Silicone gel elastic scar patch and preparation method thereof

Abstract

The present invention relates to the technical field of medical supplies, and specifically to a silicone gel elastic scar patch and a preparation method thereof, with the side close to the wound surface as the inner layer, and including a medical silicone gel layer, a hydrophilic gauze layer, a medical sponge layer impregnated with a drug, and an elastic backing layer from the inside out; the medical sponge layer impregnated with a drug is built with an air bag, and the air bag is connected to an inflation device; the drug impregnated in the medical sponge layer is chitosan-lecithin nanoparticles embedded with the drug; the material used in the medical silicone gel layer is acidic medical silicone gel. On the one hand, the hydrophilic gauze layer promotes the transfer of drug particles to the gel layer, and on the other hand, the acidic silicone gel promotes the unpacking of drug particles, promotes the release of drugs to the skin at the scar, activates the scar, and repairs the scar. At the same time, through the dual effects of the hydrophilic gauze layer and chitosan, a layer of moisturizing film is provided to the scar, and moisture is provided to reduce discomfort such as dry skin and itching at the scar.

Description

Technical Field

[0001] The invention relates to the technical field of medical supplies, and in particular to a silicone gel elastic scar patch and a preparation method thereof. Background Art

[0002] Scars are changes in the appearance and histopathology of normal skin tissue caused by various traumas. Scar formation is an inevitable product of the wound repair process. Clinically, patients often leave severe scars after wound healing, especially hypertrophic scars are very common. Hypertrophic scars are formed due to excessive growth of fibroblasts and excessive deposition of proteoglycans, glycoproteins and collagen in the extracellular matrix. A large number of clinical studies have shown that skin tissue tension plays a key role in the formation of wound scars. The greater the tension, the greater the possibility of scar formation after wound healing. Therefore, by reducing the tension of the skin tissue around the scar, scar hyperplasia can be effectively reduced or inhibited. At present, pressure therapy is often used in clinical practice, such as silicone dressings combined with elastic clothing or elastic sleeves, which can prevent the formation of hypertrophic scars to a certain extent. However, pressure therapy is only effective for hypertrophic scars, and has no effect on other scars such as sunken scars. In addition, pressure therapy is not suitable for uneven parts such as hands, feet, and joints. In addition, the elastic force of the elastic garment or elastic sleeve used in pressure therapy cannot be effectively controlled as needed, and the pressure is usually uneven, uncomfortable or even unbearable to wear, inconvenient to use and expensive.

[0003] For example, Chinese patent CN 104983495 A discloses a positive pressure silicone gel elastic scar removal belt and a preparation method, including an elastic belt, a medical silicone gel layer for scar removal is attached to the elastic belt, a protective layer is provided on the medical silicone gel layer, and the two ends of the elastic belt are a pair of breathable fixed elastic belt devices. The patent adopts the synergistic effect of the promotion layer and the silicone layer, and combines pressure therapy to promote the rapid repair of scars. However, the promotion layer and silicone layer of the patent can only act on the scar through slow drug sustained release. The drug takes a long time to reach the scar and the concentration is low, and a long action cycle is required for the recovery of the scar; and the pressure of the patented product on the scar is fixed by the elastic belt to achieve the effect. During the operation, excessive pressure is easy to damage the skin at the scar, and too little pressure will not achieve the effect. The pressure of the elastic belt cannot be monitored and adjusted in real time, which is not convenient and intelligent enough.

[0004] Therefore, it is necessary to make innovative improvements to the structure and components of elastic scar patches to meet the various needs of scar repair. Summary of the invention

[0005] In order to overcome the defects of the prior art, the purpose of the present invention is to provide a silicone gel elastic scar patch that can apply pressure to the wound surface, can achieve controllable drug release, has a fast drug release rate, can meet the needs of wound repair, is easy to use, and can effectively reduce or inhibit scars.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A silicone gel elastic scar patch, with the side close to the wound surface as the inner layer, and including, from the inside to the outside, a medical silicone gel layer, a hydrophilic gauze layer, a medical sponge layer impregnated with a drug, and an elastic backing layer; an air bag is built in the medical sponge layer impregnated with a drug, and the air bag is connected to an inflation device;

[0008] The medicine impregnated in the medical sponge layer is chitosan-lecithin nanoparticles embedded with medicine; the material used in the medical silicone gel layer is acidic medical silicone gel.

