Color developing particles, absorbable microneedle patch and application of absorbable microneedle patch in skin marking

Abstract

The invention belongs to the technical field of transdermal microneedles, and particularly relates to a color developing particle, an absorbable microneedle patch and application of the absorbable microneedle patch in skin marking. The invention discloses a microneedle color developing particle, which is prepared by reacting an amine compound (cyclohexyl methylamine or 2, 4, 6-trimethylaniline) with genipin under a specific condition. When the transdermal microneedle patch prepared from the color developing particles is used for skin marking, the color developing time can be obviously prolonged, the problem of frequent supplementary coating of marks in radiotherapy is avoided, the accuracy and consistency of treatment are improved, and the influence on the daily life of a patient is reduced. The transdermal microneedle patch provided by the invention can realize patterned marking of no / slight pain operation on the skin, the marked pattern is a temporary mark, and the patient acceptability is high. In addition, the transdermal microneedle patch is simple and convenient in preparation process, simple and mild in reaction condition, low in raw material cost, suitable for large-scale production and good in application value and prospect.

Description

Technical Field

[0001] The present invention belongs to the field of transdermal microneedle technology, and more specifically, relates to a color-developing particle and an absorbable microneedle patch and their application in skin marking. Background Art

[0002] During radiotherapy, it is necessary to mark the surface of the patient's body in order to achieve multiple, repeatable, and precise positioning of the treatment area. Currently, the commonly used surface marking methods mainly include marking pen marking and tattoo marking. Marking with a marking pen is easy to operate, low-cost, and will not cause harm to the patient, but the visibility of the mark will be weakened by factors such as daily bathing and clothing friction. It has a short maintenance time and requires frequent re-application, which increases the complexity of the operation and the risk of error. Tattoo marking is a permanent mark. Although it has the advantages of long-lasting stability, its production process is complicated and requires professional skills and equipment. It will cause pain to the patient during marking, and the marking pattern will permanently exist on the body surface, which is easy to cause aesthetic, religious or psychological resistance in patients. Therefore, it is urgent to develop a long-lasting but non-permanent surface marking technology.

[0003] As a painless or slightly painful drug delivery method, transdermal microneedle technology has been used in the field of beauty to make tattoos in recent years. However, the marking coloring materials used in existing transdermal microneedles for making tattoos are generally permanent marking tattoo pigments (such as Chinese patent CN108325065A), and the coloring time of non-permanent pigments is too short (usually less than 16 weeks). These do not meet the requirements of radiotherapy body surface marking time, which is non-permanent and preferably not less than half a year, limiting the clinical application effect and convenience of transdermal microneedles in skin marking. Although the existing absorbable transdermal microneedles used for skin marking can achieve painless or slightly painful patterned marking, the permanent marking ink is used, and the marking pattern will permanently exist on the body surface. Most patients are unwilling to adopt this solution, and the remaining marking coloring materials are easily metabolized or excreted by the skin, and the stability in the skin is insufficient, resulting in a short coloring marking time, which is difficult to meet the needs of long-term treatment.

[0004] Therefore, developing skin marking technology with a color development time of 6-12 months has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] The present invention aims to overcome the obvious shortcomings of existing color-developing transdermal microneedles in color development time, and provides a microneedle color-developing particle. After the transdermal microneedle patch prepared by the color-developing particle is marked on the skin surface, it can stably develop color on the skin for a long time, and the color development time can be up to 45 weeks.

[0006] The first object of the present invention is to provide a microneedle patch color-developing particle and a preparation method thereof.

[0007] The second object of the present invention is to provide an absorbable transdermal microneedle patch.

[0008] The third object of the present invention is to provide applications of the above-mentioned color-developing particles and the above-mentioned absorbable transdermal microneedle patch.

[0009] The above-mentioned purpose of the present invention is achieved through the following technical solutions: The present invention introduces a new type of color-developing particles into the microneedles. When the transdermal microneedle patch prepared by using the color-developing particles is used for skin marking, the color-developing time can be significantly prolonged. Therefore, the present invention claims protection for the following solutions: The present invention provides a method for preparing microneedle patch color-developing particles, comprising the following steps: S1. Add genipin to the amine compound solution, stir the reaction at 50-70 ° C under anaerobic conditions for 2.5-3.5 hours, and recover the solid reaction product; S2. The solid reaction product obtained in step S1 is dissolved in a solvent, stirred and reacted at 70-90° C. for 5-7 hours, and the solid reaction product is recovered to obtain color-developing particles; Wherein, the amine compound is cyclohexylmethylamine or 2,4,6-trimethylaniline.

