Eutectic coating composition as well as preparation method and application thereof

Abstract

The invention relates to the technical field of cosmetics, in particular to a co-crystal wrapping composition as well as a preparation method and application thereof. The caffeine gel is prepared from the following raw materials in percentage by mass: 40-60% of caffeine, 20-30% of glycerol, 20-30% of nicotinamide, 20-30% of cyclodextrin and the balance of water. The caffeine, the nicotinamide and the glycerol creatively form a supramolecular compound through the interaction of covalent bonds and non-ionic bonds, and the supramolecular compound is wrapped by the cyclodextrin with a hydrophobic cavity inside to form the eutectic wrapped composition, so that the problem of solubility of the caffeine can be solved while the irritation of the caffeine is solved; the slow release effect is further achieved. When the composition is applied to cosmetics, the irritation problem is not caused, and the composition is suitable for sensitive skin.

Description

Technical Field

[0001] The present invention relates to the technical field of cosmetics, and in particular to a eutectic encapsulation composition and a preparation method and application thereof. Background Art

[0002] As people's quality of life continues to improve, the consumption concept of cosmetics is undergoing a profound change. The public has more stringent demands for skin care products, especially those with specific functions. At the same time, due to the accelerated pace of modern life, the number of people with sensitive skin continues to rise. Many brands have emphasized the importance of skin barrier and healthy, normal skin conditions, which has further promoted the market demand for skin barrier protection and barrier function enhancement products. In this context, it is particularly important to develop skin care products that can meet specific functional requirements while ensuring the mildness of the product.

[0003] Caffeine, as a xanthine alkaloid, is increasingly used in the cosmetics industry due to its small molecular weight, high biological activity and good skin permeability. In the field of beauty and skin care, caffeine has shown multiple functions: it can effectively prevent excessive accumulation of fat in cells, has antioxidant capacity, and helps slow down the aging process of the skin caused by light; by promoting blood circulation in the skin and inhibiting the activity of 5-reductase, caffeine can also stimulate hair growth; when applied topically, it can also improve the skin barrier function, enhance skin properties, and exert anti-wrinkle effects. Therefore, the application prospects of caffeine in skin care products are generally optimistic.

[0004] Chinese patent CN104039303A discloses a cosmetic composition containing high concentrations of caffeine and niacinamide. Caffeine and niacinamide are used together. Niacinamide can prevent the precipitation of caffeine and improve the stability of the solution dissolved in caffeine at low temperatures. However, when using caffeine-added skin care products, itching, stinging, redness and swelling will occur. This skin irritation problem needs to be solved urgently. Therefore, how to develop safe, mild and effective caffeine-containing skin care products is a hot topic for those skilled in the art. Summary of the invention

[0005] In order to solve the problems in the prior art, the first aspect of the present invention provides a eutectic encapsulation composition. The preparation raw materials include, by mass percentage: 40-60% caffeine, 20-30% glycerol, 20-30% nicotinamide, 20-30% cyclodextrin, and water to make up the balance.

[0006] In one embodiment, the mass ratio of caffeine, nicotinamide and cyclodextrin is (4-5):(2-3):(2-3), which can be 2:1:1, 4:3:3, 4:2:3, 4:3:3, 5:2:2, 5:2:3, 5:3:3, 5:3:2.

[0007] In one embodiment, the mass ratio of caffeine, nicotinamide and cyclodextrin is 2:1:1.

[0008] In the present invention, caffeine molecules, nicotinamide molecules and glycerol are interacted through non-covalent bonds and non-ionic bonds to form a supramolecular complex, and the supramolecular complex does not involve changes in the chemical structures of caffeine, nicotinamide and glycerol. At the same time, by using cyclodextrin with a hydrophobic cavity inside to encapsulate the above-mentioned complex to form a eutectic encapsulation composition, the irritation of caffeine can be effectively solved while solving its solubility problem, and further playing a sustained release effect.

[0009] In one embodiment, the cyclodextrin includes at least one of basic cyclodextrin and cyclodextrin derivatives.

