An ergothioneine patch

Abstract

The application discloses a patch of ergothioneine, and belongs to the field of beauty care and transdermal drug delivery. The patch of ergothioneine is a soluble microneedle patch, which comprises a needle tip layer loaded with ergothioneine and a base layer. The base material of the needle tip layer is a water-soluble high molecular compound with high biocompatibility, and the base material of the base layer is a water-soluble high molecular compound with low water solubility. The application uses the method of polyethylene glycol to modify the mold of conventional soluble microneedles, i.e. a PDMS mold, so as to weaken the interaction between the PDMS and the base material and facilitate demolding. In addition, the drug-containing needle tip layer is enriched at the needle tip through centrifugation, and is not easy to adhere to the mold with the help of polyethylene glycol, thereby improving the precision of drug delivery.

Description

TECHNICAL FIELD

[0001] The present application relates to a transdermal patch of ergothioneine, belonging to the field of cosmetic skin care and transdermal drug delivery. BACKGROUND

[0002] Studies have shown that the antioxidant properties of ergothioneine can inhibit the formation of hydrogen peroxide and eliminate the generation of free radicals. The keratinocytes, fibroblasts and melanocytes in human epidermal cells can express ergothioneine transporters, which can absorb and accumulate ergothioneine. Ergothioneine has an absorption wavelength similar to DNA in the ultraviolet absorption range, which can effectively prevent cell damage caused by ultraviolet radiation. At the same time, ergothioneine also has antioxidant capacity, and under the condition of continuous ultraviolet irradiation for 18 hours, 70% of the cells still have reducing properties, inhibit lipid peroxidation reaction, prevent the generation of active oxygen, and reduce the apoptosis of irradiated cells.

[0003] The antioxidant capacity of ergothioneine is mainly due to the presence of terminal thiol groups, but when it is made into liquid preparations such as essence and lotion, semi-solid preparations such as emulsion and cream, it is easy to be oxidized and lose efficacy. In addition, ergothioneine has strong water solubility, and the transdermal efficiency is very limited.

[0004] With the rapid development of microfabrication technology, microneedle drug delivery system has emerged and received widespread attention. Microneedle is a new type of physical penetration technology, which is composed of multiple micron-sized fine needle tips connected in an array on the base. The length (25 μm-1000 μm), size and shape of microneedle can be individually designed according to the treatment needs. As a new type of transdermal drug delivery method, microneedle drug delivery combines the advantages of subcutaneous injection and transdermal patch, which is painless and minimally invasive, and has high drug absorption efficiency. In addition, patients can self-administer when using microneedle drug delivery, which is convenient and safe, and has good patient compliance. Microneedle transdermal drug delivery is widely used in the transdermal delivery of small molecules, biological agents, vaccines, intracellular DNA / RNA, etc., covering the fields of cosmetics, medicine, medical devices and other diseases.

[0005] The preparation methods of the microneedles include solvent casting, photolithography, droplet air blowing, 3D printing, stretch lithography, hot pressing, micromolding and ultrasonic welding, etc. Among them, the most commonly used, the simplest and the easiest to realize large-scale application is the micromolding method. The micromolding method mainly includes the following steps: 1) preparation, including the preparation of the drug-containing substrate solution and the non-drug substrate solution; 2) pouring the drug-containing substrate solution into the mold, making it as close as possible to the mold needle tip; 3) continue to pour the non-drug substrate solution into the mold, making it as close as possible to the mold; 4) drying and forming; 5) demolding; 6) packaging. Among them, the drug can be enriched to the needle tip site by centrifugation, but it is easy to cause drug residue on the mold, resulting in inaccurate drug loading. At the same time, it will also increase the difficulty of demolding the substrate from the mold. SUMMARY

[0006] [TECHNICAL PROBLEM]

[0007] The technical problem to be solved by the present application is that when the existing method for preparing microneedles is used to prepare ergothioneine-containing microneedles, there is a problem of inaccurate drug loading and greater difficulty in demolding.

[0008] [TECHNICAL SCHEME]

[0009] The present application provides an ergothioneine patch, which is a soluble microneedle patch, comprising a needle tip layer loaded with ergothioneine and a base layer; the substrate of the needle tip layer is a water-soluble high molecular compound with high biocompatibility, and the substrate of the base layer is a water-soluble high molecular compound with low water solubility.

