A preparation method of a double-layer microneedle patch for atopic dermatitis

Abstract

The present invention discloses a method for preparing a double-layer microneedle patch for atopic dermatitis. The method comprises the following steps: using double templates to replicate a double-layer microneedle; using methacrylate gelatin, forming an inner needle tip layer by ultraviolet curing; then transferring the formed microneedle into a large template; using sodium hyaluronate, forming an outer needle tip layer by drying, thereby preparing the double-layer microneedle patch. The double-layer microneedle patch prepared by the present invention has excellent mechanical properties and can successfully penetrate the thickened skin of atopic dermatitis patients. After penetration, the needle tip and the backing layer quickly separate, and the outer needle tip quickly dissolves under the action of tissue fluid, leaving the inner needle tip with strong biocompatibility and capable of sustained-release therapeutic drugs. While providing anti-inflammatory effects, it also repairs the epidermal barrier, thereby alleviating the symptoms of atopic dermatitis. The double-layer microneedle patch prepared by the present invention has diverse functions, significant efficacy, and a wide range of applications.

Description

Technical Field

[0001] The present invention relates to the technical field of biomedical materials, and in particular to a double-layer microneedle patch for atopic dermatitis and a preparation method thereof. Background Art

[0002] Atopic dermatitis is a common, recurring, chronic inflammatory skin disease characterized by dry skin, itching, eczematous plaques, epidermal barrier defects, and immune hyperreactivity to allergens. It significantly impacts the quality of life of individuals and their families, posing a significant threat to patients and the economy. Currently, atopic dermatitis is primarily treated clinically with topical or injectable medications. However, direct topical application of these medications has drawbacks such as requiring multiple applications, low utilization rates, and poor compliance. Injections, on the other hand, inevitably cause pain and can even lead to serious consequences such as vascular rupture and necrosis at the injection site.

[0003] Microneedles have been proven to be an effective drug delivery tool that can penetrate the epidermis and enter internal tissues non-invasively and infection-free. They can not only avoid multiple dosing through controlled release but also minimize the required dose through targeted delivery. Due to their microscopic size, microneedles deliver drugs by puncturing small holes in the skin, avoiding blood vessels and peripheral nerves, thus causing no pain or bleeding.

[0004] CN107405301A relates to a microneedle patch composition comprising one or more microneedles, each of which comprises: (a) a tapered tip portion containing a therapeutically active ingredient dispersed in a matrix of a biodegradable polymer, which is capable of providing sustained release of the therapeutically active ingredient after the one or more microneedles are inserted into the skin, and (b) a dissolvable microneedle backing layer portion containing a water-soluble polymer covering the tip portion, the one or more microneedles being attached to and extending from the surface of a removable substrate.

[0005] WO 02 / 046193 discloses a microneedle device (10) and a method of manufacture for transporting molecules or energy across or into a biological barrier, such as the skin. The device may include one or more microneedles formed from a first material and a second material, wherein the second material is dispersed throughout the first material or forms a portion of the microneedle. The first material is preferably a polymer. The second material may be a pore former, a structural component, a biosensor, or a molecule for release, such as a drug. The device may also include a substrate and a plurality of microneedles extending from the substrate, wherein the microneedles have a beveled or tapered tip portion, a longitudinally extending external channel, or both. Methods of manufacturing these devices include providing a mold having a plurality of microrecesses that define a surface of the microneedles; filling the microrecesses with a first molding material; and molding the material to form the microneedles.

[0006] Although some microneedle patches have been studied and developed in the above-mentioned prior art, there are still some problems in the prior art. For example, there is no microneedle patch specifically for atopic dermatitis, and the microneedle patch cannot successfully penetrate the thickened skin of atopic dermatitis patients into the deep epidermis due to insufficient mechanical properties, resulting in poor treatment effect.

