shape of the individual melanosomes, as these affect light scattering. Accordingly, the skin of Black Africans exhibits more large, spheroidal, and solitary melanosomes, while Caucasians tend to have smaller melanosomes occurring in groups.

[0009] Hyperpigmentation of the skin can have various causes. It can occur as a side effect of many biological processes, such as UV radiation (e.g., freckles, ephelides), abnormal pigmentation of the skin during wound healing or scarring (post-inflammatory hyperpigmentation), or during skin aging (e.g., lentigines seniles).

[0010] Particularly after inflammatory reactions, the skin's pigmentation system can react with hyperpigmentation or hypopigmentation. These reactions frequently occur, for example, in atopic dermatitis, lupus erythematosus, and psoriasis. The appearance of dark circles under the eyes can also be considered a post-inflammatory hyperpigmentation. In these cases, however, the underlying inflammation is usually subclinical. Many hyperpigmentation reactions can be exacerbated by exposure to UV radiation.

[0011] To counteract hyperpigmentation, active ingredients and preparations are known that are essentially based on hydroquinone. However, these formulations and preparations are highly controversial because they can potentially cause irreversible changes to the skin's pigmentation system.

[0012] Furthermore, there are known skin-peeling methods, which, however, can lead to inflammation. This, in turn, can result in post-inflammatory hyperpigmentation.

[0013] Furthermore, other substances for skin lightening have already been described. These include, among others: hexadecene-1,16-dicarboxylic acid, kojic acid, arbutin, ascorbic acid and its derivatives, flavonoids, and various resorcinol derivatives, such as 4-n-butylresorcinol, 4-n-heylresorcinol, and 4-(1-phenylethyl)benzene-1,3-diol.

[0014] In a publication (Bioorganic & Medicinal Chemistry Letter 17 (2007) 6871-6875), JM Ready describes the effect of substituted thiazole derivatives on the inhibition of mushroom tyrosinase. Furthermore, substituted thiazolamines and hydrothiazolamines are described for skin lightening in publication WO 2009099195.

[0015] The majority of skincare products are typically emulsions. These are heterogeneous systems that are blended together using emulsifiers, resulting in a homogeneous emulsion. However, customers are also interested in other application methods for skincare. Particularly when addressing hyperpigmentation, customers prefer targeted application. In addition to classic emulsions, professionals are also familiar with aqueous cosmetic preparations, especially serums, which are used for skincare.

[0016] A serum is a thin, low-viscosity product applied directly to the skin, containing a high concentration of active ingredients. Serums are water-based and have a gel-like or aqueous consistency that is quickly absorbed into the skin. Their high surface tension allows for precise application of individual drops to specific areas of the skin.

[0017] To achieve the desired texture of a serum from an aqueous solution, thickeners are added to the preparations. Consumers increasingly prefer cosmetic preparations based on sustainable ingredients, which is why biopolymers are being used more frequently as thickeners.

[0018] If active ingredients are to be incorporated into a cosmetic preparation and be able to exert their full effect, it must be ensured that they are made bioavailable at an effective concentration. In aqueous preparations, especially serums, it is therefore not a problem to incorporate water-soluble active ingredients.

[0019] However, the incorporation of poorly water-soluble active ingredients, such as alkylamidothiazoles, into aqueous preparations, especially serums, presents a challenge. Issues such as odor stability or light stability of the active ingredient can frequently arise. Another problem is that active ingredients like alkylamidothiazoles tend to crystallize in aqueous cosmetic preparations, thus affecting the quality of the preparation. If an active ingredient is affected by crystallization, this also impacts the product's efficacy, as the bioavailability of the active ingredient is reduced.

[0020] Stabilizing active ingredients in emulsions has the advantage of providing lipophilic and hydrophilic components, which enable the solubility of both lipophilic and hydrophilic active ingredients. In lipophobic systems, such as water-based serums, the incorporation of lipophilic active ingredients, especially at high concentrations, is galenically challenging. To ensure this, very high concentrations of solubilizers and / or ethanol must be added. A high proportion of solubilizers has clearly perceptible sensory disadvantages for the consumer, and the use of high amounts of ethanol (>6%) is also undesirable for the consumer for sensory reasons. Furthermore, there is a demand, particularly from consumers with sensitive, dry skin, for ethanol-free formulations. There is a fundamental need for ethanol-free preparations containing non-water-soluble active ingredients, such as alkylamidothiazoles.