[0010] In some embodiments of the present application, the substrate of the needle tip layer is selected from at least one of chitosan, hyaluronic acid, sodium alginate, polyvinyl alcohol, polyvinylpyrrolidone, sodium carboxymethyl cellulose, maltose and cyclodextrin.

[0011] In some embodiments of the present application, the substrate of the base layer is selected from at least one of chitin, polyvinyl alcohol, polylactic acid, polylactic acid-glycolic acid copolymer polycarbonate, polyethylene, polyvinyl chloride and polyester.

[0012] In some embodiments of the present application, the ergothioneine patch has 100 microneedles arranged in an array of 10x10, each microneedle has a height of 500 μm, each microneedle has a needle tip diameter of 5-10 μm and a needle base diameter of 200 μm, the distance between the needle tips is 800 μm, and the area of the entire patch is 1.5-2 cm 2 . The loading amount of ergothioneine in the ergothioneine patch is 5-10 μg.

[0013] In some embodiments of the present application, the shape of the ergothioneine patch is square or circular.

[0014] The present application provides a method for preparing the ergothioneine patch, comprising the following steps:

[0015] (1) Preparation of the solution of the tip layer: a certain amount of ergothioneine is dissolved in ultrapure water, and the base material of the tip layer (a water-soluble high-molecular compound with high biocompatibility) is gradually added, and the heating and stirring are maintained during the addition process, so that the ergothioneine and the base material of the tip layer are fully dissolved and dispersed in water to obtain the solution A of the tip layer;

[0016] (2) Preparation of the solution of the base layer: the base material (a high-molecular compound with low water solubility) of the base layer is dispersed in an organic solvent to obtain the solution B of the base layer;

[0017] (3) Modification of the mold: a certain mass fraction of the aqueous polyethylene glycol solution is prepared, 100 μL of the aqueous polyethylene glycol solution is vertically dropped onto the surface of the PDMS mold, and the aqueous polyethylene glycol solution is ensured to completely cover the surface of the PDMS mold; the PDMS mold is placed in a 12-well plate, and centrifuged at a centrifugal force of 300-2400 g at room temperature for 1-5 min, so that the aqueous polyethylene glycol solution is gathered on the surface of the groove of the PDMS mold, and dried at 40-60 °C for 0.5-1 h to remove the excess aqueous polyethylene glycol solution;

[0018] (4) The solution A of the tip layer prepared in step (3) is added to the mold prepared in step (3), and centrifuged at a centrifugal force of 300-2400 g for 1-5 min to deposit the solution A of the tip layer on the surface of the groove of the mold, and the excess solution A of the tip layer is scraped off, and the mold together with the solution A of the tip layer is placed in a 40-50 °C air oven for drying for 0.5-2 h, and the mold is taken out;

[0019] (5) The solution B of the base layer is added to the mold of step (4), and vacuum dried at 25-40 °C for 5-10 h, and the mold is taken out, and demolded, and the ergothioneine patch of the present embodiment is obtained. After vacuum drying at 25-40 °C for 5-10 h, the finished ergothioneine patch is automatically separated from the mold and can be easily taken out.

[0020] In some embodiments of the present application, the ratio of the amount of ergothioneine to water in step (1) is 0.0005-0.1% (w / w), and the ratio of the amount of the base material of the tip layer to water is 0.1-60% (w / w).

[0021] In some embodiments of the present application, the temperature range of heating in step (1) is 30-60 °C.

[0022] In some embodiments of the present application, the organic solvent in step (2) is selected from one of ethanol, dichloromethane, dimethyl sulfoxide, diethyl ether, N,N-dimethylformamide, and acetone.

[0023] In some embodiments of the present application, the ratio of the substrate of the base layer to the organic solvent in step (2) is 0.2%-20%.

[0024] In some embodiments of the present application, the average molecular weight Mn of the polyethylene glycol used in step (3) is 10000-100000, preferably Mn is 20000-50000.

[0025] In some embodiments of the present application, the mass fraction of the polyethylene glycol in the aqueous polyethylene glycol solution used in step (3) is 0.05-5%, preferably 0.1-1%.

[0026] In some embodiments of the present application, the centrifugal force in step (3) is preferably 850g-1500g.

[0027] [Advantages]

[0028] 1. Compared with traditional cosmetic formulations, the patch of the present application uses soluble microneedle technology to improve the transdermal absorption efficiency, and significantly improves the whitening and spot-fading effect.

[0029] 2. The method of the present application uses polyethylene glycol to modify the mold of conventional soluble microneedles, i.e. PDMS mold, which can weaken the interaction between PDMS and the substrate (including substrates with good and poor water solubility), and is more beneficial to demolding. In addition, the drug-containing needle tip layer is enriched at the needle tip by centrifugation, and is not easy to adhere to the mold with the help of polyethylene glycol, thereby improving the precision of drug delivery. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 Structure diagram of ergothioneine patch.

[0031] Figure 2 is the transdermal efficiency of the ergothioneine patch in the embodiments of the present application. DETAILED DESCRIPTION

[0032] The centrifuge used in the following examples is Centrifuge 5810-microcentrifuge (Eppendorf company).

[0033] Example 1: Preparation method and optimization of ergothioneine patch

[0034] The ergothioneine patch of the present example is a soluble microneedle patch. There are 100 microneedles in the ergothioneine patch, which are arranged in an array of 10x10, each microneedle has a height of 500μm, the diameter of each microneedle tip is 5-10μm, the diameter of the needle base is 200μm, and the distance between the microneedle tips is 800μm. The shape of the ergothioneine patch is circular, and the area of the patch is 1.5cm 2 . As Figure 1As shown, the dissolvable microneedle patch comprises a base layer 1 and an ergothioneine-loaded tip layer 2, and the dissolvable microneedles are arranged in an array on the base layer; the tip layer 2 contains the content ergothioneine 21, which is mainly distributed in the tip, i.e. away from the base layer, due to the influence of centrifugal force. In use, the tip layer 2 is easily broken or dissolved when it encounters interstitial fluid, so that the content ergothioneine 21 is released.

[0035] Specifically, the present embodiment uses polylactic acid-glycolic acid copolymer (PLGA) as the base material of the base layer; and polyvinylpyrrolidone (PVP) is selected as the base material of the tip layer. In the present embodiment, the PLGA is purchased from Shanghai Aladdin Biochemical Scientific Co., Ltd., the PVP is purchased from Shanghai Aladdin Biochemical Scientific Co., Ltd., and the ergothioneine is from Shenzhen Zhongke Xinyang Biological Technology Co., Ltd.

[0036] Specifically, the preparation method of the ergothioneine patch of the present embodiment comprises the following steps:

[0037] 1. Preparation of tip layer solution: 0.5 mg of ergothioneine is dissolved in a small amount of ultrapure water, and PVP is added while maintaining heating and stirring, so that the final concentration of PVP is 500 mg / mL, ultrapure water is added to make the final volume 10 mL, and after 20 min, a milky white dispersion is obtained, and at this time the concentration of ergothioneine is 0.05 mg / mL;

[0038] 2. Preparation of base layer solution: 100 mg of PLGA is dissolved in 10 mL of diethyl ether to obtain a base layer solution;

[0039] 3. Modification of the mold: prepare a 0.01%-3% (w / v) polyethylene glycol (PEG-20000) aqueous solution. 100 μL of the prepared polyethylene glycol aqueous solution is vertically added to the surface of the above-mentioned PDMS mold to ensure complete coverage; the mold is placed in a 12-well plate, and centrifuged at 300-2400 g at room temperature for 1-5 min to make the solution gather on the surface of the groove, and then dried at 40°C for 45 min to remove the excess polyethylene glycol aqueous solution;

[0040] 4. Add 100 μL of the tip layer solution of step 1 to the mold modified in step 3, centrifuge at 80-2400 g for 5 min, deposit the polymer at the bottom of the groove of the mold, scrape off the excess tip solution on the surface, and then place the mold in a blast oven, dry at 40-50°C for 0.5-2 h, and take out the mold;

[0041] 5. Add 100 μL of the base layer solution of step 2 to the mold of step 4, and vacuum dry at 25°C for 10 h, take out the mold, demold, and obtain the ergothioneine patch of the present embodiment.

[0042] In this embodiment, the volume of each patch containing drug microneedles is about 20 μL, and the concentration of ergothioneine is 0.05 mg / mL, so the drug loading of the patch should be 10 μg.

[0043] In this embodiment, the concentration of polyethylene glycol in step 3 and the centrifugal speed in step 4 are compared and optimized by the molding rate of microneedles (i.e. the proportion of the final molded patches to the total number of patches when 50 same ergothioneine patches are made at the same time) and the average drug loading (i.e. the mass of ergothioneine in the microneedle tip layer, taking the average of 10 molded ergothioneine patches). The patches in this embodiment have 100 microneedles arranged in an array of 10x10, and the patches that can form a complete 100 independent microneedle patch are considered as molded or qualified, otherwise they are considered as unmolded or unqualified patches.

[0044] The results are shown in Table 1. When the concentration of polyethylene glycol is between 0.1-1% and the centrifugal speed in step 4 is between 3000-4000 rpm, the molding rate of the patch is 100% and the drug loading is the highest. This result shows that under this process, the connection between the tip and the mold is relatively loose, easy to demold, and the drug is not easy to remain on the surface of PDMS, ensuring the drug loading of the patch.

[0045] Table 1 Optimization of the preparation method of ergothioneine patch

[0046]

[0047] Example 2 Detection of transdermal efficiency of ergothioneine patch

[0048] Precise drug loading and high efficiency of drug delivery can ensure the application value of the ergothioneine patch in the above embodiments, therefore, the applicant conducted a study on the transdermal efficiency of ergothioneine patch.

[0049] The preparation method of the patch used in this embodiment is as follows:

[0050] 1. Preparation of tip layer solution: 10 mg of ergothioneine was dissolved in a small amount of ultrapure water, and hyaluronic acid sodium (average molecular weight 500,000) was added while maintaining heating and stirring to obtain a milky white dispersion. At this time, the final concentration of hyaluronic acid sodium is 80 mg / mL, and the concentration of ergothioneine is 0.01 mg / mL.

[0051] 2. Preparation of base layer solution: 200 mg of polyvinyl alcohol (PVA) was dissolved in 10 mL of ethanol to obtain the base layer solution.

[0052] 3. Modification of the mold: prepare 0.1% (w / v) polyethylene glycol (PEG-30000) aqueous solution. Vertically drop 100 μL of the prepared polyethylene glycol solution onto the surface of the PDMS mold, ensuring complete coverage; place the mold in a 12-well plate, centrifuge at 1200g at room temperature for 1-5 min, so that the solution is gathered on the surface of the groove, dry at 60°C for 1 h, and remove the excess polyethylene glycol aqueous solution;

[0053] 4. Add 100 μL of the needle tip layer solution of step 1 to the mold modified in step 3, centrifuge at 1200g for 5 min, deposit the polymer on the surface of the groove of the mold, scrape off the excess needle tip solution, and then place the mold in a blast oven, dry at 40-50°C for 0.5-2 h, and take out the mold;

[0054] 5. Add 100 μL of the base layer solution of step 2 to the mold of step 4, vacuum dry at 25°C for 10 h, take out the mold, demold, and obtain the ergothioneine patch of the present example.

[0055] The mass fraction of ergothioneine in the present example is 0.01 mg / mL, and an ergothioneine-PVP dispersion solution at the same concentration is set up as a control group. In vitro transdermal diffusion is studied using an in vitro transdermal diffusion cell (Franz diffusion cell), and the transdermal efficiency of ergothioneine is quantitatively and systematically evaluated in real time using high performance liquid chromatography (HPLC).

[0056] Before the experiment, the pig skin is pretreated, including: hair removal, fat removal, and removal of surface dirt. Dry ergothioneine patches are vertically pressed onto the surface of fresh pig skin at a ventilated place and kept for 2 min, and 0.5 ml of ergothioneine-PVP dispersion solution is evenly applied to the surface of the pig skin. Then, it is transferred to a Franz in vitro transdermal diffusion cell, and the receiving cell is filled with PBS solution. The solution is taken out for HPLC quantitative detection at 30 min, 1 h, 2 h, 4 h, 8 h, 12 h, 16 h, and 24 h, respectively.

[0057] The results are shown in Figure 2 The transdermal efficiency of the ergothioneine patch increases with time, and the transdermal efficiency at 24 h reaches 78%, while the transdermal efficiency of the control group is only about 10%, indicating that the transdermal efficiency of the ergothioneine patch of the present application is higher.

[0058] Example 3

[0059] Tyrosinase is the main rate-limiting enzyme for the synthesis of melanin, and the amount of melanin synthesis is closely related to the activity of the enzyme. Tyrosinase has a dual catalytic function of monophenolase and diphenolase. Under the action of monophenolase, L-tyrosine is hydroxylated to form L-DOPA, and under the action of diphenolase, L-DOPA is oxidized to form dopaquinone, which is then converted into melanin through a series of reactions. Therefore, the applicant studied the inhibitory ability of ergothioneine soluble microneedles on the activity of tyrosinase, using L-tyrosine and L-DOPA as substrates, respectively, to investigate the inhibitory ability of ergothioneine patches on the activity of tyrosine monophenolase and tyrosine diphenolase.

[0060] The preparation method of the patch used in this example is as follows:

[0061] 1. Preparation of the solution of the tip layer: 0.1 mg of ergothioneine was dissolved in 10 mL of ultrapure water, and carboxymethyl cellulose sodium was added while maintaining heating and stirring, so that the final concentration was 400 mg / mL, and the concentration of ergothioneine was 0.01 mg / mL, finally obtaining a milky white dispersion;

[0062] 2. Preparation of the solution of the base layer: 80 mg of PLGA was dissolved in 10 mL of N,N-dimethylformamide to obtain the solution of the base layer;

[0063] 3. Modification of the mold: 0.5% (w / v) polyethylene glycol (PEG-50000) aqueous solution was prepared. 100 μL of the prepared polyethylene glycol solution was vertically added to the surface of the PDMS mold to ensure complete coverage. The mold was placed in a 12-well plate and centrifuged at 850 g at room temperature for 2 min to make the solution gather on the surface of the groove. The mold was dried at 40°C for 0.5 h to remove the excess polyethylene glycol aqueous solution;

[0064] 4. 100 μL of the solution of the tip layer in step 1 was added to the mold modified in step 3, and centrifuged at 850 g for 5 min to deposit the polymer on the surface of the groove of the mold. The excess tip solution was scraped off, and then the mold was placed in a blast oven and dried at 40°C for 2 h. The mold was removed;

[0065] 5. 100 μL of the solution of the base layer in step 2 was added to the mold in step 4, and vacuum dried at 25°C for 10 h. The mold was removed and demolded to obtain the ergothioneine patch of this example.

[0066] The experimental results are as follows:

[0067] 1. Inhibitory ability of ergothioneine microneedles on the activity of tyrosine monophenolase

[0068] Before the experiment, ergothioneine patch was dissolved in PBS (A1). Experimental group: 1 mM L-tyrosine solution was added to the 96-well plate, 10 μL of A1 solution was added, mixed, and incubated at 30°C for 10 min; 10 μL of tyrosinase solution was added, shaken, and incubated at 30°C for 30 min, and the absorbance was measured at 475 nm. Sample control group (A2) used an equal amount of PBS instead of tyrosinase. Blank group (A3) used PBS instead of sample solution. Blank control group (A4) used an equal amount of PBS to replace tyrosinase and sample solution, respectively. Vitamin C was used to replace the sample solution as a positive control group, and Table 1 shows the inhibition rate (%) of tyrosinase monophenolase activity; the inhibition rate calculation formula is as follows:

[0069]

[0070] Wherein A1 is the absorbance of the experimental group or the positive control group, A2 is the absorbance of the sample control group, A3 is the absorbance of the blank group, and A4 is the absorbance of the blank control group.

[0071] The results are shown in Table 2, and the inhibition ability of ergothioneine on monophenolase activity showed an upward trend with increasing concentration between 0-0.5 mg / ml, and at the same concentration, the inhibition ability of ergothioneine on monophenolase activity was higher than that of traditional antioxidant vitamin C.

[0072] Table 2 Inhibition ability of ergothioneine and vitamin C on tyrosine monophenolase activity

[0073] 0 0.01 mg / ml 0.05 mg / ml 0.1 mg / ml 0.5 mg / ml Vitamin C 0.4±0.05％ 20±0.1％ 39±2.5％ 51±5.0％ 55±4.1％ Vitamin C 0.5±0.05％ 40±0.8％ 70±3.4％ 85±5.5％ 90±6.5％

[0074] 2. Inhibition ability of ergothioneine microneedles on tyrosine diphenolase activity

[0075] Before the experiment, ergothioneine patch was dissolved in PBS (A1), and the experimental group: 100 μL of 0.05% levodopa (w / w) was added to the 96-well plate, 10 μL of sample solution was added, mixed, and incubated at 30°C for 10 min, 10 μL of tyrosinase solution was added, shaken, and incubated at 30°C for 30 min, and the absorbance was immediately measured at 475 nm. Sample control group (A2) used an equal amount of PBS instead of tyrosinase. Blank group (A3) used PBS instead of sample solution. Blank control group (A4) used an equal amount of PBS to replace tyrosinase and sample solution, respectively. Vitamin C was used to replace the sample solution as a positive control group, and Table 2 shows the inhibition rate (%) of tyrosinase monophenolase activity; the calculation formula is as follows:

[0076]

[0077] Wherein A1 is the absorbance of the experimental group or the positive control group, A2 is the absorbance of the sample control group, A3 is the absorbance of the blank group, and A4 is the absorbance of the blank control group.

[0078] The results are shown in Table 3. The inhibitory ability of ergothioneine on the activity of tyrosinase increased with the increase of the concentration of ergothioneine between 0 and 0.5 mg / ml. At the same concentration, the inhibitory ability of ergothioneine on the activity of tyrosinase was higher than that of traditional antioxidant vitamin C.

[0079] Table 3 Inhibitory ability of ergothioneine and vitamin C on the activity of tyrosinase

[0080] 0 0.01 mg / ml 0.05 mg / ml 0.1 mg / ml 0.5 mg / ml Vitamin C 0.2±0.05％ 10±0.8％ 23±4.5％ 32±2.0％ 49±4.1％ Vitamin C 0.01 mg / ml 0.05 mg / ml 0.1 mg / ml 0.5 mg / ml Vitamin C Vitamin C 0.01 mg / ml 0.05 mg / ml 0.1 mg / ml 0.5 mg / ml Vitamin C Vitamin C 0.01 mg / ml 0.05 mg / ml 0.1 mg / ml 0.5 mg 0.2±0.05％ 42±3.1％ 59±3.5％ 76±3.5％ 86±2.2％

Claims

1. A method for preparing ergothioneine-soluble microneedle patches, characterized in that, The ergothioneine soluble microneedle patch comprises a needle tip layer loaded with ergothioneine and a base layer. The substrate of the needle tip layer is selected from at least one of sodium hyaluronate, polyvinylpyrrolidone, and sodium carboxymethyl cellulose, and the substrate of the base layer is selected from at least one of polyvinyl alcohol and polylactic acid-glycolic acid copolymer. Includes the following steps: (1) Preparation of needle tip layer solution: Ergothioneine was dissolved in ultrapure water, and the substrate of the needle tip layer was gradually added to dissolve and disperse the ergothioneine and the substrate of the needle tip layer in water to obtain needle tip layer solution A; (2) Preparation of base layer solution: The base material is dispersed in an organic solvent to obtain a uniform base layer solution B; (3) Mold preparation: Add polyethylene glycol aqueous solution to the surface of the PDMS mold, ensuring that the polyethylene glycol aqueous solution completely covers the surface of the PDMS mold; centrifuge the PDMS mold to allow the polyethylene glycol aqueous solution to accumulate on the groove surface of the PDMS mold, and dry to remove excess polyethylene glycol aqueous solution; the average molecular weight of polyethylene glycol Mn is 20000-50000; the mass fraction of polyethylene glycol in the polyethylene glycol aqueous solution is 0.1-1%; (4) Add the prepared needle tip layer solution A to the mold prepared in step (3), centrifuge to deposit the needle tip layer solution A on the surface of the groove of the mold, scrape off the excess needle tip layer solution A, dry the mold together with the needle tip layer solution A, and take out the mold; the centrifugation force is 850-1500g; (5) Add base solution B to the mold in step (4), dry, remove the mold, demold, and obtain ergothionein soluble microneedle patch.

2. The method according to claim 1, characterized in that, In step (1), the ratio of ergothioneine to water is 0.0005-0.1%w / w, and the ratio of substrate to water in the needle tip layer is 0.1-60%w / w.

3. The method according to claim 1, characterized in that, The organic solvent mentioned in step (2) is selected from one of ethanol, dichloromethane, dimethyl sulfoxide, diethyl ether, N,N-dimethylformamide, and acetone.

4. Ergothioneine soluble microneedle patch prepared by the method of claim 1.

5. The ergothioneine-soluble microneedle patch according to claim 4, characterized in that, The ergothioneine patch contains 100 microneedles arranged in a 10×10 array. Each microneedle is 500 μm high, with a tip diameter of 5-10 μm and a base diameter of 200 μm. The distance between the tips is 800 μm, and the total area of ​​the patch is 1.5-2 cm². 2 .

6. The ergothioneine-soluble microneedle patch according to claim 4, characterized in that, The ergothioneine patch is square or circular in shape.

Images