[0007] Therefore, the present invention has developed a double-layer microneedle patch through a double-template replication and curing method. It has excellent mechanical properties and can successfully penetrate the thickened skin of patients with atopic dermatitis. After penetrating the skin, the needle tip and the backing layer separate, and the outer needle tip quickly dissolves under the action of tissue fluid. The remaining inner needle tip has strong biocompatibility and can slowly release therapeutic drugs, repairing the epidermal barrier while fighting inflammation, thereby alleviating the symptoms of atopic dermatitis. It has diverse functions, significant therapeutic effects, and a wide range of applications, and is of great significance for alleviating the symptoms of atopic dermatitis. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to provide a double-layer microneedle patch for atopic dermatitis and a preparation method thereof in view of the deficiencies of the above-mentioned prior art.

[0009] To achieve the above technical objectives, the technical solution adopted by the present invention is: a method for preparing a double-layer microneedle patch for atopic dermatitis, comprising the following steps:

[0010] 1) Preparation of inner layer microneedles: Filling a small template with needle-shaped holes with a solution of the raw material of the inner layer of the microneedle tips containing the therapeutic drug. After the solution of the raw material of the inner layer of the microneedle tips solidifies, filling the template with a solution of the raw material of the microneedle backing layer. After drying and demolding, the inner layer microneedle patch is obtained;

[0011] 2) Preparation of double-layer microneedles: Fill the outer layer raw material solution of the microneedle tip into a large template with needle-shaped holes. After scraping off the excess solution, the inner layer microneedle patch is firmly pressed into the large template. After drying, demolding is carried out to prepare a double-layer microneedle patch.

[0012] Furthermore, the raw material solution of the inner layer of the microneedle tip is selected from one or more of methacrylate gelatin, methacrylated hyaluronic acid, and polyethylene glycol diacrylate, and the therapeutic drug loaded therein is selected from one or more of triamcinolone acetonide, mometasone furoate, and dexamethasone, with a concentration of 20-25 mg / mL.

[0013] Furthermore, the raw material solution of the microneedle backing layer and the raw material solution of the microneedle tip outer layer are selected from one or more of sodium hyaluronate, polyvinyl alcohol, and polyvinyl pyrrolidone.

[0014] Furthermore, the raw material solution of the inner layer of the microneedle tip needs to be kept away from light before solidification.

[0015] Furthermore, the array number of needle tips of the microneedle patch is greater than 20, the length of the inner layer needle tips is 0.2-1 mm, and the length of the outer layer needle tips is 0.4-1.5 mm.

[0016] Furthermore, the needle tip is conical, triangular pyramidal or quadrangular pyramidal. When the needle tip is conical, the radius of its bottom is 100-300 μm; when the needle tip is triangular pyramidal or quadrangular pyramidal, the side length of its bottom is 100-300 μm.

[0017] Furthermore, the outer layer of the needle tip is conical, triangular pyramidal or quadrangular pyramidal. When the outer layer of the needle tip is conical, its bottom radius is 100-600 μm; when the outer layer of the needle tip is triangular pyramidal or quadrangular pyramidal, its bottom side length is 100-600 μm.

[0018] Furthermore, the raw material solution of the inner layer of the microneedle tip and the raw material solution of the outer layer of the microneedle tip are fully filled into the template by vacuum or centrifugation.

[0019] Furthermore, the curing method of the raw material solution of the inner layer of the microneedle tip is to add 1% by volume of 2-hydroxy-2-methylpropiophenone to the raw material solution of the inner layer of the microneedle tip, and polymerize it under ultraviolet light.

[0020] Furthermore, after adding the raw material solution of the microneedle backing layer and the raw material solution of the microneedle tip outer layer, the drying temperature of the microneedle patch is 37°C.

