Vitamin C composite nano microcapsule as well as preparation method and application thereof

Abstract

The invention discloses a vitamin C composite nano microcapsule as well as a preparation method and application thereof. The microcapsule is of a multi-shell structure and comprises a shell layer A serving as an inner shell layer, vitamin C serving as a core layer and a shell layer B serving as an outer shell layer, and the surface of the shell layer B is of a hydrophilic group structure. The vitamin C composite nano microcapsule is successfully prepared by utilizing an intermolecular interaction and interface compounding technology. The vitamin C is endowed with excellent stability (24 months), and the vitamin C is uniformly dispersed and efficiently entrapped in the water-based emulsion and cream (the highest content is 15%). Compared with the prior art, the vitamin C composite nano microcapsule prepared by the invention not only has excellent stability and water solubility, but also has adjustable and controllable vitamin C concentration in milk and cream; the process is simple, and the production cost is low; the invention provides an efficient and economic stabilization solution for the application of vitamin C in the cosmetic industry, and has a wide market application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of cosmetic skin care, and particularly relates to a vitamin C composite nano microcapsule, a preparation method thereof, and an application thereof. Background Art

[0002] Skin health and beauty are fields that have been increasingly emphasized in modern society. With the deepening of the understanding of the impact of environmental factors and lifestyle on the skin, people are increasingly seeking effective skin care ingredients to protect and improve the skin condition.

[0003] Vitamin C (also known as ascorbic acid) has been proven to have significant advantages and various application potentials in the skin care field. Its technical advantages in the skin care field are specifically manifested in the following aspects. First, antioxidant property: it can delay the signs of skin aging. Second, whitening effect: it helps to fade skin spots and even out skin tone to achieve a whitening effect. Third, promoting collagen synthesis: enhancing the elasticity and firmness of the skin. Fourth, anti-inflammatory effect: it has a positive effect on treating acne and other inflammatory skin conditions. Fifth, photoprotective effect: reducing the risk of photoaging. Sixth, repair and regeneration: promoting wound healing. Seventh, synergistic effect: the combined application of vitamin C with other active ingredients such as vitamin E, niacinamide, etc. can enhance the skin care effect and achieve a more comprehensive skin care efficacy. Eighth, safety and tolerance: it is suitable for long-term use on various skin types. Ninth, versatility: in addition to the above advantages, vitamin C can also improve the skin barrier function, regulate sebum secretion, reduce the impact of environmental pollutants on the skin, etc. As a naturally occurring substance, vitamin C has high availability and cost-effectiveness, making its application in skin care products more extensive. To achieve these functions of vitamin C, improving the stability of vitamin C in an aqueous medium is the key.

[0004] Currently, the main methods for improving the stability of vitamin C are as follows: 1) Making vitamin C into derivatives, such as vitamin C ethyl ether, vitamin C glucoside, sodium ascorbyl phosphate, etc.; however, making derivatives will increase the cost on the one hand and also weaken the efficacy of vitamin C. 2) Using cyclodextrin, microcapsules, liposomes, etc. to encapsulate vitamin C; however, due to the very good water solubility of vitamin C, the encapsulation rate of these encapsulation technologies for vitamin C is very low, and the stabilization effect is not ideal. 3) Dispersing vitamin C in an anhydrous system to stabilize vitamin C by preventing its contact with water and oxygen; however, this method limits the product dosage form and the skin feel during use. 4) The product packaging adopts a separate compartment packaging material with powder and liquid separated or a freeze-dried dosage form to independently store vitamin C in a form that does not contact water and oxygen, and mix it evenly during use; this method has a certain effect, but it costs more in packaging and is also more inconvenient to use. Although vitamin C has the above-mentioned significant advantages in the skin care field, it still faces technical challenges such as stability in an aqueous medium and skin permeability in practical applications.