[0010] As an optional embodiment, in the amine compound solution in step S1, the final concentration of the amine compound is 15-35 mg / mL, and the final concentration of genipin is 15-25 mg / mL.

[0011] As an optional embodiment, in the amine compound solution in step S1, the final concentration of the amine compound is 16-34 mg / mL, and the final concentration of genipin is 16-20 mg / mL.

[0012] As an optional embodiment, the solvent in step S2 needs to be able to dissolve the solid reaction product of step S1 and not react with it, and the solvent can be methanol or ethanol.

[0013] As an optional embodiment, the concentration of the methanol solution is 30-70% (preferably 50%).

[0014] As an optional embodiment, the solvent of the amine compound solution in step S1 is a solvent mixed with water, anhydrous ethanol and phosphate buffered saline in a volume ratio of 1:1:1.

[0015] As an optional embodiment, the anaerobic condition in step S1 can be provided in the following manner: deoxygenating the reaction solution, such as by nitrogen bubbling.

[0016] Preferably, the amine compound solution in step S1 also contains polyamino acid.

[0017] More preferably, in the amine compound solution in step S1, the final concentration of polyamino acid is 8-20 mg / mL.

[0018] Further more preferably, in the amine compound solution in step S1, the final concentration of polyamino acid is 10-17 mg / mL.

[0019] Preferably, in the amine compound solution in step S1, the concentration ratio of the polyamino acid to the amine compound is (1-3): (1-7).

[0020] More preferably, in the amine compound solution in step S1, the concentration ratio of polyamino acid to amine compound is 1:1 or 3:7.

[0021] As an alternative embodiment, the polyamino acid includes polyleucine, polyaspartic acid, polylysine, polythreonine, polycysteine ​​and polyglutamic acid.

[0022] As an alternative embodiment, the polyamino acid is polyglutamic acid or polylysine.

[0023] As an optional implementation scheme, the solid reaction product is recovered in step S1 by extraction and drying, and the specific extractant used is dichloromethane.

[0024] As an optional embodiment, the solid reaction product is recovered in step S2 by washing and drying, and the specific washing liquid used is dichloromethane.

[0025] As an optional embodiment, the drying in steps S1 and S2 is vacuum drying.

[0026] As an optional specific embodiment, a method for preparing microneedle patch color-developing particles comprises the following steps: S1. Adding genipin and polyamino acid to the amine compound solution, bubbling the solution with nitrogen, and then stirring the reaction at 50-70 ° C for 2.5-3.5 hours, and the reaction product is extracted and dried to obtain a solid; S2. dissolving the solid obtained in step S1 in a methanol solution, stirring and reacting at 70-90° C. for 5-7 hours, and washing and drying the reaction product to obtain color-developing particles; The amine compound is cyclohexylmethylamine or 2,4,6-trimethylaniline, the polyamino acid is polyglutamic acid or polylysine, and the concentration ratio of the polyamino acid to the amine compound in the amine compound solution is (1-3): (1-7).

[0027] The microneedle patch color-developing particles prepared by the above preparation method are also within the protection scope of the present invention, and the particle size of the color-developing particles is 30 μm-120 μm.

[0028] Preferably, the particle size of the color-developing particles is 60 μm to 90 μm.

[0029] The present invention also provides an absorbable transdermal microneedle patch, comprising a substrate and a needle tip, wherein the needle tip is filled with a needle body suspension, and the needle body suspension comprises an absorbable polymer material and the above-mentioned color-developing particles.

[0030] Preferably, in the absorbable transdermal microneedle patch, the mass ratio of the absorbable polymer material to the color-developing particles is 200:(45-60).

[0031] Specifically, the substrate includes an absorbable polymer material and a stabilizer, and the absorbable polymer material is at least one of polyvinyl pyrrolidone, hyaluronic acid, and polyvinyl alcohol.

[0032] As an alternative embodiment, the stabilizer includes sucrose, propylene glycol, lactose, trehalose and inorganic salts (preferably sucrose or propylene glycol).

[0033] As an optional embodiment, the preparation method of the above absorbable transdermal microneedle patch comprises the following steps: (1) dissolving the absorbable polymer material and the stabilizer in a phosphate buffer to obtain a basal layer solution; (2) mixing the absorbable polymer material and the color-developing particles in a phosphate buffer to obtain a needle suspension; (3) Fill the needle body suspension into the needle tip area of ​​the mold and centrifuge to remove bubbles; (4) Filling the base layer solution into the base area of ​​the mold, drying and molding, and then demolding to obtain the absorbable transdermal microneedle patch.

[0034] As an optional embodiment, in step (1), the mass ratio of the absorbable polymer material to the stabilizer is 200:(15-20).

[0035] As an optional embodiment, in step (1), the concentration of the absorbable polymer material in the base layer solution is 80-120 mg / mL, and the concentration of the stabilizer is 5-10 mg / mL.

[0036] As an optional embodiment, the concentration of the absorbable polymer material in the base layer solution in step (1) is 100 mg / mL, and the concentration of the stabilizer is 7.5-10 mg / mL.

[0037] As an optional embodiment, in step (2), the mass ratio of the absorbable polymer material to the color-developing particles is 200:(45-60).

[0038] As an optional implementation scheme, in step (2), the concentration of the absorbable polymer material in the needle suspension is 100-150 mg / mL, and the concentration of the color-developing particles is 25-35 mg / mL.

[0039] As an optional implementation scheme, in step (2), the concentration of the absorbable polymer material in the needle suspension is 100-133 mg / mL, and the concentration of the color-developing particles is 30 mg / mL.

[0040] As an optional embodiment, the centrifugation in step (3) is performed at 5000-6000 rpm.

[0041] As an optional embodiment, the drying in step (4) is vacuum drying at 37° C. for 15 hours.

[0042] The use of the above-mentioned color-developing particles or the above-mentioned absorbable transdermal microneedle patch in the preparation of skin marking products should also be within the protection scope of the present invention.

[0043] The present invention has the following beneficial effects: The present invention introduces new color-developing particles into transdermal microneedles, and when the transdermal microneedle patch prepared by the color-developing particles is used for skin marking, the color-developing time can be significantly prolonged. The color-developing particles provided by the present invention are adapted to the absorbable transdermal microneedle system of the present invention, and the color-developing particles have good biocompatibility and absorbability, and can also stably exist in the skin, and the marking time can reach 29 weeks to 45 weeks, avoiding the problem of frequent re-applying of markings during radiotherapy, improving the accuracy and consistency of treatment, reducing the impact on the patient's daily life, and the marking time is within 12 months, and the marking time is not too long, which is suitable for radiotherapy skin markings.

[0044] The transdermal microneedle patch of the present invention can realize patterned marking on the skin without / slightly painful operation, and the marked pattern is a temporary mark, which is highly accepted by patients. The marking time is extended. In addition, the preparation process of the transdermal microneedle patch of the present invention is simple, the reaction conditions are simple and mild, the raw material cost is low, and it is suitable for large-scale production, and has good application value and prospects in the field of skin marking. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Flow chart for transdermal microneedle patch preparation.

[0046] Figure 2 This is an appearance diagram of the transdermal microneedle patch of Example 1.

[0047] Figure 3 These are the skin marking effects of the transdermal microneedle patch of Example 1, (a) is the effect of mouse skin marking on day 0, and (b) is the effect of mouse skin marking on week 25. DETAILED DESCRIPTION

[0048] The present invention is further described below in conjunction with the accompanying drawings and specific examples, but the examples do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0049] Transdermal microneedle patch preparation process Figure 1 shown.

[0050] Unless otherwise specified, the reagents and materials used in the following examples are commercially available.

[0051] Genipin, CAS No.: 6902-77-8, structural formula: .

[0052] Cyclohexylmethylamine, CAS number: 3218-02-8, structural formula: .

[0053] 2,4,6-Trimethylaniline, CAS No.: 88-05-1, structural formula: .

[0054] Polylysine, CAS number: 25104-18-1.

[0055] Polyglutamic acid, CAS number: 25513-46-6. In the following examples, the mold used to prepare the microneedle patch is a PDMS mold, the manufacturer is Microchip Pharmaceutical Technology Co., Ltd., model number is Y254 (the microneedle prepared by this mold has a length of 800 μm, a diameter of 320 μm, and a conical shape).

