A microcapsule emulsion containing collagen and preparation method thereof

Abstract

The present invention belongs to the technical field of cosmetic preparations, specifically to a microcapsule emulsion containing collagen and its preparation method. The present invention utilizes tranexamic acid to adjust the pH and zeta potential of the collagen solution system, enabling the collagen to exhibit minimal solubility and conductivity near its isoelectric point. This successful preparation of a microcapsule formulation containing collagen improves collagen stability and transdermal absorption, while also providing sustained-release properties to improve skin condition.

Description

Technical Field

[0001] The present invention belongs to the technical field of cosmetic preparations, and in particular relates to a microcapsule emulsion containing collagen and a preparation method thereof. Background Art

[0002] As we age, lifestyle factors such as prolonged UV exposure, irregular sleep patterns, and poor nutrition can easily lead to a loss of collagen in the body, contributing to skin aging. This loss of collagen causes structural changes and functional decline in the skin, manifesting as signs of aging, including decreased elasticity, sagging skin, wrinkles and fine lines, pigmentation, dryness, roughness, and increased sensitivity.

[0003] Adding collagen to cosmetics can effectively replenish the loss of collagen in the skin. Collagen raw materials are now increasingly used in cosmetic formulas. As a safe ingredient with multiple functions such as anti-aging and moisturizing, how to improve its utilization efficiency and exert its efficacy is the research starting point of this application. Studies in the prior art have found that large-molecule collagen is difficult to be absorbed by the skin, and consumers are also very concerned about whether the collagen added to the formula can really play a role through the skin. If the collagen directly added to the formula system cannot be absorbed by the skin, it may be wasted on the skin surface through light or microbial decomposition. Since collagen for external use on the skin generally has the problem of being difficult to fully absorb, collagen peptides prepared by enzymatic hydrolysis are usually used for external use on the skin. Collagen peptides have a smaller molecular weight and are more easily absorbed through the skin. The collagen used in this application are all small-molecule collagen peptide raw materials.

[0004] In addition, formulation encapsulation technology can solve the problem of transdermal absorption, thereby improving the bioavailability of collagen and exerting its sustained release effect. However, the carboxyl and amino groups of collagen itself are amphoteric in aqueous solution, and their charges vary depending on the pH value of the solution. Therefore, conventional formulation methods are difficult to achieve encapsulation of bicharged collagen.

[0005] For example, Chinese patent application CN202311025794 discloses an anti-hair loss stock solution containing transdermal recombinant collagen and a preparation method thereof. This technical method uses recombinant collagen with skin affinity and tissue compatibility as the basic component, and utilizes glycerol encapsulation technology to encapsulate highly active recombinant collagen in glycerol body vesicles, so that it has the characteristics of high stability, controlled sustained release, safety and mildness. However, this technical method introduces ethanol as an organic solvent and uses ultrasound and other processes at the same time, which makes the process complex and the production process cumbersome. Chinese patent application CN202410583047 discloses a supramolecular collagen microcapsule suitable for sensitive skin and its preparation method and application. This technology uses low eutectic solvent technology to compound dipalmitoylhydroxyproline and bisabolol to prepare a new type of low eutectic solvent, which can effectively encapsulate and deliver the composite protein to form a system-stable supramolecular microcapsule, effectively improving the protein encapsulation rate, thereby achieving the advantages of efficient penetration and targeted delivery of the composite protein on the skin. However, this technical method has disadvantages such as a complex process for preparing low eutectic solvents, the need for light protection or nitrogen protection, and a long reaction time.

[0006] In view of this, it is necessary to develop a new microcapsule emulsion containing collagen in order to maximize the efficacy of collagen. Summary of the Invention

[0007] To overcome the shortcomings and deficiencies of the prior art, the present invention provides a microcapsule emulsion containing collagen and a method for its preparation. This innovative method utilizes tranexamic acid to adjust the pH and zeta potential of the collagen solution, enabling the collagen to exhibit minimal solubility and conductivity near its isoelectric point. This successful preparation of a microcapsule formulation containing collagen improves collagen stability and transdermal absorption, while also providing sustained-release properties to improve skin condition.