[0005] Therefore, it is of great significance to explore a simple and efficient method to prepare a vitamin C composition with high concentration and high stability in aqueous media. While increasing the concentration of vitamin C in skin care products such as lotions, milks, and creams, enhance its stability; at the same time, expand the efficacy and application scope of vitamin C in the skin care field. Whether for the in-depth expansion of cutting-edge scientific research or the implementation and application in the broad market, it contains inestimable value. Summary of the Invention

[0006] To solve the above problems, the present invention provides a vitamin C composite nano-microcapsule, its preparation method and application. The nano-microencapsulation technology of the present invention effectively overcomes the defect that traditional vitamin C has poor stability in aqueous media.

[0007] The present invention is realized through the following technical solutions: The present invention provides a vitamin C composite nano-microcapsule. The microcapsule has a multi-shell structure, which includes a shell layer A as the inner shell layer, vitamin C as the core layer, and a shell layer B as the outer shell layer. The surface of the shell layer B has a hydrophilic group structure.

[0008] Further, the microcapsule includes the following components in parts by weight: 100 parts of shell layer A, 30 parts of vitamin C, and 15 parts of shell layer B.

[0009] Further, both the shell layer A and the shell layer B are polyether polyol polymers.

[0010] Further, the shell layer A is polyethylene glycol with a molecular weight of 180 - 500.

[0011] Further, the shell layer B is polyethylene glycol with a molecular weight of 3800 - 22000.

[0012] Further, the particle size distribution of the microcapsule is 10 - 20 nm.

[0013] The present invention also provides a preparation method of a vitamin C composite nano-microcapsule, which is characterized by including the following steps: Step 1: Slowly add the shell layer A to vitamin C under stirring conditions until it becomes clear and transparent; Step 2: Control the temperature of the clear solution obtained in Step 1 at 30 - 60 °C, slowly add the shell layer B, and stir until it becomes a paste to obtain the vitamin C composite nano-microcapsule.

[0014] The present invention also provides an application of the vitamin C composite nano-microcapsule in cosmetics. The application method is: adding the vitamin C composite nano-microcapsule to water, milk, and cream.

[0015] The beneficial effects of the present invention are as follows: 1. The present invention applies supramolecular technology to prepare a vitamin C composite nano-microcapsule protected by a double shell layer, with a maximum vitamin C loading capacity of 20%; the nano-microcapsule has good dispersibility in an aqueous medium, and the dispersion liquid is clear and transparent; the highest concentration of vitamin C in an aqueous solution can reach 15%, realizing its efficient encapsulation in water-based emulsions and creams; 2. The present invention breakthroughly uses non-covalent intermolecular interactions and interfacial compounding strategies, with vitamin C as the core layer and polyethylene glycols with different molecular weights as the inner shell layer and the outer shell layer respectively; among them, there is a hydrogen bond interaction between the core layer and the inner shell layer, and an intermolecular force interaction between shell layer A and B; effectively overcoming the stability defect of traditional vitamin C being easily degraded, the surface of shell layer B of the composite microcapsule is a hydrophilic group; endowing vitamin C with excellent stability and water solubility; 3. The preparation method of a vitamin C composite nano-microcapsule of the present invention has a simple process, low production cost, and is easy to industrialize. It not only enhances the chemical stability of vitamin C but also improves its bioavailability in skin care products, thus bringing users a more efficient and safe new skin care option, fully demonstrating the excellent potential of vitamin C in skin care. Description of the Drawings