[0056] The mice used in the following examples were purchased from Guangdong Provincial Animal Center and were SD female rats.

[0057] Example 1 Preparation of transdermal microneedle patch 1. Preparation of color-developing components 1. Prepare mixed solvent Deionized water, anhydrous ethanol and PBS (pH = 7.4) were mixed in a volume ratio of 1:1:1 to obtain a mixed solvent.

[0058] 2. Preparation of color-developing particles 0.5 g of cyclohexylmethylamine was dissolved in 15 mL of mixed solvent and treated with nitrogen bubbling. Subsequently, 0.25 g of genipin powder was slowly added and stirred at 60 °C for 3 hours. After the reaction was completed, dichloromethane was used for extraction and vacuum dried to obtain a solid, which was then dissolved in 30 mL of 50% methanol solution (volume ratio of water: methanol = 1:1), stirred at 80 °C for 6 hours, and the obtained product was washed with dichloromethane and vacuum dried to obtain color-developing particles.

[0059] The color-developing particles were screened using a 170-mesh sieve to select color-developing particles with a particle size of 60 to 90 μm.

[0060] 2. Preparation of Microneedle Patches (1) Prepare the basal layer solution: Dissolve 200 mg of hyaluronic acid and 15 mg of propylene glycol in 2 mL of PBS solution (0.01 M, pH = 7.4) to form the basal layer solution; (2) Preparing a color-developing needle suspension: Mix 200 mg of hyaluronic acid and 45 mg of the color-developing particles (60-90 μm) prepared in this example in 1.5 mL of PBS solution (0.01 M, pH = 7.4) to obtain a needle suspension; (3) Filling the needle tip: Take 0.5 mL of the color-developing needle suspension and fill it into the mold; (4) Centrifugation: Place in a centrifuge at 5500 rpm for centrifugation; (5) Filling the base: Take 1 mL of the base layer solution and fill it into the mold until the mold is completely covered; (6) Molding: The mold was placed in a vacuum oven at 37°C and dried for 15 hours. The transdermal microneedle patch was finally obtained after demolding. The appearance of the transdermal microneedle patch is as follows: Figure 2 shown.

[0061] Example 2 Preparation of transdermal microneedle patch 1. Preparation of color-developing particles A mixed solvent (water: anhydrous ethanol: PBS = 1:1:1) was prepared according to the method of Example 1, 0.5 g of 2,4,6-trimethylaniline was dissolved in 15 mL of the mixed solvent, and nitrogen was used for bubbling. Subsequently, 0.3 g of genipin powder was slowly added and stirred at 60 ° C for 3 hours. After the reaction was completed, dichloromethane was used for extraction, and a solid was obtained by vacuum drying, which was then dissolved in 30 mL of 50% methanol solution (volume ratio of water: methanol = 1:1), stirred at 80 ° C for 6 hours, and the obtained product was washed with dichloromethane and vacuum dried to obtain color-developing particles.

[0062] The color-developing particles were screened using a 170-mesh sieve to select color-developing particles with a particle size of 60 to 90 μm.

[0063] 2. Preparation of Microneedle Patches (1) Prepare the basal layer solution: Dissolve 200 mg of hyaluronic acid and 20 mg of sucrose in 2 mL of PBS solution (0.01 M, pH = 7.4) to form the basal layer solution; (2) Preparing a color-developing needle suspension: Mix 200 mg of hyaluronic acid and 45 mg of the color-developing particles (60-90 μm) prepared in this example in 1.5 mL of PBS solution (0.01 M, pH = 7.4) to obtain a needle suspension; (3) Filling the needle tip: Take 0.5 mL of the color-developing needle suspension and fill it into the mold; (4) Centrifugation: Place in a centrifuge at 5500 rpm for centrifugation; (5) Filling the base: Take 1 mL of the base layer solution and fill it into the mold until the mold is completely covered; (6) Molding: The mold was placed in a vacuum oven at 37°C and dried for 15 hours. The transdermal microneedle patch was finally obtained after demolding.

