Skin-care microneedle patch with micro-thermal cycle and preparation method of skin-care microneedle patch

Abstract

The invention discloses a skin care microneedle patch with micro-thermal circulation and a preparation method, and relates to the technical field of medical administration instruments. Microneedles are arranged on the surface of the dosing side of the microneedle bottom sheet at intervals, a heating sheet is tightly attached to the surface of the non-dosing side of the microneedle bottom sheet, sharp blade heads are arranged at the tip ends of the microneedles, the section of each sharp blade head is of a star-shaped structure, medicine storage blind holes are formed in a protection sheet at intervals, and the positions of the medicine storage blind holes correspond to the positions of the microneedles. The microneedles are inserted into the medicine storage blind holes, and medicine is stored in the medicine storage blind holes. The star-shaped multi-blade structure obviously improves the moment of inertia of section, reduces the puncture resistance, can cut a tough cuticle with an extremely small stress area and is not easy to break, and the rhombic blades protect medicaments stored in the reserved rhombic grooves from being physically scraped. The geometric configuration of the rhombic groove quickly and uniformly guides the high-concentration medicament to the subcutaneous tissue along the channel, so that the actual delivery rate of the active component is greatly improved.

Description

Technical Field

[0001] This invention relates to the technical field of medical drug delivery devices, and in particular to a microneedle patch for skin care with microthermal circulation and its preparation method. Background Technology

[0002] Microneedling technology is a novel transdermal drug delivery system that combines the advantages of subcutaneous injection and transdermal patches. Microneedle patches typically consist of a micron-scale array arranged on a substrate, long enough to penetrate the stratum corneum of the skin surface without touching the nerve endings and capillaries in the dermis. Therefore, microneedles can establish tiny drug delivery channels on the skin surface in a painless, non-invasive, or minimally invasive manner, greatly improving the transdermal absorption efficiency of macromolecular active substances. Microneedle patches have been widely used in skin care and medical aesthetics and have shown great potential. They can precisely and quantitatively deliver active skin care ingredients to the target deep layers of the skin and are widely used in skin care scenarios such as anti-aging and wrinkle removal, acne treatment and scar fading, skin brightening and whitening, and deep hydration, becoming an efficient and convenient at-home beauty method.

[0003] During the use of microneedle patches, the introduction of the "micro-thermal circulation" mechanism has a significant synergistic effect on improving skin care results. Moderate micro-thermal circulation can not only dilate skin pores, but also promote local microvascular dilation, accelerate blood circulation and tissue metabolism, increase the permeability of skin cell membranes, and improve the thermal motion rate of active ingredient molecules.

[0004] Existing microneedle patches still face many technical bottlenecks in practical applications. First, existing drug-loaded microneedles are limited by their surface area and small volume, resulting in very low drug loading capacity, which is insufficient to meet the skincare needs requiring high doses of active ingredients. Second, although existing soluble microneedle patches encapsulate active ingredients directly in a polymer matrix material, once inserted into the skin, they rely entirely on limited interstitial fluid to dissolve the matrix. This passive dissolution process leads to extremely slow release of drugs or skincare ingredients, often requiring users to leave the patch on for several hours or even overnight to achieve the desired effect, greatly reducing user comfort and compliance.

[0005] Currently available portable skin care microneedle patches face challenges in long-term preservation. To maintain the mechanical strength of the microneedles and the bioactivity of the skin care active ingredients, microneedle patches have extremely high requirements for the temperature and humidity of the storage environment. When portable packaging experiences environmental temperature fluctuations or long-term storage, the microneedles may become damaged and unable to pierce the skin, or the heat-sensitive and water-sensitive skin care active ingredients may degrade and become ineffective.

[0006] Publication No. CN121360331A discloses a biomimetic self-locking microneedle structure, microneedle patch, and preparation method. The biomimetic self-locking microneedle structure includes a needle body and wing-like structures. The wing-like structures are uniformly distributed along the circumference of the needle body. The tips of the wing-like structures are in the same direction as the tips of the needles, and the angle between the tips is 25°-45°. The length of the wing-like structures is less than the length of the needle body. The wing-like structures are located 200-800 micrometers away from the bottom of the needle. The number of wing-like structures is 2-10. This technology uses wing-like structures to improve the puncture effect while achieving a self-locking structure. However, the small size of the wing-like structures makes them difficult to process and limits the amount of liquid medicine they can carry. Summary of the Invention

[0007] To address the shortcomings of existing microneedle patches, such as low drug loading capacity, slow release, and difficulty in long-term preservation, this invention provides a microneedle patch for skin care with microthermal circulation and its preparation method.

[0008] On the one hand, the microneedle patch for skin care with micro-thermal circulation provided by the present invention adopts the following technical solution: A microneedle patch for skin care with micro-thermal circulation includes a microneedle base. Microneedles are arranged at intervals on the surface of the microneedle base on the side where the medication is administered. A heating element is attached to the surface of the microneedle base on the side where the medication is not administered. Each microneedle has a sharp tip with a star-shaped cross-section. In its packaged state, a protective sheet is attached to the microneedle side of the microneedle base. In its usage state, the microneedle base is attached to and punctures the skin on the microneedle side. The protective sheet has drug-storage blind holes arranged at intervals. The positions of the drug-storage blind holes correspond to the microneedles, and the microneedles are inserted into the drug-storage blind holes, which store medication.

[0009] In its packaged state, the device cleverly integrates physical microneedles with skincare medication by setting corresponding blind holes on the protective sheet and inserting the microneedles into them. The blind holes act as miniature reservoirs for the medication, facilitating long-term storage and protecting the microneedles. The blind hole structure provides a relatively sealed, light-proof microenvironment for both the microneedles and the medication, effectively isolating them from the influence of external temperature and humidity on the microneedle strength and preventing oxidative degradation of the active medication. This significantly extends the shelf life and storage stability of the finished portable patch. The microneedle tip of this invention uses a star-shaped cross-section, which has a higher moment of inertia than the traditional conical cross-section, significantly enhancing the bending strength of the microneedle tip and ensuring it is not easily broken or bent when piercing the stratum corneum. The recessed portion of the star-shaped structure increases the amount of medication carried. Simultaneously, the concave portion of the star-shaped structure... After the microneedles pierce the skin, the grooved portion forms a natural capillary channel, accelerating the penetration of the medication into the deeper layers of the skin along the star-shaped grooves, thus improving drug delivery efficiency. A heating element is attached to the non-drug side of the microneedle base. When the microneedles pierce the skin and establish a physical microchannel, the micro-thermal circulation generated by the heating element directly acts on the drug delivery area. The thermal effect not only dilates local pores and promotes blood circulation in subcutaneous capillaries, but also provides kinetic energy for the molecular thermal motion of the medication attached to the microneedles in the drug storage holes, achieving rapid and efficient absorption of skincare ingredients. This highly integrates the drug delivery system, drug storage and protection system, and penetration enhancement system. Users simply need to peel off the protective film and apply the microneedle base with the heating element to the skin. The operation is simple and quick, eliminating the need for complicated application or long waiting times, greatly improving the portability and user experience of home skincare.

[0010] Furthermore, the microneedles include insoluble microneedles and soluble microneedles, the height of the microneedles is 300-600 micrometers, and the microneedle density on the microneedle substrate is 400-800 microneedles / cm². 2 .

