Aqueous cosmetic preparations containing an active ingredient combination of alkylamidothiazoles and niacinamide

Abstract

The present invention relates to aqueous cosmetic and / or dermatological preparations containing alkylamidothiazoles and niacinamide.

Description

[0001] Beiersdorf Aktiengesellschaft

[0002] Hamburg

[0003] Active ingredient combination of alkylamidothiazoles and niacinamide and aqueous cosmetic preparations containing these

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

[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. The condition and appearance of the skin plays a significant role in a beautiful and attractive appearance.

[0006] A common problem affecting skin condition and appearance is hyperpigmentation, which can arise from a variety of causes or accompanying phenomena of many biological processes, such as UV radiation (e.g., freckles, ephelides), genetic predisposition, abnormal pigmentation of the skin during wound healing or scarring (post-inflammatory hyperpigmentation), or skin aging (e.g., lentigines seniles). Melanocytes are responsible for hyperpigmentation. These pigment-producing cells are located in the stratum basale, the deepest layer of the epidermis, and occur individually or in greater or lesser numbers, depending on skin type.

[0007] To counteract hyperpigmentation, alkylamidothiazole derivatives are known, for example, for the cosmetic or dermatological treatment and / or prophylaxis of unwanted skin pigmentation, as described in WO 2013041526 A1.

[0008] Furthermore, DE 102013204110 A1 also describes a variety of cosmetic preparations for the skin care of human skin containing alkylamidothiazoles.

[0009] Experts are familiar with a wide variety of cosmetic preparations containing alkylamidothiazoles. However, this should not obscure the fact that numerous problems can arise during the formulation of cosmetic and / or dermatological preparations, such as the solubility of alkylamidothiazoles, crystallization, odor stability, and color stability. If active ingredients like alkylamidothiazoles are to be incorporated into a cosmetic preparation and exert their full efficacy, it must be ensured that they are bioavailable at an effective concentration. This requires guaranteeing the solubility of alkylamidothiazoles. The incorporation of poorly water-soluble active ingredients like alkylamidothiazoles presents a particular challenge. Problems such as odor stability or light stability of the active ingredient can frequently occur.Another problem is that active ingredients such as alkylamidothiazoles tend to crystallize in cosmetic and / or 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.

[0010] Stabilizing active ingredients in emulsions offers the advantage of containing both lipophilic and hydrophilic components, thus enabling the solubility of these active ingredients. In lipophobic systems, such as water-based serums, the incorporation of lipophilic active ingredients, especially at high concentrations, presents a significant galenic challenge. To achieve this, very high concentrations of solubilizers and / or ethanol must be added. A high proportion of solubilizers has clearly perceptible sensory drawbacks for consumers, and the use of high amounts of ethanol (>6%) is also undesirable for consumers due to sensory considerations. Furthermore, there is a demand, particularly from consumers with sensitive, dry skin, for ethanol-free formulations. There is a fundamental need for new solubilizers for alkylamidothiazoles in cosmetic and / or dermatological preparations.

[0011] Niacinamide is a well-known ingredient in cosmetic products. Niacinamide is the amide of nicotinic acid, also known as vitamin B, and belongs to the group of water-soluble vitamins. In the body, niacinamide exists in equilibrium with nicotinic acid and plays a role in cellular metabolic processes as part of the coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). Niacinamide is used in cosmetic and / or dermatological preparations due to its conditioning properties, which have a positive effect on the appearance of dry skin. Niacinamide influences ceramide synthesis in the skin barrier, thus helping to stabilize it.

[0012] Those skilled in the art are familiar with EP2968100 B1, which discloses cosmetic and / or dermatological preparations containing a combination of alkylamidothiazoles and niacinamide. However, the amounts of niacinamide used did not provide any indication of the present invention. Moreover, the preparations in question are oil-in-water emulsions, which, due to their oil phase, facilitate the incorporation of hydrophobic active ingredients such as alkylamidothiazoles.

[0013] 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.

[0014] Another object of the present invention was to provide aqueous cosmetic preparations with a low viscosity which serve to lighten human skin.

[0015] 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.

[0016] The present invention relates to an aqueous cosmetic and / or dermatological preparation containing

[0017] a) One or more alkylamidothiazoles; and

[0018] b) Niacinamide, wherein the niacinamide content is from 5.0 wt.% to 22.0 wt.% based on the total weight of the preparation.

[0019] Another object of the invention is the use of the aqueous cosmetic and / or dermatological preparation according to the invention for lightening human skin.

[0020] If this disclosure contains 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. Should any weight percentages (wt%) be given below without reference to a specific composition or mixture, these always refer to the total weight of the cosmetic cleansing preparation.Should ratios of components / substances / groups of substances be disclosed below, these ratios refer to weight ratios of the mentioned components / substances / groups of substances.

[0021] 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.

[0022] Unless otherwise stated, all tests were conducted under standard conditions. "Standard conditions" means 20°C, 1013 hPa, and a relative humidity of 50%.

[0023] When the term skin is used, it preferably refers to human skin.

[0024] Unless otherwise described in this disclosure, emulsifiers are defined as follows:

[0025] 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).

[0026] Where weight percentage ranges for the components of the preparation are specified below, the disclosure of the present application also includes all individual values ​​in steps of 0.1 wt.% within these weight percentage ranges.

[0027] The active ingredient combination 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 as follows.

[0028]

[0029] at which

[0030] R 1 , R 2 , X and Y can be different, partially the same or completely the same and can mean independently of each other:

[0031] 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,

[0032] 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,

[0033] 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,

[0034] 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-dihydrohydroxyphenyl, -2,4-Dimethoxyphenyl, -2,3-Dimethoxyphenyl, -COO-Alkyl, -COO-Alkenyl, -COO-Cycloalkyl, -COO-Aryl, -COO-Heteroaryl, means,

[0035] and X, Y may also mean = condensed aromatic compound,

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042]

[0043] 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. Especially such compounds in which

[0044]

[0045] Y= H

[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),

[0048] Z = -H, -OH, -F, -CI, -Br, -I, -OMe, -NH2, -CN, acetyl.

[0049] Particularly preferred are those connections in which

[0050]

[0051] Y= H

[0052] 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,R 2 = -H.

[0053] According to the invention, the connections are preferred.

[0054]

[0055] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)pivalamide

[0056]

[0057] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)isobutyramide

[0058]

[0059] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)butyramide

[0060]

[0061] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)heptanamide

[0062]

[0063] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-6-hydroxyhexanamide

[0064]

[0065] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-3-hydroxypropanamide

[0066]

[0067] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-2-methoxyacetamide

[0068]

[0069] 3-amino- / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)propanamide

[0070]

[0071] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)acetamide

[0072]

[0073] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-4-(hydroxymethyl)cyclohexane-1 -carboxamide

[0074]

[0075] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)cyclohexanecarboxamide

[0076] and

[0077]

[0078] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)-2-(4-(hydroxymethyl)phenyl)acetamide

[0079] The connection is particularly preferred

[0080]

[0081] / V-(4-(2,4-dihydroxyphenyl)thiazol-2-yl)isobutyramide

[0082] The above alkylamidothiazoles, their synthesis and their use were described in EP2758381A1.

[0083] It is particularly advantageous if the aqueous preparations contain unencapsulated alkylamidothiazoles.

[0084] 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.

[0085] According to the invention, the aqueous cosmetic and / or dermatological preparation advantageously comprises niacinamide. If niacinamide is included, it is advantageous if the proportion of niacinamide is 5.0 wt.% to 22.0 wt.%, preferably 6.0 wt.% to 15.0 wt.%, and particularly preferably 7.5 wt.% to 10.0 wt.% based on the total weight of the preparation.

[0086] In a preferred embodiment of the invention, the weight ratio of niacinamide to one or more alkylamidothiazoles is from 25:1 to 120:1, preferably 45:1 to 100:1 and particularly preferably 50:1 to 65:1.

[0087] Aqueous cosmetic and / or dermatological preparations, particularly serums, are preferred, 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 30 mPa s, and particularly preferably at least 50 mPa s. Accordingly, the viscosity of the aqueous cosmetic and / or dermatological preparation is advantageously 1 to 5000 mPa s, more preferably 30 to 3500 mPa s, and particularly preferably 50 mPa s to 1500 mPa s.

[0088] 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.

[0089] The preparation according to the invention can advantageously contain one or more substances (thickening agents) that increase the viscosity of aqueous preparations. Preferably, the at least one thickening agent is selected from the group consisting of starch, gelatin, casein, konjac root flour, cellulose, cellulose gum, xanthan gum, xanthan gum, algin, scleroglucan, gellan gum, gellan gum, highly acylated gellan gum, dehydroxanthan gum, hydroxypropyl starch phosphate, hydroxypropyl guar gum, pectin, Acacia senegal gum, carrageenan, and / or guarana.

[0090] 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.

[0091] A preferred embodiment of the invention is characterized in that cellulose gum is contained in the preparation according to the invention in a proportion of 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.

[0092] A preferred embodiment of the invention is characterized in that cellulose gum in the preparation according to the invention is contained in a proportion of hydroxypropyl guar of 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.

[0093] 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.

[0094] 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.

[0095] 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).

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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. 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] The preparation according to the invention may advantageously contain glycerin. If glycerin is included, it is advantageous if the proportion of this component is from 2.0 wt.% to 15.0 wt.%, preferably from 3.0 wt.% to 12.0 wt.%, and particularly preferably from 3.5 wt.% to 8.0 wt.%, based on the total weight of the hydrodispersion preparation.

[0104] 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.

[0105] 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.%.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] A preferred embodiment of the invention is characterized in that ethyl ascorbic acid is contained in the 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.

[0110] 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

[0111] The following examples are intended to illustrate the present invention without limiting it. Unless otherwise stated, all quantities, proportions, and percentages are based on weight and total quantity or total weight of the preparation.

[0112] The following formulations were prepared for the comparative tests. Viscosities between 10 and 100 mPa s were measured for all formulations. Formulations 2, 4, 7, and 8 are according to the invention, while formulations 1, 3, 5, and 6 are not.

[0113]

[0114] *The formation of alkylamidothiazole crystals was determined microscopically as described above.

[0115]

[0116] *The formation of alkylamidothiazole crystals was determined microscopically as described above.

[0117] The preparations listed above were produced and their properties were investigated in a comparative experiment with regard to the crystallization of alkylamidothiazoles. For preparations 2, 4, 7, and 8 according to the invention, it was shown that no crystallization of alkylamidothiazoles occurred. In contrast, preparations that did not contain the combination according to the invention showed the formation of alkylamidothiazole crystals after 24 hours. The following examples are intended to further illustrate the invention without limiting it:

[0118]

[0119]

[0120]

Claims

Patent claims 1. Aqueous cosmetic and / or dermatological preparation containing a. One or more alkylamidothiazoles, and b. Niacinamide, wherein the niacinamide content is from 5.0 wt.% to 22.0 wt.% based on the total weight of the preparation.

2. Preparation according to claim 1 characterized in that the total proportion of one or more alkylamidothiazoles is selected to be 0.000001 to 10 wt.%, in particular 0.0001 to 3 wt.%, and most particularly 0.001 to 1 wt.%, based on the total weight of the 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: R1 = -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 Alky-Morpholino, -C1-C24 Alky-Piperidino, -C1-C24 Alky-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-CylcIoalkyl, -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 structure:

5. Preparation according to one of the preceding claims characterized in that the alkylamidothiazole(s) are unencapsulated.

6. Preparation according to one of the preceding claims characterized in that the total proportion of niacinamide is 5.0 wt.% to 22.0 wt.%, preferably 6.0 wt.% to 15.0 wt.% and particularly preferably 7.5 wt.% to 10.0 wt.%, based on the total weight of the preparation.

7. Preparation according to one of the preceding claims characterized in that the weight ratio of niacinamide to alkylamidothiazoles is 25:1 to 120:1, preferably 45:1 to 100:1 and particularly preferably 50:1 to 65:

1.

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 proportion of water is 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 the preparation has a viscosity of 1 to 5000 mPa s, preferably 30 to 3500 mPa s, and particularly preferably 50 mPa s to 1500 mPa s.

12. 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.%.

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

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