Cannabidiol wrapped wound patch and preparation method thereof

Abstract

The invention provides a cannabidiol wrapped wound patch and a preparation method thereof. The wound patch comprises a hydrophilic polymer and a spherical inclusion. The spherical inclusion comprises a lipid carrier and cannabidiol, and the lipid carrier is wrapped outside the cannabidiol. The cannabidiol accounts for 0.5%-2% of the mass of the hydrophilic polymer. And the lipid carrier accounts for 5%-8% of the mass of the hydrophilic polymer. A spherical inclusion is prepared by a high-pressure homogenization method, and a lipid carrier is embedded into a hydrophilic polymer. The spherical inclusion can stably wrap cannabidiol, when the spherical inclusion makes contact with a wound, slow release of cannabidiol can be achieved, and the patch has good flexibility and adhesion. The wound patch is suitable for assisting healing of wounds, especially wounds needing long-term nursing.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wound care materials, and particularly relates to a cannabidiol-coated wound patch and a preparation method. BACKGROUND

[0002] In the field of medical wound care, wound patches, as common care products, need to have good drug release performance, flexibility and adhesion to meet the needs of different wounds, especially long-term care wounds. Cannabidiol (CBD) has anti-inflammatory and cell repair-promoting properties and shows potential application value in wound healing assistance.

[0003] However, there are many problems in the prior art when applying cannabidiol to wound patches. On the one hand, cannabidiol has poor stability and is easily degraded by external environment, making it difficult to continuously play a role in wound care; on the other hand, traditional wound patches cannot achieve slow release of cannabidiol, and the drug is released in a large amount in a short time, which not only may irritate the wound, but also makes the drug action time short, failing to meet the needs of long-term care wounds. At the same time, some wound patches containing cannabidiol perform poorly in flexibility and adhesion, and are prone to wrinkles when fitted to the wound, affecting the care effect, and are prone to falling off after long-term wearing, failing to continuously protect and supply drugs to the wound.

[0004] Therefore, it is necessary to improve the existing wound patches. SUMMARY

[0005] The purpose of the present application is to achieve stable coating and slow release of cannabidiol, while ensuring that the wound patch has good flexibility and adhesion to meet the needs of long-term care wounds.

[0006] A cannabidiol-coated wound patch, comprising a hydrophilic polymer and a spherical coating body, the spherical coating body comprising a lipid carrier and cannabidiol, the lipid carrier being coated outside the cannabidiol, the mass percentage of the cannabidiol in the hydrophilic polymer being 0.5%-2%, and the mass percentage of the lipid carrier in the hydrophilic polymer being 5%-8%.

[0007] Optionally, the hydrophilic polymer is at least one of hyaluronic acid, sodium carboxymethyl cellulose and chitosan.

[0008] Optionally, the lipid carrier is at least one of lecithin, cholesterol and pegylated lipid.

[0009] Optionally, the particle size of the spherical coating body is 100-300 nm.

[0010] Optionally, the thickness of the wound patch is 0.3-0.8 mm.

[0011] Optionally, the water absorption rate of the wound patch is 200%-400%.

[0012] Optionally, the wound patch has a cannabidiol release rate of 30%-50% within 24h.

[0013] Optionally, the wound patch further comprises an antibacterial agent, and the mass percentage of the antibacterial agent in the hydrophilic polymer is 0.1%-0.5%.

[0014] Optionally, the antibacterial agent is at least one of nano-silver and polyhexamethylene biguanide hydrochloride.