[0011] Insoluble microneedles, serving as a framework, provide superior mechanical strength, ensuring effective overcoming of the elastic resistance of skin tissue upon application, stably opening and maintaining microchannels. Soluble microneedles, after penetrating the epidermal layer rich in tissue fluid, dissolve and release the medication. By limiting the height of the microneedles, they can precisely penetrate the stratum corneum barrier that hinders drug absorption, delivering the medication directly to the deep epidermis or superficial dermis, avoiding deep pain nerves and capillaries, reducing pain and bleeding. The controlled density of the microneedles ensures that the pressure applied to the patch is converted into sufficient pressure to pierce the stratum corneum, while also constructing an extremely rich drug delivery network per unit skin area. Combined with the microthermal circulation of the heating pad, this maximizes the absorption area and efficiency of skincare ingredients.

[0012] Furthermore, the pointed tip is composed of multiple rhomboid blades combined into a star-shaped structure, and rhomboid grooves are reserved between the rhomboid blades for storing medicine.

[0013] The star-shaped multi-blade structure significantly reduces puncture resistance, enabling minimally invasive and rapid skin penetration. It can easily cut through the tough stratum corneum with a very small force area, greatly reducing overall puncture resistance. Diamond grooves are reserved between the diamond blades. These grooves form a three-dimensional micro-liquid reservoir at the tip of the microneedle. The drug is safely stored in the concave area of ​​the diamond groove. During the microneedle puncture of the skin, the raised diamond blades bear all the frictional force with the skin tissue, thus perfectly protecting the drug in the groove from physical scraping of the stratum corneum and greatly improving the actual subcutaneous delivery rate of active ingredients. When the microneedle pierces into the epidermis filled with tissue fluid, the geometric configuration of the diamond groove can generate a significant capillary effect, which quickly and evenly guides and diffuses the dissolved high-concentration drug into the surrounding tissue along the groove.

[0014] Furthermore, the microneedle substrate has an adhesive layer coated on the side surface where the microneedles are located, and an easy-tear opening is provided at the edge of the adhesive layer. The adhesive of the adhesive layer bypasses the easy-tear opening and the microneedle location.

[0015] The adhesive layer is intentionally designed to avoid the microneedles, preventing the adhesive from covering the microneedle surface and altering their geometry or dulling the sharpness of the star-shaped or rhomboid blades. The outer adhesive layer provides sufficient adhesion to ensure the patch adheres tightly to the skin without displacement during microthermal circulation. The easy-tear opening and partially adhesive-free design greatly improve ease of use, preventing sticky adhesive from hindering operation and effectively avoiding finger contact and contamination of the microneedles and medication areas inside the patch. This achieves sterile and high hygiene standards during the operation process, significantly enhancing the user experience.

[0016] Furthermore, the microneedle substrate has binding strips on both sides, the binding strips are coated with adhesive on the side facing the microneedle for drug delivery, and the binding strips have intermittent linear slits.

[0017] By setting straps with segmented slits on both sides of the microneedle base, the patch is endowed with excellent mechanical tensile properties. The segmented slits can deform and open when subjected to tension, allowing the patch to perfectly fit areas with frequent joint or muscle activity, significantly improving the stability of the application. The spaced segmented slits on the straps form breathable gaps when the patch is in place, effectively avoiding skin maceration, itching, or allergic reactions caused by prolonged application, greatly improving the user's physiological comfort throughout the entire drug delivery process.

[0018] Furthermore, the protective sheet has an adhesion layer on the surface facing the microneedle substrate, the adhesion layer being made of a hydrophobic material, and the tip being made of a hydrophilic material.

[0019] The hydrophobic adhesive layer on the side of the protective sheet facing the microneedle substrate has extremely low surface energy and highly smooth surface properties. When the protective sheet comes into contact with the adhesive layer of the microneedle substrate, only a very weak interfacial adhesion is generated between the two. When the user removes the protective sheet before use, the peeling force required is minimal, which greatly improves the success rate of product opening and user experience. The tip of the microneedle is made of a hydrophilic material, while the adhesive layer of the protective sheet is made of a hydrophobic material. The hydrophobic adhesive layer can effectively block the penetration and migration of hydrophilic agents into the protective sheet. At the moment of peeling off the protective sheet, the hydrophobic adhesive layer has zero adhesion to the hydrophilic tip. The hydrophilic material of the microneedle is easy to carry a large amount of liquid medicine, reducing drug loss when tearing, and ensuring that each microneedle can penetrate the stratum corneum of the skin with a precise load dose.

[0020] Furthermore, the heating element is filled with at least reduced iron powder, activated carbon, and inorganic salt solution. A thermally conductive interlayer is provided between the heating element and the microneedle substrate. The thermally conductive interlayer is made of thin metal sheet. In the packaged state, a sealing patch is attached to the outside of the heating element. The sealing patch and the microneedle substrate are tightly attached to each other and seal the heating element. In the use state, the outside of the heating element is in direct contact with the air.

[0021] Using reduced iron powder, activated carbon, and inorganic salt solution as the heating matrix, it provides a heat source based on the principle of exothermic oxidation, eliminating the need for an external power supply and greatly improving portability and safety. In its packaged state, the outer sealing patch is tightly attached to the microneedle substrate, sealing and encapsulating the heating element, completely isolating it from external oxygen and ensuring that the product will not react prematurely during storage, thus extending its shelf life. In use, simply removing the sealing patch allows the heating element to directly contact the air, quickly initiating the heating reaction. This achieves a highly convenient, ready-to-use, on-demand activation mechanism. The metal thermally conductive interlayer ensures efficient and uniform temperature distribution, guaranteeing that all microneedles in the array can operate in a consistent, mild thermal environment.

[0022] On the other hand, the method for preparing a microneedle patch for skin care with micro-thermal circulation provided by the present invention adopts the following technical solution: A method for preparing a microneedle patch for skin care with microthermal circulation includes the following processing steps: The microneedle substrate and protective sheet are manufactured separately by injection molding using molds. An adhesive layer is coated onto the surface of the microneedle film; Apply the medication to the side of the protective film with the pre-drained drug storage hole, wait for the medication to penetrate into the drug storage hole, and then scrape off the medication from the surface of the protective film. The microneedle film and protective film are glued together and cut into the predetermined shape and size; The binding sheet and the heating element are attached to the lower surface of the microneedle substrate in sequence, and the heating element is sealed with a sealing patch. The assembled microneedle substrate, protective sheet, binding sheet, and heating element are packaged and sealed.

[0023] By pre-setting drug-filling blind holes on the protective sheet and employing a quantitative drug loading method involving application, penetration, and scraping, the problem of uneven drug loading in the traditional direct coating method for microneedles is overcome. The drug enters the blind holes through physical penetration, and excess drug is scraped off. When the protective sheet is aligned with the microneedle substrate, the drug can precisely contact the microneedle tip, achieving accurate control of the dosage and significantly improving the batch stability of skin care products. The process of first injection molding the microneedle substrate and protective sheet, and then filling and bonding the drug, avoids the influence of drug components on the mechanical properties of the microneedle substrate, ensuring that the microneedle tip has sufficient rigidity when piercing the skin. The production of the microneedle substrate, protective sheet, adhesive layer, heating element, and sealing patch is modularized, achieving seamless integration from functional component assembly to packaging and sealing, and improving the efficiency of large-scale industrial production.

[0024] Furthermore, the specific process for processing the microneedle substrate includes: The raw materials of the microneedle substrate are injected into the injection mold of the microneedle substrate under pressure. After solidification, the substrate is demolded and the microneedle formation is inspected using a magnification device. The demolded microneedle substrate is placed in a plasma cleaner for oxygen plasma treatment. After isolating the microneedles on the microneedle film using a protective mold, the adhesive material of the adhesive layer is dripped onto the center of the microneedle film. Use a blower to blow air onto the adhesive material on the surface of the microneedle film until the adhesive material is evenly coated.

[0025] By immediately introducing a magnified device for microscopic morphology inspection after injection molding and demolding, the integrity of the microneedle tips can be monitored in real time, such as whether the tips have barbs, missing parts, or incomplete filling. Defective products are eliminated early in the process, avoiding resource waste in subsequent high-value drug loading and assembly processes. Plasma treatment significantly enhances the interfacial bonding between heterogeneous materials. Oxygen plasma is used to treat the demolded microneedle substrate, and high-energy particle bombardment introduces polar functional groups such as hydroxyl and carboxyl groups, which greatly improves the surface hydrophilicity of the microneedle substrate. A protective mold is used to isolate the microneedle array before the adhesive material is added, ensuring that the adhesive material is only distributed in the base area of ​​the substrate and does not contaminate or encapsulate the microneedle tips, thus preserving the sharpness required for microneedle penetration into the skin. The directional airflow generated by the fan is used to spread the adhesive material, making it diffuse evenly in a radial pattern from the center outwards. This ensures a high degree of consistency in the thickness of the adhesive layer and completely avoids physical collisions or deformations that mechanical instruments may cause to the microneedle's fine structure, achieving zero-damage processing of micron-level structures.

[0026] Furthermore, the specific processing steps for the protective sheet include: The raw materials of the protective tablet are injected into the injection mold of the protective tablet under pressure. After solidification, the tablet is demolded and the formation of the drug storage blind hole on the protective tablet is checked using magnification equipment. Then, the protective sheet is placed upside down with the drug storage blind hole side facing up, and a hydrophobic material is coated on the surface to form an adhesion layer.

[0027] Immediately after injection molding and demolding, a magnifying device is used to inspect the microstructure of the blind holes. This allows for precise identification of microscopic defects such as residual air bubbles, incomplete injection, or hole wall damage within the blind holes. This ensures that the drug storage space volume of each qualified protective sheet is highly consistent, providing a qualified physical container for subsequent quantitative drug loading. When coating with a hydrophobic material to form an adhesion layer, the side with the drug storage blind hole is inverted. This cleverly utilizes gravity and physical spatial relationships to reduce the seepage of hydrophobic coating material into the blind holes during processing. This ensures the complete cleanliness of the internal space of the blind holes and that the effective volume is not compressed. This guarantees that the subsequent drug can smoothly and adequately fill the holes, and also significantly reduces the loss of expensive drug solutions adhering to the walls in non-working areas, improving drug utilization and loading efficiency.

[0028] In summary, the present invention has the following beneficial technical effects: 1. The star-shaped multi-blade structure significantly improves the moment of inertia of the cross section and greatly reduces the puncture resistance. It can cut through the tough stratum corneum with a very small force area without easily breaking. At the same time, the rhomboid blade bears the friction force during puncture, which perfectly protects the medicine stored in the reserved rhomboid groove from physical scratches. After puncture, the geometric configuration of the rhomboid groove generates a significant capillary effect, which guides the high concentration of medicine to the subcutaneous tissue quickly and evenly along the groove, greatly improving the actual delivery rate of active ingredients.

[0029] 2. After the microneedles penetrate the stratum corneum to establish physical microchannels, the heat generated by the heating pad is evenly distributed through the metal thermal conductive interlayer and directly acts on the drug delivery area. This micro-thermal circulation not only dilates local pores and promotes blood circulation in subcutaneous capillaries, but also directly provides the molecular thermal motion kinetic energy for the drugs attached to the microneedles, upgrading static physical drug delivery to dynamic thermal energy penetration, which greatly improves the absorption efficiency of skin care ingredients.

[0030] 3. By setting up drug storage blind holes on the protective sheet that correspond one-to-one with the microneedles and inserting the microneedles into them, the physical microneedles and skin care agents are cleverly modularly integrated. The blind hole structure provides the agent with a relatively sealed and light-proof microenvironment, effectively isolating the influence of external temperature and humidity on the strength of the microneedles, preventing the oxidative degradation of the active agent, and greatly extending the shelf life and storage stability of the finished patch.

[0031] 4. Insoluble microneedles provide excellent mechanical strength as a framework, ensuring that they can instantly overcome the skin's elastic resistance and stably open the microchannels; while soluble microneedles can quickly dissolve and release the drug after precisely penetrating deep into the epidermal layer rich in tissue fluid. With a height of 300-600 micrometers and specific density control, they can avoid deep pain nerves and capillaries, achieving painless and non-invasive treatment, while also building an extremely rich targeted drug delivery network per unit area.

[0032] 5. The hydrophobic material on the surface of the protective patch has extremely low surface energy, effectively blocking the migration and spread of hydrophilic drugs to the protective patch plane; when peeling off the protective patch, the hydrophobic adhesion layer exhibits zero adhesion to the hydrophilic tip. This synergistic design of hydrophilic and hydrophobic interfaces not only makes the peeling force required to tear the patch extremely small, but also ensures that the drug is completely attached to the hydrophilic microneedles, guaranteeing the accurate loading dose of each microneedle.

[0033] 6. The binding strips with line segment cuts on both sides of the microneedle base give the patch excellent mechanical tensile properties, which can perfectly fit the joints or muscles that are frequently in motion. The gaps formed by the cuts ensure breathability and prevent skin maceration and itching. At the same time, the adhesive layer deliberately avoids the easy-tear opening and the microneedle position, which not only prevents the adhesive from blunting the sharpness of the microneedles, but also prevents the user's fingers from touching and contaminating the microneedle area, achieving a high standard of hygiene for the user experience.

[0034] 7. When in the packaged state, the sealing patch is tightly attached to the microneedle base plate, completely isolating oxygen to ensure that the heating element does not react prematurely. When using, the user only needs to peel off the protective sheet and sealing patch, and the heating element will immediately come into contact with the air to start the heating reaction. This highly integrated design eliminates the hassle of external power supply and realizes a minimalist skin care experience of tearing open and applying, and heating up immediately after application.

[0035] 8. In film processing, polar functional groups are first introduced through oxygen plasma treatment to significantly improve the hydrophilicity of the substrate, thereby enhancing the adhesion of the adhesive layer and preventing delamination. Then, under the premise of isolating the microneedles with a protective mold, non-contact airflow is used to apply the adhesive. This combined process completely avoids the physical collision of traditional mechanical scraping with the microneedle structure, ensuring both uniform adhesive layer thickness and perfect preservation of the sharpness of the microneedles.