[0008] The purpose of the present invention can be achieved through the following technical solutions:

[0009] In a first aspect, the present invention provides a method for preparing microcapsules containing collagen, the preparation method comprising the following steps:

[0010] (1) Add 0.01-1g acetic acid or formic acid to 10-100g water, add 0.1-5g chitosan until completely dissolved, then dissolve 0.02-2g surfactant and 0.1-5g calcium chloride, and homogenize until no obvious particles are formed to form solution A;

[0011] (2) Dissolve 0.1-5 g of collagen and 0.1-1 g of tranexamic acid in 5-50 g of water and disperse them evenly in the water to form solution B;

[0012] (3) Pre-dissolve 2g of sodium alginate in 5-50g of water until it is completely dissolved to form solution C;

[0013] (4) Solution B and solution C are added dropwise to solution A at a dropping speed of 0.01-0.1 g / s while homogenizing at a speed of 5000-10000 rpm to form solution D, i.e., a microcapsule solution containing collagen.

[0014] As an optional mode, in the above preparation method, the preparation method comprises the following steps:

[0015] (1) Add 0.1-0.5 g acetic acid or formic acid to 30-80 g of water, add 0.5-2 g chitosan until completely dissolved, then dissolve 0.2-1 g surfactant and 0.5-2 g calcium chloride, and homogenize until no obvious particles are formed to form solution A;

[0016] (2) Dissolve 0.5-2g collagen and 0.5-1g tranexamic acid in 10-30g water and disperse them evenly in the water to form solution B;

[0017] (3) Pre-dissolve 2g of sodium alginate in 10-30g of water until it is completely dissolved to form solution C;

[0018] (4) Solution B and solution C were added dropwise to solution A at a rate of 0.02-0.08 g / s while homogenizing at a rate of 7000-10000 rpm to form solution D, i.e., a microcapsule solution containing collagen.

[0019] As an optional manner, in the above preparation method, the preparation method includes the following steps: the surfactant is selected from one or more of the following: Tween-80, Span-80, monoglyceride of fatty acid or sucrose ester of fatty acid.

[0020] Preferably, in the above preparation method, in step (1), 0.01-1 g of Tween-80 and 0.01-1 g of Span-80 are used as surfactants.

[0021] More preferably, in the above preparation method, in step (1), 0.1-0.5 g of Tween-80 and 0.1-0.5 g of Span-80 are used as surfactants.

[0022] As an optional manner, in the preparation method of the present invention, the collagen used is derived from fish skin and has a molecular weight of less than 1000 Da.

[0023] In a second aspect, the present invention provides microcapsules containing collagen prepared by the preparation method described in the first aspect.

[0024] In a third aspect, the present invention provides a method for preparing a microcapsule emulsion containing collagen, the preparation method comprising the following steps:

[0025] (1) Take 50-150 g of the collagen microcapsule solution described in the second aspect above, and pre-dissolve 0.1-5 g of glycerol and 0.1-15 g of polyol until completely dissolved to form solution A;

[0026] (2) dissolving 0.1-5 g of cetearyl glucoside or glyceryl stearate in 1-10 g of oil and uniformly dispersing at 70-90° C. to form solution B;

[0027] (3) Solution B is added to solution A and homogenized at a speed of 5000-10000 rpm to form an emulsion sample, i.e., a microcapsule emulsion containing collagen.

[0028] As an optional mode, in the above preparation method, the preparation method comprises the following steps:

[0029] (1) Take 80-120 g of the collagen microcapsule solution described in the second aspect above, and pre-dissolve 0.5-2 g of glycerol and 0.5-10 g of polyol until completely dissolved to form solution A;

[0030] (2) dissolving 0.5-2 g of cetearyl glucoside or glyceryl stearate in 1-10 g of caprylic capric triglyceride or jojoba oil and uniformly dispersing at 80° C. to form solution B;

[0031] (3) Solution B is added to solution A and homogenized at a speed of 7000-10000 rpm to form an emulsion sample, i.e., a microcapsule emulsion containing collagen.