[0021] The present invention also provides a double-layer microneedle patch for atopic dermatitis prepared by the above-mentioned preparation method. The patch has excellent mechanical properties and can successfully penetrate the thickened skin of atopic dermatitis patients. After penetrating the skin, the needle tip and the backing layer separate, and the outer needle tip quickly dissolves under the action of tissue fluid. The remaining inner needle tip has strong biocompatibility and can slowly release therapeutic drugs, repairing the epidermal barrier while fighting inflammation, thereby alleviating the symptoms of atopic dermatitis. It has diverse functions, significant therapeutic effects, and a wide range of applications.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1) The present invention provides a method for preparing a double-layer microneedle patch for atopic dermatitis. The method comprises the following steps: filling a small template with needle-shaped holes with a solution of a raw material for the inner layer of the microneedle tips through multi-template replication and step-by-step curing; curing the solution of the raw material for the inner layer of the microneedle tips; filling the template with a solution of a raw material for the microneedle backing layer; and drying and demolding the template to obtain an inner-layer microneedle patch; filling a large template with needle-shaped holes with a solution of a raw material for the outer layer of the microneedle tips; scraping off excess solution; and then forcibly pressing the inner-layer microneedle patch into the large template; drying and demolding the template to obtain a double-layer microneedle patch. The preparation method is simple and reliable.

[0024] 2) After the double-layer microneedle patch provided by the present invention is inserted into the skin, the needle tip and the backing layer separate, and the outer needle tip quickly dissolves under the action of tissue fluid, leaving the inner needle tip with strong biocompatibility and less likely to produce immune rejection reactions;

[0025] 3) The double-layer microneedle patch provided by the present invention can slowly release therapeutic drugs after being inserted into the skin, thereby repairing the epidermal barrier while fighting inflammation, thereby alleviating the symptoms of atopic dermatitis; BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the preparation of a double-layer microneedle patch for atopic dermatitis according to the present invention;

[0027] Figure 2 Schematic diagram of the double-layer microneedle patch structure of the present invention;

[0028] Figure 3 Schematic diagram of the needle tip structure of the double-layer microneedle patch of the present invention;

[0029] Figure 4 These are HE staining images of the control group and the experimental group in Example 3, where A is the HE staining result of the control group and B is the HE staining result of the experimental group. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the embodiments of the present invention are described in further detail below with reference to the accompanying drawings.

[0031] The experimental methods used in the following examples are conventional methods unless otherwise specified, and the reagents, methods and equipment used are conventional reagents, methods and equipment in the art unless otherwise specified.

[0032] The present invention provides a method for preparing a double-layer microneedle patch for atopic dermatitis, comprising the following steps:

[0033] 1) Preparation of inner layer microneedles: Filling a small template with needle-shaped holes with a solution of the raw material of the inner layer of the microneedle tips containing the therapeutic drug. After the solution of the raw material of the inner layer of the microneedle tips solidifies, filling the template with a solution of the raw material of the microneedle backing layer. After drying and demolding, the inner layer microneedle patch is obtained;

[0034] 2) Preparation of double-layer microneedles: Fill the outer layer raw material solution of the microneedle tip into a large template with needle-shaped holes. After scraping off the excess solution, the inner layer microneedle patch is firmly pressed into the large template. After drying, demolding is carried out to prepare a double-layer microneedle patch.

[0035] The raw material solution of the inner layer of the microneedle tip is selected from one or more of methacrylate gelatin, methacrylated hyaluronic acid, and polyethylene glycol diacrylate. The therapeutic drug loaded therein is selected from one or more of triamcinolone acetonide, mometasone furoate, and dexamethasone, with a concentration of 20-25 mg / mL.

[0036] The raw material solution of the microneedle backing layer and the raw material solution of the microneedle tip outer layer are selected from one or more of sodium hyaluronate, polyvinyl alcohol, and polyvinyl pyrrolidone.

[0037] The raw material solution of the inner layer of the microneedle tip needs to be kept away from light before solidification.

[0038] The array number of needle tips of the microneedle patch is greater than 20, the length of the inner needle tips is 0.2-1 mm, and the length of the outer needle tips is 0.4-1.5 mm.