[0021] One object of the present invention was to eliminate the disadvantages of the prior art. Consequently, it was an object of the present invention to provide aqueous cosmetic preparations with a low viscosity which stabilize active ingredients that tend to crystallize.

[0022] Another object of the present invention was to provide aqueous cosmetic preparations with a low viscosity which serve to lighten human skin.

[0023] Surprisingly for those skilled in the art, it has now been found that the problem of crystallization of alkylamidothiazoles in aqueous cosmetic preparations with low viscosity could be solved by the present invention.

[0024] The present invention relates to an aqueous cosmetic and / or dermatological preparation containing

[0025] a) One or more alkylamidothiazoles; and

[0026] b) Cellulose gum and / or hydroxypropyl guar.

[0027] Another object of the present invention is an aqueous cosmetic and / or dermatological preparation containing a) one or more alkylamidothiazoles; and

[0028] b) Cellulose Gum.

[0029] Another object of the present invention is an aqueous cosmetic and / or dermatological preparation containing

[0030] a) One or more alkylamidothiazoles; and

[0031] b) Hydroxypropyl Guar.

[0032] Another object of the invention is the use of the aqueous cosmetic and / or dermatological preparation according to the invention for lightening human skin.

[0033] If this disclosure provides information on the crystallization of active ingredients, all information refers to measurements taken using crossed polarization microscopy with an Olympus BX53 microscope. For the measurements, the preparations were first manufactured and then stored at room temperature (normal conditions) for 24 hours until microscopy. Subsequently, microscopic images were taken with the aforementioned microscope (at 20x magnification, at room temperature) and the images were evaluated.

[0034] Where weight percentages (wt%) are given below without reference to a specific composition or mixture, these percentages always refer to the total weight of the cosmetic cleansing preparation. Where ratios of components / substances / groups of substances are disclosed below, these ratios refer to the weight ratios of the components / substances / groups of substances mentioned.

[0035] The terms “according to the invention”, “advantageous according to the invention”, “advantageous in the sense of the present invention”, etc., always refer, within the scope of the present disclosure, to both the preparation according to the invention and the use according to the invention.

[0036] Unless otherwise stated, all tests were conducted under standard conditions. "Standard conditions" means 20°C, 1013 hPa, and a relative humidity of 50%.

[0037] When the term skin is used, it refers primarily to human skin. Unless otherwise described in this disclosure, emulsifiers are defined as follows:

[0038] Emulsifiers are defined as all substances listed as "emulsifying agents" in the International Cosmetic Ingredient Dictionary and Handbook, Thirteenth Edition 2010 (ISBN 1-882621-47-6). Surfactants are defined as all substances listed as "surfactants" in the International Cosmetic Ingredient Dictionary and Handbook, Thirteenth Edition 2010 (ISBN 1-882621-47-6).

[0039] Aqueous cosmetic and / or dermatological preparations, particularly serums, are preferably characterized by their low viscosity. The aqueous preparation of the present invention is advantageously characterized by having a viscosity of less than 5000 mPa s under normal conditions, more preferably less than 3000 mPa s, and particularly preferably less than 1500 mPa s. Furthermore, it is advantageous if the aqueous preparation has a viscosity of at least 1 mPa s, more preferably at least 10 mPa s, and particularly preferably at least 30 mPa s. Accordingly, the viscosity of the aqueous cosmetic and / or dermatological preparation is advantageously 1 to 5000 mPa s, more preferably 10 to 3500 mPa s, and particularly preferably 30 mPa s to 1500 mPa s.

[0040] It was surprisingly found that the use of the invention makes it possible to obtain preparations which exhibit a low viscosity and stabilize alkylamidothiazoles in aqueous cosmetic and / or dermatological preparations.