[0032] As an optional manner, in the above preparation method, in step (1), the polyol is selected from one or more of the following: propylene glycol, butylene glycol or pentanediol.

[0033] Preferably, in the above preparation method, in step (1), 0.1-5 g of butanediol and 1-10 g of pentanediol are used as polyols.

[0034] More preferably, in the above preparation method, in step (1), 0.5-2 g of glycerol and 0.5-2 g of butanediol are used as polyols.

[0035] In a fourth aspect, the present invention provides a microcapsule emulsion containing collagen prepared by the preparation method described in the third aspect.

[0036] In a fifth aspect, the present invention provides use of the collagen-containing microcapsules described in the second aspect or the collagen-containing microcapsule emulsion described in the fourth aspect in the preparation of cosmetics.

[0037] As an optional mode, in the above use, the cosmetic is toner, lotion, essence, cream, ointment, facial mask or freeze-dried powder.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) Since collagen has a dual charge, conventional microencapsulation methods are difficult to achieve cross-linking and encapsulation of collagen. This application utilizes the isoelectric point of collagen to achieve cross-linking and encapsulation of collagen. The process is simple and can be achieved using conventional equipment and experimental conditions.

[0040] (2) The pH value and Zeta potential value are adjusted by tranexamic acid so that the collagen is prepared in the isoelectric point state, which plays a synergistic role between tranexamic acid and collagen and makes up for the shortcoming of collagen's insufficient whitening effect;

[0041] (3) The preparation of microcapsules was achieved by cross-linking and encapsulating collagen, which effectively improved the transdermal absorption effect of collagen. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 : Microscopic photograph of the collagen-containing microcapsules prepared by the method of Example 1.

[0043] Figure 2 : Comparison of the permeability of microcapsule emulsion containing collagen (sample 1) and ordinary emulsion containing collagen (sample 2).

[0044] Figure 3 : Sample photos of collagen-containing microcapsules prepared by the methods of Example 1 and Comparative Examples 1-6. From left to right are Comparative Examples 1-6 and Example 1. DETAILED DESCRIPTION

[0045] The present invention will be further described below with reference to specific embodiments. It should be understood that the specific embodiments described herein are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0046] If no specific techniques or conditions are specified in the examples, the experiments were carried out according to the techniques or conditions described in the literature in the field or according to the product instructions. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0047] The experimental methods in the following examples are conventional methods unless otherwise specified. The experimental materials used in the following examples are commercially available products unless otherwise specified.

[0048] Example 1: Preparation of microcapsules containing collagen of the present invention

[0049] (1) Add 0.2 g of acetic acid to 60 g of water, add 1 g of chitosan until completely dissolved, then dissolve 0.2 g of Tween-80, 0.2 g of Span-80, and 1 g of calcium chloride and homogenize until no obvious particles are formed to form solution A;

[0050] (2) Dissolve 1 g of collagen (derived from fish skin, with a molecular weight of less than 1000 Da, the following collagen indicators are the same) and 0.7 g of tranexamic acid in 20 g of water and uniformly disperse them in the water to form solution B;

[0051] (3) Pre-dissolve 2 g of sodium alginate in 20 g of water until it is completely dissolved to form solution C;

[0052] (4) Solution B and solution C were added dropwise to solution A at a dropping speed of 0.05 g / s while homogenizing at a speed of 8000 rpm to form solution D, i.e., a microcapsule solution containing collagen.

[0053] The pH value of the collagen-containing microcapsule solution was 6.8, and the Zeta potential value was -10.58 mV.