[0064] Example 3 Preparation of transdermal microneedle patch 1. Preparation of color-developing particles A mixed solvent (water: anhydrous ethanol: PBS = 1:1:1) was prepared according to the method of Example 1, 0.15 g of polyglutamic acid and 0.35 g of 2,4,6-trimethylaniline were dissolved in 15 mL of the mixed solvent, and nitrogen was used for bubbling. Subsequently, 0.3 g of genipin powder was slowly added and stirred at 60 ° C for 3 hours. After the reaction was completed, dichloromethane was used for extraction, and a solid was obtained by vacuum drying, which was then dissolved in 30 mL of 50% methanol solution (volume ratio of water: methanol = 1:1), stirred at 80 ° C for 6 hours, and the obtained product was washed with dichloromethane and vacuum dried to obtain color-developing particles.

[0065] The color-developing particles were screened using a 170-mesh sieve to select color-developing particles with a particle size of 60 to 90 μm.

[0066] 2. Preparation of Microneedle Patches (1) Prepare the basal layer solution: Dissolve 200 mg of hyaluronic acid and 20 mg of sucrose in 2 mL of PBS solution (0.01 M, pH = 7.4) to form the basal layer solution; (2) Preparing a color-developing needle suspension: Mix 200 mg of hyaluronic acid and 60 mg of the color-developing particles (60-90 μm) prepared in this example in 2 mL of PBS solution (0.01 M, pH = 7.4) to obtain a needle suspension; (3) Filling the needle tip: Take 0.5 mL of the color-developing needle suspension and fill it into the mold; (4) Centrifugation: Place in a centrifuge at 5500 rpm for centrifugation; (5) Filling the base: Take 1 mL of the base layer solution and fill it into the mold until the mold is completely covered; (6) Molding: The mold was placed in a vacuum oven at 37°C and dried for 15 hours. The transdermal microneedle patch was finally obtained after demolding.

[0067] Example 4 Preparation of transdermal microneedle patch 1. Preparation of color-developing particles A mixed solvent (water: anhydrous ethanol: PBS = 1:1:1) was prepared according to the method of Example 1, 0.25 g of polylysine and 0.25 g of cyclohexylmethylamine were dissolved in 15 mL of the mixed solvent, and nitrogen was used for bubbling. Subsequently, 0.3 g of genipin powder was slowly added and stirred at 60 ° C for 3 hours. After the reaction was completed, dichloromethane was used for extraction, and a solid was obtained by vacuum drying, which was then dissolved in 30 mL of 50% methanol solution (volume ratio of water: methanol = 1:1), stirred at 80 ° C for 6 hours, and the obtained product was washed with dichloromethane and vacuum dried to obtain color-developing particles.

[0068] The color-developing particles were screened using a 170-mesh sieve to select color-developing particles with a particle size of 60 to 90 μm.

[0069] 2. Preparation of Transdermal Microneedle Patches (1) Prepare the basal layer solution: Dissolve 200 mg of polyvinyl alcohol and 15 mg of propylene glycol in 2 mL of PBS solution (0.01 M, pH = 7.4) to form the basal layer solution; (2) Preparing a color-developing needle suspension: Mix 200 mg of polyvinyl alcohol and 45 mg of the color-developing particles (60-90 μm) prepared in this example in 1.5 mL of PBS solution (0.01 M, pH = 7.4) to obtain a needle suspension; (3) Filling the needle tip: Take 0.5 mL of the color-developing needle suspension and fill it into the mold; (4) Centrifugation: Place in a centrifuge at 5500 rpm for centrifugation; (5) Filling the base: Take 1 mL of the base layer solution and fill it into the mold until the mold is completely covered; (6) Molding: The mold was placed in a vacuum oven at 37°C and dried for 15 hours. The transdermal microneedle patch was finally obtained after demolding.

[0070] Comparative Example 1 Preparation of transdermal microneedle patch 1. Preparation of color-developing particles A mixed solvent (water: anhydrous ethanol: PBS = 1:1:1) was prepared according to the method of Example 1, 0.5 g of chitosan was dissolved in 15 mL of the mixed solvent, and nitrogen was used for bubbling. Subsequently, 0.25 g of genipin powder was slowly added and stirred at 60 ° C for 3 hours. After the reaction was completed, dichloromethane was used for extraction, and a solid was obtained by vacuum drying. The solid was then dissolved in 30 mL of 50% methanol solution (volume ratio of water: methanol = 1:1), stirred at 80 ° C for 6 hours, and the obtained product was washed with dichloromethane and vacuum dried to obtain color-developing particles.