[0016] Figure 1 In Figure 1-1 is the infrared spectrum of vitamin C (VC) used in the examples and comparative examples of the present invention; Figure 1-2 is the infrared spectrum of polyethylene glycol-8000 (PEG-8000) used in the examples and comparative examples; Figure 1-3 is the infrared spectrum of vitamin C simply encapsulated with polyethylene glycol-400 (VC@PEG-400) in Comparative Example 3; Figure 1-4 is the infrared spectrum of the vitamin C composite nano-microcapsule (VC@PEG-400@PEG-8000) prepared in Example 4; Figure 1-5 Figure 1-5 is the infrared spectrum of the microcapsule without encapsulating vitamin C (PEG-400@PEG-8000) in Comparative Example 1; Figure 2 (1) is the particle size distribution diagram of the vitamin C composite microcapsule (VC@PEG-400 @PEG-20000) prepared in Example 7; Figure 2 (2) is the particle size distribution diagram of the composite microcapsule (PEG-400@PEG-20000) without loading vitamin C in Comparative Example 2; Figure 2 (3) is the particle size distribution diagram of the microcapsule (VC@PEG-400) with vitamin C encapsulated by a single shell layer of polyethylene glycol 400 in Comparative Example 3; Figure 2 (4) is the particle size distribution diagram of the vitamin C aqueous solution (VC / H2O) state in Comparative Example 4; Figure 3 (1),Figure 3 (2), Figure 3 (3) are the ultraviolet-visible absorption spectra of the vitamin C composite nano-microcapsules prepared in Example 3, the microcapsules coated with single-layer PEG-400 in Comparative Example 3, and the pure vitamin C aqueous solution in Comparative Example 4 after being placed for different times; Figure 4 It is the ultraviolet-visible absorption spectrum diagram of the vitamin C composite nano-microcapsules in Example 5 of the present invention after being placed at 45 °C for different times; Figure 5 It is the dispersion picture of the vitamin C composite nano-microcapsules in Example 8 of the present invention in water; Figure 6 It is the schematic structural diagram of the vitamin C composite nano-microcapsules in Examples 1-8 of the present invention. Specific implementation manners

[0017] Vitamin C has significant whitening and antioxidant effects in the skin care field, but it is easily oxidized in aqueous solution, which limits its effectiveness and durability in practical applications; enhancing the chemical stability of vitamin C in an aqueous medium is a key technical challenge for its wide application in cosmetics.

[0018] The present invention discloses a vitamin C composite nano-microcapsule. The microcapsule has a multi-shell structure, and the particle size distribution of the microcapsule is 10-20 nm. The composition of the vitamin C composite nano-microcapsule is as follows: calculated by mass parts of the maximum loading amount of vitamin C, 100 parts of shell layer A, 30 parts of vitamin C, and 15 parts of shell layer B. Vitamin C is the core layer, shell layer A is the inner shell layer, and shell layer B is the outer shell layer; there is a hydrogen bond interaction between the core layer and the inner shell layer, and there is an intermolecular force interaction between shell layer A and B; the surface of shell layer B of the composite microcapsule is a hydrophilic group; shell layer A is polyethylene glycol with a molecular weight of 180-500. Shell layer B is polyethylene glycol with a molecular weight of 3800-22000.

[0019] A preparation method of a vitamin C composite nano-microcapsule, comprising the following steps: Step 1: Slowly add shell layer A to vitamin C under stirring conditions until it is clear and transparent; Step 2: Control the temperature of the clear solution obtained in Step 1 at 30-60 °C, slowly add shell layer B, and stir until it becomes a paste to obtain the vitamin C composite nano-microcapsule.

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0021] Example 1: A preparation method of a vitamin C composite nano-microcapsule (vitamin C loading: 4.2%) comprises the following steps: (1) Take 100 g of polyethylene glycol - 200, and slowly add 5 g of vitamin C under stirring conditions until it becomes clear and transparent; (2) Slowly heat up the above-mentioned clear solution and control the temperature at 30 °C, slowly add 15 g of polyethylene glycol - 8000, and stir until it becomes a paste, thus obtaining the vitamin C composite nano-microcapsule with a vitamin C loading of 4.2%.

[0022] Example 2: A preparation method of a vitamin C composite nano-microcapsule (vitamin C loading: 4.2%) comprises the following steps: (1) Take 100 g of polyethylene glycol - 600, and slowly add 5 g of vitamin C under stirring conditions until it becomes clear and transparent; (2) Slowly heat up the above-mentioned clear solution and control the temperature at 45 °C, slowly add 15 g of polyethylene glycol - 3350, and stir until it becomes a paste, thus obtaining the vitamin C composite nano-microcapsule with a vitamin C loading of 4.2%.