[0054] Literature research and experimental results show that sodium alginate with anions is complexed with cationic chitosan through electrostatic interactions, and collagen is cross-linked to the sodium alginate interface layer through hydrogen bonds. There are also studies reporting that heating and acidic conditions can promote the formation of a complex between chitosan and collagen through hydrogen bonds. The sodium alginate and chitosan complex formed by electrostatic interactions undergoes interfacial self-assembly into capsules. At the same time, collagen further enhances the mechanical stability of the capsule through hydrogen bonds, thereby improving the overall compressive properties of the microcapsules.

[0055] Experimental work revealed that due to the active charge properties of collagen, a stable potential interface under specific pH conditions is required to stabilize the alginate-chitosan capsules. Capsules formed through the adsorption of positive and negative charges are particularly sensitive to the stability of the environmental charge. Collagen obtained by different processes may have different isoelectric points, requiring experimental exploration to determine the appropriate pH and zeta potential.

[0056] The microcapsule samples prepared by the above method are shown in the following microscope photos: Figure 1 shown. Figure 1The microscope photos in the figure were obtained using a fluorescent inverted microscope with a magnification of 200 times. It can be seen from the photos that the microcapsules are uniform and stable, there is no obvious adhesion between the microcapsules, and the average particle size of the microcapsules is about 10 μm.

[0057] Comparative Example 1: Preparation of Microcapsules Containing Collagen - Without Tranexamic Acid

[0058] (1) Add 0.2 g of acetic acid to 60 g of water, add 1 g of chitosan until completely dissolved, then dissolve 0.2 g of Tween-80, 0.2 g of Span-80, and 1 g of calcium chloride and homogenize until no obvious particles are formed to form solution A;

[0059] (2) Dissolve 1 g of collagen in 20 g of water and disperse it evenly in the water to form solution B;

[0060] (3) Pre-dissolve 2 g of sodium alginate in 20 g of water until it is completely dissolved to form solution C;

[0061] (4) Solution B and solution C were added dropwise to solution A at a dropping speed of 0.05 g / s while homogenizing at a speed of 8000 rpm to form solution D, i.e., a microcapsule solution containing collagen.

[0062] The pH value of the collagen-containing microcapsule solution was 3.8, and the Zeta potential value was -2.17 mV. Observation revealed that the microcapsule solution sample was obviously flocculated.

[0063] Comparative Example 2: Preparation of Microcapsules Containing Collagen - Using Tranexamic Acid and Sodium Hydroxide

[0064] (1) Add 0.2 g of acetic acid to 60 g of water, add 1 g of chitosan until completely dissolved, then dissolve 0.2 g of Tween-80, 0.2 g of Span-80, and 1 g of calcium chloride and homogenize until no obvious particles are formed to form solution A;

[0065] (2) Dissolve 1g collagen and 0.7g tranexamic acid in 20g water and mix with an appropriate amount of sodium hydroxide to uniformly disperse them in the water to form solution B;

[0066] (3) Pre-dissolve 2 g of sodium alginate in 20 g of water until it is completely dissolved to form solution C;

[0067] (4) Solution B and solution C were added dropwise to solution A at a dropping speed of 0.05 g / s while homogenizing at a speed of 8000 rpm to form solution D, i.e., a microcapsule solution containing collagen.

[0068] The pH value of the collagen-containing microcapsule solution was 7.3, and the Zeta potential value was -13.26 mV. Observation revealed that the microcapsule solution sample was obviously flocculated.

[0069] Comparative Example 3: Preparation of microcapsules containing collagen - adding collagen together

[0070] (1) Add 0.2 g acetic acid to 80 g water, add 1 g chitosan until completely dissolved, then dissolve 0.2 g Tween-80, 0.2 g Span-80, 1 g calcium chloride, 1 g collagen, and 0.7 g tranexamic acid and homogenize until no obvious particles are formed into solution A;

[0071] (2) Pre-dissolve 2 g of sodium alginate in 20 g of water until it is completely dissolved to form solution B;

[0072] (3) Solution B was added dropwise to solution A at a dropping speed of 0.05 g / s, and homogenization was performed while adding the solution. The homogenization speed was 8000 rpm to form solution C, i.e., a microcapsule solution containing collagen.

[0073] The microcapsule samples showed obvious flocculation and the microcapsules showed obvious adhesion.

[0074] Comparative Example 4: Preparation of microcapsules containing collagen - different dropwise addition order

[0075] (1) Dissolve 2 g of sodium alginate in 60 g of water until completely dissolved, then dissolve 0.2 g of Tween-80 and 0.2 g of Span-80 and mix homogenously to form solution A.

[0076] (2) Dissolve 1 g of collagen in 20 g of water, and then disperse 0.7 g of tranexamic acid in the water to form solution B.

[0077] (3) Add 1 g of chitosan to 0.2 g of acetic acid in 20 g of water until completely dissolved, and then add 1 g of calcium chloride until completely dissolved to form solution C;

[0078] (4) Solution B and solution C were added dropwise to solution A at a dropping speed of 0.05 g / s while homogenizing at a speed of 8000 rpm to form solution D, i.e., a microcapsule solution containing collagen.

[0079] The microcapsule samples showed obvious flocculation and the microcapsules showed obvious adhesion.

[0080] Comparative Example 5: Preparation of microcapsules containing collagen - different dropwise addition order

[0081] (1) Dissolve 2 g of sodium alginate in 60 g of water until completely dissolved, then dissolve 0.2 g of Tween-80 and 0.2 g of Span-80 and mix homogenously to form solution A.

[0082] (2) Dissolve 1 g of collagen in 20 g of water, and then disperse 0.7 g of tranexamic acid in the water to form solution B.

[0083] (3) Add 1 g of chitosan to 0.2 g of acetic acid in 10 g of water until completely dissolved to form solution C;

[0084] (4) Add solution B and solution C to solution A simultaneously at a dropwise addition rate of 0.05 g / s, homogenizing at a speed of 8000 rpm to form solution D.

[0085] (5) Add 1 g of calcium chloride to 10 g of water until it is completely dissolved to form solution E;

[0086] (6) Solution E was added dropwise to solution D at a dropping speed of 0.05 g / s, and homogenization was performed while adding the solution. The homogenization speed was 8000 rpm to form solution F, i.e., a microcapsule solution containing collagen.

[0087] The microcapsule samples showed obvious flocculation and the microcapsules showed obvious adhesion.

[0088] Comparative Example 6: Preparation of microcapsules containing collagen - different dropwise addition order

[0089] (1) Dissolve 2 g of sodium alginate in 60 g of water until completely dissolved, then dissolve 0.2 g of Tween-80 and 0.2 g of Span-80 and mix homogenously to form solution A.

[0090] (2) Dissolve 1 g of collagen in 20 g of water, and then disperse 0.7 g of tranexamic acid in the water to form solution B.

[0091] (3) In 10 g of water, 1 g of calcium chloride is completely dissolved to form solution C;

[0092] (4) Add solution B and solution C to solution A simultaneously at a dropwise addition rate of 0.05 g / s, homogenizing at a speed of 8000 rpm to form solution D.

[0093] (5) Add 1 g of chitosan to 0.2 g of acetic acid in 10 g of water until completely dissolved to form solution E;

[0094] (6) Solution E was added dropwise to solution D at a dropping speed of 0.05 g / s, and homogenization was performed while adding the solution. The homogenization speed was 8000 rpm to form solution F, i.e., a microcapsule solution containing collagen.

[0095] The microcapsule samples showed obvious flocculation and the microcapsules showed obvious adhesion.

[0096] The sample photos of the microcapsules containing collagen prepared by the methods of Example 1 and Comparative Examples 1-6 are as follows: Figure 3 shown.

