Method for preparing wet dressing patch based on fat emulsion technology and prepared wet dressing patch

Abstract

The invention relates to the field of medical dressing patches, and particularly discloses a method for preparing a wet type dressing patch based on a fat emulsion technology and the prepared wet type dressing patch, and the method comprises the following steps: S1, dissolving sodium guaiazulene sulfonate, phospholipid A, a radix astragali extract and a radix platycodonis extract in water to prepare a water-phase solution; s2, mixing olive oil, phospholipid B and the radix arnebiae seu lithospermi extract, heating and stirring to obtain an oil phase solution; s3, adding the oil phase solution into the water phase solution, and shearing to obtain a primary emulsion solution; s4, homogenizing the primary emulsion solution to obtain fat emulsion liquid medicine; s5, soaking a sponge carrier in the fat emulsion liquid medicine, and drying to obtain a wet dressing patch; the invention further discloses the wet dressing patch prepared by adopting the method. The preparation method has the characteristics that the prepared wet dressing patch can effectively promote wound healing, has good air permeability and antibacterial performance, and can uniformly release medicine components.

Description

Technical Field

[0001] This application relates to the field of medical dressings, and more specifically, it relates to a method for preparing a wet dressing based on fat emulsion technology and the resulting wet dressing. Background Technology

[0002] With the increasing aging of the global population and the continued rise in the incidence of chronic diseases such as obesity and diabetes, chronic wounds have become an increasingly prominent problem in clinical medicine. Chronic wounds generally refer to skin tissue damage caused by various reasons that fails to heal within the normal timeframe (usually exceeding 4 weeks). These wounds not only cause patients significant physical pain and psychological burden but also significantly reduce their quality of life. Common types of chronic wounds include diabetic foot ulcers, venous leg ulcers, and pressure ulcers (such as bedsores).

[0003] Patients with chronic wounds often have multiple underlying diseases, such as diabetes and vascular diseases, which further increase the difficulty of wound healing. During treatment, patients often face multiple symptoms including pain, oozing, odor, and sleep disturbances, which not only affect their daily functional activities but may also lead to serious complications such as secondary infections, sepsis, and even amputation, endangering their lives. Furthermore, the long treatment period and high cost of chronic wounds place a heavy financial burden on patients and their families.

[0004] Currently, traditional treatments for chronic wounds mainly include non-surgical measures such as infection control, wound cleaning, and removal of necrotic tissue. Guided by the theory of moist wound healing, the use of functional dressings has become an important means of promoting wound healing. There are many types of functional dressings available, including film dressings, foam dressings, hydrocolloid dressings, hydrogel dressings, alginate dressings, bioactive dressings, tissue-engineered skin, and medicated dressings. These dressings each have their advantages in absorbing exudate, keeping the wound moist, and promoting healing, but they still have many limitations.

[0005] On the one hand, existing nursing products are mostly focused on physical pressure relief, while their functions in promoting wound healing and preventing infection are relatively weak. On the other hand, some dressings may stick to the wound, cause pain or skin damage during use, affecting patient comfort and treatment compliance. For certain special types of wounds, such as infected wounds or dry wounds, the existing dressing options may not meet clinical needs.

[0006] There is a need to develop new types of moist functional dressings that can: 1) effectively promote wound healing by containing extracts of traditional Chinese medicine with effects such as promoting tissue regeneration, blood circulation, anti-inflammation, and antibacterial properties, thereby accelerating the wound repair process; 2) have good breathability and moisture absorption to maintain the balance of the wound environment and prevent exudate accumulation and bacterial growth; 3) release drug components evenly to ensure the continuous action of the drug on the wound surface and improve treatment efficacy; and 4) have low cost and good ease of use so as to be widely used in clinical practice. Summary of the Invention

[0007] In order to obtain a dressing that can effectively promote wound healing, has good breathability and antibacterial properties, and can uniformly release drug components, this application provides a method for preparing a wet dressing based on fat emulsion technology and the prepared wet dressing.

[0008] In a first aspect, this application provides a method for preparing a wet dressing based on fat emulsion technology, employing the following technical solution: A method for preparing a wet dressing based on fat emulsion technology includes the following steps: S1. Dissolve sodium guaiac sulfonate, phospholipid A, astragalus extract and euphorbia extract in water to prepare an aqueous solution; S2. Mix olive oil, phospholipid B, and comfrey extract, and heat and stir to obtain an oil phase solution; S3. Add the oil phase solution to the aqueous phase solution and shear to obtain the primary emulsion solution; S4. Homogenize the colostrum solution to obtain a fat emulsion solution; S5. After soaking the sponge carrier in the fat emulsion solution, dry it to obtain a wet dressing.

[0009] By adopting the above technical solutions, the extract of *Hedyotis diffusa* has antibacterial, anti-inflammatory, and analgesic effects, which can effectively relieve the pain and inflammation caused by bedsores. The extract of *Lithospermum erythrorhizon* has the effects of cooling the blood, promoting blood circulation, detoxifying, and promoting tissue regeneration, and has excellent repair effects on burns and bedsores. Astragaloside A in the extract of *Astragalus membranaceus* stands out in inhibiting inflammation, activating cell survival, and angiogenesis, making it suitable for chronic, inflammatory, and difficult-to-heal wounds. Phospholipids, as emulsifiers, improve the stability and bioavailability of the drugs. Olive oil has moisturizing and skin-nourishing effects, improving dry skin conditions. Sodium guaiacium sulfonate has anti-inflammatory, antibacterial, and wound-healing-promoting effects. Ultimately, the raw material system of this application, consisting of *Hedyotis diffusa* extract, *Astragalus membranaceus* extract, *Lithospermum erythrorhizon* extract, and sodium guaiacium sulfonate, can work synergistically to accelerate wound healing and shorten healing time. Furthermore, *Hedyotis diffusa* extract and sodium guaiacium sulfonate have good antibacterial properties, effectively inhibiting bacterial growth and reducing the risk of infection. Using a sponge as a carrier provides good breathability, keeping the wound dry and promoting wound healing.

[0010] Building upon this foundation, fat emulsion technology (which involves mixing and emulsifying oil and aqueous phases to control particle size while ensuring the stability of the fat emulsion) serves as an advanced drug delivery system, offering advantages in improving drug stability and bioavailability. By combining traditional Chinese medicine extracts with fat emulsions, wet functional dressings with uniform drug dispersion and stable release properties can be prepared. In this application, key extracts are combined with fat emulsions using fat emulsion technology, ensuring uniform drug dispersion within the emulsion and guaranteeing uniform release of drug components, thereby enhancing therapeutic efficacy. This not only fully leverages the therapeutic effects of traditional Chinese medicine but also improves the physical and chemical properties of the dressing, enhancing its effectiveness and safety in clinical applications.

[0011] Optionally, the colostrum solution may contain the following ingredients by weight percentage: 0.8-1.2% Astragalus membranaceus extract, 1.0-3.0% Citrus aurantium extract, 0.6-1.0% phospholipid A, 0.02-0.05% sodium guaiac sulfonate, 9-12% olive oil, 0.7-0.9% phospholipid B, 2.5-3% Lithospermum erythrorhizon extract, 0.2-0.3% guaiac blue oleane, and 0.01-0.03% vitamin E, with the balance being water.

[0012] By employing the above-mentioned technical solutions, Astragalus extract contains various bioactive components, such as Astragalus polysaccharides and Astragalus saponins. Within this addition range, an appropriate amount of Astragalus extract can stimulate cell proliferation and migration, promote granulation tissue formation, and accelerate the wound healing process. If the addition amount is below 0.8%, it may not be able to fully exert its healing-promoting effect; while above 1.2%, the concentration of components may be too high, producing certain toxicity to cells or interfering with normal cell metabolism, thus affecting the healing effect. *Houttuynia cordata* extract is rich in various volatile oils and flavonoids, and has anti-inflammatory and blood circulation-promoting effects. At an addition amount of 1.0-3.0%, it can effectively reduce wound inflammation, improve the local wound microenvironment, and provide favorable conditions for wound healing. Insufficient addition will result in insignificant anti-inflammatory and healing-promoting effects; excessive addition may cause local irritation or allergic reactions. Phospholipid A, as an emulsifier in the aqueous phase, can effectively reduce the interfacial tension between the aqueous and oil phases within this addition range, enabling the proemulsion solution to form a stable droplet structure. Insufficient addition will result in poor emulsification, unstable colostrum solution, and easy stratification; excessive addition may increase the viscosity of the system, affecting subsequent processing and drug release.

[0013] Sodium guaiac sulfonate promotes cell regeneration and repair. At this concentration, it can stimulate cell proliferation and differentiation at the wound site, accelerating wound healing. Too low a concentration will not significantly promote healing; too high a concentration may irritate or toxicize cells. Olive oil is rich in unsaturated fatty acids and has excellent moisturizing properties. At a concentration of 9-12%, it can form a protective film on the wound surface, preventing excessive moisture loss and maintaining a moist environment conducive to wound healing. Too low a concentration will result in insufficient protection and moisturization; too high a concentration may make the dressing too greasy and affect breathability.

[0014] Phospholipid B, acting as an emulsifier in the oil phase, works synergistically with phospholipid A to maintain the stability of the fat emulsion. Within this addition range, it ensures sufficient emulsification of the oil and aqueous phases, forming a uniform and stable fat emulsion solution. Insufficient addition results in poor emulsification and an unstable fat emulsion; excessive addition may affect other properties of the fat emulsion, such as drug release. Lithospermum erythrorhizon extract has cooling, blood-activating, detoxifying, and rash-relieving effects. Containing active ingredients such as shikonin, at this addition level, it can promote blood circulation at the wound site, accelerate metabolism, and promote wound healing. Too low an addition will not significantly promote healing; too high an addition may irritate the wound.

[0015] Optionally, in step S2, guaiac blue hydrocarbon is added along with olive oil, and the mass percentage of guaiac blue hydrocarbon in the colostrum solution is 0.2-0.3%.

[0016] By employing the above-mentioned technical solution, guaiac blue oleane can promote the growth and repair of epithelial cells. Within this dosage range, it can accelerate the epithelialization process of the wound surface and promote wound healing. If the dosage is too low, the effect of promoting epithelial growth will not be obvious; if the dosage is too high, it may cause local irritation or allergic reactions.

[0017] Optionally, in step S2, vitamin E is added along with olive oil, and the mass percentage of vitamin E in the colostrum solution is 0.01-0.03%.

[0018] By employing the above-mentioned technical solution, vitamin E, a powerful antioxidant, at this added amount, can prevent the oils in the fat emulsion from oxidizing and deteriorating, thus extending the shelf life of the dressing. Simultaneously, its antioxidant effect also helps protect wound tissue from free radical damage, promoting wound healing.

[0019] Optionally, in step S2, the mixture is heated to 60-80°C and stirred to obtain an oil phase solution.

[0020] Optionally, in step S4, the homogenization pressure is 100-200 MPa, and the number of homogenization cycles is 3-5.

[0021] Optionally, the comfrey extract in step S2 may be added after microencapsulation, specifically as follows: 1) Add the extract of Lithospermum erythrorhizon to a copolymer solution of sodium alginate-PNIPAM-acrylic acid containing PEG 2000, stir to form an emulsion, then add the emulsion dropwise to a calcium chloride solution, react for 30-60 minutes to form gel microspheres, filter and wash with water to obtain sodium alginate microspheres; 2) After washing the sodium alginate microspheres with water, add them to a PNIPAM-acrylic acid solution containing PEG 2000. Under a nitrogen atmosphere, add ammonium persulfate and react at 60-70℃ for 2-3 hours. After the reaction is completed, centrifuge to collect the microcapsules, wash with water until neutral, and freeze-dry to obtain microcapsule comfrey extract.

[0022] By employing the above-mentioned technical solution, the extract of Lithospermum erythrorhizon contains active ingredients such as shikonin, which has the effects of cooling blood and promoting blood circulation, detoxifying and relieving rashes. It also has an inhibitory effect on various bacteria, can promote blood circulation at the wound site, accelerate metabolism, and is beneficial to wound healing. However, the shikonin component is easily affected by alkaline environments and light, leading to a decrease in activity. Therefore, in this application, it is microencapsulated to improve its stability and activity. Based on this, this application introduces acrylic acid-modified sodium alginate and poly(N-isopropylacrylamide) double-coated microcapsules. Utilizing the pH-responsive properties of acrylic acid, the pH-responsive properties of sodium alginate, and the temperature-sensitive properties of PNIPAM, a response mechanism to the inflammatory microenvironment is achieved. The introduction of the pore-forming agent PEG 2000 forms a porous structure within the coating. Under normal conditions, sodium alginate and acrylic acid-grafted PNIPAM polymers are in a swollen state with closed pores, allowing the comfrey extract to be slowly released through diffusion, thus promoting wound healing. However, under inflammatory conditions, the carboxylic acid groups of sodium alginate are protonated, causing the molecular chains to contract, while the hydrophobic segments of poly(N-isopropylacrylamide) aggregate, opening the pores of the coating layer. The comfrey extract is then rapidly released through these "dual channels," achieving rapid release of the active ingredients and accelerating its therapeutic effect.

[0023] Optionally, in step 1), the sodium alginate-PNIPAM-acrylic acid copolymer solution is prepared by dissolving the sodium alginate-PNIPAM-acrylic acid copolymer in 10-15 times the mass of water, the mass ratio of the added Lithospermum erythrorhizon extract to the sodium alginate-PNIPAM-acrylic acid copolymer is 1:(1.2-1.5), the mass concentration of the calcium chloride solution is 2-3%, and the mass ratio of the added calcium chloride to the sodium alginate-PNIPAM-acrylic acid copolymer is 1:(1.5-1.8). In step 2), the PNIPAM-acrylic acid solution is prepared by dissolving acrylic acid-PNIPAM prepolymer in 10-15 times the mass of water. The mass ratio of sodium alginate microspheres to PNIPAM-acrylic acid prepolymer is 1:(1.5-1.8), and the amount of ammonium persulfate added is 3-5 wt% of sodium alginate microspheres.

[0024] Optionally, the PNIPAM-acrylic acid prepolymer in step 2) is prepared by the following method: In a nitrogen atmosphere, N-isopropylacrylamide and acrylic acid were mixed in a molar ratio of (8-9):1 and dissolved in water. Then, N,N'-methylenebisacrylamide and sodium dodecyl sulfonate were added, followed by PEG 2000. After ultrasonic dispersion, the initial reaction solution was prepared. The temperature was raised to 65-75℃, ammonium persulfate was added dropwise, and the reaction was carried out for 2-3 hours. After cooling, the mixture was subjected to dialysis with a molecular weight cutoff of 10kDa and then freeze-dried to obtain acrylic acid-PNIPAM prepolymer. The initial reaction solution contains 0.5-1 wt% N,N'-methylenebisacrylamide, 0.3-0.5% sodium dodecyl sulfonate, 4-6% PEG 2000, 20-30% N-isopropylacrylamide, and 0.3-0.5 wt% ammonium persulfate.

[0025] Optionally, the sodium alginate-PNIPAM-acrylic acid copolymer in step 1) is prepared by the following method: Sodium alginate was dissolved in water to prepare a sodium alginate solution with a mass concentration of 1-3 wt%. Then, acrylic acid-PNIPAM prepolymer and PEG 2000 were added. After ultrasonic dispersion, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide were added. After stirring at room temperature for 20-22 h, the solution was subjected to dialysis treatment with a molecular weight cutoff of 10 kDa and then freeze-dried to obtain sodium alginate-PNIPAM-acrylic acid copolymer. The mass ratio of acrylic acid-PNIPAM prepolymer to sodium alginate is 1:(1.8-2.2), the amount of PEG 2000 added is 5-8 wt% of sodium alginate, the amount of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride added is 1-3% of acrylic acid-PNIPAM prepolymer, and the amount of N-hydroxysuccinimide added is 0.5-1 wt% of acrylic acid-PNIPAM prepolymer.

[0026] Secondly, this application provides a wet dressing, which adopts the following technical solution: A wet dressing is prepared by the method described above.

[0027] In summary, this application has the following beneficial effects: In this application, the extracts of *Hedyotis diffusa*, *Astragalus membranaceus*, *Lithospermum erythrorhizon*, and sodium guaiac sulfonate work synergistically to accelerate wound healing and shorten healing time. Furthermore, the extracts of *Hedyotis diffusa* and sodium guaiac sulfonate possess excellent antibacterial properties, effectively inhibiting bacterial growth and reducing the risk of infection. The use of a sponge as a carrier provides excellent breathability, keeping the wound dry and promoting healing. The fat emulsion technology combines the key extracts with the fat emulsion, ensuring uniform dispersion of the drug components in the emulsion and enhancing the therapeutic effect. Detailed Implementation

[0028] The following detailed description of this application is provided in conjunction with the embodiments. It should be noted that: unless otherwise specified, the conditions in the following embodiments are performed under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following embodiments are all from commercially available sources.

[0029] In the following examples, the Astragalus extract used was the Astragalus extract from Shaanxi Junhe Biotechnology Co., Ltd. The extract of *Cinnamomum camphora* is selected from *Cinnamomum camphora* extract from Xi'an Qiancao Biotechnology Co., Ltd.; The comfrey extract used is the comfrey extract with a specification of 20:1 from Lanzhou Waterles Biotechnology Co., Ltd.

[0030] Example 1

[0031] A method for preparing a wet dressing based on fat emulsion technology includes the following steps: S1. Dissolve sodium guaiac sulfonate, phospholipid A, astragalus extract and euphorbia extract in water and stir to prepare an aqueous solution; S2. Take olive oil, add phospholipid B, comfrey extract, guaiac oil and vitamin E, mix, heat to 70°C and stir to obtain an oil phase solution; S3. Add the oil phase solution to the aqueous phase solution, and shear for 20 minutes to obtain the primary emulsion solution; Based on 100 mL of colostrum solution, the mass percentage of each of the above ingredients added is as follows: 1.0% Astragalus membranaceus extract, 3.0% Ligusticum chuanxiong extract, 0.8% phospholipid A, 0.02% sodium guaiacol sulfonate, 10% olive oil, 0.8% phospholipid B, 2.5% Lithospermum erythrorhizon extract, 0.2% guaiac blue oleane and 0.02% vitamin E, and the balance being water; S4. The colostrum solution is processed by a high-pressure homogenizer, the homogenization pressure is controlled at 150MPa, and the homogenization is performed 4 times to obtain the fat emulsion solution. S5. After soaking a sponge carrier with a size of 8×60×60mm in the fat emulsion solution for 30 minutes, it is dried. The drug loading capacity of the sponge carrier is 1g (the total drug loading capacity of the active pharmaceutical ingredients in the fat emulsion solution includes Astragalus membranaceus extract, Ligusticum chuanxiong extract, sodium guaiac sulfonate, Lithospermum erythrorhizon extract and guaiac blue hydrocarbon is 1g) to prepare a wet dressing.

[0032] Example 2

[0033] A method for preparing a wet dressing based on fat emulsion technology includes the following steps: S1. Dissolve sodium guaiac sulfonate, phospholipid A, astragalus extract and euphorbia extract in water and stir to prepare an aqueous solution; S2. Take olive oil, add phospholipid B, comfrey extract, guaiac blue hydrocarbon and vitamin E, mix, heat to 60°C and stir to obtain an oil phase solution; S3. Add the oil phase solution to the aqueous phase solution, and shear for 20 minutes to obtain the primary emulsion solution; Based on 100 mL of colostrum solution, the mass percentage of each of the above ingredients added is as follows: 0.8% Astragalus membranaceus extract, 1.0% Ligusticum chuanxiong extract, 0.6% phospholipid A, 0.03% sodium guaiacol sulfonate, 9% olive oil, 0.7% phospholipid B, 2.5% Lithospermum erythrorhizon extract, 0.2% guaiac blue oleane and 0.01% vitamin E and the balance being water; S4. The colostrum solution is processed by a high-pressure homogenizer, the homogenization pressure is controlled at 100MPa, and the homogenization is performed 5 times to obtain a fat emulsion solution. S5. After soaking a sponge carrier with a size of 8×60×60mm in the fat emulsion solution for 30 minutes, it is dried. The drug loading capacity of the sponge carrier is 1g (the total drug loading capacity of the active pharmaceutical ingredients in the fat emulsion solution includes Astragalus membranaceus extract, Ligusticum chuanxiong extract, sodium guaiac sulfonate, Lithospermum erythrorhizon extract and guaiac blue hydrocarbon is 1g) to prepare a wet dressing.

[0034] Example 3

[0035] A method for preparing a wet dressing based on fat emulsion technology includes the following steps: S1. Dissolve sodium guaiac sulfonate, phospholipid A, astragalus extract and euphorbia extract in water and stir to prepare an aqueous solution; S2. Take olive oil, add phospholipid B, comfrey extract, guaiac oil and vitamin E, mix, heat to 80°C and stir to obtain an oil phase solution; S3. Add the oil phase solution to the aqueous phase solution, and shear for 20 minutes to obtain the primary emulsion solution; Based on 100 mL of colostrum solution, the mass percentage of each of the above ingredients added is as follows: 1.2% Astragalus membranaceus extract, 2.0% Ligusticum chuanxiong extract, 1.0% phospholipid A, 0.05% sodium guaiacol sulfonate, 12% olive oil, 0.9% phospholipid B, 3% Lithospermum erythrorhizon extract, 0.3% guaiacol blue oleane and 0.03% vitamin E and the balance being water; S4. The colostrum solution is processed by a high-pressure homogenizer, the homogenization pressure is controlled at 200MPa, and the homogenization is performed 3 times to obtain a fat emulsion solution. S5. After soaking a sponge carrier with a size of 8×60×60mm in the fat emulsion solution for 30 minutes, it is dried. The drug loading capacity of the sponge carrier is 1g (the total drug loading capacity of the active pharmaceutical ingredients in the fat emulsion solution includes Astragalus membranaceus extract, Ligusticum chuanxiong extract, sodium guaiac sulfonate, Lithospermum erythrorhizon extract and guaiac blue hydrocarbon is 1g) to prepare a wet dressing.

[0036] Example 4-11 A method for preparing wet dressings based on fat emulsion technology is carried out according to the method in Example 1, except that guaiacol and vitamin E are not added to the promulgated solution in step S3. The amount of raw materials added is shown in Table 1 below.

[0037] Table 1:

[0038] Comparative Example 1 A method for preparing a wet dressing based on fat emulsion technology is carried out according to the method in Example 1, except that no comfrey extract is added to the raw materials.

[0039] Comparative Example 2 A method for preparing a wet dressing based on fat emulsion technology is carried out according to the method in Example 1, except that the hand fragrance extract is not added to the raw materials.

[0040] Comparative Example 3 A method for preparing a wet dressing based on fat emulsion technology is carried out according to the method in Example 1, except that sodium guaiacol sulfonate is not added to the raw materials.

[0041] Performance testing The dressings prepared in the above examples and comparative examples were used on animal skin for irritation testing. Those that did not cause irritation continued to be tested. The results are shown in Table 2. Examples 4 and 5 failed the irritation test, while the other examples and comparative examples passed the irritation test and were subsequently tested.

[0042] Table 2:

[0043] Based on the results in Table 2 above, it can be seen that excessive amounts of sodium guaiacol sulfonate in the raw materials can cause skin irritation, and its dosage should be controlled within a safe range.

[0044] In addition, the wound healing effect of the dressings in Examples 1-3, 6-11 and Comparative Examples 1-3 was tested. Specifically, a chronic healing rat wound model was used, with diabetic rats as the chronic healing subjects. Ordinary SD rats were acclimatized for one week in a housing environment with a temperature of 24°C, humidity of 55%, and a light / dark cycle (12h / 12h). After feeding the rats a high-fat, high-sugar diet for three weeks and fasting but allowing free water for 12 hours, they were given a single injection of 1% streptozotocin (STZ) at a dose of 85 mg / kg on an empty stomach. They were then fed a high-fat, high-sugar diet for another week. After one week, the rats' blood glucose was measured, and rats with a random blood glucose level ≥16.7 mmol / L were identified as diabetic rats. Subsequently, the rats were anesthetized with 1% sodium pentobarbital (40 mg / kg), and the hair on the back of the anesthetized rats was removed. The exposed skin was cleaned and disinfected with povidone-iodine and physiological saline, and a circular full-thickness skin defect with a diameter of 0.5 cm was created with a scalpel.

[0045] A blank control experiment was conducted by applying the wet functional dressings described in Examples 1-3, 6-11 and Comparative Examples 1-3 of this application, commercially available functional dressings, and gauze to the backs of rats. The dressings were changed daily, and wound healing was observed and the healing time was recorded. The statistical results are shown in Table 3 below.

[0046] