Eutectic probenecid soluble microneedle as well as preparation method and application thereof

Abstract

The invention discloses a eutectic probenecid soluble microneedle as well as a preparation method and application thereof, and belongs to the technical field of microneedle preparations. The technical problem to be solved is to provide the preparation method of the deep-eutectic probenecid soluble microneedle with excellent mechanical property and better dissolution and transdermal penetration capacity. The deep-eutectic probenecid soluble microneedle disclosed by the invention improves the solubility and bioavailability of probenecid. The key point of the technical scheme is as follows: the eutectic probenecid soluble microneedle comprises the following components: probenecid, a eutectic solvent and a matrix material, wherein the eutectic solvent comprises basic amino acid and polyhydric alcohol; the molar ratio of the basic amino acid to the polyhydric alcohol is 1: (5-7.5).

Description

Technical Field

[0001] The present invention belongs to the technical field of microneedle preparations and relates to a eutectic probenecid soluble microneedle and a preparation method and application thereof. Background Art

[0002] Gout is a chronic metabolic disease caused by uric acid metabolism disorders and is a type of crystal-based arthritis. It primarily results from impaired purine metabolism or decreased uric acid excretion, leading to hyperuricemia. This leads to the formation of urate crystals that deposit in joints and surrounding tissues, triggering an inflammatory response. Uric acid is the end product of purine metabolism. When blood uric acid levels exceed saturation (>420 μmol / L), urate crystals precipitate and deposit in joints, synovium, tendons, and other areas, triggering an inflammatory response that causes pain and swelling. Predisposing factors include diet (alcohol (especially beer), high-fructose beverages, and red and processed meats), metabolic abnormalities (often accompanied by obesity, hypertension, diabetes, and hyperlipidemia), and genetics and physical constitution. People with a family history of gout are more likely to develop. Furthermore, the majority of patients with the disease are men, with a higher risk in postmenopausal women.

[0003] Gout drug treatment must strictly adhere to staging principles, employing appropriate strategies for different stages. During an acute attack, the core goal is to rapidly control inflammation and relieve joint pain and swelling. Commonly used medications include nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine, and glucocorticoids. After entering remission (intermission), treatment focuses on long-term uric acid-lowering therapy, with a target serum uric acid level of <360 μmol / L. Commonly used medications during this period include allopurinol, febuxostat, and bromobendanone.

[0004] Probenecid (PRO) is a synthetic sulfonamide that has the dual effects of promoting uric acid excretion and inhibiting penicillin excretion, effectively alleviating gout symptoms to a certain extent. However, PRO suffers from poor solubility and low bioavailability. Furthermore, oral anti-gout medications are often associated with side effects such as gastrointestinal reactions, allergic reactions, and bone marrow suppression.

[0005] Microneedles (MNs) are categorized into solid, hollow, coated, and soluble microneedles. Dissolvable microneedles (DMNs) are made by combining biodegradable polymers like hyaluronic acid (HA) and polyvinylpyrrolidone (PVP) with drugs. Upon penetration into the skin, the biodegradable material gradually degrades within the microenvironment, releasing the drug simultaneously. The drug molecules then penetrate the stratum corneum and are absorbed into the body through the subcutaneous tissue. This significantly improves patient medication compliance and targets gout inflammation, avoiding the complications associated with oral administration. Dissolvable microneedles have been applied in various fields, including drug delivery, skin disease treatment, and vaccine delivery.

[0006] Relevant patent documents retrieved: Publication country: China, publication number: CN118806686A, publication date: October 22, 2024. This document discloses a composite microneedle with sustained-release function, its preparation method, and application. The composite microneedle comprises small intestinal submucosal matrix (SIS) and hyaluronic acid. In this invention, the SIS is dissolved in acid, hyaluronic acid is added, and the pH is adjusted using basic amino acids. This combination effectively solves the problem of polyelectrolyte precipitation that easily forms when SIS and hyaluronic acid are blended.

[0007] Relevant non-patent literature retrieved: "Study of pH-responsive microneedle patches for the treatment of acute gouty arthritis," published on September 14, 2023. This document describes combining microneedle patch technology with a pH-responsive drug delivery system to create a pH-responsive microneedle patch with excellent biocompatibility and rapid dissolution for the treatment of acute gouty arthritis (AGA). In this paper, the anti-gout drug is curcumin, which is loaded onto hollow calcium carbonate microspheres and fabricated using a fractionated vacuum casting method.

[0008] The prior art represented by the aforementioned documents has at least the following unresolved technical problems or defects: CN118806686A adopts acidic conditions to dissolve SIS, but not all drugs can be dissolved in this way and then hyaluronic acid can be added.

[0009] The present invention has encountered the following difficulties and obstacles in solving the above problems or overcoming the above defects: PRO is a synthetic sulfonamide with good permeability but poor water solubility. According to literature, its solubility in water at 37°C is only 72.2 μg / mL, which significantly affects its bioavailability. However, the synthesis of PRO salts with pyridine compounds involves complex steps and the use of organic solvents, which inevitably lead to environmental impacts and high toxicity, making it difficult to improve drug bioaccessibility. Summary of the Invention

[0010] The object of the present invention is to provide: A low-melting probenecid soluble microneedle and a preparation method and use thereof are used to solve technical problems such as poor bioavailability of probenecid or a combination thereof.

[0011] Terminology Notes: Unless otherwise defined, all technical and scientific terms herein have the same meanings as commonly understood by persons skilled in the art to which the claimed subject matter belongs. Unless otherwise indicated, all patents, patent applications, and publications cited herein are incorporated by reference in their entirety. If multiple definitions of a term are used herein, the definitions in this section shall prevail.

[0012] It should be understood that the above brief description and the following detailed description are exemplary and explanatory only and do not limit the subject matter of the present invention in any way. In the present invention, unless otherwise specifically stated, the use of the singular also includes the plural. It should also be noted that unless otherwise stated, the use of "or" and "or" means "and / or". In addition, the use of the term "including" and other forms such as "comprising", "including" and "containing" are not limiting.

[0013] Definitions of standard chemical terms may be found in the reference "Complete Dictionary of Pharmacy".

[0014] Unless otherwise specified, conventional methods within the technical scope of the art, such as thermogravimetric analysis (TGA), ultraviolet spectrophotometry, transdermal absorption testing, etc., were used.

[0015] Unless otherwise specified, standard techniques are used for the use of various commercially available products herein. For example, the methods can be performed using the manufacturer's instructions for use of the kits, or according to methods known in the art or as described herein. The above-described techniques and methods can generally be performed according to conventional methods well known in the art, as described in the various general and more specific references cited and discussed throughout this specification.