[0015] A preparation method of the above-mentioned cannabidiol-encapsulated wound patch, comprising the following steps: S101: preparing a lipid carrier dispersion liquid: adding a lipid carrier into deionized water, stirring at a speed of 500-800r / min at a temperature of 30-40℃ for 10-15min to obtain a lipid carrier dispersion liquid; S102: preparing a cannabidiol-lipid carrier mixed solution: dissolving cannabidiol in ethanol to obtain a cannabidiol ethanol solution, then slowly adding it into the lipid carrier dispersion liquid, stirring at a speed of 1000-1200r / min under nitrogen protection for 20-30min to obtain a cannabidiol-lipid carrier mixed solution; S103: preparing a spherical encapsulate dispersion liquid: treating the cannabidiol-lipid carrier mixed solution by high-pressure homogenization, the homogenization pressure is 30-50MPa, and the homogenization times is 3-5 times to obtain a spherical encapsulate dispersion liquid; S104: preparing a wound patch stock solution: adding a hydrophilic polymer into deionized water, stirring at a speed of 800-1000r / min at a temperature of 50-60℃ until completely dissolved, then adding the spherical encapsulate dispersion liquid into the hydrophilic polymer solution, continuing to stir for 30-40min to obtain a wound patch stock solution; S105: forming and drying: uniformly spreading the wound patch stock solution on a PET substrate, the spreading thickness is 0.5-1mm, then placing it in a vacuum drying oven at a temperature of 40-50℃ for 2-3h, peeling off the PET substrate after drying to obtain a cannabidiol-encapsulated wound patch.

[0016] Beneficial effects In the present application, the cannabidiol is wrapped by the lipid carrier to form a spherical inclusion body, and is combined with a hydrophilic polymer, so that the spherical inclusion body can stably coat the cannabidiol, prevent degradation of the cannabidiol, and realize slow release of the cannabidiol, the hydrophilic polymer provides a basic structural support for the wound patch, and the mass ratio of the cannabidiol and the lipid carrier can ensure good combination of the spherical inclusion body and the hydrophilic polymer while ensuring the drug effect. DETAILED DESCRIPTION

[0017] In an embodiment of the present application, a cannabidiol wrapped wound patch is provided, which comprises a hydrophilic polymer and a spherical inclusion body, the spherical inclusion body comprises a lipid carrier and cannabidiol, the lipid carrier is wrapped outside the cannabidiol, the mass percentage of the cannabidiol in the hydrophilic polymer is 0.5%-2%, and the mass percentage of the lipid carrier in the hydrophilic polymer is 5%-8%.

[0018] The molecular structure of cannabidiol is easily affected by light, temperature and oxygen to cause degradation, and the traditional direct mixing method leads to loss of effective ingredients during storage and use, and cannot continuously play the role of anti-inflammatory and promoting repair. In the present application, the lipid carrier is wrapped outside the cannabidiol to form a lipid carrier-cannabidiol core-shell structure, the membrane structure characteristics of the lipid carrier are used to form a physical barrier outside the CBD, reduce the direct contact of the external environment (oxygen, moisture, light) with the CBD, and spatially inhibit the degradation reactions such as oxidation and hydrolysis of the CBD. At the same time, the mass percentage of the lipid carrier in the hydrophilic polymer is limited to 5%-8%, which can not only ensure that the lipid carrier forms a complete and stable coating film, avoid incomplete coating due to insufficient amount, or too thick film structure affecting subsequent drug release, but also ensure the compatibility of the spherical inclusion body and the hydrophilic polymer matrix, and avoid aggregation of the inclusion body to damage the barrier effect.

[0019] In addition, in the traditional patch, the drug is directly exposed to the matrix and is quickly dissolved after contacting with the wound exudate, which leads to too high drug concentration in a short time, may stimulate the wound, and the drug concentration drops sharply after 24 hours, which cannot meet the long-term care needs of chronic wounds (such as bedsores and diabetic foot ulcers). In the present application, the lipid carrier membrane has semi-permeability, the moisture in the wound exudate needs to slowly penetrate into the inside of the inclusion body, and then dissolve the CBD before releasing it through the membrane, forming a slow release process of penetration-dissolution-diffusion. At the same time, the hydrophilic polymer has a three-dimensional network structure, the spherical inclusion body is uniformly dispersed in the network structure, and after the drug is released from the inclusion body, it needs to further diffuse through the pores of the polymer grid to the wound surface, forming a secondary controlled release, further delaying the release speed. In addition, the mass percentage of CBD in the hydrophilic polymer is limited to 0.5%-2%, which is matched with the double controlled release structure, if the amount of CBD is too high, even with the controlled release structure, the drug release will still be too fast due to the too large difference in drug concentration; if the amount is too low, it cannot reach the effective treatment concentration.