[0071] The color-developing particles were screened using a 170-mesh sieve to select color-developing particles with a particle size of 60 to 90 μm.

[0072] 2. Preparation of Microneedle Patches (1) Prepare the basal layer solution: Dissolve 200 mg of sodium hyaluronate and 15 mg of propylene glycol in 2 mL of PBS solution (0.01 M, pH = 7.4) to form the basal layer solution; (2) Preparing a color-developing needle suspension: dissolve 200 mg of sodium hyaluronate and 45 mg of the color-developing particles (60-90 μm) prepared in this comparative example in 1.5 mL of PBS solution (0.01 M, pH = 7.4) to obtain a needle suspension; (4) Filling the needle tip: Take 0.5 mL of the color-developing needle suspension and fill it into the mold; (5) Centrifugation: Place in a centrifuge at 5500 rpm; (6) Filling the base: Take 1 mL of the base layer solution and fill it into the mold until the mold is completely covered; (7) Molding: The mold was placed in a vacuum oven at 37°C and dried for 15 hours. The transdermal microneedle patch was finally obtained after demolding.

[0073] Comparative Example 2 Preparation of transdermal microneedle patch 1. Preparation of color-developing particles A mixed solvent (water: anhydrous ethanol: PBS = 1:1:1) was prepared according to the method of Example 1, 0.5 g of polylysine was dissolved in 15 mL of the mixed solvent, and nitrogen was used for bubbling. Subsequently, 0.25 g of genipin powder was slowly added and stirred at 60 ° C for 3 hours. After the reaction was completed, dichloromethane was used for extraction, and a solid was obtained by vacuum drying, which was then dissolved in 30 mL of 50% methanol solution (volume ratio of water: methanol = 1:1), stirred at 80 ° C for 6 hours, and the obtained product was washed with dichloromethane and vacuum dried to obtain color-developing particles.

[0074] The color-developing particles were screened using a 170-mesh sieve to select color-developing particles with a particle size of 60 to 90 μm.

[0075] 2. Preparation of Microneedle Patches (1) Prepare the basal layer solution: Dissolve 200 mg of sodium hyaluronate and 15 mg of propylene glycol in 2 mL of PBS solution (0.01 M, pH = 7.4) to form the basal layer solution; (2) Preparing a color-developing needle suspension: dissolve 200 mg of sodium hyaluronate and 45 mg of the color-developing particles (60-90 μm) prepared in this comparative example in 1.5 mL of PBS solution (0.01 M, pH = 7.4) to obtain a needle suspension; (3) Filling the needle tip: Take 0.5 mL of the color-developing needle suspension and fill it into the mold; (4) Centrifugation: Place in a centrifuge at 5500 rpm for centrifugation; (5) Filling the base: Take 1 mL of the base layer solution and fill it into the mold until the mold is completely covered; (6) Molding: The mold was placed in a vacuum oven at 37 °C for 15 hours and finally demolded to obtain a transdermal microneedle patch.

[0076] Comparative Example 3 Preparation of transdermal microneedle patch 1. Preparation of color-developing particles A mixed solvent (water: anhydrous ethanol: PBS = 1:1:1) was prepared according to the method of Example 1, 0.5 g of dimethylethylamine was dissolved in 15 mL of the mixed solvent, and nitrogen was used for bubbling. Subsequently, 0.25 g of genipin powder was slowly added and stirred at 60 ° C for 3 hours. After the reaction was completed, dichloromethane was used for extraction, and a solid was obtained by vacuum drying, which was then dissolved in 30 mL of 50% methanol solution (volume ratio of water: methanol = 1:1), stirred at 80 ° C for 6 hours, and the obtained product was washed with dichloromethane and vacuum dried to obtain color-developing particles.

[0077] The color-developing particles were screened using a 170-mesh sieve to select color-developing particles with a particle size of 60 to 90 μm.