[0016] The term "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes both occurring and not occurring.

[0017] The term “dissolving microneedles (DMN)” used in this article refers to microneedles made of degradable polymer materials.

[0018] The term "deep eutectic solvents" (DES) as used herein refers to two- or three-component eutectic mixtures composed of a stoichiometric ratio of hydrogen bond acceptors (such as quaternary ammonium salts) and hydrogen bond donors (such as amides, carboxylic acids, and polyols), whose freezing points are significantly lower than the melting points of the pure components. Common deep eutectic solvents include choline chloride-urea, lactic acid-choline, choline chloride-glycerol, choline chloride-urea-glycerol, and choline chloride-glycerol-malic acid-water.

[0019] The term "gout" as used herein refers to a disease caused by excessive deposition of uric acid.

[0020] The term "Hydrogen Bond Acceptor" (HBA) as used herein refers to an atom or group in a molecule that can accept hydrogen bonds. These atoms are typically highly electronegative atoms such as oxygen, nitrogen, and fluorine, but can also be quaternary ammonium salts. Common hydrogen bond acceptors include choline chloride, betaine, tetrabutylphosphonium bromide, imidazole, pyridine, acetate, formate, and zinc chloride.

[0021] The term "Hydrogen Bond Donor (HBD)" as used herein refers to an atom or group in a molecule that can provide hydrogen bonds, such as carboxylic acids and alcohols. Common hydrogen bond donors include methanol, glycerol, formic acid, oxalic acid, urea, acetamide, phenol, and aniline.

[0022] In a first aspect, the present invention provides a low eutectic probenecid-soluble microneedle, comprising components: probenecid, a low eutectic solvent and a matrix material; wherein the low eutectic solvent comprises: a basic amino acid and a polyol; the molar ratio of the basic amino acid to the polyol is 1:5-7.5.

[0023] Preferably, the molar ratio of the basic amino acid to the polyol is 1:5.

[0024] Preferably, the basic amino acid is lysine, arginine or histidine.

[0025] Preferably, the polyol is glycerol.

[0026] Preferably, the matrix material is selected from at least one of polylactic acid-glycolic acid copolymer, polyethylene glycol, polyvinyl pyrrolidone, polymethyl methacrylate, and hyaluronic acid.

[0027] Preferably, the mass ratio of the basic amino acid, the polyol and the probenecid is 1:3.149-3.964:1.244-1.315.

[0028] Further preferably, the mass ratio of the basic amino acid, polyol and probenecid is 1:3.149:1.315.

[0029] Preferably, probenecid and a deep eutectic solvent are mixed to form a basic amino acid-probenecid-containing deep eutectic solvent; the mass ratio of the total mass of the basic amino acid-probenecid-containing deep eutectic solvent to the matrix material is 0.05-0.4:1.4.

[0030] Further preferably, the mass ratio of the total mass of the basic amino acid-probenecid-containing deep eutectic solvent to the matrix material is 0.3-0.4:1.4.

[0031] Further preferably, the mass ratio of the total mass of the basic amino acid-probenecid-containing deep eutectic solvent to the matrix material is 0.05-0.3:1.4.

[0032] In a second aspect, the present invention provides a method for preparing the above-mentioned eutectic probenecid soluble microneedles, comprising the steps of: S1. Preparation of a basic amino acid-containing probenecid deep eutectic solvent: stirring the deep eutectic solvent under heating conditions until transparent, adding probenecid, and continuing to stir until transparent to obtain a basic amino acid-containing probenecid deep eutectic solvent; S2. Preparation of eutectic probenecid soluble microneedles, comprising the steps of: S21, preparation of a mother liquor: mixing the basic amino acid-probenecid-containing deep eutectic solvent obtained in step S1 with water to form a preliminary solution; mixing the preliminary solution with a portion of the matrix material, stirring, and then centrifuging to obtain a mother liquor; S22, preparation of base solution: mixing the remaining matrix material with water, stirring, and centrifuging to prepare a base solution; S23. Preparation of microneedles: aspirate the mother liquid onto the microneedle mold and perform initial drying to obtain the first layer; then aspirate the next layer of mother liquid or base liquid and perform secondary drying to obtain the second layer; finally aspirate the base liquid onto the second layer and perform final drying to obtain low-eutectic probenecid-soluble microneedles.

[0033] Preferably, in step S1, the heating temperature is 60-80°C; more preferably 70°C.

[0034] Preferably, in step S21, the mass ratio of the basic amino acid-probenecid-containing deep eutectic solvent to water is 0.5-4:96-99.5.

[0035] Further preferably, in step S21, the mass ratio of the basic amino acid-probenecid-containing deep eutectic solvent to water is 0.5-3:97-99.5.

[0036] Further preferably, in step S21, the mass ratio of the basic amino acid-probenecid-containing deep eutectic solvent to water is 3-4:96-97.

[0037] Preferably, in step S21, the water may be deionized water or an aqueous solution containing the second antigout drug.

[0038] Further preferably, the second antigout drug is colchicine, allopurinol, febuxostat or bromobendanone; the concentration of the second antigout drug in the aqueous solution is 0.4%-0.6%; the concentration of the second antigout drug in the aqueous solution is further preferably 0.45%.

[0039] Preferably, in step S21, in the mother liquor, the mass ratio of the preliminary solution to part of the matrix material is 9.3:0.5-0.8; more preferably, it is 9.3:0.7.

[0040] Preferably, in step S21, the stirring followed by centrifugation specifically comprises: stirring for 0.5-1.5 h, 5000-8000 rpm; and centrifuging for 5-15 min.

[0041] Further preferably, in step S21, the stirring followed by centrifugation is specifically: stirring for 1 hour, 6000 rpm; and centrifuging for 10 minutes.

[0042] Preferably, in step S2, the mass ratio of water to the remaining matrix material in the base liquid is 9.3:0.5-0.8; more preferably 9.3:0.7.

[0043] Preferably, in step S22, the stirring and centrifugation is specifically: stirring for 0.5-1.5 hours, 5000-8000 rpm; and centrifuging for 5-15 minutes.

[0044] Further preferably, in step S22, the stirring and centrifuging is specifically: stirring for 1 hour, 6000 rpm; and centrifuging for 10 minutes.

[0045] Preferably, in step S23, each time the mother liquid or base liquid is drawn onto the microneedle mold, a bubble removal process is required; The degassing is specifically performed by vacuuming at -0.3 to -0.8 MPa and ultrasonicating for 8 to 12 minutes; more preferably, by vacuuming at -0.5 MPa and ultrasonicating for 10 minutes.

[0046] Preferably, in step S23, the initial drying is performed at 40-50°C for 1-3 hours; further preferably, the initial drying is performed at 45°C for 2 hours.