[0020] Therefore, in the present application, the cannabidiol is wrapped by the lipid carrier to form a spherical inclusion, and is combined with a hydrophilic polymer, so that the spherical inclusion can stably coat the cannabidiol, prevent degradation of the cannabidiol, and achieve slow release of the cannabidiol, the hydrophilic polymer provides basic structural support for the wound patch, and the mass ratio of the cannabidiol and the lipid carrier can ensure good combination of the spherical inclusion and the hydrophilic polymer while ensuring the drug effect.

[0021] In some embodiments, the hydrophilic polymer is at least one of hyaluronic acid, sodium carboxymethyl cellulose, and chitosan. The hyaluronic acid, sodium carboxymethyl cellulose, and chitosan have good biocompatibility and water absorption, can provide a moist healing environment for the wound, promote wound healing, and have good compatibility with the spherical inclusion, so that the spherical inclusion can be uniformly dispersed in the hydrophilic polymer. Through selection of the hydrophilic polymer, the hydrophilic polymer not only plays a role in providing basic structural support, but also cooperates with the spherical inclusion to further improve the wound healing auxiliary effect of the wound patch and create more suitable healing conditions for the wound due to its excellent biocompatibility and water absorption.

[0022] In some embodiments, the lipid carrier is at least one of lecithin, cholesterol, and pegylated lipid. The lecithin, cholesterol, and pegylated lipid have good biocompatibility and membrane formation ability, can effectively wrap the cannabidiol to form a stable spherical inclusion, and can adjust the membrane structure of the spherical inclusion to further control the release rate of the cannabidiol and improve the dispersibility of the spherical inclusion in the hydrophilic polymer. These lipid carriers can better stably coat the cannabidiol and cooperate with the hydrophilic polymer to not only ensure the stability of the cannabidiol but also more accurately control the release of the cannabidiol and improve the use effect of the wound patch.

[0023] In some embodiments, the particle size of the spherical inclusion is 100-300 nm. The spherical inclusion with the particle size in this range has good dispersibility in the hydrophilic polymer and is not prone to agglomeration, so that the cannabidiol can be uniformly distributed in the wound patch to achieve uniform drug release, and the particle size allows the spherical inclusion to better contact the wound tissue to improve the absorption effect of the drug. At the same time, the particle size range can control the specific surface area of the membrane, and a too small particle size leads to too large membrane area and causes too fast drug release, and a too large particle size leads to too small membrane area and causes too slow drug release. Through selection of the particle size range of the spherical inclusion, the spherical inclusion can stably exist and uniformly disperse in the hydrophilic polymer, thereby ensuring uniformity and effectiveness of drug release and improving the overall drug effect of the wound patch.

[0024] In some embodiments, the thickness of the wound patch is 0.3-0.8 mm. The wound patch with the thickness range has good flexibility, can closely fit different shapes of wounds, is not prone to wrinkles, has certain strength, can protect the wound, and has moderate thickness, does not bring obvious foreign body sensation to the user, and improves wearing comfort.

[0025] In some embodiments, the water absorption rate of the wound patch is 200%-400%. The water absorption rate range can make the wound patch effectively absorb wound exudate, maintain the wet environment of the wound, avoid excessive exudate from causing wound infection, and also not become too thick and heavy due to excessive water absorption, affecting the air permeability of the wound and the wearing comfort. The characteristics of the hydrophilic polymer cooperate with the water absorption rate parameter, and the spherical inclusions ensure drug release while not affecting the water absorption performance of the hydrophilic polymer, so that the wound patch can achieve slow release of the drug and effective absorption of the exudate, providing a good environment for wound healing.