[0097] Example 2: Preparation of the collagen-containing microcapsule emulsion of the present invention

[0098] (1) Take 90 g of the collagen-containing microcapsule solution prepared in Example 1, and pre-dissolve 1 g of glycerol, 1 g of butylene glycol, and 3 g of pentanediol until they are completely dissolved to form solution A;

[0099] (2) dissolving 1 g of cetearyl glucoside in 4 g of caprylic / capric triglyceride and dispersing the mixture uniformly at 80°C to form solution B;

[0100] (3) Solution B was added to solution A and homogenized at a speed of 8000 rpm to form an emulsion sample, i.e., a microcapsule emulsion containing collagen.

[0101] The performance test results of the emulsion sample obtained in Example 2 are shown in Table 1 below.

[0102] Table 1: Performance test results of collagen microcapsule emulsion samples

[0103]

[0104]

[0105] As can be seen from the data in the above table, the collagen microcapsule emulsion sample prepared in Example 2 has a uniform and stable appearance and remains stable under high and low temperature conditions without any stratification or demulsification. The pH value is weakly acidic, which meets the relevant standards of the cosmetics industry.

[0106] Example 3: Comparison of transdermal absorption between the collagen-containing microcapsule emulsion of the present invention and conventional emulsion

[0107] With reference to the preparation process of the collagen microcapsule emulsion in Example 2, a common emulsion was prepared.

[0108] The general emulsion preparation process is as follows:

[0109] (1) Take 90 g of an aqueous solution containing 0.9 g of collagen and pre-dissolve 1 g of glycerol, 1 g of butylene glycol, and 3 g of pentanediol until completely dissolved to form solution A;

[0110] (2) dissolving 1 g of cetearyl glucoside in 4 g of caprylic / capric triglyceride and dispersing the mixture uniformly at 80°C to form solution B;

[0111] (3) Solution B was added to solution A and homogenized at a speed of 8000 rpm to form an emulsion sample, i.e., a common emulsion containing collagen.

[0112] The artificial membrane was directly fixed between the sample pool and the receiving pool. The sample pools were the emulsion prepared in Example 2 (sample one) and the ordinary emulsion sample (sample two), and normal saline was used as a blank control. The receiving pool was filled with normal saline to a capacity of 8 mL, and constant stirring and constant temperature were maintained. The water temperature was maintained at 37°C ± 0.5°C and the rotation speed was 200 rpm. 1 mL of sample was taken at 2, 4, 6, 8 and 24 h, and an equal amount of normal saline was added at the same time. The mass concentration of hydroxyproline in the extracted liquid was determined, and the cumulative permeation per unit area (Q n ), the concentration of hydroxyproline added to the sample pool is recorded as (Q m ), and the hydroxyproline permeability is (P).

[0113]

[0114] Where: C n - Hydroxyproline mass concentration measured at the nth sampling point, μg / mL;

[0115] C i - the mass concentration of hydroxyproline measured at the i-th sampling point, μg / mL;

[0116] Conversion coefficient of 10-hydroxyproline and collagen peptide;

[0117] V-receiving pool capacity is 8mL;

[0118] V0 - 1 mL of volume was taken at each time point;

[0119] A-penetration area is 1.5cm 2 .

[0120] Determination of hydroxyproline content: GB / T9695.23-2008.

[0121] Prepare hydroxyproline standard solution: accurately weigh 50 mg of hydroxyproline, dilute to 100 mL with water, and add one drop of 3 mol / L sulfuric acid solution to make a standard solution.

[0122] Prepare a buffer solution with a pH of 6.8 by adding 14 g of sodium hydroxide, 78 g of anhydrous acetic acid solution, 26 g of citric acid monohydrate, and 250 mL of n-propanol to a 1 L volumetric flask, shake well, and bring to volume.

[0123] Prepare chloramine T solution: dissolve 1.41 g of chloramine T in 100 mL of pH 6.8 buffer prepared in the previous step.

[0124] Prepare the developer solution: weigh 10 g of p-dimethylaminobenzaldehyde, dissolve it in 35 mL of 60% perchloric acid solution, mix well, slowly add 65 mL of isopropanol solution, and dilute to 100 mL in a volumetric flask.

[0125] Draw a hydroxyproline standard curve: Dilute the above hydroxyproline standard solution to 0.5 μg / mL, 1.0 μg / mL, 1.5 μg / mL, 2.0 μg / mL, and 2.5 μg / mL, using deionized water as a blank sample. Take 4 mL of the dilution and add 2 mL of chloramine T, mix thoroughly, and let it stand for 20 minutes. Then add 2 mL of the colorimetric reagent and place it in a colorimetric tube. Heat in a 60°C water bath for 20 minutes. Remove and cool under running water for at least 3 minutes. Let it stand for 30 minutes, then measure the absorbance at a wavelength of 558 nm ± 2 nm.

[0126] Sample determination: After taking out the sample from the receiving cell and diluting it, add 2mL of chloramine T and mix it. After standing at room temperature for 20 minutes, add 2mL of color developer and place it in a colorimetric tube. Heat it in a 60℃ water bath for 20 minutes. After taking it out, cool it under running water for at least 3 minutes. After standing at room temperature for 30 minutes, measure the absorbance value at a wavelength of 558±2nm.

[0127] Conclusion: If Figure 2 As shown in the figure, the permeability of collagen microcapsule emulsion is significantly better than that of ordinary emulsion. It can be seen that collagen microcapsules can significantly improve the permeation and absorption efficiency of collagen, and the trend of permeation data shows that the sustained release of collagen is achieved.

[0128] Example 4: Whitening efficacy experiment

[0129] With reference to the preparation process of collagen microcapsule emulsion in Example 2, a common emulsion (sample 3) was prepared. The preparation process of sample 3 common emulsion is as follows:

[0130] (1) Take 90 g of an aqueous solution containing 0.7 g of tranexamic acid and pre-dissolve 1 g of glycerol, 1 g of butylene glycol, and 3 g of pentanediol until completely dissolved to form solution A;

[0131] (2) dissolving 1 g of cetearyl glucoside in 4 g of caprylic / capric triglyceride and dispersing the mixture uniformly at 80°C to form solution B;

[0132] (3) Solution B was added to solution A and homogenized at a homogenization speed of 8000 rpm to form an emulsion sample, i.e., a common emulsion containing tranexamic acid.

[0133] Experimental Principle: Tyrosinase catalyzes the production of dopaquinone from the substrate tyrosine, which then undergoes a series of reactions to ultimately produce melanin. The tyrosinase-catalyzed reaction is considered the rate-limiting step in melanin production, so substances that inhibit tyrosinase activity are considered to have potential whitening activity. Dopaquinone is a colored substance with a characteristic absorption peak at 470nm. The amount of dopaquinone produced is proportional to the activity of the enzyme. Therefore, the amount of dopaquinone produced in the system can be measured with a spectrophotometer to reflect the enzyme's activity.

[0134] Main reagents: tyrosinase (from mushrooms) (Shanghai Yihe Biotechnology Co., Ltd., ≥500 U / mg); L-tyrosine (Aladdin, 99.0%-101.0%); α-arbutin (DSM, ≥98%); disodium hydrogen phosphate (Na2HPO4·12H2O) and sodium dihydrogen phosphate (NaH2PO4·2H2O) were all domestically produced analytical grade.

[0135] Sample preparation: The sample was diluted 8 times with phosphate buffer to obtain the test sample. The positive control was vitamin C.

[0136] Table 2: Tyrosinase inhibition rate of microcapsule emulsion containing collagen (sample 1), ordinary emulsion containing collagen (sample 2), and ordinary emulsion containing tranexamic acid (sample 3)

[0137] Sample number Sample 1 Sample 2 Sample 3 Positive control Inhibition rate 84.21％ 30.36％ 52.16％ 65.32％

[0138] Conclusion: As shown in Table 2, through the tyrosinase activity inhibition experiment, it was found that collagen itself has the ability to inhibit tyrosinase activity, but the inhibitory ability is not strong. When collagen is combined with tranexamic acid, it can play a synergistic role and significantly improve the activity of inhibiting tyrosinase.

[0139] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A method for preparing microcapsules containing collagen, characterized in that: The preparation method comprises the following steps: (1) Add 0.01-1g acetic acid or formic acid to 10-100g water, add 0.1-5g chitosan until completely dissolved, then dissolve 0.02-2g surfactant and 0.1-5g calcium chloride, and homogenize until no obvious particles are formed to form solution A; (2) Dissolve 0.1-5 g of collagen and 0.1-1 g of tranexamic acid in 5-50 g of water and disperse them evenly in the water to form solution B; (3) Pre-dissolve 2g of sodium alginate in 5-50g of water until it is completely dissolved to form solution C; (4) Solution B and solution C are added dropwise to solution A at a dropping speed of 0.01-0.1 g / s while homogenizing at a speed of 5000-10000 rpm to form solution D, i.e., a microcapsule solution containing collagen.

2. The preparation method according to claim 1, wherein: The preparation method comprises the following steps: (1) Add 0.1-0.5 g acetic acid or formic acid to 30-80 g of water, add 0.5-2 g chitosan until completely dissolved, then dissolve 0.2-1 g surfactant and 0.5-2 g calcium chloride, and homogenize until no obvious particles are formed to form solution A; (2) Dissolve 0.5-2g collagen and 0.5-1g tranexamic acid in 10-30g water. It is uniformly dispersed in water to form solution B; (3) Pre-dissolve 2g of sodium alginate in 10-30g of water until it is completely dissolved to form solution C; (4) Solution B and solution C were added dropwise to solution A at a rate of 0.02-0.08 g / s while homogenizing at a rate of 7000-10000 rpm to form solution D, i.e., a microcapsule solution containing collagen.

3. The preparation method according to claim 1 or claim 2, characterized in that: The surfactant is selected from one or more of the following: Tween-80, Span-80, monoglyceride of fatty acid or sucrose ester of fatty acid.

4. Collagen-containing microcapsules prepared by the preparation method according to any one of claims 1 to 3.

5. A method for preparing a microcapsule emulsion containing collagen, characterized in that: The preparation method comprises the following steps: (1) Take 50-150 g of the collagen microcapsule solution according to claim 4, and pre-dissolve 0.1-5 g of glycerol and 0.1-15 g of polyol until completely dissolved to form solution A; (2) dissolving 0.1-5 g of cetearyl glucoside or glyceryl stearate in 1-10 g of oil and uniformly dispersing at 70-90° C. to form solution B; (3) Solution B is added to solution A and homogenized at a speed of 5000-10000 rpm to form an emulsion sample, i.e., a microcapsule emulsion containing collagen.

6. The preparation method according to claim 5, characterized in that: The preparation method comprises the following steps: (1) Take 80-120 g of the collagen microcapsule solution according to claim 4, and pre-dissolve 0.5-2 g of glycerol and 0.5-10 g of polyol until completely dissolved to form solution A; (2) dissolving 0.5-2 g of cetearyl glucoside or glyceryl stearate in 1-10 g of caprylic capric triglyceride or jojoba oil and uniformly dispersing at 80° C. to form solution B; (3) Solution B is added to solution A and homogenized at a speed of 7000-10000 rpm to form an emulsion sample, i.e., a microcapsule emulsion containing collagen.

7. The preparation method according to claim 5 or claim 6, characterized in that: In step (1), the polyol is selected from one or more of the following: propylene glycol, butylene glycol or pentanediol.

8. A microcapsule emulsion containing collagen prepared by the preparation method according to any one of claims 5 to 7.

9. Use of the collagen-containing microcapsules according to claim 4 or the collagen-containing microcapsule emulsion according to claim 8 in the preparation of cosmetics.

10. The use according to claim 9, characterized in that: The cosmetics are toner, lotion, essence, cream, ointment, facial mask or freeze-dried powder.

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