[0047] Preferably, in step S23, the secondary drying is performed at 40-50°C for 3-5 hours; more preferably, the secondary drying is performed at 45°C for 4 hours.

[0048] Preferably, in step S23, the final drying is performed at 40-50°C for 10-16 hours; further preferably, the final drying is performed at 45°C for 12 hours.

[0049] Finally, the present invention provides the use of the eutectic probenecid soluble microneedles in the preparation of a drug for treating gout.

[0050] The beneficial effects of the present invention are: The present invention has at least the following beneficial effects: 1. Compared with the prior art, the present invention improves the solubility and bioavailability of probenecid, provides a low-melting probenecid soluble microneedle, and has better technical effects; according to experimental tests, the present invention increases the solubility of probenecid from 72.2 μg / mL in the prior art to 14.04 mg / mL.

[0051] 2. Compared with the existing technology, the low-eutectic probenecid soluble microneedles prepared by the present invention not only have significant transdermal absorption and in vitro uric acid degradation capabilities, but also exhibit the following beneficial effects: they can effectively relieve swelling at the inflammatory site and reduce the expression of inflammatory factors, avoiding the problems caused by oral medication while broadening the application of soluble microneedles in drug delivery and treatment of gout-related diseases.

[0052] In addition, based on the present invention: Based on a comparison of Examples 1-6 and Comparative Examples 1-2, the present invention achieves novel technical effects by utilizing a combination of probenecid, a basic amino acid, a polyol, a matrix material, and the ratio of the basic amino acid to the polyol, as well as the ratio of the basic amino acid to the polyol to the matrix material. This combination improves the solubility and bioavailability of probenecid and provides a method for preparing eutectic probenecid-soluble microneedles. The resulting technical effect is superior to the sum of the effects of each individual technical approach. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 Graphs showing the water solubility of PRO and Example 1-2; wherein, (a) is a photograph of PRO and Example 1-2 dispersed in water in Test Example 1; and (b) is a comparison graph showing the dynamic solubility of PRO and the samples of Example 1-2.

[0054] Figure 2 This is a full wavelength scanning diagram of the degradation of UA by PBS from 0 to 180 min.

[0055] Figure 3 This is a full-wavelength scanning diagram of the degradation process of UA from 0 to 180 minutes in Example 1.

[0056] Figure 4 This is a full-wavelength scanning diagram of the degradation process of UA from 0 to 180 minutes in Example 2.

[0057] Figure 5 This is a graph showing the degradation rates of UA by the samples of Example 1-2 and PBS.

[0058] Figure 6 These are morphological diagrams of the soluble microneedles prepared in Examples 3-6 and Comparative Example 2.

[0059] Figure 7 A comparison chart of the mechanical properties of the soluble microneedles prepared in Examples 3-6 and Comparative Example 2.

[0060] Figure 8 This is the HE staining image of the insertion force of the soluble microneedles prepared in Example 3.

[0061] Figure 9 This is a diagram showing the dissolution ability of the soluble microneedles prepared in Example 3.

[0062] Figure 10 Graphs showing the transdermal release and retention amounts of the soluble microneedles prepared in Examples 1, 3, and 6, wherein (a) is a comparison graph of the transdermal release amounts of the soluble microneedles prepared in Examples 1, 3, and 6; and (b) is a comparison graph of the skin retention amounts of the soluble microneedles prepared in Examples 1, 3, and 6.

[0063] Figure 11 The figure is a comparison of skin irritation between Examples 3, 6, Comparative Example 2 and the model group.

[0064] Figure 12 HE staining comparison of Examples 3, 6 and Comparative Example 2, the model group and the normal group.

[0065] Figure 13 The figures reflect the swelling of the knee joints in mice with acute gout modeling, where (a) is a comparison of the swelling values ​​of the mouse knee joints over time after the injection of sodium urate crystals; (b) is a comparison of the swelling of the mouse knee joints within 24 hours after the injection of sodium urate crystals.

[0066] Figure 14 The figures show the knee joint swelling of the mice in the drug-treated group, model group and normal group, wherein (a) is a comparison of the numerical values ​​of the knee joint swelling of the mice after 5 hours of treatment with Example 3-Example 6 and Comparative Example 2, the model group and the normal group; (b) is a comparison of the redness and swelling of the knee joint of the mice after 5 hours of treatment with Example 3-6 and Comparative Example 2, the model group and the normal group.

[0067] Figure 15 The figures are comparative diagrams of inflammatory factors in the mouse drug-treated group, model group and normal group, wherein (a) is a comparative diagram of TNF-α concentration in Example 3-Example 6 and Comparative Example 2, with the model group and normal group; (b) is a comparative diagram of IL-1β concentration in Example 3-Example 6 and Comparative Example 2, with the model group and normal group; and (c) is a comparative diagram of myeloperoxidase (MPO) concentration in mice in Example 3-Example 6 and Comparative Example 2, with the model group and normal group. DETAILED DESCRIPTION

[0068] The following non-limiting examples are provided to enable those skilled in the art to more fully understand the present invention, but are not intended to limit the present invention in any way. The following are merely illustrative of the scope of the present invention, and those skilled in the art may make various changes and modifications to the present invention based on the disclosed content, which should also fall within the scope of the present invention.

[0069] The present invention is further described below by way of specific examples. Unless otherwise specified, all the various instruments, devices, equipment, reagents, products, etc. used in the examples of the present invention were obtained through conventional commercial channels.

[0070] Example 1: Preparation of a deep eutectic solvent containing probenecid S1. Weigh 1 g of lysine and 3.149 g of glycerol (molar ratio 1:5) into a 50 mL round-bottom flask. Dissolve in water at 70°C and stir to obtain a homogeneous, clear solution (i.e., Lys-DES). Slowly add 1.315 g of PRO in batches and continue stirring until a clear, homogeneous liquid is obtained. This is the lysine-probenecid-containing deep eutectic solvent (Lys-DES-PRO). Store at room temperature in the dark until ready for use.

[0071] Example 2: Preparation of a deep eutectic solvent containing probenecid S1. Weigh 1 g of arginine and 3.964 g of glycerol (molar ratio 2:15) into a 50 mL round-bottom flask. Dissolve in water at 70°C and stir to obtain a homogeneous, clear solution (i.e., Arg-DES). Slowly add 1.244 g of PRO in batches and continue stirring until a clear, homogeneous liquid is obtained. This is the arginine-probenecid-containing deep eutectic solvent (Arg-DES-PRO). Store at room temperature in the dark until ready for use.

[0072] Example 3: Preparation of eutectic probenecid soluble microneedles S21. ① Weigh 9.6 g of deionized water and 0.4 g of the sample prepared in Example 1, stir for 0.5 h to prepare a preparative solution; ② Weigh 9.3 g of the preparative solution and 0.7 g of HA, stir for 1 h, and centrifuge at 6000 rpm for 10 min to prepare a mother solution; S22. Weigh 0.7 g HA and 9.3 g deionized water in another beaker, stir for 1 h, and centrifuge at 6000 rpm for 10 min to prepare the base solution. S23. Pipette an appropriate amount of mother liquor onto the microneedle mold. Ultrasonicate for 10 minutes, then place in a vacuum drying oven (vacuum degree: -0.5 MPa) for 10 minutes. After vacuuming, ultrasonicate to remove bubbles, and place in a 45°C drying oven for 2 hours. This will form the first layer. After drying for 2 hours, pipette an appropriate amount of mother liquor onto the first layer of the mold. Ultrasonicate for 10 minutes, and place in a 45°C drying oven for 4 hours. This will form the second layer. After drying for 4 hours, pipette an appropriate amount of base liquid onto the second layer of the mold. Ultrasonicate for 10 minutes, and place in a 45°C drying oven for 12 hours. Carefully demold the mold to obtain a high-dose lysine-containing low-melting probenecid-soluble microneedle (Lys-DES-PRO-DMN).

[0073] Example 4: Preparation of eutectic probenecid soluble microneedles S21. ① Weigh 9.7 g of deionized water and 0.3 g of Lys-DES-PRO (Example 1), stir for 0.5 h to prepare a preparative solution; ② Weigh 9.3 g of the preparative solution and 0.7 g of HA, stir for 1 h, and centrifuge at 6000 rpm for 10 min to prepare a mother solution; S22. Weigh 0.7 g HA and 9.3 g deionized water in another beaker, stir for 1 h, and centrifuge at 6000 rpm for 10 min to obtain the base solution. S23. Pipette an appropriate amount of the mother solution onto the microneedle mold. Ultrasonicate for 10 minutes, then place in a vacuum drying oven (vacuum level: -0.5 MPa) for 10 minutes. After vacuuming, ultrasonicate to remove bubbles, and place in a 45°C drying oven for 2 hours. This will form the first layer. After drying for 2 hours, pipette an appropriate amount of the base solution onto the first layer of the mold. Ultrasonicate for 10 minutes, and place in a 45°C drying oven for 4 hours. This will form the second layer. After drying for 4 hours, pipette an appropriate amount of the base solution onto the second layer of the mold. Ultrasonicate for 10 minutes, and place in a 45°C drying oven for 12 hours. Carefully demold the mold to obtain a medium-dose lysine-containing low-melting probenecid-soluble microneedle (Lys-DES-PRO-DMN).

[0074] Example 5: Preparation of eutectic probenecid soluble microneedles S21. ① Weigh 9.95 g of deionized water and 0.05 g of Lys-DES-PRO (Example 1), stir for 0.5 h to prepare a preparative solution; ② Weigh 9.3 g of the preparative solution and 0.7 g of HA, stir for 1 h, and centrifuge at 6000 rpm for 10 min to prepare a mother solution; S22. Weigh 0.7 g HA and 9.3 g deionized water in another beaker, stir for 1 h, and centrifuge at 6000 rpm for 10 min to obtain the base solution. S23. Pipette an appropriate amount of mother liquor onto the microneedle mold. Ultrasonicate for 10 minutes, then place in a vacuum drying oven (vacuum level: -0.5 MPa) for 10 minutes. After vacuuming, ultrasonicate to remove bubbles, and place in a 45°C drying oven for 2 hours. This will form the first layer. After drying for 2 hours, pipette an appropriate amount of mother liquor onto the first layer of the mold. Ultrasonicate for 10 minutes, and place in a 45°C drying oven for 4 hours. This will form the second layer. After drying for 4 hours, pipette an appropriate amount of base liquid onto the second layer of the mold. Ultrasonicate for 10 minutes, and place in a 45°C drying oven for 12 hours. Carefully demold the mold to obtain low-dose lysine-containing eutectic probenecid-soluble microneedles (Lys-DES-PRO-DMN).

[0075] Example 6: Preparation of eutectic probenecid-colchicine mixed soluble microneedles S21. ① Weigh 9.7 g of 0.45% COL (colchicine) aqueous solution and 0.3 g of Lys-DES-PRO (Example 1), stir for 0.5 h to prepare a preparative solution; ② Weigh 9.3 g of the preparative solution and 0.7 g of HA, stir for 1 h, and centrifuge at 6000 rpm for 10 min to prepare a mother solution; S22. Weigh 0.7 g HA and 9.3 g deionized water in another beaker, stir for 1 h, and centrifuge at 6000 rpm for 10 min to prepare the base solution. S23. Pipette an appropriate amount of the mother solution onto the microneedle mold. Ultrasonicate for 10 minutes, then place in a vacuum drying oven (vacuum degree: -0.5 MPa) for 10 minutes. After vacuuming, ultrasonicate to remove bubbles, and place in a 45°C drying oven for 2 hours. This will form the first layer. After drying for 2 hours, pipette an appropriate amount of the base solution onto the first layer of the mold. Ultrasonicate for 10 minutes, then place in a 45°C drying oven for 4 hours. This will form the second layer. After drying for 4 hours, pipette an appropriate amount of the base solution onto the second layer of the mold. Ultrasonicate for 10 minutes, then place in a 45°C drying oven for 12 hours. Carefully demold the mold to obtain a mixed Lys-DES-PRO / COL-DMN.

[0076] Comparative Example 1: Preparation of Comparative Deep Eutectic Solvents 1 g of histidine and 17.806 g of glycerol (molar ratio 1:30) were weighed into a 50 mL round-bottom flask and dissolved in water at 70°C with stirring. When the temperature was raised to 90°C, a homogeneous clear solution could not be obtained, indicating that no eutectic solvent was formed. Therefore, the mixture was not used in the following test.

[0077] Comparative Example 2: Preparation of blank soluble microneedles Weigh 0.7 g HA and 9.3 g deionized water in a beaker, stir for 1 hour, and centrifuge at 6000 rpm for 10 minutes. This is the mother solution, which is also the base solution. Pipette an appropriate amount of base liquid onto the microneedle mold. Ultrasonicate for 10 minutes, then place in a vacuum drying oven (vacuum level: -0.5 MPa) for 10 minutes. After vacuuming, ultrasonicate to remove bubbles, and place in a 45°C drying oven for 2 hours. This will create the first layer. After drying for 2 hours, pipette an appropriate amount of base liquid onto the first layer of the mold. Ultrasonicate for 10 minutes, then place in a 45°C drying oven for 4 hours. This will create the second layer. After drying for 4 hours, pipette an appropriate amount of base liquid onto the second layer of the mold. Ultrasonicate for 10 minutes, then place in a 45°C drying oven for 12 hours. Carefully demold the mold to obtain a blank soluble microneedle.