[0026] In some embodiments, the cannabidiol release rate of the wound patch within 24 h is 30%-50%. The release rate range realizes slow release of cannabidiol, can make the drug continuously act on the wound within 24 h, meets the needs of long-term care of the wound, avoids that the drug is released in a large amount in a short time to stimulate the wound, and ensures the effective concentration of the drug in the critical period of wound healing.

[0027] In some embodiments, the cannabidiol-encapsulated wound patch further comprises an antibacterial agent, and the mass percentage of the antibacterial agent in the hydrophilic polymer is 0.1%-0.5%. The addition of the antibacterial agent can effectively inhibit the growth and reproduction of bacteria on the wound surface, prevent wound infection, cooperate with the anti-inflammatory and repair-promoting effects of cannabidiol, and further improve the wound healing speed and effect, and the mass ratio of the antibacterial agent can achieve good antibacterial effect and will not be toxic to wound tissue.

[0028] In some embodiments, the antibacterial agent is at least one of nano-silver and polyhexamethylene biguanide hydrochloride. Nano-silver and polyhexamethylene biguanide hydrochloride have broad-spectrum antibacterial properties, long-lasting antibacterial effect, and high biological safety, and have good compatibility with the hydrophilic polymer and the spherical inclusions, can be uniformly dispersed in the wound patch, and continuously exert the antibacterial effect to effectively prevent wound infection. At the same time, these antibacterial agents can better integrate into the wound patch system, and jointly act with cannabidiol and the hydrophilic polymer, to ensure slow release of the drug and a wet environment of the wound, while providing reliable antibacterial protection, and further improving the comprehensive performance of the wound patch.

[0029] Another embodiment of the present application provides a preparation method of the above-mentioned cannabidiol-encapsulated wound patch, comprising the following steps: S101: Preparation of a lipid carrier dispersion: The lipid carrier is added to deionized water, stirred at a speed of 500-800 r / min at a temperature of 30-40°C for 10-15 min to obtain a lipid carrier dispersion.

[0030] S102: Preparation of a cannabidiol-lipid carrier mixture: Cannabidiol is dissolved in ethanol to obtain a cannabidiol ethanol solution, which is then slowly added to the lipid carrier dispersion, stirred at a speed of 1000-1200 r / min under nitrogen protection for 20-30 min to obtain a cannabidiol-lipid carrier mixture.

[0031] S103: Preparation of a spherical inclusion dispersion: The cannabidiol-lipid carrier mixture is treated by high-pressure homogenization, the homogenization pressure is 30-50 MPa, and the homogenization times is 3-5 times to obtain a spherical inclusion dispersion.

[0032] S104: Preparation of a wound patch stock solution: The hydrophilic polymer is added to deionized water, stirred at a speed of 800-1000 r / min at a temperature of 50-60°C until completely dissolved, then the spherical inclusion dispersion is added to the hydrophilic polymer solution, and continue to stir for 30-40 min to obtain a wound patch stock solution.

[0033] S105: Forming and drying: The wound patch stock solution is evenly spread on a PET substrate with a thickness of 0.5-1 mm, then placed in a vacuum drying oven at 40-50°C for 2-3 h, and the PET substrate is peeled off after drying to obtain a cannabidiol-encapsulated wound patch.

[0034] In this preparation method, by controlling specific temperature, speed, pressure and other parameters, the stable encapsulation of the lipid carrier on the cannabidiol can be effectively guaranteed, forming spherical inclusions with uniform particle size, and the spherical inclusions can be uniformly dispersed in the hydrophilic polymer. The prepared wound patch has good flexibility, adhesion and slow drug release performance, and is suitable for industrial production.

[0035] The following are examples and comparative examples.

[0036] Example 1 The preparation method of the wound patch in this example is: S101: Preparation of a lipid carrier dispersion: 5 g of lipid carrier lecithin is added to 100 mL of deionized water, stirred at a speed of 600 r / min at a temperature of 35°C for 12 min to obtain a lipid carrier dispersion; S102: Preparation of a cannabidiol-lipid carrier mixed solution: 0.5 g of cannabidiol is dissolved in ethanol to obtain a cannabidiol ethanol solution, which is then slowly added to the lipid carrier dispersion liquid, stirred at a speed of 1100 r / min for 25 min under nitrogen protection, to obtain a cannabidiol-lipid carrier mixed solution.