[0010] In a preferred embodiment, the cyclodextrin comprises a cyclodextrin derivative.

[0011] In one embodiment, the cyclodextrin derivative includes at least one of hydroxypropyl-β-cyclodextrin, hydroxyethyl-β-cyclodextrin, methyl-β-cyclodextrin, and sulfobutyl-β-cyclodextrin.

[0012] In a preferred embodiment, the cyclodextrin derivative is hydroxypropyl-β-cyclodextrin.

[0013] In the present invention, caffeine and nicotinamide cocrystals form a supramolecular complex, the surface charge of the complex is densely distributed to form a hydrophilic electron cloud, glycerol and water are tightly associated to form a structurally stable hydration layer around it, and then embedded in the cyclodextrin. Since the inner cavity of hydroxypropyl-β-cyclodextrin is composed of hydrogen atoms, carbon atoms and oxygen of a glycoside ether structure, a non-polar hydrophobic cavity of a truncated cone structure is formed. Through non-covalent bond interactions, such as hydrogen bonds, van der Waals forces, etc., the supramolecular complex of caffeine-cyclodextrin-glycerol-water is fully or partially embedded in the cavity of cyclodextrin to form a stable inclusion compound.

[0014] The second aspect of the present invention provides a method for preparing a eutectic encapsulation composition, which comprises at least the following steps: dissolving caffeine and nicotinamide in a mixture of water and glycerol, adding cyclodextrin under homogenizing conditions, and stirring evenly until the mixture is in a white emulsion state.

[0015] The homogenization in the present invention is not limited to dry grinding, wet grinding, or mixed stirring.

[0016] A third aspect of the present invention provides an application of a eutectic encapsulation composition for the preparation of cosmetics.

[0017] In one embodiment, the amount of the eutectic encapsulation composition added to the cosmetic is 0.1-5wt%, which can be 0.1wt%, 0.2wt%, 0.3wt%, 0.4wt%, 0.5wt%, 0.6wt%, 0.7wt%, 0.8wt%, 0.9wt%, 1wt%, 2wt%, 4wt%, 5wt%.

[0018] In one embodiment, the raw materials for preparing the cosmetics include at least, by weight percentage: 0.2-5% of eutectic encapsulation composition, 0.1-0.3% of thickener, 2-15% of moisturizer, 0.01-0.5% of antioxidant, 0.01-0.3% of pH adjuster, and the balance is made up of solvent.

[0019] In one embodiment, the thickener includes at least one of carbomer, xanthan gum, transparent xanthan gum, sodium polyacrylate, and cetearyl alcohol.

[0020] In a preferred embodiment, the thickener is carbomer and transparent xanthan gum.

[0021] In a more preferred embodiment, the brand of the carbomer is PEMULEN TR-1 Polymer, which is purchased from Lubrizol Specialty Chemicals (Shanghai) Co., Ltd.

[0022] In one embodiment, the mass ratio of the carbomer to the transparent xanthan gum is 4:1.

[0023] In one embodiment, the moisturizing agent includes at least one of glycerin, butylene glycol, dipropylene glycol, 1,2-hexanediol, betaine, and panthenol. Preferably, the moisturizing agent is a combination of glycerin, dipropylene glycol, 1,2-hexanediol, betaine, and panthenol.

[0024] In a preferred embodiment, the mass ratio of glycerol, dipropylene glycol, 1,2-hexanediol, betaine and panthenol is 4:5:0.4:1:0.5.

[0025] In one embodiment, the antioxidant comprises at least one of p-hydroxyacetophenone and tocopherol acetate. Preferably, the antioxidant is p-hydroxyacetophenone.

[0026] In one embodiment, the pH adjuster is arginine.

[0027] In one embodiment, the solvent is water.

[0028] In one embodiment, the method for preparing the cosmetics at least comprises: uniformly stirring the eutectic encapsulation composition, a thickener, a moisturizer, an antioxidant, a pH adjuster and a solvent to obtain the cosmetics.