[0078] Test Example 1: Dynamic Water Solubility Study 500 mg of PRO and the probenecid-containing deep eutectic solvent prepared in Example 1-2 containing an equal amount of PRO were added to 10 mL of deionized water and stirred. 1 mL was taken at 5, 10, 15, 30, 60, 120, 180, and 360 min, respectively, and passed through a 0.22 μm membrane. After dilution, the PRO content was measured using an ultraviolet spectrophotometer at 248 nm.

[0079] like Figure 1 (a) and Figure 1 As shown in (b), PRO dissolved in water at a concentration of only 0.08 mg / mL. Examples 1-2 were uniformly dispersed in water, and dynamic dissolution experiments demonstrated that Examples 1-2 significantly improved PRO solubility in water. At 360 minutes, the concentrations of the probenecid-containing deep eutectic solvents prepared in Examples 1-2 were 14.04 mg / mL and 8.98 mg / mL, respectively. Thus, by preparing probenecid-containing deep eutectic solvents in Examples 1-2, PRO solubility was increased by 176 and 112 times, respectively.

[0080] This is because when DES is added to water, a mixed solvent system is formed. On the one hand, glycerol reduces the polarity of water, and the amino acids ionize to produce ions, forming a "salt-dissolving" effect. On the other hand, the hydrogen bonding between the DES system may hinder the orderly arrangement of PRO into crystal nuclei, thereby increasing the solubility of PRO in water.

[0081] Test Example 2: Thermogravimetric Analysis (TGA) Approximately 5-7 mg of PRO standard, the probenecid-containing deep eutectic solvent prepared in Examples 1-2, arginine, lysine, and glycerol were placed in an alumina container. The temperature was increased from 25°C to 500°C at a heating rate of 10°C / min and a nitrogen flow rate of 100 mL / min. The thermal decomposition temperatures of the raw materials and samples were compared.

[0082] As shown in Table 1, the thermal decomposition temperatures of the probenecid-containing deep eutectic solvents prepared in Examples 1 and 2 were 137°C and 135°C, respectively, significantly lower than the thermal decomposition temperature of the PRO raw material, 208°C. This is because a large number of hydrogen bonds are formed in the DES system, turning the probenecid-containing deep eutectic solvents prepared in Examples 1-2 into stable liquid mixtures. A lower freezing point is a significant indicator of successful DES preparation. This indicates that the probenecid-containing deep eutectic solvents prepared in Examples 1-2 have a lower thermal decomposition temperature, significantly improving the solubility rate while also having a certain degree of thermal stability.

[0083] Table 1 Comparison of thermal decomposition temperatures of various raw materials and Examples 1-2

[0084] Test Example 3: In vitro uric acid dissolution test (1) Preparation of standard solution and full wavelength scanning test Accurately weigh 12.5 mg of uric acid (UA) standard, dissolve in 0.1 M NaOH, and dilute to a 100 mL volumetric flask. Shake thoroughly to obtain a stock solution with a concentration of 0.125 mg / mL. Scan the standard solution at 200-800 nm using a UV spectrophotometer to identify the wavelength of maximum UV absorption.

[0085] (2) Drawing of the standard curve Gradually prepare standard solutions of varying concentrations from 5 to 20 μg / mL using the standard stock solution. Establish a linear working curve for the standard solutions at the wavelength of maximum absorption. Plot a standard curve by performing a linear regression of absorbance (Y) against standard concentration (X).

[0086] The maximum UV absorption wavelength of the UA standard solution is 290 nm. At 290 nm, the UA standard solution has good linearity within the range of 5-20 μg / mL. The standard curve is Y=0.03643X+0.01321, (Y is the peak area, X is the concentration of UA (μg / mL), R 2 =0.9976).

[0087] (3) Spectral degradation analysis of samples to UA PRO, the probenecid-containing deep eutectic solvent prepared in Example 1-2, and PBS (pH = 7.4) were placed in a 10 mL centrifuge tube at a volume ratio of 2:1. A certain amount of UA (48 mg / mL) was added to the centrifuge tube. The mixture was stirred at 37°C for 0-180 min, with a point taken every 10 min. Spectral scanning was performed at 290 nm.

[0088] like Figure 2-Figure 4 As shown in the figure (the curves in the figure are the spectral scanning curves from top to bottom at 0-180 min), pure PBS is difficult to degrade PRO, which verifies the poor water solubility of PRO raw materials. However, as time increases, the spectral absorbance of Examples 1-2 at 290 nm gradually decreases, indicating that they can significantly degrade UA. Figure 5 As shown, at 180 minutes, Example 1 achieved a UA degradation rate of 85.72%, while Example 2 achieved a UA degradation rate of 75.48%. The degradation rate of Example 1 was 57.41% higher than that of pure PBS. Based on the above tests, Example 1 exhibited superior solubility and more significant in vitro UA degradation. Therefore, Example 1 has significant research significance for degrading uric acid and alleviating acute gout attacks.

[0089] Test Example 4: Testing the morphology of the blank microneedles prepared in Comparative Example 2 and the soluble microneedles prepared in Examples 3-6 The blank microneedles prepared in Comparative Example 2 and the soluble microneedles prepared in Examples 3-6 were placed under a mechanical microscope, and the morphology of the microneedles was photographed using a 64x microscope.

[0090] The results are as follows Figure 6 As shown, the blank microneedles prepared in Comparative Example 2 and the soluble microneedles prepared in Examples 3-6 all have complete needle shapes and excellent morphology, indicating that the soluble microneedles prepared under this formula have excellent morphology.

[0091] Test Example 5: Testing the Mechanical Properties of the Blank Microneedles Prepared in Comparative Example 2 and the Dissolvable Microneedles Prepared in Examples 3-6 The blank microneedles prepared in Comparative Example 2 and the soluble microneedles of Examples 3-6 were tested using a displacement force tester with the probe moving toward the microneedles at a speed of 0.02 mm / s. The force and displacement were recorded every 0.02 mm until the probe reached the preset distance of 0.62 mm.