[0037] S103: Preparation of a spherical inclusion dispersion liquid: the cannabidiol-lipid carrier mixed solution is treated by high-pressure homogenization, the homogenization pressure is 40 MPa, and the homogenization times are 4, to obtain a spherical inclusion dispersion liquid. The particle size of the spherical inclusion is 200 nm.

[0038] S104: Preparation of a wound patch stock solution: 100 g of a hydrophilic polymer, hyaluronic acid, is added to 500 mL of deionized water, stirred at a speed of 900 r / min at a temperature of 55°C until completely dissolved, and then the spherical inclusion dispersion liquid is added to the hydrophilic polymer solution, and continues to be stirred for 35 min to obtain a wound patch stock solution.

[0039] S105: Forming and drying: the wound patch stock solution is evenly applied on a PET substrate with a thickness of 0.8 mm, and then placed in a vacuum drying oven at 45°C for 2.5 h. After drying, the PET substrate is peeled off to obtain a cannabidiol encapsulated wound patch, and the thickness of the patch is 0.5 mm.

[0040] Example 2 The preparation method of the wound patch in this example is: S101: Preparation of a lipid carrier dispersion liquid: 6 g of a lipid carrier, cholesterol, is added to 100 mL of deionized water, stirred at a speed of 500 r / min at a temperature of 30°C for 15 min, to obtain a lipid carrier dispersion liquid; S102: Preparation of a cannabidiol-lipid carrier mixed solution: 1 g of cannabidiol is dissolved in ethanol to obtain a cannabidiol ethanol solution, which is then slowly added to the lipid carrier dispersion liquid, stirred at a speed of 1000 r / min for 30 min under nitrogen protection, to obtain a cannabidiol-lipid carrier mixed solution.

[0041] S103: Preparation of a spherical inclusion dispersion liquid: the cannabidiol-lipid carrier mixed solution is treated by high-pressure homogenization, the homogenization pressure is 30 MPa, and the homogenization times are 5, to obtain a spherical inclusion dispersion liquid. The particle size of the spherical inclusion is 120 nm.

[0042] S104: Preparation of a wound patch stock solution: 100 g of a hydrophilic polymer sodium carboxymethyl cellulose was added to 500 mL of deionized water, and stirred at a speed of 800 r / min at a temperature of 50 °C until completely dissolved, and then the spherical encapsulate dispersion liquid was added to the hydrophilic polymer solution, and continued to be stirred for 40 min to obtain a wound patch stock solution. S105: Forming and drying: the wound patch stock solution was uniformly applied on a PET substrate with a thickness of 0.9 mm, and then placed in a vacuum drying oven at 40 °C for drying for 3 h, and then the PET substrate was peeled off to obtain a cannabidiol encapsulated wound patch, and the thickness of the patch was 0.6 mm.

[0043] Example 3 The preparation method of the wound patch in this example is as follows: S101: Preparation of a lipid carrier dispersion liquid: 8 g of a lipid carrier polyethylene glycolized lipid was added to 100 mL of deionized water, and stirred at a speed of 800 r / min at a temperature of 40 °C for 10-15 min to obtain a lipid carrier dispersion liquid.

[0044] S102: Preparation of a cannabidiol-lipid carrier mixed solution: 2 g of cannabidiol was dissolved in ethanol to obtain a cannabidiol ethanol solution, which was then slowly added to the lipid carrier dispersion liquid, and stirred at a speed of 1200 r / min under nitrogen protection for 20 min to obtain a cannabidiol-lipid carrier mixed solution.

[0045] S103: Preparation of a spherical encapsulate dispersion liquid: the cannabidiol-lipid carrier mixed solution was treated by high-pressure homogenization, the homogenization pressure was 50 MPa, and the homogenization times were 3 times to obtain a spherical encapsulate dispersion liquid. The particle size of the spherical encapsulate was 300 nm.