[0029] Beneficial Effects

[0030] 1. The present invention provides a eutectic encapsulation composition, which has a wide range of applications, good compatibility with other cosmetic raw materials, and can significantly reduce the irritation of caffeine.

[0031] 2. The present invention creatively forms a supramolecular complex with caffeine, nicotinamide and glycerol through the interaction of covalent bonds and non-ionic bonds, and uses cyclodextrin with a hydrophobic cavity inside to encapsulate the supramolecular complex to form a eutectic encapsulation composition, which can solve the irritation of caffeine while solving its solubility problem, and further play a sustained release effect.

[0032] 3. The present invention adopts hydroxypropyl-β-cyclodextrin and utilizes its non-polar hydrophobic cavity of truncated cone structure to embed the supramolecular complex of caffeine-cyclodextrin-glycerol-water into the cavity of cyclodextrin in whole or in part through non-covalent bond interaction, thereby improving the stability of the product.

[0033] 4. The eutectic encapsulation composition provided by the present invention can inhibit and eliminate the irritation and solubility problems caused by caffeine. When used in cosmetics, it will not cause irritation problems and is suitable for sensitive skin. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 IR spectra of the eutectic encapsulation compositions prepared in Example 1, Example 4, Comparative Example 3, and Comparative Example 5; in the figure, composition 1 corresponds to Comparative Example 3, composition 2 corresponds to Comparative Example 5, composition 3 corresponds to Example 1, and composition 4 corresponds to Example 4. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the examples and drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. The experimental methods for which specific conditions are not specified in the examples are carried out under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used that do not specify the manufacturer are all conventional products that can be purchased commercially.

[0036] Example 1 (other raw materials are all commercially available cosmetic grade)

[0037] In a first aspect, the present embodiment provides a eutectic encapsulation composition, wherein the raw materials for preparation include, by weight percentage, 40% caffeine, 20% glycerol, 30% nicotinamide, 20% cyclodextrin, and the balance made up of water.

[0038] The cyclodextrin is hydroxypropyl-β-cyclodextrin purchased from Beautéby of ROQUETTE FRERES CD110.

[0039] The second aspect of this embodiment provides a method for preparing a eutectic encapsulation composition, comprising the following steps: dissolving caffeine and nicotinamide in a mixture of water and glycerol, adding cyclodextrin under homogenizing conditions, and stirring evenly until the mixture is in a white emulsion state.

[0040] A third aspect of this embodiment provides an application of a eutectic encapsulation composition for use in the preparation of cosmetics.

[0041] Calculated by weight percentage, the raw materials for preparing the cosmetics include: 0.2% of the eutectic encapsulation composition, 0.25% of the thickener, 10.9% of the moisturizer, 0.4% of the antioxidant, 0.2% of the pH adjuster, and the balance is made up of the solvent.

[0042] The thickener is carbomer and transparent xanthan gum, and the mass ratio of the carbomer to the transparent xanthan gum is 4:1.

[0043] The moisturizer is a combination of glycerin, dipropylene glycol, 1,2-hexanediol, betaine and panthenol. The mass ratio of glycerin, dipropylene glycol, 1,2-hexanediol, betaine and panthenol is 4:5:0.4:1:0.5.

[0044] The pH regulator is arginine.

[0045] The antioxidant is p-hydroxyacetophenone.

[0046] The preparation method of the cosmetic comprises: uniformly stirring the eutectic encapsulation composition, a thickener, a moisturizer, an antioxidant, a pH regulator and a solvent to obtain the cosmetic.

[0047] Example 2

[0048] The specific implementation of this embodiment is the same as that of Example 1, except that, in terms of weight percentage, the raw materials for preparing the cosmetic include: 0.5% of the eutectic encapsulation composition, 0.25% of the thickener, 10.9% of the moisturizer, 0.4% of the antioxidant, 0.2% of the pH adjuster, and the balance is made up of the solvent.

[0049] Example 3

[0050] The specific implementation of this embodiment is the same as that of Example 1, except that, in terms of weight percentage, the raw materials for preparing the cosmetics include: 1% eutectic encapsulation composition, 0.25% thickener, 10.9% moisturizer, 0.4% antioxidant, 0.2% pH adjuster, and the balance is made up of solvent.

[0051] Example 4

[0052] The specific implementation of this embodiment is the same as that of Example 1, except that the cyclodextrin is hydroxypropyl-β-cyclodextrin purchased from Shandong Binzhou Zhiyuan Biotechnology Co., Ltd.

[0053] Comparative Example 1

[0054] This comparative example provides a cosmetic. The raw materials for preparing the cosmetic include, by mass percentage, 0.1% caffeine, 0.25% thickener, 10.9% moisturizer, 0.4% antioxidant, 0.2% pH adjuster, and the balance is made up of solvent.

[0055] Comparative Example 2

[0056] The specific implementation of this comparative example is the same as that of Example 1, except that, in terms of mass percentage, the raw materials for preparing the eutectic encapsulation composition include: 50% caffeine, 25% nicotinamide, and 25% water.

[0057] Comparative Example 3

[0058] The specific implementation of this comparative example is the same as that of Example 1, except that, in terms of mass percentage, the raw materials for preparing the eutectic encapsulation composition include: 50% caffeine and 50% cyclodextrin.

[0059] Comparative Example 4

[0060] The specific implementation of this comparative example is the same as that of Example 1, except that, in terms of mass percentage, the raw materials for preparing the eutectic encapsulation composition include: 50% caffeine and 50% cyclodextrin.

[0061] Calculated by weight percentage, the raw materials for preparing the cosmetics include: 1% of the eutectic encapsulation composition, 0.25% of the thickener, 10.9% of the moisturizer, 0.4% of the antioxidant, 0.2% of the pH adjuster, and the balance is made up of the solvent.

[0062] Comparative Example 5

[0063] The specific implementation of this comparative example is the same as that of Example 1, except that the raw materials for preparing the eutectic encapsulation composition do not contain glycerol.

[0064] Figure 1 IR spectra of the eutectic encapsulation compositions prepared in Example 1, Example 4, Comparative Example 3, and Comparative Example 5; in the figure, composition 1 corresponds to Comparative Example 3, composition 2 corresponds to Comparative Example 5, composition 3 corresponds to Example 1, and composition 4 corresponds to Example 4.

[0065] Performance Testing

[0066] 1. Mildness test

[0067] Samples: cosmetics prepared in Examples 1-3 and Comparative Examples 1-4, and Blank Examples 1 and 2.

[0068] According to the percentage by mass, the raw materials for the preparation of the cosmetics in Blank Example 1 are: 0.25% thickener, 10.9% moisturizer, 0.4% antioxidant, and water makes up the balance. The preparation method is the same as that in Example 1;

[0069] According to the percentage by mass, the raw materials for the preparation of the cosmetics of Blank Example 2 are: niacinamide 0.5%, thickener 0.25%, moisturizer 10.9%, antioxidant 0.4%, pH adjuster 0.2%, and solvent makes up the balance. The preparation method is the same as that of Example 1.

[0070] Test method:

[0071] Thirty volunteers aged 18-40 were selected. They self-reported being sensitive, had no skin problems such as skin lesions, inflammation, birthmarks in the test area, had no serious systemic diseases, no immunodeficiency or autoimmune diseases, no active allergic diseases, no history of allergies to skin care cosmetics, had not used systemic hormone drugs and immunosuppressants within 1 month, were not pregnant or lactating, and had no ethical contraindications.

[0072] The cosmetics of each embodiment, comparative example and blank example were applied to the face of volunteers in the form of facial masks, and the sensory state of the volunteers' skin was recorded after 20 minutes. If persistent itching, numbness, pain and other irritation symptoms appeared, it was counted as "×", otherwise it was counted as "√". The test results are shown in Tables 1 and 2.

[0073] 2. Infrared spectrum test

[0074] The IR spectra of the eutectic encapsulation compositions prepared in Example 1, Example 4, Comparative Example 3 and Comparative Example 5 were tested, wherein Composition 1 corresponds to Comparative Example 3, Composition 2 corresponds to Comparative Example 5, Composition 3 corresponds to Example 1, and Composition 4 corresponds to Example 4.