[0023] Example 3: A preparation method of a vitamin C composite nano-microcapsule (vitamin C loading: 4.2%) comprises the following steps: (1) Take 100 g of polyethylene glycol - 400, and slowly add 5 g of vitamin C under stirring conditions until it becomes clear and transparent; (2) Slowly heat up the above-mentioned clear solution and control the temperature at 60 °C, slowly add 15 g of polyethylene glycol - 20000, and stir until it becomes a paste, thus obtaining the vitamin C composite nano-microcapsule with a vitamin C loading of 4.2%.

[0024] Example 4: A preparation method of a vitamin C composite nano-microcapsule (vitamin C loading: 4.2%) comprises the following steps: (1) Take 100 g of polyethylene glycol - 400, and slowly add 5 g of vitamin C under stirring conditions until it becomes clear and transparent; (2) Slowly heat up the above-mentioned clear solution and control the temperature at 45 °C, slowly add 15 g of polyethylene glycol - 8000, and stir until it becomes a paste, thus obtaining the vitamin C composite nano-microcapsule with a vitamin C loading of 4.2%.

[0025] Example 5: A preparation method of a vitamin C composite nano-microcapsule (vitamin C loading: 4.2%) comprises the following steps: (1) Take 100 g of polyethylene glycol - 200, and slowly add 5 g of vitamin C under stirring conditions until it becomes clear and transparent; (2) Slowly heat up the above - mentioned clear solution and control the temperature at 45 °C, then slowly add 15 g of polyethylene glycol - 20000, and stir until it becomes a paste to obtain the vitamin C composite nano - microcapsules with a vitamin C loading of 4.2%.

[0026] Example 6: A preparation method of vitamin C composite nano - microcapsules (vitamin C loading: 4.2%) includes the following steps: (1) Take 100 g of polyethylene glycol - 600, and slowly add 5 g of vitamin C under stirring conditions until it becomes clear and transparent; (2) Slowly heat up the above - mentioned clear solution and control the temperature at 50 °C, then slowly add 15 g of polyethylene glycol - 8000, and stir until it becomes a paste to obtain the vitamin C composite nano - microcapsules with a vitamin C loading of 4.2%.

[0027] Example 7: A preparation method of vitamin C composite nano - microcapsules (vitamin C loading: 8%) includes the following steps: (1) Take 100 g of polyethylene glycol - 400, and slowly add 10 g of vitamin C under stirring conditions until it becomes clear and transparent; (2) Slowly heat up the above - mentioned clear solution and control the temperature at 45 °C, then slowly add 15 g of polyethylene glycol - 20000, and stir until it becomes a paste to obtain the vitamin C composite nano - microcapsules with a vitamin C loading of 8%.

[0028] Example 8: A preparation method of vitamin C composite nano - microcapsules (vitamin C loading: 20%) includes the following steps: (1) Take 100 g of polyethylene glycol - 400, and slowly add 30 g of vitamin C under stirring conditions until it becomes clear and transparent; (2) Slowly heat up the above - mentioned clear solution and control the temperature at 60 °C, then slowly add 15 g of polyethylene glycol - 8000, and stir until it becomes a paste to obtain the vitamin C composite nano - microcapsules with a vitamin C loading of 20%.

[0029] Comparative Example 1: A preparation method of vitamin C composite nano - microcapsules (vitamin C loading: 0%) includes the following steps: (1) Take 100 g of polyethylene glycol - 400, and slowly add 0 g of vitamin C under stirring conditions until it becomes clear and transparent; (2) Slowly heat the above clarified solution and control the temperature at 45 °C. Slowly add 15 g of polyethylene glycol-8000 and stir until a paste is obtained, namely vitamin C composite nanomicrocapsules with a vitamin C loading of 0%.