[0046] S104: Preparation of a wound patch stock solution: 100 g of a hydrophilic polymer sodium carboxymethyl cellulose was added to 500 mL of deionized water, and stirred at a speed of 800 r / min at a temperature of 50 °C until completely dissolved, and then the spherical encapsulate dispersion liquid was added to the hydrophilic polymer solution, and continued to be stirred for 40 min to obtain a wound patch stock solution.

[0047] S105: Forming and drying: the wound patch stock solution was uniformly applied on a PET substrate with a thickness of 0.9 mm, and then placed in a vacuum drying oven at 40 °C for drying for 3 h, and then the PET substrate was peeled off to obtain a cannabidiol encapsulated wound patch, and the thickness of the patch was 0.6 mm.

[0048] Comparative Example 1 There is no spherical encapsulate in this comparative example.

[0049] The preparation method of the wound patch is as follows: Preparation of the wound patch stock solution: 100 g of hyaluronic acid was added to 500 mL of deionized water, stirred at a speed of 900 r / min at a temperature of 55°C until completely dissolved, and then 0.5 g of cannabidiol was directly added to the hyaluronic acid solution, stirred for 35 min to obtain the wound patch stock solution. Molding and drying: according to the molding and drying steps of Example 1, the wound patch was obtained.

[0050] Comparative Example 2 Compared with Example 1, the difference is that the amount of lipid carrier added is 10 g. That is, the mass percentage of lipid carrier in hydrophilic polymer is 10%.

[0051] Comparative Example 3 Compared with Example 1, the difference is that the amount of cannabidiol added is 3 g. That is, the mass percentage of cannabidiol in hydrophilic polymer is 3%.

[0052] Comparative Example 4 The preparation method of the wound patch is as follows: 100 g of hyaluronic acid, 5 g of lecithin, and 0.5 g of cannabidiol were mixed and then added to 500 mL of deionized water, stirred at a speed of 900 r / min at a temperature of 55°C for 40 min to obtain a mixed solution; the mixed solution was evenly applied to a PET substrate, and the molding and drying steps of Example 1 were followed to obtain the wound patch.

[0053] Test Example (1) Cannabidiol degradation rate The content of cannabidiol in the wound patch before storage and after storage for 30 days was determined by high performance liquid chromatography (HPLC) method. The degradation rate calculation formula is: degradation rate = (content before storage - content after storage for 30 days) / content before storage × 100%.

[0054] (2) Cannabidiol release rate Phosphate buffer solution (PBS, pH = 7.4) was used as the release medium, the wound patch was cut into 1 cm × 1 cm samples, and placed in 50 mL of release medium, and shaken in a 37°C, 100 r / min shaker. 5 mL of sample was taken at 1 h, 6 h, 12 h, and 24 h, and 5 mL of fresh release medium was added at the same time. The concentration of cannabidiol in the sample was determined by HPLC method. The release rate within 24 h was calculated according to the formula: release rate = (cumulative release amount within 24 h / initial drug content of the patch) × 100%.

[0055] (3) Flexibility of the wound patch The wound patch was cut into 2 cm × 5 cm samples, and a universal material testing machine was used to bend the samples at a speed of 5 mm / min. The bending angle at which the sample broke was recorded, and each sample was tested 3 times to obtain the average value.

[0056] (4) Wound patch adhesion The wound patch was pasted on a stainless steel plate, a 2kg pressure roller was rolled back and forth once, and after 30min, 180° peeling was carried out at a speed of 300mm / min, the force value in the peeling process was recorded, the peeling strength was calculated, 3 times of test were carried out for each sample, and the average value was taken.

[0057] (5) Water absorption rate The wound patch was cut into a 1cm*1cm sample, dried to a constant weight (the mass was recorded as m0), then soaked in deionized water, taken out after 2h, the surface water was absorbed with filter paper, and the mass was weighed (recorded as m1). The water absorption rate calculation formula: water absorption rate=(m1-m0) / m0*100%.