[0078] 2. Preparation of Microneedle Patches (1) Prepare the basal layer solution: Dissolve 200 mg of sodium hyaluronate and 20 mg of sucrose in 2 mL of PBS solution (0.01 M, pH = 7.4) to form the basal layer solution; (2) Preparing a color-developing needle suspension: dissolve 200 mg of sodium hyaluronate and 45 mg of the color-developing particles (60-90 μm) prepared in this comparative example in 1.5 mL of PBS solution (0.01 M, pH = 7.4) to obtain a needle suspension; (3) Filling the needle tip: Take 0.5 mL of the color-developing needle suspension and fill it into the mold; (4) Centrifugation: Place in a centrifuge at 5500 rpm for centrifugation; (5) Filling the base: Take 1 mL of the base layer solution and fill it into the mold until the mold is completely covered; (6) Molding: The mold was placed in a vacuum oven at 37°C and dried for 15 hours. The transdermal microneedle patch was finally obtained after demolding.

[0079] Comparative Example 4 Preparation of transdermal microneedle patch 1. Preparation of color-developing particles A mixed solvent (water: anhydrous ethanol: PBS = 1:1:1) was prepared according to the method of Example 1, 0.5 g of isopropylethylamine was dissolved in 15 mL of the mixed solvent, and nitrogen was used for bubbling. Subsequently, 0.25 g of genipin powder was slowly added and stirred at 60 ° C for 3 hours. After the reaction was completed, dichloromethane was used for extraction, and a solid was obtained by vacuum drying, which was then dissolved in 30 mL of 50% methanol solution (volume ratio of water: methanol = 1:1), stirred at 80 ° C for 6 hours, and the obtained product was washed with dichloromethane and vacuum dried to obtain color-developing particles.

[0080] The color-developing particles were screened using a 170-mesh sieve to select color-developing particles with a particle size of 60 to 90 μm.

[0081] 2. Preparation of Microneedle Patches (1) Prepare the basal layer solution: Dissolve 200 mg of sodium hyaluronate and 15 mg of propylene glycol in 2 mL of PBS solution (0.01 M, pH = 7.4) to form the basal layer solution; (2) Preparing a color-developing needle suspension: dissolve 200 mg of sodium hyaluronate and 45 mg of the color-developing particles (60-90 μm) prepared in this comparative example in 1.5 mL of PBS solution (0.01 M, pH = 7.4) to obtain a needle suspension; (3) Filling the needle tip: Take 0.5 mL of the color-developing needle suspension and fill it into the mold; (4) Centrifugation: Place in a centrifuge at 5500 rpm for centrifugation; (5) Filling the base: Take 1 mL of the base layer solution and fill it into the mold until the mold is completely covered; (6) Molding: The mold was placed in a vacuum oven at 37°C and dried for 15 hours, and then demolded to obtain a transdermal microneedle patch.

[0082] Experimental Example 1 1. Marking time test method After cleaning and disinfecting the mouse skin, the transdermal microneedle patches of Examples 1-4 and Comparative Examples 1-4 were applied to the mouse skin and gently pressed for 3 minutes until the needle tip was completely dissolved and separated from the substrate. The marking color was observed every 7 days (weekly) and the marking time was recorded (if the mark disappeared after 7 days, the marking time was recorded as 1 week). The experiment was repeated 3 times, and only integers were retained for data analysis.

[0083] 2. Experimental Results The results of the experimental determination of different transdermal microneedle patch marking time are shown in Table 1. The skin marking effect of the transdermal microneedle patch of Example 1 is shown in Table 1. Figure 3 As shown, the results show that the marking time of the transdermal microneedle patch of the embodiment is significantly longer than that of the comparative example. The marking time of the embodiment is 29-45 weeks, and the marking time of the comparative example is 4-18 weeks. Among them, the transdermal microneedle patch of Example 3 has the longest marking time, which can reach 45 weeks on average, which is 2.5 times the marking time of the transdermal microneedle patch of Comparative Example 2, and 11 times the marking time of the transdermal microneedle patch of Comparative Example 1.

[0084] Table 1 Labeling time of different transdermal microneedle patches

[0085] Experimental Example 2 1. Preparation of color-developing particles Color-developing particles were prepared according to the method of Example 3. Color-developing particles with particle sizes of 0-30 μm, 30 μm-60 μm, 60 μm-90 μm, 90 μm-120 μm, 120 μm-180 μm, and 180 μm-210 μm were screened out using 400 mesh, 240 mesh, 170 mesh, 120 mesh, 80 mesh, and 70 mesh sieves, respectively.

[0086] 2. Preparation of Microneedle Patches Set up different treatment groups: Treatment group a: chromogenic particles with a particle size of 0-30 μm; Treatment group b: color-developing particles with a particle size of 30 μm to 60 μm; Treatment group c: color-developing particles with a particle size of 60 μm to 90 μm; Treatment group d: color-developing particles with a particle size of 90 μm to 120 μm; Treatment group e: chromogenic particles with a particle size of 120 μm to 180 μm; Treatment group f: color-developing particles with a particle size of 180 μm to 210 μm; (1) Prepare the basal layer solution: Dissolve 200 mg of polyvinyl alcohol and 15 mg of propylene glycol in 2 mL of PBS solution (0.01 M, pH = 7.4) to form the basal layer solution; (2) Preparation of color-developing needle suspension: Dissolve 200 mg of polyvinyl alcohol and 45 mg of color-developing particles of different treatment groups in 1.5 mL of PBS solution (0.01 M, pH = 7.4) to obtain color-developing needle suspensions of different treatment groups; (3) Filling the needle tip: Take 0.5 mL of the color-developed needle suspension of different treatment groups and fill it into the mold; (4) Centrifugation: Place in a centrifuge at 5500 rpm for centrifugation; (5) Filling the base: Take 1 mL of the base layer solution and fill it into the mold until the mold is completely covered; (6) Molding: The mold was placed in a vacuum oven at 37°C and dried for 15 hours. The transdermal microneedle patch was finally obtained after demolding.

[0087] 3. Marking time test method Referring to the marking time test method in Experimental Example 1, transdermal microneedles from different treatment groups (treatment groups af) were attached to the mouse skin and gently pressed for 3 minutes until the needle tip was completely dissolved and separated from the substrate. The marking time was subsequently recorded. The experiment was repeated 3 times, and only integers were retained for data analysis.

[0088] IV. Experimental Results The results of the transdermal microneedle patch labeling time determination of different treatment groups are shown in Table 2. The results show that the labeling time of treatment groups b, c, and d is significantly longer than that of treatment groups a and e, while treatment group f cannot achieve labeling color development. This experimental result shows that the particle size is related to the color development labeling time of the microneedle patch. Color particles with too large a particle size cannot be effectively applied to this transdermal microneedle system; color particles with too small a particle size will significantly shorten the labeling time, so choosing color particles with the appropriate particle size is very critical for labeling color development.

[0089] Table 2 Transdermal microneedle patch labeling time in different treatment groups

[0090] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. A method for preparing microneedle patch color-developing particles, characterized in that: The following steps are involved: S1. Add genipin to the amine compound solution, stir the reaction at 50-70 ° C under anaerobic conditions for 2.5-3.5 hours, and recover the solid reaction product; S2. The solid reaction product obtained in step S1 is dissolved in a solvent, stirred and reacted at 70-90° C. for 5-7 hours, and the solid reaction product is recovered to obtain color-developing particles; Wherein, the amine compound is cyclohexylmethylamine or 2,4,6-trimethylaniline.

2. The preparation method according to claim 1, characterized in that: In the amine compound solution of step S1, the final concentration of the amine compound is 15-35 mg / mL, and the final concentration of genipin is 15-25 mg / mL.

3. The preparation method according to claim 1 or 2, characterized in that: The solvent in step S2 is methanol or ethanol.

4. The preparation method according to claim 1 or 2, characterized in that: The amine compound solution in step S1 also contains polyamino acid.

5. The preparation method according to claim 3, characterized in that: In the amine compound solution of step S1, the final concentration of polyamino acid is 8-20 mg / mL.

6. The preparation method according to claim 1 or 2, characterized in that: The solid reaction product is recovered in step S1 by extraction and drying.

7. The microneedle patch color-developing particles prepared by the preparation method according to any one of claims 1 to 6, wherein the particle size of the color-developing particles is 30 μm-120 μm.

8. An absorbable transdermal microneedle patch, characterized in that: It comprises a base and a needle tip, wherein the needle tip is filled with a needle body suspension, and the needle body suspension comprises an absorbable polymer material and the color-developing particles according to claim 7.

9. The absorbable transdermal microneedle patch according to claim 8, characterized in that: The mass ratio of the absorbable polymer material to the color-developing particles is 200:(45-60).

10. Use of the color-developing particles according to claim 7 or the absorbable transdermal microneedle patch according to any one of claims 8 to 9 in the preparation of skin marking products.

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