[0030] Comparative Example 2: A preparation method of vitamin C composite nanomicrocapsules (vitamin C loading: 0%) comprises the following steps: (1) Take 100 g of polyethylene glycol-400 and slowly add 0 g of vitamin C under stirring conditions until it becomes clear and transparent; (2) Slowly heat the above clarified solution and control the temperature at 45 °C. Slowly add 15 g of polyethylene glycol-20000 and stir until a paste is obtained, namely vitamin C composite nanomicrocapsules with a vitamin C loading of 0%.

[0031] Comparative Example 3: A preparation method of vitamin C composite nanomicrocapsules (vitamin C loading: 20%) comprises the following steps: Take 100 g of polyethylene glycol-400 and slowly add 30 g of vitamin C under stirring conditions until it becomes clear and transparent.

[0032] Comparative Example 4: A preparation method of vitamin C composite nanomicrocapsules (vitamin C loading: 20%) comprises the following steps: Take 100 g of deionized water and slowly add 30 g of vitamin C under stirring conditions until it becomes clear and transparent.

[0033] The vitamin C composite nanomicrocapsules were characterized by the following methods: (I) Infrared spectrum analysis Whether the structure changes during the formation of microcapsules from vitamin C and polyethylene glycol was tested by infrared spectrum, and the results are as Figure 1 shown.

[0034] As Figure 1 can be seen from 1-1 in it, vitamin C corresponds to hydrogen bond stretching vibration, C=C stretching vibration, C=O stretching vibration and C-O-C stretching vibration at 3550 - 3230 cm -1 , 1700 - 1800 cm -1 , 1600 - 1680 cm -1 , 1000 - 1200 cm -1 respectively; all are characteristic absorption peaks of VC. As Figure 1 can be seen from 1-2 in it, polyethylene glycol is at 2800 - 3000 cm -1 , 1050 - 1150cm -1The absorption peaks at [[]] correspond to the stretching vibration of -CH2- in polyethylene glycol molecules and the asymmetric stretching vibration of ether bonds (C-O-C); in the range of 3200 - 3550 cm -1 The broad and strong absorption peak at [[]] is caused by the stretching vibration of hydroxyl groups (-OH) in the incompletely removed water in polyethylene glycol. When polyethylene glycol is complexed with vitamin C, compared with Figure 1 in 1 - 2 and Figure 1 the most obvious difference in 1 - 5 is that in the complex ( Figure 1 in 1 - 3 and Figure 1 in 1 - 4) there appears a characteristic stretching vibration absorption peak of C = C of vitamin C at 1700 - 1800 cm -1 ; indicating that the structure of vitamin C was not damaged during the formation of microcapsules.

[0035] Meanwhile, we also characterized the infrared spectra of the vitamin C - composite nano - microcapsules prepared in Examples 1, 2, 3, 5, 6, 7, and 8. We found that they had almost exactly the same absorption characteristic peaks as in Example 4; indicating that changing the degree of polymerization of PEG did not change the structure of the complex.

[0036] (II) Zeta particle size analysis Whether a nano - capsule structure was formed after the complexation of vitamin C and polyethylene glycol was analyzed by zeta particle size analysis technology; the results are as Figure 2 shown.

[0037] Figure 2 In (1), the average particle size of the vitamin C - composite microcapsule (VC@PEG - 400@PEG - 20000) prepared in Example 7 is 7.21 nm; Figure 2 In (2), the average particle size of the composite microcapsule (PEG - 400@PEG - 20000) without loading vitamin C in Comparative Example 2 is 6.54 nm; Figure 2 In (3), the average particle size of the microcapsule (VC@PEG - 400) with vitamin C encapsulated by single - shell polyethylene glycol 400 in Comparative Example 3 is 4.27 nm; Figure 2 In (4), the average particle size of the vitamin C aqueous solution (VC / H2O) in Comparative Example 4 is 1.11 nm. From the particle size analysis results, it can be seen that the vitamin C - composite microcapsules prepared in the present invention are at the nano - scale; by comparing with the comparative examples, after encapsulating vitamin C, the particle size of the composite microcapsule becomes larger, further proving the successful encapsulation of the microcapsule.

[0038] (III) Stability analysis of the composite nano - microcapsules Whether the vitamin C - composite nano - microcapsules prepared in the present invention have stability was analyzed by ultraviolet - visible absorption spectroscopy: one is the stability at room temperature; the other is the thermal stability.

[0039] 1. Room-temperature storage stability of nano microcapsules To evaluate the storage stability of nano microcapsules at room temperature (20 - 30 °C), we detected the room-temperature storage stability of the nano microcapsules in the examples. The detection method was as follows: 100 mg of the composite nano microcapsules in Example 3 were dispersed in 5 mL of water and stirred until clear and transparent; the detection time was 20 months; the characteristic absorption peak of vitamin C at 292 nm was used as the criterion for judging the stability of vitamin C. The results are as Figure 3 shown.

[0040] Figure 3 (1) in shows the ultraviolet-visible absorption spectra of the vitamin C composite nano microcapsules prepared in Example 3 after being placed for different times. Generally, the ultraviolet absorption wavelength of VC is at 245 nm. Due to the different chemical environments, the ultraviolet absorption wavelength will shift; therefore, the maximum absorption wavelength of the sample will show an obvious red shift. The absorption peak of VC at 200 - 350 nm belongs to the p→π* electron transition in C=C; when the maximum absorption wavelength is greater than 350 nm, it indicates that VC has deteriorated, and at this time the maximum absorption wavelength belongs to the n→π* of C=O. From Figure 3 (1) in, it can be seen that after being placed for 20 months, the vitamin C composite nano microcapsules still have their characteristic absorption peak at 292 nm and the color is still colorless, indicating that the vitamin C composite nano microcapsules prepared by the present invention have high storage stability; this is due to the encapsulation effect of the microcapsules, which effectively avoids the oxidation of oxygen. The stability of the microcapsules was compared with the comparative experiment; Figure 3 (2) in and Figure 3 (3) in are the ultraviolet-visible absorption spectra of the microcapsules coated with single-shell PEG-400 and pure vitamin C aqueous solution respectively. Through comparison, it was found that the microcapsules coated with single-shell PEG-400 turned orange after 45 days; the pure VC aqueous solution turned orange after 20 days. The comparative example further proved that the vitamin C composite microcapsules prepared by the double-shell coating method of the present invention can effectively isolate the oxidation of oxygen to VC and improve the stability of VC.

[0041] 2. Thermal stability of nano microcapsules To evaluate the thermal stability of nano microcapsules, we evaluated the temperature resistance stability of the nano microcapsules in Example 5. The detection method was as follows: The vitamin C composite nano microcapsules prepared in Example 5 were placed in an oven at 45 ± 3 °C; after being placed for different times, 100 mg of the microcapsules were taken, dispersed in 5 mL of water, stirred evenly, and then their ultraviolet-visible absorption spectra were measured. The characteristic absorption peak of vitamin C at 292 nm was used as the criterion for judging the stability of vitamin C. The results are as Figure 4 shown.

[0042] From Figure 4 It can be seen that after the vitamin C composite nanomicrocapsules are placed at 45 ± 3 °C for 12 months, the characteristic absorption peak of vitamin C still remains at 292 nm, indicating that the vitamin C composite microcapsules prepared by the present invention have excellent thermal stability.

[0043] (IV) Water dispersibility of the composite nanomicrocapsules Whether the vitamin C composite nanomicrocapsules designed and prepared by the present invention have water dispersibility is related to their application in cosmetics. We tested their maximum dispersion amount in water and the state after dispersion. The test method is as follows: Take a certain amount of vitamin C composite nanomicrocapsules, disperse them in 5 mL of water, and make them evenly dispersed in water by stirring; after they are evenly dispersed, continue to add until obvious sedimentation appears in the water and then stop adding; then observe the state after dispersion and calculate the maximum dispersion amount.

[0044] The dispersion experiment finally shows that the vitamin C composite nanomicrocapsules prepared by the present invention have excellent dispersibility in water: the maximum dispersion amount is 25 g, and the maximum concentration of vitamin C is 15%. Figure 5 Figure for the state of the vitamin C composite nanomicrocapsules prepared in Example 8 after dispersion. It can be seen from the figure that the vitamin C composite microcapsules form a clear and transparent solution state in water; indicating that the composite microcapsules prepared by the present invention have excellent water dispersibility in water, which provides a basis for the application of vitamin C in the field of cosmetics.

[0045] (V) Structure of the composite nanomicrocapsules According to the test results, we give the structural schematic diagram of the vitamin C composite nanomicrocapsules prepared by the present invention. The core is vitamin C, the shell layer A is low molecular weight polyethylene glycol; the shell layer B is high molecular weight polyethylene glycol; between the vitamin C in the core and between the inner shell layer are connected by hydrogen bonds, and between the shell layer A and B are acting through intermolecular forces; the surface of the outer shell layer B of the composite microcapsules is a hydrophilic group. This double-shell structure endows vitamin C with excellent stability and water dispersibility.

[0046] In summary, the present invention uses intermolecular interactions and interfacial compounding technology to successfully prepare a vitamin C composite nanomicrocapsule with a multi-shell structure. This microencapsulation technology not only endows vitamin C with excellent stability (24 months), but also realizes the uniform dispersion and high-efficiency encapsulation of vitamin C in water-based emulsions and creams (up to 15%). Compared with the prior art, the vitamin C composite nanomicrocapsules prepared by the present invention not only show excellent performance in terms of stability and water solubility, but also the vitamin C concentration can be adjusted and controlled in milk and creams; at the same time, the process is simple and the production cost is low; it provides an efficient and economical stabilization solution for the application of vitamin C in the cosmetics industry and has broad market application prospects.

[0047] It should be noted that although the present invention has been described through the above embodiments, the present invention may also have many other embodiments. Without departing from the spirit and scope of the present invention, those skilled in the art can obviously make various corresponding changes and deformations to the present invention, but these changes and deformations should all fall within the scope protected by the appended claims of the present invention and their equivalents.

Claims

1. A vitamin C composite nano-microcapsule, characterized in that: The microcapsule is a multi-shell structure, which includes a shell layer A as an inner shell layer, vitamin C as a core layer, and a shell layer B as an outer shell layer, wherein the surface of the shell layer B is a hydrophilic group structure.

2. The vitamin C composite nano-microcapsule according to claim 1, characterized in that: The microcapsule comprises the following components in parts by weight: 100 parts of shell A, 30 parts of vitamin C, and 15 parts of shell B.

3. A vitamin C composite nano-microcapsule according to claim 1 or 2, characterized in that: The shell layer A and the shell layer B are both polyether polyol polymers.

4. The vitamin C composite nano-microcapsule according to claim 3, characterized in that: The shell layer A is polyethylene glycol with a molecular weight of 180-500.

5. The vitamin C composite nano-microcapsule according to claim 3, characterized in that: The shell layer B is polyethylene glycol with a molecular weight of 3800 to 22000.

6. The vitamin C composite nano-microcapsule according to claim 1, characterized in that: The particle size distribution of the microcapsules is 10 to 20 nm.

7. A method for preparing a vitamin C composite nano-microcapsule according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: slowly add vitamin C to shell A under stirring until it becomes clear and transparent; Step 2: Control the temperature of the clear solution obtained in step 1 at 30-60°C, slowly add the shell layer B, and stir until it becomes a paste to obtain vitamin C composite nano-microcapsules.

8. Use of a vitamin C composite nano-microcapsule in cosmetics according to any one of claims 1 to 6, characterized in that: The application method is: adding the vitamin C composite nano-microcapsules into water, lotion and cream.

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