[0036] 9. When processing the protective film, it is inverted and coated with a hydrophobic material. Gravity is cleverly used to prevent hydrophobic droplets from seeping into the blind holes, ensuring the absolute integrity of the blind hole volume. Subsequently, when loading the drug, the surface tension difference between the hydrophobic layer and the hydrophilic blind hole forces the drug to spontaneously gather into the blind hole, which greatly reduces the difficulty of scraping off excess drug and reduces the waste of drug solution adhering to the wall in non-working areas.

[0037] 10. This invention changes the traditional direct coating method by first injection molding the substrate and protective film, and then using a magnification device to perform dual closed-loop testing on the integrity of the microneedles and the quality of blind hole molding. After eliminating physical defects at the source, drug drop-in penetration and modular bonding assembly are then carried out. This not only avoids the mechanical interference of drug components on the microneedle substrate during molding, but also eliminates drug dosage deviations caused by mold defects, greatly improving the batch stability and economic benefits of industrial production. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the combined structure of the microneedle patch of the present invention; Figure 2 for Figure 1 Schematic diagram of the cross-section at the center plane; Figure 3 for Figure 2 A magnified view of part A; Figure 4 This is a schematic diagram of the microneedle substrate and microneedle structure of the present invention; Figure 5 for Figure 4 A magnified view of part B; Figure 6 This is a schematic diagram of the protective sheet structure of the present invention.

[0039] Explanation of reference numerals in the attached figures: 1. Microneedle substrate; 11. Microneedle; 111. Sharp tip; 112. Diamond groove; 12. Adhesive layer; 121. Easy-tear opening; 122. Binding sheet; 2. Protective sheet; 21. Drug storage blind hole; 22. Adhesion layer; 3. Heating sheet; 31. Sealing patch; 32. Thermally conductive interlayer. Detailed Implementation

[0040] The following will be combined with the appendix Figures 1-6 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0041] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0042] This embodiment discloses a microneedle patch for skin care with micro-thermal circulation, which is mainly composed of three core modules: microneedle base 1, heating plate 3, and protective plate 2. The patch integrates physical microneedle puncture, drug storage and protection, and thermodynamic penetration enhancement technology through ingenious structural design.

[0043] Example 1: This invention discloses a microneedle patch for skin care with microthermal circulation, as described in the following embodiments. Figures 1-6 The device includes a microneedle substrate 1, on which microneedles 11 are arranged at intervals on the surface of the microneedle substrate 1 for drug administration, and a heating pad 3 is attached to the surface of the microneedle substrate 1 for non-drug administration. The tip of each microneedle 11 is provided with a sharp blade 111, which has a star-shaped cross-section. In the packaged state, a protective sheet 2 is attached to the side of the microneedle substrate 1 with microneedles 11. In the usage state, the side of the microneedle substrate 1 with microneedles 11 is attached to and punctures the skin. The protective sheet 2 has drug storage blind holes 21 arranged at intervals. The positions of the drug storage blind holes 21 correspond to the microneedles 11, and the microneedles 11 are inserted into the drug storage blind holes 21, which store the drug.

[0044] The microneedle patch 1 has microneedles 11 arranged in an array and spaced apart on the drug delivery side surface. The microneedle patch 1 serves as the basic support structure and is preferably made of a biocompatible polymer material with a certain degree of flexibility to ensure that the patch can closely fit the irregular contours of the human face or body. The microneedles 11 are used to directly penetrate the stratum corneum of the skin and establish micron-level physical microchannels on the skin surface. Through the spaced arrangement, the uniformity of drug delivery per unit area is ensured, and the skin resistance during pressing is dispersed, reducing the user's pain.

[0045] The tip of the microneedle 11 is uniquely designed as a sharp blade 111, and the horizontal cross-section of the sharp blade 111 is star-shaped. Compared with traditional conical or cylindrical microneedles, the star-shaped cross-section has a higher moment of inertia. This geometric configuration significantly enhances the bending strength of the tip of the microneedle 11, ensuring that it is not prone to breakage, curling, or bending when piercing the tough stratum corneum. The grooves naturally formed between the adjacent protruding blades of the star-shaped structure can construct natural capillary channels after the microneedle is inserted into the skin. The drug can quickly and evenly penetrate into the deep tissue of the skin along these star-shaped grooves, greatly improving the efficiency of targeted drug delivery.

[0046] The heating pad 3 is placed in close contact with the non-drug administration side of the microneedle base 1, i.e. the side facing away from the skin. When the microneedle 11 punctures the skin to establish a drug administration channel, the heating pad 3 works synchronously to generate micro-thermal circulation. The heat is conducted to the drug administration area through the microneedle base 1, producing multiple permeation-enhancing effects. First, it dilates local pores through warm stimulation. Second, it promotes blood circulation in subcutaneous capillaries, accelerating the absorption of drugs by tissues. Third, it provides kinetic energy for the molecular thermal motion of the drug carried by the microneedle, upgrading static permeation to dynamic thermal permeation.

[0047] In the product packaging and storage state, the protective sheet 2 is tightly attached to the drug delivery side of the microneedle base 1. The protective sheet 2 has drug storage blind holes 21 arranged at intervals, which correspond one-to-one with the positions of the microneedles 11. When the microneedles 11 are packaged, they are inserted into the corresponding drug storage blind holes 21. The drug storage blind holes 21 are pre-stored with skin care agents. The diameter and depth of the drug storage blind holes 21 match the microneedles 11. After the microneedles are inserted, the inner wall of the blind hole provides physical isolation for the microneedles, preventing damage to the tips of the microneedles during transportation and compression. The drug storage blind holes 21 modularly integrate the physical microneedles and skin care agents, forming a relatively sealed, light-proof micro-liquid storage environment. This effectively isolates the influence of external temperature and humidity on the strength of the microneedles and prevents the oxidation, volatilization or degradation of the active agents, greatly extending the shelf life of the patch.

[0048] Before use, clean the skin of the target drug delivery area and keep the skin surface dry to ensure patch adhesion and sterility of the microchannels. Take the patch out of the packaging bag, pinch the edge, and steadily peel the protective sheet 2 off the microneedle base 1. At this time, the microneedles 11 are pulled out from the drug storage blind hole 21. The tip 111 of the microneedles and the star-shaped groove have been precisely attached and carried the skin care agent in the blind hole. Align the side with the microneedles 11 with the target skin area, and press the back of the patch (the side of the heating pad 3) vertically downwards evenly with your fingers. Pressing will cause the tip 111 of the microneedles 11 to pierce the stratum corneum of the skin, completing the construction of the physical microchannel and the initial delivery of the drug. After the patch is applied, the heating pad 3 starts the micro-thermal circulation, and the heat continues to act on the drug delivery area. The user keeps the patch on for a certain period of time, depending on the drug absorption needs, and waits for the drug to be fully penetrated and absorbed under the heat. After the specified time is reached, gently peel off the microneedle base 1 and discard it. Then you can gently massage the drug delivery site to promote the absorption of the remaining ingredients.