[0009] Optionally, the pH of the medical silicone gel layer is 3-5.

[0010] Optionally, during the preparation process of the medical silicone gel, acetic acid is added as a raw material to make it acidic.

[0011] Furthermore, the medical silicone gel is prepared from the following raw materials in parts by weight: 20-50 parts of polydimethylsiloxane, 10-20 parts of cyclopentasiloxane, 2-8 parts of silicon dioxide, 1-10 parts of a catalyst, and 3-8 parts of acetic acid.

[0012] In order to ensure that each functional layer fully exerts its role and further improve the rate of drug dissolution and release and the controllability of drug conduction to the medical silicone gel layer, the thickness of the medical silicone gel layer is 0.2-1mm; the thickness of the medical sponge layer is 3-10mm; the thickness of the hydrophilic gauze layer is 0.01-0.5mm.

[0013] Optionally, the hydrophilic gauze layer is made of a blended material of polypropylene fiber and rayon.

[0014] Optionally, the drugs embedded in the chitosan-lecithin microparticles include Centella asiatica extract, low-molecular sodium hyaluronate, and glycerol.

[0015] In order to monitor and adjust the pressure applied to the wound surface in real time, the elastic backing layer is built with a pressure sensor, and the pressure sensor is electrically connected to a pressure display module. Furthermore, the pressure sensor is electrically connected to a pressure control module, and the pressure control module is electrically connected to an alarm device. When the pressure detected by the pressure sensor is greater than the set pressure value, the pressure control module sends a signal to control the alarm device to sound an alarm. The pressure control module can use a PLC control system, and the program sets the maximum pressure value. When the pressure detected by the pressure sensor is greater than the set pressure value, the PLC control system sends a signal, and the alarm device receives the signal and sounds an alarm.

[0016] Optionally, the size of the medical silicone gel layer is greater than or equal to that of the medical sponge layer, and the size of the elastic backing layer is greater than that of the medical silicone gel layer.

[0017] Optionally, a bonding layer is circumferentially arranged on the portion of the elastic backing layer that exceeds the medical silicone gel layer.

[0018] Optionally, the inner layer of the medical silicone gel layer is further provided with a release film layer.

[0019] Optionally, the release film layer is larger than the elastic backing layer.

[0020] Optionally, the elastic backing layer is made of one of medical stretch fabric, elastic polyurethane film, elastic tape, and elastic non-woven fabric coated with medical pressure-sensitive adhesive; the elastic backing layer is colorless and transparent or skin color.

[0021] Optionally, the release film layer is made of polypropylene or polyethylene.

[0022] Optionally, the release film layer is a triangular pattern film or a diamond pattern film.

[0023] The method for preparing the silicone gel elastic scar patch is characterized by comprising the following steps:

[0024] 1) Preparation of acidic medical silicone gel: polydimethylsiloxane, cyclopentasiloxane, silicon dioxide and acetic acid are mixed and stirred evenly, and then a catalyst is added, and the mixture is mixed and stirred evenly again to remove bubbles, thereby obtaining an acidic medical silicone gel;

[0025] 2) Preparation of a medical sponge layer impregnated with drugs:

[0026] A: Take a medical sponge and hollow out the middle to form a cavity, place the airbag in the cavity, and connect the airbag to the inflation device through a connecting tube;

[0027] B: dissolving chitosan with acetic acid to obtain chitosan acetic acid solution; dissolving lecithin and the drug to be embedded in ethanol to obtain a lecithin ethanol solution; adding the chitosan acetic acid solution dropwise to the lecithin ethanol solution under stirring, adding an emulsifier, and then subjecting the mixture to ultrasonication to form chitosan-lecithin nanoparticles embedded with the drug;

[0028] C: injecting the chitosan-lecithin nanoparticles embedded with the drug prepared in step B into the medical sponge with the built-in airbag prepared in step A to obtain a medical sponge layer impregnated with the drug;

[0029] 3) Bonding and forming each layer: evenly apply the acidic medical silicone gel prepared in step 1) on the lower surface of the hydrophilic gauze layer, bond the medical sponge layer impregnated with the drug prepared in step 2) on the upper surface of the hydrophilic gauze layer, and then bond the elastic backing layer on the upper surface of the medical sponge layer, place it at 70℃~90℃ for reaction for 15min~30min, and then transfer it to 120℃~150℃ for reaction for 10min~20min, and then complete it. Heating is used to accelerate the forming of the silicone gel layer on the lower surface of the hydrophilic gauze layer.

[0030] Optionally, the drug to be embedded in step B is composed of the following raw materials in parts by weight: 5-10 parts of Centella asiatica extract, 0.5-2 parts of low molecular weight hyaluronic acid, and 5-10 parts of glycerol;

[0031] The mass percentage concentration of the chitosan acetic acid solution in step B is 2%; the mass concentration of lecithin in the lecithin solution is 20g / L, and the mass concentration of the drug to be embedded is 5mg / mL; the volume ratio of the chitosan acetic acid solution to the lecithin ethanol solution is 1:6;

[0032] The emulsifier in step B is Tween 80; the mass dosage of the emulsifier is 1.2%.

[0033] Compared with the prior art, the silicone gel elastic scar patch of the present invention has the following beneficial effects:

[0034] 1. The elastic band and the medical sponge layer are used together to give double pressure to the scar and promote scar repair;

[0035] 2. The airbag is used in conjunction with the medical sponge impregnated with drugs. The built-in airbag is inflated to expand the airbag and compress the medical sponge layer impregnated with drugs, so that the scar treatment drugs in the sponge are released and the tension at the scar is increased at the same time, which not only applies pressure but also administers drugs. Moreover, the pressure administration by the airbag not only improves the shortcomings of the existing scar patch, such as slow sustained release of drugs and long action period, but also avoids continuous administration by pumping air, and controls the risk of excessive drug concentration causing irritation to the skin at the scar, thus achieving the scar treatment effect;

[0036] 3. Furthermore, the small pressure sensor is used in conjunction with the airbag to monitor the tension applied to the scar at all times and to adjust the tension by pumping and inflating the airbag. During the operation, the tension of the medical sponge layer can be adjusted according to the small pressure sensor in the elastic backing layer. If the pressure sensor alarms, it indicates that the pressure is too high. The airbag interface can be used to pump air to reduce the tension at the wound. If the pressure is too low, the airbag interface can be inflated to increase the tension at the wound and release the drug.

[0037] 4. The hydrophilic gauze layer is used as a load carrier of the silicone gel layer on the one hand, and chitosan is used as a skeleton material in the present invention. By introducing the hydrophobic group of lecithin, it is self-aggregated and assembled under aqueous conditions, and rearranged to form nanoparticles with a hydrophilic shell and a hydrophobic core structure. Therefore, the hydrophilic gauze layer can attract the chitosan-lecithin nanoparticles with a hydrophilic shell to be conducted to the silicone gel layer, and produce a diversion effect on the drug particles in the sponge, thereby increasing the drug release rate; at the same time, it also provides a moist environment for the skin at the scar, alleviating the discomfort of dry skin, itching, etc. at the scar;

[0038] 5. By encapsulating the drug into chitosan lecithin particles, on the one hand, the stability of the drug is increased; on the other hand, due to the formation principle of lecithin-chitosan nanoparticles, chitosan is positively charged and lecithin is negatively charged, so the positive and negative charges combine with each other within a certain range to self-assemble into nanoparticles. In an acidic environment, H + As the concentration increases, most of the negative ions of the phosphate groups in lecithin are replaced by H + Occupy, destroy the electrostatic attraction between chitosan and lecithin, resulting in the release of encapsulated drugs, so the present invention adopts acidic medical silicone gel, such as adding acetic acid, to promote the release of drug particles into silicone gel and skin, and at the same time, due to the good antibacterial, anti-inflammatory and moisturizing properties of chitosan, it can prevent scar infection and provide a moist environment for the skin to promote scar repair; lecithin is the main component of cell membrane, has strong biocompatibility with cells, can increase the stability and transdermal absorption capacity of drugs, and promote the absorption of drug ingredients such as Centella asiatica;

[0039] 6. The combination of Centella asiatica extract, low molecular weight hyaluronic acid, glycerol and other drug ingredients with chitosan and lecithin can not only bring out the advantages of Centella asiatica extract in promoting blood circulation and improving skin pigmentation at scars, but also increase the absorption of Centella asiatica through the penetration-promoting effect of lecithin and low molecular weight hyaluronic acid, thereby increasing the effects of Centella asiatica and chitosan. In addition to its penetration-promoting effect, lecithin also promotes the formation of epidermal lipid barrier, which is beneficial to epidermal recovery and promotes scar repair.

[0040] In summary, the present invention impregnates and loads the chitosan-lecithin nanoparticles embedded with drugs in a medical sponge layer, and uses them in combination with an acidic silicone gel layer and a hydrophilic gauze layer to produce a synergistic effect. On the one hand, the hydrophilic gauze layer promotes the transfer of the drug particles to the gel layer, and on the other hand, the acidic silicone gel promotes the decapsulation of the drug particles, promotes the release of the drug to the skin at the scar, activates the scar, and repairs the scar. At the same time, through the dual effects of the hydrophilic gauze layer and chitosan, a moisturizing film is provided to the scar, and moisture is provided, thereby alleviating discomfort such as dryness and itching of the skin at the scar. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic diagram of the overall structure of the elastic scar patch provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The particle size of the chitosan-lecithin nanoparticles embedded with drugs prepared in the following examples is 120-160 nm; the pore size of the hydrophilic gauze layer is 0.4-1 um;

[0043] In the following embodiments, the material used for the hydrophilic gauze layer is a blend of polypropylene fiber and rayon; the material used for the elastic backing layer is one of medical stretch fabric, elastic polyurethane film, elastic tape, and elastic non-woven fabric coated with medical pressure-sensitive adhesive; the color of the elastic backing layer is colorless and transparent or skin color; the material used for the release film layer is polypropylene or polyethylene; the release film layer is a triangular pattern film or a diamond pattern film.

[0044] The specific structure of the silicone gel elastic scar patch provided in the following embodiments is as follows: Figure 1 As shown, the side close to the wound surface is the inner layer, which includes a release film layer 10, a medical silicone gel 9, a hydrophilic gauze layer 7, a medical sponge layer 4 impregnated with drugs, and an elastic backing layer 1 from the inside to the outside; an air bag 5 is built in the medical sponge layer 4 impregnated with drugs, and the air bag 5 is connected to an inflation device 6;

[0045] The size of the hydrophilic gauze layer 7 is larger than that of the medical sponge layer 4. The portion of the hydrophilic gauze layer 7 that exceeds the medical sponge layer 4 is circumferentially provided with a gauze adhesive layer 8 for bonding the hydrophilic gauze layer 7, the elastic backing layer 4 and the medical sponge layer 1 into one;

[0046] The size of the elastic backing layer 1 is larger than the medical silicone gel layer 9. The part of the elastic backing layer 1 that exceeds the medical silicone gel layer 9 is circumferentially provided with an adhesive layer 3 for fixing the entire silicone gel elastic scar patch on the wound surface.

[0047] The medicine impregnated in the medical sponge layer 4 is chitosan-lecithin nanoparticles embedded with medicine; the material used in the medical silicone gel layer 9 is acidic medical silicone gel.

[0048] The thickness of the medical silicone gel layer is 0.2-1 mm; the thickness of the medical sponge layer is 3-10 mm; and the thickness of the hydrophilic gauze layer is 0.01-0.5 mm.

[0049] In order to monitor and adjust the pressure applied to the wound surface in real time, the elastic backing layer 1 is built with a pressure sensor 2, and the pressure sensor 2 is electrically connected to a pressure display module. Furthermore, the pressure sensor is electrically connected to a pressure control module, and the pressure control module is electrically connected to an alarm device. When the pressure detected by the pressure sensor is greater than the set pressure value, the pressure control module sends a signal to control the alarm device to sound an alarm. The pressure control module can use a PLC control system, and the program sets the maximum pressure value. When the pressure detected by the pressure sensor is greater than the set pressure value, the PLC control system sends a signal, and the alarm device receives the signal and sounds an alarm.

[0050] Example 1

[0051] The medical silicone gel of the silicone gel elastic scar patch of this embodiment is prepared from the following raw materials in parts by weight: 35 parts of polydimethylsiloxane, 15 parts of cyclopentasiloxane, 5 parts of silicon dioxide, 5 parts of catalyst, and 5 parts of acetic acid;

[0052] The drug-encapsulated chitosan-lecithin microparticles are composed of the following raw materials in parts by weight: 5 parts of Centella asiatica extract, 0.5 parts of low-molecular sodium hyaluronate, and 5 parts of glycerol.

[0053] The method for preparing the silicone gel elastic scar patch of this embodiment is characterized by comprising the following steps:

[0054] 1) Preparation of acidic medical silicone gel: polydimethylsiloxane, cyclopentasiloxane, silicon dioxide and acetic acid are mixed and stirred uniformly according to weight proportions, a catalyst is added, the mixture is mixed and stirred uniformly again, and bubbles are removed by ultrasonication to obtain acidic medical silicone gel;

[0055] 2) Preparation of a medical sponge layer impregnated with drugs:

[0056] A: Take a medical sponge and hollow out the middle to form a cavity. The distance between the left and right ends of the cavity and the corresponding left and right edges of the medical sponge is 5 cm, and the distance between the upper and lower ends and the upper and lower sides of the medical sponge is 10 cm. Place the airbag in the cavity, and connect the airbag to the inflation device through a connecting tube;

[0057] B: dissolving chitosan with acetic acid to obtain a chitosan acetic acid solution with a mass concentration of 2%; dissolving lecithin and the drug to be embedded in ethanol to obtain a lecithin ethanol solution, wherein the mass concentration of lecithin in the lecithin ethanol solution is 20 g / L, and the mass concentration of the drug to be embedded is 5 mg / mL; standing the chitosan acetic acid solution to remove bubbles, and under stirring, using a syringe (injection needle d=0.7 mm), dropping the chitosan acetic acid solution into the lecithin ethanol solution, the volume ratio of the chitosan acetic acid solution to the lecithin ethanol solution is 1:6, and adding 1.2% of an emulsifier Tween 80, and then forming chitosan-lecithin nanoparticles embedded with drugs through ultrasonic action;

[0058] C: injecting the chitosan-lecithin nanoparticles embedded with the drug prepared in step B into the medical sponge with the built-in airbag prepared in step A to obtain a medical sponge layer impregnated with the drug;

[0059] 3) Bonding and forming each layer: evenly apply the acidic medical silicone gel prepared in step 1) on the lower surface of the hydrophilic gauze layer, adhere the drug-impregnated medical sponge layer prepared in step 2) to the upper surface of the hydrophilic gauze layer, and then adhere the elastic backing layer to the upper surface of the medical sponge layer, place it at a temperature of 70°C to 90°C to react for 15min to 30min, and then transfer it to a temperature of 120°C to 150°C to react for 10min to 20min, and then apply adhesive around the elastic backing layer, cover the release film layer and bond it to the medical silicone gel layer, and it is completed.

[0060] Example 2

[0061] The medical silicone gel of the silicone gel elastic scar patch of this embodiment is prepared from the following raw materials in parts by weight: 20 parts of polydimethylsiloxane, 10 parts of cyclopentasiloxane, 2 parts of silicon dioxide, 1 part of catalyst, and 3 parts of acetic acid;

[0062] The drug-encapsulated chitosan-lecithin microparticles are composed of the following raw materials in parts by weight: 10 parts of Centella asiatica extract, 2 parts of low-molecular sodium hyaluronate, and 10 parts of glycerol.

[0063] The preparation method of the silicone gel elastic scar patch in this embodiment is different from that in Example 1 in that the mass percentage concentration of the chitosan acetic acid solution in step B is 2%; the mass concentration of lecithin in the lecithin solution is 20 g / L, and the mass concentration of the drug to be embedded is 5 mg / mL; the volume ratio of the chitosan acetic acid solution to the lecithin ethanol solution is 1:6; and the amount of the emulsifier is 1.2%.

[0064] Example 3

[0065] The medical silicone gel of the silicone gel elastic scar patch of this embodiment is prepared from the following raw materials in parts by weight: 50 parts of polydimethylsiloxane, 20 parts of cyclopentasiloxane, 8 parts of silicon dioxide, 10 parts of catalyst, and 8 parts of acetic acid;

[0066] The drug-encapsulated chitosan-lecithin microparticles are composed of the following raw materials in parts by weight: 7 parts of Centella asiatica extract, 1 part of low-molecular sodium hyaluronate, and 7.5 parts of glycerol.

[0067] The preparation method of the silicone gel elastic scar patch in this embodiment is different from that in Example 1 in that the mass percentage concentration of the chitosan acetic acid solution in step B is 2%; the mass concentration of lecithin in the lecithin solution is 20 g / L, and the mass concentration of the drug to be embedded is 5 mg / mL; the volume ratio of the chitosan acetic acid solution to the lecithin ethanol solution is 1:6; and the amount of the emulsifier is 1.2%.

[0068] It should be noted that a release film layer is provided on the silicone gel elastic scar patch provided in the above embodiment to protect the scar patch from contamination; the pressure sensor and the pressure control module are for realizing the real-time detection and alarm function of the pressure. In the actual application process, the release film layer and the pressure control module can be omitted according to the actual application occasion, which also belongs to the protection scope of the present invention. At the same time, the limitation of the thickness of each layer is for better exerting the function of each layer. In the actual application process, those skilled in the art can adjust the thickness of each layer according to actual needs, and the thickness of each layer does not constitute a limitation on the technical solution of the present invention.

[0069] The embodiments of the present invention are described in detail above in conjunction with the drawings and embodiments, but the present invention is not limited to the above embodiments and can be changed or modified within the knowledge scope of ordinary technicians in the field without departing from the purpose of the present invention.

Claims

1. A silicone gel elastic scar patch, characterized in that: The side close to the wound surface is the inner layer, which includes, from the inside to the outside, a medical silicone gel layer, a hydrophilic gauze layer, a medical sponge layer impregnated with a drug, and an elastic backing layer; the medical sponge layer impregnated with a drug is provided with an air bag, and the air bag is connected with an inflation device; the drug impregnated in the medical sponge layer is chitosan-lecithin nanoparticles embedded with the drug, and the drug embedded in the chitosan-lecithin nanoparticles is composed of the following raw materials in parts by weight: 5-10 parts of Centella asiatica extract, low molecular weight 0.5-2 parts of hyaluronic acid and 5-10 parts of glycerol; the material used for the medical silicone gel layer is acidic medical silicone gel, the pH of the medical silicone gel layer is 3-5, and the medical silicone gel is prepared from the following raw materials in parts by weight: 20-50 parts of polydimethylsiloxane, 10-20 parts of cyclopentasiloxane, 2-8 parts of silicon dioxide, 1-10 parts of catalyst, and 3-8 parts of acetic acid; the material used for the hydrophilic gauze layer is a blend of polypropylene fiber and rayon fiber.

2. The silicone gel elastic scar patch according to claim 1, characterized in that: The thickness of the medical silicone gel layer is 0.2-1 mm; the thickness of the medical sponge layer is 5-10 mm; and the thickness of the hydrophilic gauze layer is 0.01-0.5 mm.

3. The silicone gel elastic scar patch according to claim 2, characterized in that: The elastic backing layer is built with a pressure sensor, and the pressure sensor is electrically connected to a pressure display module.

4. The silicone gel elastic scar patch according to claim 3, characterized in that: The size of the hydrophilic gauze layer is greater than or equal to the medical sponge layer, and the size of the elastic backing layer is greater than the medical silicone gel layer; a bonding layer is circumferentially arranged on the part of the elastic backing layer that exceeds the medical silicone gel layer.

5. A method for preparing a silicone gel elastic scar patch according to any one of claims 1 to 4, characterized in that: The steps include: 1) Preparation of acidic medical silicone gel: polydimethylsiloxane, cyclopentasiloxane, silicon dioxide and acetic acid are mixed and stirred evenly, and then a catalyst is added, and the mixture is mixed and stirred evenly again to remove bubbles, thereby obtaining an acidic medical silicone gel; 2) Preparation of a medical sponge layer impregnated with drugs: A: Take a medical sponge and hollow out the middle to form a cavity, place the airbag in the cavity, and connect the airbag to the inflation device through a connecting tube; B: dissolving chitosan with acetic acid to obtain chitosan acetic acid solution; dissolving lecithin and the drug to be embedded in ethanol to obtain a lecithin ethanol solution; adding the chitosan acetic acid solution dropwise to the lecithin ethanol solution under stirring, adding an emulsifier, and then subjecting the mixture to ultrasonication to form chitosan-lecithin nanoparticles embedded with the drug; C: injecting the chitosan-lecithin nanoparticles embedded with the drug prepared in step B into the medical sponge with the built-in airbag prepared in step A to obtain a medical sponge layer impregnated with the drug; 3) Bonding and forming each layer: evenly apply the acidic medical silicone gel prepared in step 1) on the lower surface of the hydrophilic gauze layer, bond the drug-impregnated medical sponge layer prepared in step 2) to the upper surface of the hydrophilic gauze layer, and then bond the elastic backing layer to the upper surface of the medical sponge layer. Place the reaction at 70°C-90°C for 15min-30min, and then transfer to 120°C-150°C for 10min-20min to complete.

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