[0092] When the microneedle is inserted, it will produce a displacement caused by the elastic deformation of the skin. The turning point at the moment of insertion is the force of the microneedle into the skin. Usually, the force required to penetrate the stratum corneum of the skin is 0.1N-0.3N. Figure 7 As shown, the mechanical properties of the blank soluble microneedle in comparative example 2 is 0.227N, and the mechanical properties of embodiments 3, 4, 5 and 6 are 0.195N, 0.210N, 0.216N and 0.207N, respectively. It can be seen that both the comparative example and the embodiments meet the conditions for the required force for insertion into the skin.

[0093] Test Example 6: Testing the drug loading of the blank microneedles prepared in Comparative Example 2 and the soluble microneedles prepared in Examples 3-6 (1) Preparation of COL standard solution and full wavelength scanning test Accurately weigh 5 mg of COL standard and dilute to a 20 mL volumetric flask with methanol. Shake well and transfer 10 mL of the solution to a 25 mL volumetric flask to obtain a stock solution with a concentration of 0.1 mg / mL. Scan the standard solution at 200-800 nm using a UV spectrophotometer to identify the wavelength of maximum UV absorption.

[0094] (2) Drawing of COL standard curve Gradually prepare standard solutions of varying concentrations from 6 to 18 μg / mL using the standard stock solution. Establish a linear working curve for the standard solutions at the wavelength of maximum absorption. Plot a standard curve by performing a linear regression of absorbance (Y) against standard concentration (X).

[0095] The maximum UV absorption wavelength of the COL standard solution is 350 nm. At 350 nm, the COL standard solution has good linearity in the range of 6-18 μg / mL. The standard curve is Y=0.04405X-0.01031, (Y is the peak area, X is the concentration of COL (μg / mL), R 2 =0.9997).

[0096] (3) Determination of drug loading To determine the PRO or COL content in the soluble microneedles prepared in Examples 3-6, the same batch of microneedles was dissolved in 1 mL of PBS (pH 7.4). After stirring for 1 hour, a homogeneous solution was obtained. The absorbance was measured at 248 nm or 350 nm, and the drug content in the soluble microneedles of each example was calculated using a linear equation.

[0097] As shown in Table 2, the PRO contents in the soluble microneedles prepared in Examples 3-5 were 7.35, 4.35, and 1.11 mg, respectively; the PRO and COL contents in the soluble microneedles prepared in Example 6 were 4.22 mg and 1.10 mg, respectively. The morphology, mechanical properties, and drug loading indicate that the two different drugs mixed in the soluble microneedles in Example 6 do not repel each other.

[0098] Table 2 Comparison of drug loading of soluble microneedles prepared in Examples 3-6

[0099] Test Example 7: Insertion Study of the Dissolvable Microneedles Prepared in Test Example 3 Example 3 was inserted into ex vivo pig skin, which was fixed in 4% paramethanol for 24 hours, then immersed in OCT compound as a freezing medium at room temperature for 2 hours and sliced. Hematoxylin-eosin (HE) staining was performed, and the insertion condition was observed under a laser scanning fluorescence microscope.

[0100] like Figure 8 As shown, it can be observed on the ex vivo pig skin that Example 3 forms a micron "channel" on the skin. It also shows that after loading the drug, the microneedle of this formula can still penetrate the stratum corneum (thickness: 10-20μm), allowing the drug to be released at the site of inflammation, which can more effectively exert its effect.

[0101] Test Example 8: Study on the dissolution ability of the soluble microneedles prepared in Example 3 The soluble microneedle prepared in Example 3 was placed on the surface of pig skin and pressed with a thumb for 0-3 minutes. The dissolution of the needle tip was photographed using a mechanical microscope at 0 seconds, 10 seconds, 30 seconds, and 3 minutes.

[0102] The basal layer dissolution experiment requires an additional hydrogel film (weigh 6% PVA in a beaker, stir at 80°C for 1 hour, centrifuge at 6000 rpm for 10 minutes, remove bubbles with ultrasound, pour into a culture dish, put in a -24°C refrigerator for 6 hours, take out and thaw at room temperature for 6 hours, repeat freezing and thawing 3 times to obtain a hydrogel film.) As an external dressing to assist dissolution and adhesion, it is covered on the soluble microneedles that have been pressed for 3 minutes, and the dissolution of the basal layer is observed with the naked eye within 0-60 minutes.

[0103] like Figure 9 As shown, when the microneedles were not inserted into the pig skin at 0s, the soluble microneedles of Example 3 had excellent morphology. It was observed from a mechanical microscope that the needle tip had dissolved in 10s, and when the cumulative insertion was 30s, it could be clearly seen that the microneedles began to dissolve and swelled. After 3min, the microneedles were completely dissolved. In addition, the basal layer had dissolved within 30min, showing a gel state, and had reached complete dissolution at 60min, and gradually penetrated into the skin. It can be seen that the microneedles prepared by this formula have excellent solubility and achieve synchronous drug release during the dissolution process. Therefore, it has the advantages of not needing to remove the needle body after use, reducing the reuse rate, and avoiding cross infection.

[0104] Test Example 9: Study on the transdermal penetration ability of the soluble microneedles prepared in Examples 3-6 (1) Transdermal absorption In vitro permeation studies were conducted. The soluble microneedles prepared in Examples 3 and 6 were applied to the surface of pig skin, with the sample of Example 1 as the control. PBS (pH = 7.4) was used as the medium for the receptor chamber. In a Franz diffusion cell system, the skin (3 × 3 cm 2 ) was placed between the donor chamber and a 6-mL receiving cell (preheated to 35°C, rotating at 350 rpm) in the dark. At pre-set intervals of 0.5, 1, 2, 4, 6, 8, and 12 hours, 3-mL aliquots of sample were removed from the receiving cell and immediately refilled with 3 mL of PBS solution. Finally, the PRO or COL content of the resulting samples was measured at 248 nm or 350 nm. Substituting the corresponding linear equations to obtain the corresponding concentrations, the cumulative release (Q) was calculated according to the formula.

[0105] ; C n is the drug concentration measured at the nth sampling point (μg·mL -1 ), V is the volume of the receiving solution (6 mL), C i is the drug concentration measured at the i-th sampling point (μg·mL -1 ), V i is the sampling volume, A is the drug release area (cm 2 ).

[0106] like Figure 10 As shown in (a), the PRO release rate in the soluble microneedles prepared in Example 3 was 63.82 μg / cm in the first 0.5 h. 2 , while the PRO release rate of the probenecid-containing deep eutectic solvent prepared in Example 1 was 22.62 μg / cm 2 During the entire release process, the soluble microneedles of Example 3 showed a relatively fast linear release, with a cumulative release of 668.41 μg / cm at 12 h. 2 The cumulative release of the probenecid-containing deep eutectic solvent prepared in Example 1 was 318.28 μg / cm 2 In addition, the release amounts of PRO and COL from the mixed soluble microneedles prepared in Example 6 were 515.35 μg / cm 2 and 445.42 μg / cm 2 Compared with the DES liquid containing probenecid low eutectic solvent prepared in Example 1, the micron "road" formed by the soluble microneedles can quickly release the drug and the mixed microneedles can achieve the simultaneous release of two drugs to enhance the therapeutic effect.