[0041] Any viscosity values ​​given in this disclosure refer to measurements taken at 25°C in a 150 ml wide-mouth bottle (VWR No.: 807-001) using the Rheomat R 123 from proRheo. The Rheomat R 123 from proRheo GmbH is a rotational viscometer, meaning that a measuring element rotates within the substance being measured in a stationary measuring vessel. The force required to rotate the measuring element in the sample at a predetermined speed is measured. The viscosity is then calculated from this torque, the rotational speed of the measuring element, and the geometric dimensions of the measuring system. The measuring element used is No. 1 (article no. 2000191), suitable for a viscosity range up to 10,000 mPa s, with a rotational speed of 62.5 rpm. -1 , used. Viscosity was always measured 24 hours after preparation.

[0042] The preparation according to the invention is characterized in that it contains alkylamidothiazoles. Advantageous alkylamidothiazoles within the meaning of the present invention are substances having the general structural formula shown below.

[0043]

[0044] at which

[0045] R 1 , R 2 , X and Y can be different, partially the same or completely the same and can mean independently of each other:

[0046] R 1= -Ci-C24-Alkyl (linear and branched), -Ci-C24-Alkenyl (linear and branched), -Ci-Cs-Cycloalkyl, -Ci-Cs-Cycloalkyl-Alkylhydroxy, -C1-C24 Alkylhydroxy (linear and branched), -C1-C24 Alkylamine (linear and branched), -Ci-C24-Alkylaryl (linear and branched), -Ci-C24-Alkylaryl-Alkyl-Hydroxy (linear and branched), -Ci-C24-Alkylheteroaryl (linear and branched), -C1-C24-Alkyl-O-Ci-C24-Alkyl (linear and branched), -C1-C24 Alkyl-Morpholino, -C1-C24 Alkyl-Piperidino, -C1-C24 Alkyl-Piperazino, -C1-C24 Alkyl-piperazino-N-alkyl means,

[0047] R 2 = -H, -Ci-C24-Alkyl (linear and branched), -Ci-C24-Alkenyl (linear and branched), -Ci-Cs-Cycloalkyl, -Ci-C24-Hydroxyalkyl (linear and branched), -Ci-C24-Alkylaryl (linear and branched), -Ci-C24-Alkylheteroaryl (linear and branched), means,

[0048] X = -H, -Ci-C24-alkyl (linear and branched), -Ci-C24-alkenyl (linear and branched), -Ci-Cs-cycloalkyl, -Ci-C24-aryl (possibly singly or multiply substituted with -OH, -F, -CI, -Br, -I, -OMe, -NH2, -CN), -Ci-C24-heteroaryl (possibly singly or multiply substituted with -OH, -F, -CI, -Br, -I, -OMe, -NH2, -CN), -Ci-C24-alkylaryl (linear and branched), -Ci-C24-alkylheteroaryl (linear and branched), -aryl (possibly singly or multiply substituted with -OH, -F, -CI, -Br, -I, -OMe, -NH2, -CN), -phenyl, -2,4-dihydroxyphenyl, -2,3-dihydroxyphenyl, -2,4-dimethoxyphenyl, -2,3-dimethoxyphenyl means,

[0049] Y = -H, -Ci-C24-Alkyl (linear and branched), -Ci-C24-Alkenyl (linear and branched), -Ci-Cs-Cycloalkyl, -Ci-C24-Aryl, -Ci-C24-Heteroaryl, -Ci-C24-Alkylaryl (linear and branched), -C1-C24-Alkylheteroaryl (linear and branched), -Aryl, -phenyl, -2,4-dihydroxyphenyl, -2,3-dihydroxyphenyl, -2,4-Dimethoxyphenyl, -2,3-Dimethoxyphenyl, -COO-Alkyl, -COO-Alkenyl, -COO-Cycloalkyl, -COO-Aryl, -COO-Heteroaryl, means,

[0050] and X, Y may also mean = condensed aromatic compound,

[0051] wherein X and Y can form aromatic or aliphatic homo- or heterocyclic ring systems with up to n ring-forming atoms, and wherein the number n can take values ​​from 5 to 8, and the respective ring systems can in turn be substituted with up to n - 1 alkyl groups, hydroxyl groups, carboxyl groups, amino groups, nitrile functions, sulfur-containing substituents, ester groups and / or ether groups.