[0039] The needle tip is in the shape of a cone, a triangular pyramid or a quadrangular pyramid. When the needle tip is in the shape of a cone, the radius of its bottom is 100-300 μm; when the needle tip is in the shape of a triangular pyramid or a quadrangular pyramid, the side length of its bottom is 100-300 μm.

[0040] The outer layer of the needle tip is conical, triangular pyramidal or quadrangular pyramidal. When the outer layer of the needle tip is conical, its bottom radius is 100-600 μm; when the outer layer of the needle tip is triangular pyramidal or quadrangular pyramidal, its bottom side length is 100-600 μm.

[0041] The raw material solution of the inner layer of the microneedle tip and the raw material solution of the outer layer of the microneedle tip are fully filled into the template by vacuum or centrifugation.

[0042] The solidification method of the raw material solution of the inner layer of the microneedle tip is to add 1% by volume of 2-hydroxy-2-methylpropiophenone into the raw material solution of the inner layer of the microneedle tip, and polymerize the solution under ultraviolet light.

[0043] After adding the raw material solution of the microneedle backing layer and the raw material solution of the microneedle tip outer layer, the drying temperature of the microneedle patch is 37°C.

[0044] The present invention uses multi-template replication and step-by-step curing to fill the raw material solution of the inner layer of the microneedle tip into a small template with needle-shaped holes. After the raw material solution of the inner layer of the microneedle tip is cured, the raw material solution of the microneedle backing layer is filled into the template, and the template is dried and demolded to obtain an inner-layer microneedle patch; the raw material solution of the outer layer of the microneedle tip is filled into a large template with needle-shaped holes, and after scraping off the excess solution, the inner-layer microneedle patch is pressed into the large template with force and aligned, and the template is dried and demolded to obtain a double-layer microneedle patch. The preparation method is simple and reliable.

[0045] After the double-layer microneedle patch provided by the present invention is inserted into the skin, the needle tip and the backing layer separate, and the outer needle tip quickly dissolves under the action of tissue fluid, leaving the inner needle tip with strong biocompatibility and less likely to cause immune rejection reaction;

[0046] The double-layer microneedle patch provided by the present invention can slowly release therapeutic drugs after being inserted into the skin, thereby repairing the epidermal barrier while fighting inflammation, thereby alleviating the symptoms of atopic dermatitis.

[0047] The following are examples:

[0048] Example 1

[0049] A double-layer microneedle patch based on methacrylate gelatin and sodium hyaluronate was prepared according to the following method:

[0050] (1) Preparation of microneedle tip inner layer raw material solution

[0051] Microneedle tip inner layer raw material solution: Prepare 30% methacrylate gelatin containing a therapeutic drug (triamcinolone acetonide, concentration of 20 mg / mL) as the microneedle tip inner layer raw material solution, add 1% volume fraction of 2-hydroxy-2-methylpropiophenone to the microneedle tip inner layer raw material solution to form a microneedle raw material solution to be cured and place it away from light. The microneedle tip inner layer raw material solution to be cured is polymerized under ultraviolet light, even if the microneedle tip inner layer raw material solution is cured.

[0052] (2) Preparation of microneedle backing layer raw material solution and microneedle tip outer layer raw material solution

[0053] Microneedle tip outer layer raw material solution: Prepare a solution containing 22.5% by mass of sodium hyaluronate as the microneedle tip outer layer raw material solution, stir it evenly and centrifuge it to remove bubbles, and store it at 4°C for later use.

[0054] (3) Preparation of the inner layer of a double-layer microneedle patch

[0055] First, the raw material solution of the inner layer of the microneedle tip is added to the small template, and vacuum dried to fully fill the cavity of the template, and the excess raw material solution of the inner layer of the microneedle tip is removed. Subsequently, in order to cure the raw material solution of the inner layer of the microneedle tip, UV irradiation (350mW) is used for 30 seconds. Repeat the filling-curing steps to fully fill the template tip. Next, the raw material solution of the microneedle backing layer is added, centrifuged at 5000rpm, dried at 37°C for 12 hours, and demolded to obtain the inner layer of the double-layer microneedle patch.

[0056] (4) Preparation of double-layer microneedle patches

[0057] First, the outer layer raw material solution of the microneedle tip is added to the large template and vacuum dried to fully fill the cavity of the template, and the excess outer layer raw material solution of the microneedle tip is removed. Then the inner layer of the double-layer microneedle patch after demoulding is pressed into the large template by positioning method, dried at 37℃ for 6h, and demoulded to obtain a double-layer microneedle patch. Figure 1 、 2 shown.

[0058] Example 2

[0059] A double-layer microneedle patch based on polyethylene glycol diacrylate and polyvinyl pyrrolidone was prepared according to the following method:

[0060] (1) Preparation of microneedle tip inner layer raw material solution

[0061] Microneedle tip inner layer raw material solution: Prepare a 20% mass fraction of polyethylene glycol diacrylate containing a therapeutic drug (dexamethasone, concentration of 20 mg / mL) as the microneedle tip inner layer raw material solution, add 1% volume fraction of 2-hydroxy-2-methylpropiophenone to the microneedle tip inner layer raw material solution to form a microneedle raw material solution to be cured and place it away from light. The microneedle tip inner layer raw material solution to be cured is polymerized under ultraviolet light, even if the microneedle tip inner layer raw material solution is cured.

[0062] (2) Preparation of microneedle backing layer raw material solution and microneedle tip outer layer raw material solution

[0063] Microneedle tip outer layer raw material solution: prepare a solution containing 40% by mass of polyvinyl pyrrolidone as the microneedle tip outer layer raw material solution, stir it evenly, centrifuge it to remove bubbles, and then store it for future use.

[0064] (3) Preparation of the inner layer of a double-layer microneedle patch

[0065] First, the raw material solution of the inner layer of the microneedle tip is added to the small template, and the cavity of the template is fully filled with the raw material solution of the inner layer of the microneedle tip by vacuum drying, and the excess raw material solution of the inner layer of the microneedle tip is removed. Subsequently, in order to cure the raw material solution of the inner layer of the microneedle tip, UV irradiation (350mW) is used for 30 seconds. Repeat the filling-curing steps to fully fill the template tip. Next, the raw material solution of the microneedle backing layer is added, centrifuged at 5000rpm, dried at 37°C for 12 hours, and demolded to obtain the inner layer of the double-layer microneedle patch.

[0066] (4) Preparation of double-layer microneedle patches

[0067] First, the outer layer raw material solution of the microneedle tip is added to the large template and vacuum dried to fully fill the cavity of the template, and the excess outer layer raw material solution of the microneedle tip is removed. Then the inner layer of the double-layer microneedle patch after demoulding is pressed into the large template by positioning method, dried at 37℃ for 6h, and demoulded to obtain a double-layer microneedle patch. Figure 1 、 2 shown.

[0068] Example 3: Efficacy test of the product

[0069] Double-layer microneedle patch for atopic dermatitis in mice

[0070] Taking the double-layer microneedle patch prepared in Example 1 as an example, six male mice weighing 20-25 g were anesthetized with 4% (w / v) chloral hydrate by intraperitoneal injection. The back skin was prepared, and a mouse atopic dermatitis model was established by multiple applications of dinitrochlorobenzene.

[0071] The atopic dermatitis mice were randomly divided into a control group and an experimental group, with 3 mice in each group. The control group did not receive any treatment. The experimental group received a double-layer microneedle patch applied to the back of the mice. A small amount of normal saline was added to accelerate the dissolution of the backing layer, and the double-layer microneedle patch was fixed to the back of the mice with a 3M transparent dressing. After 12 days of treatment, samples were taken from the wound surface of the mice's back and stained with HE.