[0107] (2) Skin retention After the transdermal permeation test, the excised skin was removed intact, rinsed with PBS, minced, and added with 4 mL of methanol. Ultrasonic extraction was repeated three times for 10 minutes each time, and the extract was filtered through a 0.45 μm microporous membrane. The skin retention was measured at 248 nm or 350 nm.

[0108] like Figure 10 As shown in (b), the PRO skin retention of the soluble microneedles prepared in Example 3 was 203.85 μg / cm 2 The skin retention of PRO and COL mixed soluble microneedles in Example 6 were 287.24 and 97.36 μg / cm 2 However, the skin retention of PRO containing probenecid deep eutectic solvent prepared in Example 1 was 819.66 μg / cm 2 This indicates that the drug in the liquid state mainly stays on the surface of the skin, and the channels formed by the soluble microneedles allow the drug to directly enter the inflamed area and achieve a therapeutic effect.

[0109] Test Example 10: Skin irritation test of blank microneedles prepared in Comparative Example 2 and soluble microneedles prepared in Examples 3-6 and application in acute gout in mice (1) Animal type SPF male BALB / c mice (weight 20-25 g, 6-8 weeks old) were used.

[0110] (2) Skin irritation test After depilation, the back skin of mice was exposed to 5% SDS (sodium dodecyl sulfate) for 2 hours every day for 3 consecutive days for model control, as well as blank microneedles prepared in Comparative Example 2, and soluble microneedles prepared in Example 3 and Example 6, respectively, on the back of mice. The mice were fixed with medical breathable tape, and the skin condition was observed daily. On the 4th day, the back skin was removed and stained with hematoxylin-eosin (HE).

[0111] Skin erythema and edema were assessed using a 3-day self-administered skin irritation test. Figure 11 、 Figure 12 As shown, the 5% SDS model group developed redness, dryness and peeling, swelling, and eschar, which lasted for more than 24 hours. Furthermore, HE staining showed a large number of inflammatory cells in this group, and severe skin inflammation. However, after application of the blank microneedles prepared in Comparative Example 2 and the soluble microneedles in Examples 3 and 6 to the backs of mice, no skin irritation occurred, and HE staining showed no inflammation. This demonstrates that they are safe for skin and can be used.

[0112] (3) Application in acute gout in mice ①24h acute gout swelling analysis After hair was removed from the mouse knee joint (left side), 25 μL of 25 mg / mL sodium urate crystals (MUS) were injected into the joint cavity using a 0.3 mL microsyringe. Swelling of the left knee joint was observed at 0, 1, 2, 4, 6, 8, 12, 15, and 24 hours. The change in the minimum diameter of the left knee joint was measured using a vernier caliper. The swelling rate was calculated based on the change in diameter using the following formula to assess the degree of joint swelling.

[0113] ; Where V t represents the diameter at different times, and V0 represents the initial diameter (mm).

[0114] like Figure 13 (a) and Figure 13 As shown in (b), after MUS injection, the mouse knee joints became red and swollen over time, reaching a peak of 53.97% at 12 hours. Within 24 hours, knee swelling decreased but did not return to normal. This is due to the presence of uricase in the mice, which leads to slow recovery. Therefore, the present invention selects the peak swelling point at 12 hours as the starting point for treatment and formulates a 5-hour microneedle treatment plan. This not only mitigates the impact of self-recovery properties, but also demonstrates the advantages of microneedle rapid drug release for the treatment of acute gout.

[0115] ②Treatment of acute gout in mice After hair was shaved from the left knee joints of mice, 25 μL of MUS was injected into the joint cavity using a microsyringe to establish an acute gout model in mice. Twelve hours later, blank microneedles prepared in Comparative Example 2 and soluble microneedles from Examples 3-6 were placed in the knee joints of the mice and secured with medical breathable tape before treatment. The model group included mice in which an acute gout model was successfully established but received no treatment. In addition, a 10 μL injection of a 0.5 mg / mL aqueous solution of COL was used as a positive control, serving as the positive control. Five hours after treatment, the degree of left knee joint swelling in each group was observed, and the swelling rate was calculated.

[0116] Gout can cause joint redness and swelling during an acute attack. This is because MUS deposits in the joints and soft tissues, causing a severe inflammatory response. Soluble microneedles are crucial in reducing knee joint redness and swelling. Figure 14 (a) and Figure 14 As shown in (b), compared with the positive group, the mice treated with the soluble microneedles prepared in Examples 3-6 showed a drug dose dependence. As the drug content increased, the redness and swelling of the left knee joint of the mice slowly subsided, and the swelling rate decreased, indicating that the therapeutic effect was more significant. Among them, the therapeutic effect of the mixed soluble microneedles of Example 6 was similar to that of the high-dose soluble microneedles of Example 3. This is attributed to the synergistic effect of the two groups of drugs, medium-dose PRO and COL, in Example 7. In addition, the swelling rate of the blank soluble microneedles of Comparative Example 2 remained almost unchanged, indicating that the microneedle matrix (HA) had no therapeutic effect. It can be seen that the drug reaches the inflamed tissue site in a short time through the nano "channels" created by the soluble microneedles of Examples 3-6, improving the redness and swelling of the left knee joint of the mice, indicating that they have alleviated the swelling problem caused by acute gout to a certain extent.

[0117] ③Analysis of inflammatory factor levels in acute gout in mice To measure serum cytokine levels, orbital blood was collected from mice treated with blank microneedles from Comparative Example 2 and soluble microneedles prepared from Examples 3-6 5 hours after treatment. After 40 minutes at room temperature, the blood samples were centrifuged at 3000 rpm for 10 minutes, and the supernatant (serum) was collected. Levels of the proinflammatory cytokines IL-1β and TNF-α in mouse serum samples were analyzed and measured using a microplate reader at 450 nm according to the manufacturer's protocol for mouse interleukin-1β (IL-1β) and tumor necrosis factor α (TNF-α) ELISA kits.

[0118] In addition, knee joint tissue from mice treated with blank microneedles from Comparative Example 2 and soluble microneedles from Examples 3-6 was quickly removed and fractured with liquid nitrogen. The tissue was then placed in a homogenization tube at a volume ratio of 1:9 (tissue sample weight (g) to pre-chilled PBS (mL)). The tube was placed on ice and thoroughly ground to prepare a 10% homogenate. The prepared 10% homogenate was centrifuged at 3000 rpm for 10 minutes in a low-temperature, low-speed centrifuge (4°C). The supernatant was collected and assayed for MPO activity in the knee joint tissue samples to assess inflammation, according to the manufacturer's protocol for a mouse myeloperoxidase (MPO) ELISA kit.