[0049] When applying the microneedle patch, maintain vertical pressure and do not slide or rub the patch horizontally on the skin to avoid the microneedles 11 breaking under the skin or scratching the skin tissue. Since the sealed environment of the drug storage hole 21 is destroyed once the protective film 2 is removed, the drug may be contaminated or volatilized when exposed to air. Therefore, after removing the protective film 2, it should be applied to the skin immediately and should not be left for a long time. After the microneedle patch punctures the skin, it will come into contact with human tissue fluid. In order to avoid cross-infection and ensure efficacy, this product is for single use only and must not be reused or mixed with others. Before use, the product should be stored in a cool, dry, and dark place, and should not be subjected to heavy pressure or folding to avoid damaging the tight fit between the protective film 2 and the microneedle base 1, which may cause the drug in the drug storage hole 21 to leak out.

[0050] Example 2: Based on Example 1, the following is added: Reference Figure 4 The microneedles 11 include insoluble microneedles and soluble microneedles, the height of the microneedles 11 is 300-600 micrometers, and the density of the microneedles 11 on the microneedle substrate 1 is 400-800 needles / cm. 2 .

[0051] Reference Figure 3 and Figure 5 The pointed blade 111 is composed of multiple rhomboid blades forming a star-shaped structure, and rhomboid grooves 112 are reserved between the rhomboid blades. The rhomboid grooves 112 are used to store the medicine.

[0052] Reference Figure 4 The microneedle substrate 1 has an adhesive layer 12 coated on one side of the microneedle 11. The adhesive layer 12 has an easy-tear opening 121 at its edge. The adhesive of the adhesive layer 12 bypasses the easy-tear opening 121 and the microneedle 11.

[0053] The microneedles 11 include both insoluble microneedles and soluble microneedles, or a combination thereof. The insoluble microneedles are preferably made of biocompatible materials with high mechanical strength, such as polylactic acid (PLA), medical-grade polycarbonate (PC), medical-grade stainless steel, or titanium alloy. The soluble microneedles are preferably made of water-soluble polymers, such as hyaluronic acid, polyvinylpyrrolidone (PVP), or collagen, as a matrix. The height of the microneedles 11 is precisely controlled between 300-600 micrometers, and the distribution density of the microneedles 11 on the microneedle substrate 1 is 400-800 needles / cm². 2 .

[0054] Insoluble microneedles, acting as a framework, provide superior puncture rigidity, ensuring instantaneous expansion of the stratum corneum. Soluble microneedles, upon penetrating deep into the tissue-fluid-rich epidermis, rapidly dissolve in their matrix, releasing the encapsulated active ingredients. This balances reliable puncture with highly efficient drug release. The 300-600 micrometer height design allows for penetration of the stratum corneum to reach the epidermis or superficial dermis, while avoiding deep pain nerves and capillaries, thus achieving a painless and bleeding-free drug delivery experience. (400...) 800 roots / cm 2 The high-density array creates an extremely rich network of microchannels per unit area, ensuring the uniform penetration of large doses of skincare ingredients.

[0055] The microneedle substrate 1 has an adhesive layer 12 coated on one side of the surface where the microneedles 11 are located. The adhesive layer 12 is preferably made of medical pressure-sensitive adhesive or hydrogel. The edge of the adhesive layer 12 has an easy-tear opening 121. In particular, when the adhesive of the adhesive layer 12 is applied, it is deliberately made to avoid the easy-tear opening 121 and the core area where the microneedles 11 are located. The adhesive layer 12 ensures that the microneedle patch adheres tightly to the skin during microthermal circulation and human activity, preventing the microneedles from slipping off. The easy-tear opening 121 allows the user to quickly peel off the backing or protective sheet before use. The adhesive avoiding the microneedle 11 completely avoids the glue from encapsulating the microneedles, which would cause the tip 111 to become blunt or block the diamond groove 112. This ensures the sharpness of the microneedles and the drug release rate. The adhesive avoiding the easy-tear opening 121 also prevents the user's fingers from getting glued when pinching the easy-tear opening, improving the smoothness of operation and the level of sterility and hygiene.

[0056] After cleaning your hands and face, locate the easy-tear opening 121 without adhesive at the edge of the microneedle base 1. Pinch the easy-tear opening 121. Since there is no adhesive there, you can easily peel off the protective medium on the surface of the patch, exposing the drug delivery surface with the adhesive layer 12 and microneedles 11. Align the area of ​​the microneedles 11 without adhesive with the skin target point that needs treatment, and gently cover it. Press the back of the microneedle base 1 vertically downward with your fingers. At this time, the rhomboid blade quickly cuts through the stratum corneum, and the drug in the rhomboid groove 112 penetrates into the subcutaneous tissue with the microneedles. The outer adhesive layer 12 then adheres tightly to the surrounding skin, fixing the patch in place and keeping it in place. The soluble microneedles begin to dissolve under the action of subcutaneous tissue fluid, releasing the drug. After the treatment time is over, pinch the edge and peel off the patch.

[0057] Reference Figure 1 and Figure 2 The microneedle substrate 1 has binding sheets 122 on both sides. The binding sheets 122 are coated with adhesive on the side of the microneedle 11 that is used for drug delivery. The binding sheets 122 are provided with intermittent linear incisions.

[0058] The microneedle substrate 1 has outwardly extending binding strips 122 arranged symmetrically or asymmetrically on both sides. The binding strips 122 are preferably made of medical-grade flexible materials with high resilience and breathability, such as medical polyurethane (PU) film, elastic non-woven fabric or pure cotton elastic fabric. The length of one side is usually designed to be 30-80mm, the width is 10-30mm, and the thickness is controlled between 0.05-0.2mm.

[0059] When microneedle patches are applied to areas with large facial contours or frequent body movements, the edges are prone to lifting or shifting due to the adhesiveness of the patch itself alone. The binding patch 122, as a laterally extending mechanical anchor point, can provide stable and lasting downward pressure on the central microneedle drug delivery area, just like the side wings of a band-aid. This ensures that the microneedles remain deeply embedded under the skin during long-term application or microthermal circulation, preventing slippage.

[0060] The binding pad 122 is uniformly coated with adhesive on the side facing the microneedle 11 for drug delivery. The adhesive is preferably a low-allergenic medical acrylic pressure-sensitive adhesive or medical silicone adhesive. The adhesive allows the binding pad 122 to firmly grasp the healthy skin surrounding the microneedle drug delivery area. By applying a slight pulling force during adhesion, the adhesive fixes the binding pad 122 in a stretched state, thereby forming a transverse surface tension network on the skin surface, further locking the central microneedle substrate 1.

[0061] The binding piece 122 has multiple line segment cuts that penetrate the thickness of the piece at intervals. Preferably, these line segment cuts are arranged in an alternating manner, like a brick masonry arrangement. The length of a single line segment cut is about 2-5 mm, and the interval between adjacent cuts is 1-3 mm.

[0062] When the bandage 122 is stretched and adhered to the complex three-dimensional curved skin, traditional solid films are prone to wrinkling or uneven stress in the center. The design of the line segment cuts breaks the continuous rigidity of the material, which can open up into a mesh shape under tension, effectively releasing local stress. This allows the bandage 122 to perfectly fit various irregular skin contours, achieving a smooth and wrinkle-free finish. The tiny gaps formed by the line segment cuts after application and stretching provide excellent sweat wicking and breathability channels for the skin, preventing local skin from becoming macerated, red, or allergic due to sweat heat caused by prolonged application, significantly improving the comfort of use.

[0063] After peeling off the protective film on the back of the product, first align the area with the microneedles 11 in the center with the target skin and press vertically downwards to allow the microneedles to pierce into the skin. After the central area is firmly pressed, hold the center of the microneedle base 1 with one hand and pinch the edge of the binding piece 122 on one side with the other hand. Apply slight tension along the skin texture to stretch the binding piece 122 outwards. At this time, the line segment incision will open slightly. While maintaining tension, press the binding piece 122 coated with adhesive flat on the skin and smooth the edges with your fingertips to ensure that the adhesive is in full contact with the skin. Switch hands to hold the central area and repeat the above steps to stretch and stick the binding piece 122 on the other side in the opposite direction, ensuring that the force on both sides is even and that the central microneedle base 1 is firmly anchored on the skin.

[0064] Reference Figure 3 and Figure 6 The protective sheet 2 has an adhesion layer 22 on the side facing the microneedle substrate 1. The adhesion layer 22 is made of a hydrophobic material, and the tip 111 is made of a hydrophilic material.

[0065] The protective sheet 2 serves as the outer packaging or physical barrier for the microneedle patch during storage. An adhesion layer 22 is provided on the side of the microneedle substrate 1. The adhesion layer 22 is made of a highly hydrophobic material, preferably polytetrafluoroethylene, perfluoroethylene propylene, modified silicone coating, or long-chain alkyl silanization treatment layer.

[0066] The thickness of the adhesion layer 22 is typically between 1 micrometer and 5 micrometers. Since the tip 111 usually contains a hydrophilic drug carrier, it may have slight adhesion when the ambient humidity fluctuates. The hydrophobic adhesion layer 22 and the hydrophilic tip 111 form extremely low interfacial adhesion. This ensures that when the protective sheet is removed, the microneedle tip will not break, become blunt, or have drug residue due to intermolecular forces. The hydrophobic material can effectively block trace amounts of external moisture from penetrating into the microneedle tip, maintain the dryness of the microneedle material, and prevent the microneedle from becoming hygroscopic and softened or its active ingredients from degrading during storage.

[0067] The tip of the microneedle is a pointed tip 111, which is made of a hydrophilic material. The tip 111 is preferably made of a hydrophilic polymer material with good biocompatibility, such as hyaluronic acid (HA), carboxymethyl cellulose (CMC), polyvinylpyrrolidone (PVP), or maltose. These materials are usually used as carriers to encapsulate small molecule drugs, peptides, or vaccines. The hydrophilic material allows the tip 111 to quickly absorb water and swell or dissolve after being inserted into the skin, thereby achieving rapid drug release. The hydrophilic polymer material has a strong affinity with human tissue fluid, which can reduce foreign body sensation and skin irritation during drug administration.

[0068] Remove the microneedle patch from the outer packaging. At this time, the protective sheet 2 covers the microneedle array through the adhesion layer 22 on its surface, protecting the tip 111 from physical compression and contamination. Pinch the edge of the protective sheet 2 and slowly peel it off from the microneedle substrate 1. During the peeling process, due to the hydrophobic nature of the adhesion layer 22, the interaction force between it and the hydrophilic tip 111 is minimal, and the protective sheet can be smoothly detached. The tip 111 retains its original geometry and sharpness, and no matrix remains on the protective sheet. After peeling, immediately align the exposed tip 111 with the drug delivery site and press it. The hydrophilic tip 111 begins to work after contacting the skin tissue fluid.

[0069] Reference Figures 1-3 The heating element 3 is filled with at least reduced iron powder, activated carbon and inorganic salt solution. A thermally conductive interlayer 32 is provided between the heating element 3 and the microneedle substrate 1. The thermally conductive interlayer 32 is made of thin metal sheet. A sealing patch 31 is attached to the outside of the heating element 3 in the packaged state. The sealing patch 31 and the microneedle substrate 1 are tightly attached to each other and seal the heating element 3. The outside of the heating element 3 in the use state is in direct contact with the air.

[0070] The heating element 3 is filled with a heating matrix, which includes at least reduced iron powder, activated carbon, and inorganic salt solution. It is usually supplemented with water-absorbing resin or vermiculite as a water-retaining agent. The reduced iron powder is preferably an ultrafine powder with a particle size of 100-300 mesh to ensure sufficient reaction surface area. The heating element 3 uses the principle of galvanic cell to release heat. When the reduced iron powder comes into contact with oxygen in the air, a continuous and mild exothermic oxidation reaction occurs under the combined action of inorganic salt solution and activated carbon. The heat generated is between 40℃ and 45℃, which can effectively expand skin pores and accelerate local blood circulation, thereby significantly improving the penetration rate and absorption efficiency of drugs carried by microneedles.

[0071] A thermally conductive interlayer 32 is provided between the heating pad 3 and the microneedle substrate 1. This interlayer is made of a metal sheet material with a high thermal conductivity, preferably medical-grade pure aluminum foil or copper foil. Its thickness is usually controlled between 50 micrometers and 200 micrometers. The metal sheet has excellent in-plane thermal conductivity, which can quickly and evenly distribute the heat generated by the heating pad 3 to the entire microneedle substrate 1, effectively eliminating local hot spots and preventing skin burns or thermal degradation of the microneedle matrix caused by uneven heating. As a dense physical barrier, the thermally conductive interlayer 32 completely blocks the penetration of chemical substances in the heating pad 3 into the microneedle substrate 1 and the skin side, ensuring the absolute cleanliness and safety of the drug delivery environment.

[0072] In its packaged state, the heating element 3 has a sealing patch 31 attached to its outer side. This patch is preferably made of a high-barrier multilayer composite film, such as PET, aluminum foil, or PE composite film. The sealing patch 31 is tightly attached to the edge of the microneedle substrate 1, completely sealing and wrapping the heating element 3 inside, isolating it from external air (oxygen). This keeps the heating element 3 in a dormant state during storage and transportation, preventing it from undergoing premature oxidation and failure, and ensuring the product's shelf life.

[0073] Remove the microneedle patch from the outer packaging bag and check whether the sealing patch 31 is intact, undamaged, or bulging. Before applying the patch, pinch the easy-tear end of the sealing patch 31 and completely peel it off the microneedle patch. At this time, the outer breathable membrane of the heating pad 3 is in direct contact with the air. After removing the sealing patch 31, oxygen in the air quickly enters the interior of the heating pad 3, triggering an exothermic reaction. At this time, the microneedle patch should be pressed onto the target skin area as soon as possible. During the application process, the heating pad 3 continuously generates gentle heat. The heat is evenly transferred to the microneedle base 1 and subcutaneous tissue through the heat-conducting interlayer 32, achieving warm-assisted drug delivery. The heating process can usually be maintained for 15-30 minutes.

[0074] Example 3: This invention discloses a method for preparing a microneedle patch for skin care with micro-thermal circulation, comprising the following processing steps: Microneedle substrate 1 and protective sheet 2 are respectively manufactured by injection molding using a mold. An adhesive layer 12 is coated on the upper surface of the microneedle film 1; Apply the drug to the side of the protective sheet 2 with the drug storage blind hole 21, wait for the drug to penetrate into the drug storage blind hole 21, and scrape off the drug on the surface of the protective sheet 2. The microneedle substrate 1 and the protective film 2 are glued together and cut into the predetermined shape and size; The binding strip 122 and the heating element 3 are attached to the lower surface of the microneedle substrate 1 in sequence, and the heating element 3 is sealed with the sealing patch 31. The assembled microneedle substrate 1, protective sheet 2, binding sheet 122 and heating element 3 are packaged and sealed.

[0075] The injection molding process requires strict control of temperature and pressure. The microneedle substrate 1 is usually made of a polymer material with good biocompatibility to ensure that it has sufficient mechanical strength to penetrate the stratum corneum. The protective film 2 needs to be reserved with drug storage blind holes 21 to contain the drug. The diameter and depth of the holes need to match the microneedle array. The processing accuracy is usually controlled at the micron level.

[0076] The coating process can employ screen printing or spraying techniques to ensure the uniformity of the coating. The adhesive layer 12 is preferably made of medical-grade pressure-sensitive adhesive, such as acrylic adhesive, to ensure that it can firmly adhere to the patient's skin during subsequent application and has a low sensitization rate.

[0077] Apply the prepared drug solution or gel evenly to the side of the protective sheet 2 with the drug storage blind hole 21. Wait for a certain period of time to allow the drug to fully penetrate and fill the drug storage blind hole 21. Then, use a flexible scraper to scrape off the excess drug on the surface of the protective sheet 2. To improve the drug penetration efficiency, this step can be carried out in a slightly negative pressure (vacuum) environment to remove the air in the blind hole. The scraping operation must ensure that the surface is flat to avoid the excess drug causing contamination or adhesion during subsequent assembly. After filling, low-temperature drying is usually required to solidify the drug.

[0078] The microneedle substrate 1 and the protective sheet 2 are precisely aligned and glued together to properly protect the microneedle structure. Then, the assembled sheet is cut into a predetermined shape and size, such as a circle, an oval, or a specific shape that fits the eye area, using a die-cutting device. The alignment process requires the use of a high-precision vision positioning system (CCD) to ensure that the microneedle substrate 1 and the protective sheet 2 are tightly bonded and that the internal microneedle structure is not damaged.

[0079] The binding strip 122 and the heating element 3 are sequentially attached to the lower surface of the microneedle substrate 1. After attachment, the heating element 3 is immediately completely sealed and wrapped with the sealing patch 31, and the edge of the sealing patch 31 is tightly attached to the microneedle substrate 1. The binding strip 122 is used to provide additional fixation or support. The assembly of the heating element 3 must be carried out in a low-oxygen or inert gas protective environment to prevent the heating substrate from reacting prematurely when it comes into contact with oxygen during the production process. The sealing patch 31 must have extremely high oxygen and water vapor barrier rates.

[0080] The assembled microneedle substrate 1, protective sheet 2, binding sheet 122 and heating element 3 are placed as a complete product unit into an outer packaging bag for final sealing. The outer packaging is usually an aluminum foil composite bag. The packaging process can be combined with vacuuming or nitrogen filling, and a desiccant can be placed inside. This not only further prevents the heating element from failing, but also ensures that the microneedle patch is not contaminated by moisture and microorganisms during its shelf life.

[0081] The specific process for processing the microneedle substrate 1 includes: The raw material of microneedle substrate 1 is injected into the injection mold of microneedle substrate 1 under pressure. After solidification, it is demolded and the microneedles 11 on microneedle substrate 1 are inspected using magnification equipment. The demolded microneedle substrate 1 was placed in a plasma cleaner for oxygen plasma treatment. After isolating the microneedles 11 on the microneedle substrate 1 using a protective mold, the adhesive material of the adhesive layer 12 is dripped onto the center of the microneedle substrate 1. Use a blower to blow air onto the adhesive material on the upper surface of the microneedle substrate 1 until the adhesive material is evenly coated.

[0082] After the polymer component of the microneedle substrate 1 is heated and melted, it is injected into the pre-designed injection mold of the microneedle substrate 1 through a high-pressure injection machine. The pressure is maintained until the raw material cools and solidifies, and then the demolding process is carried out. Subsequently, the forming condition of the microneedles 11 on the microneedle substrate 1 is checked using a high-magnification CCD vision inspection system.

[0083] During the injection molding process, the injection pressure is usually controlled between 50-150MPa to ensure that the molten material can completely fill the micron-level needle tip cavity in the mold, avoiding the occurrence of insufficient glue or flat head phenomenon. The quality inspection carried out by the magnification equipment focuses on checking the needle sharpness, height consistency and whether there are broken needles or air bubbles of the microneedles 11, to ensure that the microneedles can effectively and painlessly penetrate the stratum corneum of the skin.

[0084] The demolded and quality-inspected microneedle substrate 1 is placed in a plasma cleaner and oxygen is introduced for oxygen plasma treatment. The vacuum degree during the treatment is usually maintained at 10-50 Pa, and the treatment time is set to 1-5 minutes. The oxygen plasma can not only remove trace organic contaminants from the surface of the microneedle substrate 1, but more importantly, it can introduce polar oxygen-containing functional groups such as hydroxyl and carboxyl groups on the surface of the polymer material. This step greatly improves the surface tension and hydrophilicity of the non-needle surface of the microneedle substrate 1, providing excellent interfacial bonding for the subsequent adhesion of the adhesive layer 12 and preventing the adhesive from delaminating during use.

[0085] Using a dedicated protective mold that matches the microneedle substrate 1, the microneedle 11 area on the microneedle substrate 1 is physically isolated and covered. After confirming that the microneedles 11 are completely protected, the adhesive material of the prepared adhesive layer 12 (such as medical pressure-sensitive adhesive solution) is precisely dripped onto the center of the non-needle surface of the microneedle substrate 1 using a precision dispensing device. The design of the protective mold is crucial. It must fit tightly with the boundary of the microneedle array to ensure that the adhesive material will not penetrate or overflow onto the microneedles 11 and damage their penetration function during the subsequent adhesive application process. The center dispensing method can precisely control the amount of adhesive used in a single patch.

[0086] Remove the dispensing head and use a dedicated blower or airflow nozzle to blow air onto the adhesive material on the surface of the microneedle substrate 1. Utilize the outward radiation pressure of the airflow to cause the adhesive material in the center to spread outwards until the adhesive material is evenly coated on the surface of the microneedle substrate 1. The blower should preferably be perpendicular to the substrate surface, and the airflow speed and temperature should be controlled. This non-contact airflow leveling process replaces the traditional mechanical scraping or roller coating, avoiding stress damage or minor deformation that may be caused to the substrate by mechanical contact. The airflow propels the adhesive to spread evenly in a radial pattern. Combined with the high wettability brought about by the previous plasma treatment, a uniform and bubble-free adhesive layer 12 can be formed. After coating, the adhesive material can be quickly cured by heating or ultraviolet irradiation.

[0087] The specific processing technology for the protective sheet 2 includes: The raw materials of protective film 2 are injected into the injection mold of protective film 2 under pressure. After solidification, the film is demolded and the molding condition of the drug storage blind hole 21 on the protective film 2 is checked using magnification equipment. Then, the protective sheet 2 is set up with one side of the drug storage blind hole 21 facing upside down, and a hydrophobic material is coated on the surface to form an adhesion layer 22.

[0088] The raw materials of the protective sheet 2 are heated and melted, and then injected into the pre-designed injection mold of the protective sheet 2 under pressure. The pressure is maintained and cooled for a certain period of time. After the raw materials are completely solidified, the mold is demolded. Then, the protective sheet 2 after demolding is inspected using magnification equipment, with a focus on observing the forming of the drug storage blind hole 21 on its surface.

[0089] The mold temperature and injection pressure during the injection molding process need to be precisely controlled to ensure that the tiny drug storage blind hole 21 can be finely formed. The main indicators for magnification equipment testing include: whether the hole diameter and hole depth of the drug storage blind hole 21 meet the design tolerance, whether the hole wall is smooth, and whether there are burrs or flash at the hole opening.

[0090] The quality-inspected protective sheet 2 is flipped over so that the side with the drug storage blind hole 21 is placed face down on a special tooling fixture, i.e., placed upside down. Then, a layer of hydrophobic material is evenly coated on the exposed surface of the protective sheet 2, and after it cures, an adhesion layer 22 is formed.

[0091] By using an inverted placement combined with gravity or a specific shielding fixture, it is possible to effectively prevent hydrophobic materials from accidentally flowing into or clogging the drug storage blind holes 21 during the coating process. This is because the inside of the drug storage blind holes 21 usually needs to remain hydrophilic to facilitate the filling of water-based drugs. The coating can be performed using ultrasonic atomization spraying or vapor deposition processes to ensure that the coating is ultra-thin and uniform. The hydrophobic material is preferably a fluoropolymer or silane coupling agent with low surface energy. The formed hydrophobic adhesion layer 22 can significantly reduce the surface tension of the protective sheet 2. In subsequent steps, when the excess drug on the surface is scraped off, the hydrophobic properties prevent the aqueous drug solution from adhering to and remaining on the surface of the protective sheet, thus ensuring that only the drug storage blind holes 21 contain the drug. This avoids drug waste and ensures the cleanliness of the patch assembly interface, preventing poor adhesion problems in subsequent processes.

[0092] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the scope defined by the structure of the invention, and all such modifications and additions should fall within the protection scope of the present invention.

Claims

1. A microneedle patch for skin care with micro-thermal circulation, comprising a microneedle base (1), wherein microneedles (11) are arranged at intervals on the surface of the microneedle base (1) on the side for drug administration, and a heating element (3) is attached to the surface of the microneedle base (1) on the side for non-drug administration, characterized in that: The microneedle (11) is provided with a sharp blade (111) at its tip. The sharp blade (111) has a star-shaped cross-section. The microneedle base (1) in the packaged state has a protective sheet (2) closely attached to one side of the microneedle (11). In the use state, the microneedle base (1) has a microneedle (11) closely attached to and piercing the skin. The protective sheet (2) has drug storage blind holes (21) arranged at intervals. The position of the drug storage blind holes (21) corresponds to the microneedle (11), and the microneedle (11) is inserted into the drug storage blind hole (21). The drug is stored in the drug storage blind hole (21).

2. The microneedle patch for skin care with microthermal circulation according to claim 1, characterized in that: The microneedles (11) include insoluble microneedles and soluble microneedles. The height of the microneedles (11) is 300-600 micrometers, and the density of the microneedles (11) on the microneedle substrate (1) is 400-800 needles / cm. 2 .

3. The microneedle patch for skin care with microthermal circulation according to claim 1, characterized in that: The pointed tip (111) is composed of multiple rhomboid blades forming a star-shaped structure, and rhomboid grooves (112) are reserved between the rhomboid blades. The rhomboid grooves (112) are used to store the medicine.

4. A microneedle patch for skin care with microthermal circulation according to claim 1, characterized in that: The microneedle substrate (1) has an adhesive layer (12) coated on the side surface where the microneedles (11) are located. The adhesive layer (12) has an easy-tear opening (121) at its edge. The adhesive of the adhesive layer (12) bypasses the easy-tear opening (121) and the microneedle (11).

5. A microneedle patch for skin care with microthermal circulation according to claim 4, characterized in that: The microneedle substrate (1) has binding strips (122) on both sides. The binding strips (122) are coated with adhesive on the side facing the microneedle (11) for drug delivery. The binding strips (122) have intermittent line segment cuts.

6. A microneedle patch for skin care with microthermal circulation according to claim 1, characterized in that: The protective sheet (2) has an adhesion layer (22) on the side facing the microneedle substrate (1). The adhesion layer (22) is made of a hydrophobic material, and the tip (111) is made of a hydrophilic material.

7. A microneedle patch for skin care with microthermal circulation according to claim 1, characterized in that: The heating element (3) is filled with at least reduced iron powder, activated carbon and inorganic salt solution. A thermally conductive interlayer (32) is provided between the heating element (3) and the microneedle substrate (1). The thermally conductive interlayer (32) is made of thin metal sheet. A sealing patch (31) is pasted on the outside of the heating element (3) in the packaged state. The sealing patch (31) and the microneedle substrate (1) are tightly attached to each other and seal the heating element (3). The outside of the heating element (3) in the use state is in direct contact with the air.

8. A method for preparing a microneedle patch for skin care with microthermal circulation, characterized in that, The processing steps include the following: Microneedle substrate (1) and protective sheet (2) were respectively manufactured by injection molding using a mold. An adhesive layer (12) is coated on the upper surface of the microneedle film (1); Apply the drug to the side of the protective sheet (2) with the drug storage blind hole (21), wait for the drug to penetrate into the drug storage blind hole (21), and scrape off the drug on the surface of the protective sheet (2); The microneedle substrate (1) and the protective film (2) are glued together and cut into the predetermined shape and size; The binding strip (122) and the heating element (3) are attached to the lower surface of the microneedle substrate (1) in sequence, and the heating element (3) is sealed with a sealing patch (31); The assembled microneedle substrate (1), protective sheet (2), binding sheet (122) and heating element (3) are packaged and sealed.

9. A microneedle patch for skin care with microthermal circulation according to claim 8, characterized in that, The specific process for processing the microneedle substrate (1) includes: The raw materials of the microneedle substrate (1) are injected into the injection mold of the microneedle substrate (1) under pressure. After solidification, the substrate is demolded and the microneedles (11) on the microneedle substrate (1) are inspected using a magnifying device. The demolded microneedle substrate (1) was placed in a plasma cleaner for oxygen plasma treatment; After isolating the microneedles (11) on the microneedle substrate (1) using a protective mold, the adhesive material of the adhesive layer (12) is dripped onto the center of the microneedle substrate (1); Use a blower to blow air onto the adhesive material on the upper surface of the microneedle substrate (1) until the adhesive material is evenly coated.

10. The method for preparing a microneedle patch for skin care with microthermal circulation according to claim 8, characterized in that, The specific processing technology for the protective sheet (2) includes: The raw materials of the protective film (2) are injected into the injection mold of the protective film (2) under pressure. After solidification, the film is demolded and the molding condition of the drug storage blind hole (21) on the protective film (2) is checked using a magnifying device. Then, the protective sheet (2) is set with the drug storage blind hole (21) upside down, and a hydrophobic material is coated on the surface to form an adhesion layer (22).

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