[0072] Depend on Figure 4 The HE staining results shown show that the epidermis of the control group was thickened, indicating that the symptoms of atopic dermatitis were severe; while the epidermis of the mice in the experimental group was thinned, close to normal, and the skin was basically recovered, indicating that the double-layer microneedle patch for atopic dermatitis can repair the epidermal barrier while fighting inflammation. It has diverse functions, significant therapeutic effects, and a wide range of applications. Compared with the self-repair of the control group, this double-layer microneedle patch has a good ability to alleviate the symptoms of atopic dermatitis.

[0073] Compared with commercially available dexamethasone cream and tacrolimus ointment and microneedle patches, the double-layer microneedle patch for atopic dermatitis prepared by the present invention can significantly reduce epidermal thickness, promote the repair of the skin's natural barrier function, and improve atopic dermatitis symptoms after treatment with the soluble microneedle patch.

[0074] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a double-layer microneedle patch for atopic dermatitis, characterized in that: The steps include: (1) Preparation of raw material solution for the inner layer of microneedle tip: Microneedle tip inner layer raw material solution: prepare methacrylate gelatin containing a therapeutic drug at a mass fraction of 30% as the microneedle tip inner layer raw material solution, add 2-hydroxy-2-methylpropiophenone at a volume fraction of 1% to the microneedle tip inner layer raw material solution to form a microneedle raw material solution to be cured and place it in the dark. The microneedle tip inner layer raw material solution to be cured polymerizes under ultraviolet light, that is, the microneedle tip inner layer raw material solution is cured; (2) Prepare the raw material solution of the microneedle backing layer and the raw material solution of the microneedle tip outer layer: Microneedle tip outer layer raw material solution: Prepare a solution containing 22.5% sodium hyaluronate by mass as the microneedle tip outer layer raw material solution, stir evenly and centrifuge to remove bubbles, and store at 4°C for later use; (3) Preparation of the inner layer of a double-layer microneedle patch: The raw material solution of the inner layer of the microneedle tip was added to the small template and vacuum dried to fully fill the cavity of the template. The excess raw material solution of the inner layer of the microneedle tip was removed. Subsequently, in order to cure the raw material solution of the inner layer of the microneedle tip, UV irradiation at 350 mW for 30 seconds was used. The filling-curing steps were repeated until the template tip was fully filled. The raw material solution of the microneedle backing layer was added, and after centrifugation at 5000 rpm, it was dried at 37°C for 12 hours and demolded to obtain the inner layer of the double-layer microneedle patch. (4) Preparation of double-layer microneedle patch: The raw material solution of the outer layer of the microneedle tip was added to the large template and vacuum dried to fully fill the cavity of the template. The excess raw material solution of the outer layer of the microneedle tip was removed, and the inner layer of the double-layer microneedle patch after demolding was pressed into the large template by the positioning method, dried at 37°C for 6 hours, and demolded to obtain a double-layer microneedle patch.

2. The preparation method according to claim 1, wherein: The therapeutic drug loaded therein is selected from one or more of triamcinolone acetonide, mometasone furoate and dexamethasone, with a concentration of 20-25 mg / mL.

3. The preparation method according to claim 2, wherein: The therapeutic drug loaded therein is selected from triamcinolone acetonide, with a concentration of 20 mg / mL.

4. The preparation method according to claim 1, wherein: The number of needle tips in the double-layer microneedle array is greater than 20, the length of the inner layer needle tips is 0.2-1 mm, and the length of the outer layer needle tips is 0.4-1.5 mm.

5. The preparation method according to claim 4, characterized in that: The inner layer of the needle tip is conical, triangular pyramidal or quadrangular pyramidal. When the inner layer of the needle tip is conical, its bottom radius is 100-300 μm; when the inner layer of the needle tip is triangular pyramidal or quadrangular pyramidal, its bottom side length is 100-300 μm.

6. The preparation method according to claim 4, characterized in that: The outer layer of the needle tip is conical, triangular pyramidal or quadrangular pyramidal. When the outer layer of the needle tip is conical, its bottom radius is 100-600 μm; when the outer layer of the needle tip is triangular pyramidal or quadrangular pyramidal, its bottom side length is 100-600 μm.

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