[0052] The aforementioned thiazoles can exist both as free bases and as salts: e.g., as fluoride, chloride, bromide, iodide, sulfate, carbonate, ascorbate, acetate, or phosphate. In particular, they exist as halogen salts, such as chloride and bromide.

[0053] Furthermore, an advantageous realization of the present invention consists in cosmetic or dermatological preparations containing an effective amount of one or more of the aforementioned alkylamidothiazoles.

[0054] According to the invention, the aforementioned alkylamidothiazoles are also used for the treatment and / or prophylaxis of unwanted skin pigmentation. This treatment and / or prophylaxis of unwanted skin pigmentation can be carried out in both cosmetic and pharmaceutical contexts.

[0055] Pharmaceutical (or dermatological) treatment is primarily understood to refer to pathological skin conditions, whereas cosmetic treatment and / or prophylaxis of unwanted skin pigmentation primarily concerns healthy skin.

[0056] Advantageously, X is chosen from the group of substituted phenyls, where the substituents (Z) can be chosen from the group -H, -OH, -F, -CI, -Br, -I, -OMe, -NH2, -CN, Acetyl and can be the same or different.

[0057]

[0058] Particularly advantageous is X chosen from the group of phenyl groups substituted with one or more hydroxy groups, wherein the substituent (Z) can be chosen from the group -H, -OH, -F, -CI, -Br, -I, -OMe, -NH2, -CN, Acetyl and the following generic structure is preferred, in which Y, R 1 and R 2 which may have the aforementioned properties.

[0059]

[0060] Connections are particularly advantageous in which

[0061]

[0062] Y = H

[0063] R 1 = -Ci-C24-Alkyl (linear and branched), -Ci-C24-Alkenyl (linear and branched), -Ci-Cs-Cycloalkyl, -Ci-Cs-Cycloalkyl-Alkylhydroxy, -Ci-C24 Alkylhydroxy (linear and branched), -Ci-C24 Alkylamine (linear and branched), -Ci-C24-Alkylaryl (linear and branched), -Ci-C24-Alkylaryl-Alkyl-Hydroxy (linear and branched), -Ci-C24-Alkylheteroaryl (linear and branched), -Ci-C24-Alkyl-O-Ci-C24-Alkyl (linear and branched), -Ci-C24 Alkyl-Morpholino, -Ci-C24 Alkyl-Piperidino, -Ci-C 24 Alkyl-Piperazino, -Ci-C24 Alkyl-Piperazino-N-Alkyl means,

[0064] R 2 = -H, -Ci-C24-Alkyl (linear and branched),

[0065] Z = -H, -OH, -F, -Cl, -Br, -I, -OMe, -NH2, -CN, acetyl.

[0066] Particularly preferred are those connections in which

[0067]

[0068] Y = HR 1 = -Ci-C24-Alkyl (linear and branched), -Ci-C24-Alkenyl (linear and branched), -Ci-Cs-Cycloalkyl, -Ci-Cs-Cycloalkyl-Alkylhydroxy, -C1-C24 Alkylhydroxy (linear and branched), -C1-C24 Alkylamine (linear and branched), -Ci-C24-Alkylaryl (linear and branched), -Ci-C24-Alkylaryl-Alkyl-Hydroxy (linear and branched), -Ci-C24-Alkylheteroaryl (linear and branched), -C1-C24-Alkyl-O-Ci-C24-Alkyl (linear and branched), -C1-C24 Alkyl-Morpholino, -C1-C24 Alkyl-Piperidino, -C1-C24 Alkyl-Piperazino, -C1-C24 Alkyl-piperazino-N-alkyl means,

[0069] R 2 = -H.

[0070] According to the invention, the connections are preferred.