[0075] From the infrared spectrum we can see:

[0076] Composition 1: Cyclodextrin-caffeine at 3226 cm -1 , 1697cm -1 , 1651cm -1 , 1023cm -1 , with characteristic peaks;

[0077] Composition 2: Cyclodextrin-caffeine-nicotinamide at 3352 cm -1 , 1694cm -1 , 1651cm -1 , 1025cm -1 , with characteristic peaks;

[0078] Composition 3: Roquette cyclodextrin-caffeine-niacinamide-glycerol at 3337 cm -1 , 1694cm -1 , 1654cm -1 , 1024cm -1 , with characteristic peaks;

[0079] Composition 4: Zhiyuan cyclodextrin-caffeine-nicotinamide-glycerol at 3357cm -1 , 1693cm -1 , 1654cm -1 , 1026cm -1 , with characteristic peaks;

[0080] Comparison of the IR spectra of composition 2 and composition 1 shows that the hydroxyl group OH shifted to the left, 1694 cm -1 The characteristic peak shifts to the right.

[0081] Compositions 3 and 4, compared with composition 1, cyclodextrin-caffeine-nicotinamide-glycerol cocrystal, characteristic peak 1694cm -1 , 1651cm -1 There is a 3 cm displacement at the position. It is speculated that after adding nicotinamide and glycerol, hydrogen bonds are formed between the cyclodextrin-caffeine-nicotinamide-glycerol eutectic composition or hydrogen bonds formed at other positions, which have an impact on the CH=CH characteristic peak. This shows that there is an intermolecular hydrogen bond interaction, which has significantly changed the peak shape and peak position of the characteristic peak.

[0082] Table 1

[0083]

[0084]

[0085] Table 2

[0086]

[0087]

Claims

1. A eutectic encapsulation composition, characterized in that: Calculated by mass percentage, the raw materials include: 40-60% caffeine, 20-30% glycerol, 20-30% nicotinamide, 20-30% cyclodextrin, and the balance is made up of water.

2. The eutectic encapsulation composition according to claim 1, characterized in that: The mass ratio of caffeine, nicotinamide and cyclodextrin is (4-5):(2-3):(2-3).

3. The eutectic encapsulation composition according to claim 2, characterized in that: The mass ratio of caffeine, nicotinamide and cyclodextrin is 2:1:

1.

4. The eutectic encapsulation composition according to claim 1, characterized in that The cyclodextrin includes at least one of basic cyclodextrin and cyclodextrin derivatives.

5. The eutectic encapsulation composition according to claim 4, characterized in that: The cyclodextrin derivative includes at least one of hydroxypropyl-β-cyclodextrin, hydroxyethyl-β-cyclodextrin, methyl-β-cyclodextrin, and sulfobutyl-β-cyclodextrin.

6. A method for preparing the eutectic coating composition according to any one of claims 1 to 5, characterized in that: The method comprises at least the following steps: dissolving caffeine and nicotinamide in a mixture of water and glycerol, adding cyclodextrin under homogenizing conditions, and stirring evenly until the mixture is in a white emulsion state.

7. An application of the eutectic coating composition according to any one of claims 1 to 5, characterized in that: Used in the preparation of cosmetics.

8. The use of the eutectic coating composition according to claim 7, characterized in that: The added amount of the eutectic encapsulation composition in the cosmetic is 0.1-5wt%.

9. The use of the eutectic coating composition according to claim 7 or 8, characterized in that: Calculated by weight percentage, the raw materials for preparing the cosmetics at least include: 0.2-5% of eutectic encapsulation composition, 0.1-0.3% of thickener, 2-15% of moisturizer, 0.01-0.5% of antioxidant, 0.01-0.3% of pH adjuster, and the balance is made up of solvent.

10. The use of the eutectic coating composition according to claim 9, characterized in that: The thickener includes at least one of carbomer, xanthan gum, sodium polyacrylate and cetearyl alcohol.

Images