[0119] After the injection of MSU crystals, it will stimulate the cleavage of interleukin-1β and the secretion of other pro-inflammatory cytokines, leading to the recruitment of neutrophils, increasing the infiltration of inflammatory cells, and inducing the onset of acute gout or tophi. The determination of the levels of IL-1β and TNF-α in mouse serum and the MPO activity in tissue samples can verify whether the soluble microneedles can alleviate the acute gout attack. Figure 15 (a) Figure 15 (b) and Figure 15 As shown in (c), one-way analysis of variance (ANOVA) and Bonferroni post hoc test were used to compare with the normal group ( P<0.05, P<0.001, P<0.001), compared with the model group ( ### P < 0.001), the difference was considered statistically significant. The blank soluble microneedles in Comparative Example 2 were similar to the model group, indicating that it had no therapeutic effect. The levels of proinflammatory factors and MPO activity in both groups were reduced to varying degrees after treatment with the soluble microneedles of Examples 3-6. It can be seen that the reduction of joint redness and swelling and the reduction of inflammatory factors indicate that the soluble microneedles of Examples 3-6 can alleviate the onset of acute gout.

[0120] Verification of technical effects and / or analysis of technical problem solving The present invention constructs a basic amino acid-glycerol deep eutectic solvent system to prepare a probenecid-containing deep eutectic solvent. The probenecid-containing deep eutectic solvent prepared in Example 1 increased the solubility of PRO by 23.20%. The probenecid-containing deep eutectic solvent (Lys-DES-PRO) prepared in Example 1 exhibits high solubility, excellent stability, and significant in vitro degradation of UA. By delivering Lys-DES-PRO via a soluble microneedle carrier, the resulting probenecid-soluble deep eutectic microneedles (Lys-DES-PRO-DMN) at varying doses not only exhibit significant transdermal penetration, mechanical properties, and solubility, but also demonstrate safety and non-irritation as demonstrated by skin irritation testing. In vivo acute gout experiments in mice demonstrated effective reduction of swelling at the inflammatory site and decreased expression of the inflammatory factors IL-1β and TNF-α, as well as MPO activity in tissue samples. Furthermore, the Lys-DES-PRO-DMN of the present invention can be supplemented with colchicine, providing a new option for combination therapy against gout. Therefore, the low-dose eutectic probenecid soluble microneedles prepared by the present invention have broad prospects in the medicaments for relieving and preventing gout.

[0121] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A eutectic probenecid soluble microneedle, characterized in that: The invention comprises the following components: probenecid, a low eutectic solvent and a matrix material; wherein the low eutectic solvent comprises: a basic amino acid and a polyol; and the molar ratio of the basic amino acid to the polyol is 1:5-7.

5.

2. The eutectic probenecid soluble microneedle according to claim 1, characterized in that: The molar ratio of the basic amino acid to the polyol is 1:

5.

3. The eutectic probenecid soluble microneedle according to claim 1, characterized in that: The basic amino acid is lysine, arginine or histidine.

4. The eutectic probenecid soluble microneedle according to claim 1, characterized in that: The polyol is glycerol; The matrix material is selected from at least one of polylactic acid-glycolic acid copolymer, polyethylene glycol, polyvinyl pyrrolidone, polymethyl methacrylate, and hyaluronic acid.

5. The eutectic probenecid soluble microneedle according to claim 1, characterized in that: The mass ratio of the basic amino acid, the polyol and the probenecid is 1:3.149-3.964:1.244-1.

315.

6. The eutectic probenecid soluble microneedle according to claim 1, characterized in that: Probenecid and a deep eutectic solvent are mixed to form a basic amino acid-probenecid-containing deep eutectic solvent; the mass ratio of the basic amino acid-probenecid-containing deep eutectic solvent to the matrix material is 0.05-0.4:1.

4.

7. The method for preparing the eutectic probenecid soluble microneedles according to any one of claims 1 to 6, characterized in that: Including steps: S1. Preparation of a basic amino acid-containing probenecid deep eutectic solvent: stirring the deep eutectic solvent under heating conditions until transparent, adding probenecid, and continuing to stir until transparent to obtain a basic amino acid-containing probenecid deep eutectic solvent; S2. Preparation of eutectic probenecid soluble microneedles, comprising the steps of: S21, preparation of a mother liquor: mixing the basic amino acid-probenecid-containing deep eutectic solvent obtained in step S1 with water to form a preliminary solution; mixing the preliminary solution with a portion of the matrix material, stirring, and then centrifuging to obtain a mother liquor; S22, preparation of base solution: mixing the remaining matrix material with water, stirring, and centrifuging to prepare a base solution; S23. Preparation of microneedles: aspirate the mother liquid onto the microneedle mold and perform initial drying to obtain the first layer; then aspirate the next layer of mother liquid or base liquid and perform secondary drying to obtain the second layer; finally aspirate the base liquid onto the second layer and perform final drying to obtain low-eutectic probenecid-soluble microneedles.

8. The preparation method according to claim 7, characterized in that In step S1, the heating temperature is 60-80°C, preferably 70°C; In step S21, the mass ratio of the basic amino acid-probenecid-containing deep eutectic solvent to water is 0.5-4:96-99.5; in step S21, the water can be deionized water or an aqueous solution containing the second antigout drug; in step S21, the mass ratio of the preparatory solution to the portion of the matrix material in the mother liquor is 9.3:0.5-0.8; preferably 9.3:0.7; In step S22, the mass ratio of water to the remaining matrix material in the base liquid is 9.3:0.5-0.8, preferably 9.3:0.

7.

9. The preparation method according to claim 7, characterized in that In step S23, each time the mother liquid or base liquid is drawn onto the microneedle mold, a bubble removal process is required; In step S23, the initial drying is performed at 40-50°C for 1-3 hours; preferably, the initial drying is performed at 45°C for 2 hours; In step S23, the secondary drying is performed at 40-50°C for 3-5 hours; preferably, the secondary drying is performed at 45°C for 4 hours; In step S23, the final drying is performed at 40-50°C for 10-16 hours; preferably, the final drying is performed at 45°C for 12 hours.

10. Use of the eutectic probenecid soluble microneedles according to any one of claims 1 to 6 or the eutectic probenecid soluble microneedles prepared by the preparation method according to any one of claims 7 to 9 in preparing a drug for treating gout.

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