[0071]

[0072] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)pivalamide

[0073]

[0074] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)isobutyramide

[0075]

[0076] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)butyramide

[0077]

[0078] A / -(4-(2,4-dihydroxyphenyl)thiazol-2-yl)heptanamide

[0079]

[0080] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-6-hydroxyhexanamide

[0081]

[0082] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-3-hydroxypropanamide

[0083]

[0084] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-2-methoxyacetamide

[0085]

[0086] 3-amino- / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)propanamide

[0087]

[0088] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)acetamide

[0089]

[0090] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-4-(hydroxymethyl)cyclohexane-1 -carboxamide

[0091]

[0092] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)cyclohexanecarboxamide

[0093] and

[0094]

[0095] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-2-(4-(hydroxymethyl)phenyl)acetamide

[0096] The connection is particularly preferred

[0097]

[0098] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)isobutyramide

[0099] The above alkylamidothiazoles, their synthesis and their use were described in EP2758381A1.

[0100] It is particularly advantageous if the preparations contain 0.000001 to 10 wt.%, in particular 0.0001 to 3 wt.%, and most especially 0.001 to 1 wt.% of one or more of the alkylamidothiazoles used according to the invention, based on the total weight of the preparation.

[0101] The preparation according to the invention is characterized in that it contains water. Furthermore, it is advantageous if the aqueous cosmetic preparation according to the present invention contains water as a cosmetic carrier, wherein water is present in a proportion of at least 55% by weight, preferably at least 60% by weight, and particularly preferably at least 65% by weight, based on the total weight of the preparation.

[0102] According to the invention, the preparation advantageously comprises cellulose gum and / or hydroxypropyl guar. If cellulose gum and / or hydroxypropyl guar are included, it is advantageous if the proportion of cellulose gum and / or hydroxypropyl guar is from 0.001 wt.% to 2.0 wt.%, preferably from 0.01 wt.% to 1.0 wt.%, and particularly preferably from 0.05 wt.% to 0.7 wt.% based on the total weight of the preparation.

[0103] According to the invention, the preparation advantageously comprises cellulose gum. If cellulose gum is included, it is advantageous if the proportion of cellulose is from 0.001 wt.% to 2.0 wt.%, preferably from 0.01 wt.% to 1.0 wt.% and particularly preferably from 0.05 wt.% to 0.7 wt.% based on the total weight of the preparation.

[0104] According to the invention, the preparation advantageously comprises hydroxypropyl guar. If hydroxypropyl guar is included, it is advantageous if the proportion of hydroxypropyl guar is from 0.001 wt.% to 2.0 wt.%, preferably from 0.01 wt.% to 1.0 wt.%, and particularly preferably from 0.05 wt.% to 0.7 wt.% based on the total weight of the preparation.

[0105] It can be advantageous to avoid other substances that increase the viscosity of aqueous preparations ("thickeners"). In particular, it is advantageous to avoid synthetic thickeners, such as polyacrylates or crosspolymers, which increase the viscosity of aqueous preparations.

[0106] The preparation according to the invention can advantageously contain one or more polyols. Polyols are chemical compounds that contain at least two hydroxyl groups. Therefore, polyols belong to the group of polyhydric alcohols.

[0107] Advantageously, at least one polyol is selected from the group consisting of 1,3-propylene glycol, 1,2-propylene glycol, dipropylene glycol, butylene glycol (INCI: Butylene Glycol), ethylene glycol, methylpropanediol (INCI: Methylpropanediole), panthenol, ethylhexylglycerin, 1,2-octanediol (INCI: Caprylyl Glycol), pentane glycol (INCI: Pentylene Glycol), and 1,2-hexanediol (INCI: 1,2-Hexanediol).

[0108] Particularly advantageous in the sense of the present invention is the selection of at least one polyol from the compounds: 1,3-propylene glycol, dipropylene glycol, methylpropanediol, 1,2-hexanediol, butylene glycol, 1,2-propylene glycol, pentylene glycol and / or caprylyl glycol.

[0109] Furthermore, it is advantageous in the sense of the invention if the total proportion of polyols, in particular of the polyols previously listed as particularly advantageous, in the preparation according to the invention is 0.5 to 30 wt.%, preferably 1 wt.% to 20 wt.% and particularly preferably 2 to 10 wt.% based on the total weight of the preparation.

[0110] Another preferred embodiment of the invention is characterized in that methylpropanediol is contained in the preparation according to the invention in a proportion of 0.5 to 6 wt.%, preferably 1 to 5 wt.% and particularly preferably 2 to 4 wt.% based on the total weight of the cleaning preparation.

[0111] Another preferred embodiment of the invention is characterized in that dipropylene glycol is contained in the preparation according to the invention in a proportion of 0.5 to 10 wt.%, preferably 1 to 7 wt.% and particularly preferably 2 to 5 wt.% based on the total weight of the cleaning preparation.

[0112] Another preferred embodiment of the invention is characterized in that 1,2-propylene glycol is contained in the preparation according to the invention in a proportion of 0.5 to 10 wt.%, preferably 1 to 7 wt.% and particularly preferably 2 to 6 wt.% based on the total weight of the cleaning preparation.

[0113] Another preferred embodiment of the invention is characterized in that 1,3-propylene glycol is contained in the preparation according to the invention in a proportion of 0.5 to 10 wt.%, preferably 1 to 7 wt.% and particularly preferably 2 to 5 wt.% based on the total weight of the cleaning preparation.

[0114] Another preferred embodiment of the invention is characterized in that butylene glycol is contained in the preparation according to the invention in a proportion of 0.5 to 12 wt.%, preferably 2 to 10 wt.% and particularly preferably 4 to 6 wt.% based on the total weight of the cleaning preparation.

[0115] Another preferred embodiment of the invention is characterized in that pentylene glycol is contained in the preparation according to the invention in a proportion of 0.05 to 1 wt.%, preferably 0.1 to 0.8 wt.% and particularly preferably 0.1 to 0.6 wt.% based on the total weight of the cleaning preparation.

[0116] The preparation according to the invention may advantageously contain glycerin. If glycerin is included, it is advantageous if the proportion of this component is between 2.0 wt.% and 15.0 wt.%, preferably between 3.0 wt.% and 12.0 wt.%, and particularly preferably between 3.5 wt.% and 8.0 wt.%, based on the total weight of the hydrodispersion preparation. The preparation according to the invention may advantageously contain preservatives. Preservatives are those preservative substances that are authorized for use in cosmetic products in accordance with the German Cosmetics Regulation and Regulation (EC) No. 1223 / 2009 on cosmetic products for use in cosmetic products in Europe.

[0117] Furthermore, it is preferred in accordance with the present invention if the preparation contains ethanol in a proportion of less than 4 wt.%, preferably less than 1 wt.% and particularly preferably 0 wt.%.

[0118] The at least one preservative can advantageously be selected from the group consisting of hydroxyacetophenones, phenoxyethanol, sodium benzoate (INCI: Sodium Benzoate) and / or benzyl alcohol (INCI: Benzyl Alcohol). Advantageously, the proportion of the at least one preservative, in particular the preservatives previously listed as particularly advantageous, in the preparation according to the invention is 0.1 wt.% to 2.0 wt.%, preferably 0.2 wt.% to 1.5 wt.%, and particularly preferably 0.4 wt.% to 1.1 wt.%, based on the total weight of the cleaning preparation.

[0119] A preferred embodiment of the invention is characterized in that phenoxyethanol is contained in the cosmetic preparation according to the invention in a proportion of 0.1 wt.% to 2.0 wt.%, preferably 0.2 wt.% to 1.5 wt.% and particularly preferably 0.4 wt.% to 1.1 wt.%, based on the total weight of the preparation.

[0120] Furthermore, the preparation according to the invention may advantageously contain at least one antioxidant selected from the group consisting of tocopherol, ethyl ascorbic acid, diethylhexyl syringylidene malonate (and) caprylic / capric triglyceride and / or tocopherol (and) Helianthus annuus (sunflower) seed oil.

[0121] A preferred embodiment of the invention is characterized in that ethyl ascorbic acid is present in the preparation according to the invention in a proportion of 0.1 wt.% to

[0122] 2.0 wt.%, preferably from 0.2 wt.% to 1.5 wt.% and particularly preferably from 0.4 wt.% to 1.1 wt.%, based on the total weight of the preparation.

[0123] Furthermore, it has proven advantageous in accordance with the invention if the preparations exhibit a pH value of 3.9 to 8.0, preferably 4.0 to 7.0, and particularly preferably 4.2 to 6.5. Comparative tests and examples

[0124] The following examples are intended to illustrate the present invention without limiting it. Unless otherwise stated, all quantities, proportions, and percentages are based on the weight and total quantity or total weight of the preparations.

[0125] The following formulations were prepared for the comparative tests. Formulations Example 1 and Example 2 are according to the invention, while Examples 3 to 9 are not.

[0126]

[0127]

[0128] true.

[0129] The hydrodispersion preparations listed above were prepared and their properties were investigated in a comparative experiment with regard to the crystallization of alkylamidothiazoles. For hydrodispersions according to the invention, it was shown that the preparations exhibited no crystallization after a time of 24 h. In contrast, hydrodispersions not according to the invention showed the formation of alkylamidothiazole crystals after 24 h.

[0130] The following examples are intended to further illustrate the invention without limiting it:

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

Claims

Patent claims 1. Aqueous cosmetic and / or dermatological preparation containing a. One or more alkylamidothiazoles b. Cellulose gum and / or hydroxypropyl guar.

2. Preparation according to claim 1, characterized in that the content of alkylamidothiazoles is from 0.000001 to 10.0 wt.%, preferably from 0.0001 to 3.0 wt.% and in particular preferably from 0.001 to 1.0 wt.% based on the total weight of the cosmetic cleaning preparation.

3. Preparation according to one of the preceding claims, characterized in that the alkylamidothiazole(s) are substances of the general formula is or are, at which R 1 , R 2 X and Y can be different, partially the same, or completely the same, and can mean things independently of each other: R 1= -Ci-C24-Alkyl (linear and branched), -Ci-C24-Alkenyl (linear and branched), -Ci-Cs- Cycloalkyl, -Ci-Cs-Cycloalkyl-Alkylhydroxy, -C1-C24 Alkylhydroxy (linear and branched), -C1-C24 Alkylamine (linear and branched), -Ci-C24-Alkylaryl (linear and branched), -C1-C24-Alkylaryl-Alkyl-Hydroxy (linear and branched), -Ci-C24-Alkylheteroaryl (linear and branched), -Ci-C24-Alkyl-O-Ci-C24-Alkyl (linear and branched), -C1-C24 Alkyl-Morpholino, -C1-C24 Alkyl-Piperidino, -C1-C24 Alkyl-Piperazino, -C1-C24 Alkyl-piperazino-N-alkyl means, R 2 = H, -Ci-C24-Alkyl (linear and branched), -Ci-C24-Alkenyl (linear and branched), -Ci-Cs-Cycloalkyl, -Ci-C24-Hydroxyalkyl (linear and branched), -Ci-C24-Alkylaryl (linear and branched), -Ci-C24-Alkylheteroaryl (linear and branched), means, X = -H, -Ci-C24-alkyl (linear and branched), -Ci-C24-alkenyl (linear and branched), -Ci-Cs-cycloalkyl, -Ci-C24-aryl (possibly singly or multiply substituted with -OH, -F, -CI, -Br, -I, -OMe, -NH2, -CN), -Ci-C24-heteroaryl (possibly singly or multiply substituted with -OH, -F, -CI, -Br, -I, -OMe, -NH2, -CN), -Ci-C24-alkylaryl (linear and branched), -Ci-C24-alkylheteroaryl (linear and branched), -aryl (possibly singly or multiply substituted with -OH, -F, -CI, -Br, -I, -OMe, -NH2, -CN), -phenyl, -2,4-dihydroxyphenyl, -2,3-dihydroxyphenyl, -2,4-dimethoxyphenyl, -2,3-dimethoxyphenyl means, Y = H, -Ci-C24-Alkyl (linear and branched), -Ci-C24-Alkenyl (linear and branched), -C1-Cs-Cycloalkyl, -Ci-C24-Aryl, -Ci-C24-Heteroaryl, -Ci-C24-Alkylaryl (linear and branched), -Ci-C24-Alkylheteroaryl (linear and branched), -Aryl, -phenyl, -2,4-dihydroxyphenyl, -2,3-dihydroxyphenyl, -2,4-Dimethoxyphenyl, -2,3-Dimethoxyphenyl, -COO-Al-kyl, -COO-Alkenyl, -COO-Cycloalkyl, -COO-Aryl, -COO-Heteroaryl, means, The alkylamidothiazoles can exist both as a free base and as salts that can be used cosmetically and / or dermatologically.

4. Preparation according to one of the preceding claims, characterized in that the alkylamidothiazole(s) have the following structures: / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)pivalamide / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)isobutyramide / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)butyramide A / -(4-(2,4-dihydroxyphenyl)thiazol-2-yl)heptanamide / \ / -(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-6-hydroxyhexanamide / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-3-hydroxypropanamide / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-2-methoxyacetamide 3-amino- / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)propanamide / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)acetamide / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-4-(hydroxymethyl)cyclohexane-1 -carboxamide / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)cyclohexanecarboxamide und / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-2-(4-(hydroxymethyl)phenyl)acetamide 5. Preparation according to one of the preceding claims, characterized in that the alkylamidothiazole(s) may be present as halide, carbonate, ascorbate, sulfate and / or phosphate.

6. Preparation according to one of the preceding claims, characterized in that it contains cellulose gum, wherein it is further preferred that the total proportion of cellulose gum is 0.001 wt.% to 2.0 wt.%, preferably 0.01 wt.% to 1.0 wt.% and particularly preferably 0.05 wt.% to 0.7 wt.%, based on the total weight of the preparation.

7. Preparation according to any one of the preceding claims, characterized in that it contains hydroxypropyl guar, wherein it is further preferred that the total proportion of cellulose gum is from 0.001 wt.% to 2.0 wt.%, preferably 0.01 wt.% to 1.0 wt.% and particularly preferably 0.05 wt.% to Contains 0.7% by weight, based on the total weight of the preparation.

8. Preparation according to one of the preceding claims, characterized in that the preparation contains one or more polyols selected from the group consisting of 1,3-propylene glycol, 1,2-propylene glycol, dipropylene glycol, butylene glycol (INCI: Butylene Glycol), ethylene glycol, methylpropanediol (INCI: Methylpropanediole), panthenol, ethylhexylglycerin, 1,2-octanediol (INCI: Caprylyl Glycol), pentane glycol (INCI: Pentylene Glycol), 1,2-hexanediol (INCI: 1,2-Hexanediol).

9. Preparation according to one of the preceding claims characterized in that the total proportion of the polyols contained is from 0.5 to 30 wt.%, preferably from 1 wt.% to 20 wt.% and particularly preferably from 2 to 10 wt.% based on the total weight of the preparation.

10. Preparation according to one of the preceding claims, characterized in that the total proportion of water is at least 55 wt.%, preferably at least 60 wt.%, and particularly preferably at least 65 wt.%, based on the total weight of the preparation.

11. Preparation according to one of the preceding claims, characterized in that it contains ethanol in a proportion of less than 4 wt.%, preferably less than 1 wt.% and particularly preferably 0 wt.%.

12. Preparation according to one of the preceding claims, characterized in that the preparation has a viscosity of 1 mPa s to 5000 mPa s, preferably 10 mPa s to 3000 mPa s and particularly preferably of 30 mPa s to 1500 mPa s.

13. Preparation according to one of the preceding claims, characterized in that it has a pH value of 3.9 to 8.0, preferably of 4.0 to 7.0, particularly preferably of 4.2 to 6.

5.

14. Use of the preparation according to any of the preceding claims for lightening human skin.

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