[0058]

[0059] As can be seen from the above table, the wound patch of the present application can realize stable coating and slow release of cannabidiol, while ensuring that the wound patch has good flexibility and adhesion, meeting the needs of long-term nursing of wounds. Comparative example 1 and comparative example 4 have no spherical inclusion, the drug is released quickly, and the 24h release rate is too fast. Comparative example 3 has too high a cannabidiol dosage, and the release rate also exceeds the reasonable range, which cannot meet the long-term nursing needs. Comparative example 2 has too high a lipid carrier dosage, the inclusion is too thick, resulting in too low a release rate, the drug cannot effectively play a role, and the flexibility is poor.

[0060] The above only describes the preferred embodiments of the present application and should not be used to limit the present application, and any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

[0061] For those skilled in the art, according to the idea of the present application, there will be changes in specific embodiments and application scope, and in summary, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A cannabidiol-coated wound patch, characterized in that, The invention comprises a hydrophilic polymer and a spherical inclusion, wherein the spherical inclusion comprises a lipid carrier and cannabidiol, wherein the lipid carrier is wrapped around the cannabidiol, the cannabidiol accounts for 0.5%-2% of the mass of the hydrophilic polymer, and the lipid carrier accounts for 5%-8% of the mass of the hydrophilic polymer.

2. The cannabidiol-coated wound patch as described in claim 1, characterized in that, The hydrophilic polymer is at least one of hyaluronic acid, sodium carboxymethyl cellulose, and chitosan.

3. The cannabidiol-coated wound patch as described in claim 1, characterized in that, The lipid carrier is at least one of lecithin, cholesterol, and polyethylene glycol-modified lipids.

4. The cannabidiol-coated wound patch as described in claim 1, characterized in that, The spherical inclusions have a particle size of 100-300 nm.

5. The cannabidiol-coated wound patch as described in claim 1, characterized in that, The thickness of the wound patch is 0.3-0.8 mm.

6. The cannabidiol-coated wound patch as described in claim 1, characterized in that, The wound patch has a water absorption rate of 200%-400%.

7. The cannabidiol-coated wound patch as described in claim 1, characterized in that, The wound patch has a cannabidiol release rate of 30%-50% within 24 hours.

8. The cannabidiol-coated wound patch as described in any one of claims 1-7, characterized in that, It also includes an antibacterial agent, which accounts for 0.1%-0.5% of the mass of the hydrophilic polymer.

9. The cannabidiol-coated wound patch as described in claim 8, characterized in that, The antibacterial agent is at least one of nano-silver and polyhexamethylene biguanide hydrochloride.

10. A method for preparing a cannabidiol-coated wound patch according to any one of claims 1-9, characterized in that, Includes the following steps: S101: Preparation of lipid carrier dispersion: Add lipid carrier to deionized water and stir at 500-800 r / min for 10-15 min at 30-40℃ to obtain lipid carrier dispersion. S102: Preparation of cannabidiol-lipid carrier mixture: Cannabidiol is dissolved in ethanol to obtain cannabidiol ethanol solution, and then it is slowly added dropwise to lipid carrier dispersion. Under nitrogen protection, the mixture is stirred at 1000-1200 r / min for 20-30 min to obtain cannabidiol-lipid carrier mixture. S103: Preparation of spherical inclusion dispersion: The cannabidiol-lipid carrier mixture was treated by high-pressure homogenization at a pressure of 30-50 MPa and for 3-5 homogenization cycles to obtain spherical inclusion dispersion. S104: Preparation of wound patch stock solution: Add the hydrophilic polymer to deionized water and stir at 800-1000 r / min at 50-60℃ until completely dissolved. Then add the spherical inclusion dispersion to the hydrophilic polymer solution and continue stirring for 30-40 min to obtain the wound patch stock solution. S105: Molding and Drying: Apply the wound patch concentrate evenly to the PET substrate to a thickness of 0.5-1mm, then place it in a vacuum drying oven at 40-50℃ for 2-3 hours. After drying, peel off the PET substrate to obtain a cannabidiol-coated wound patch.

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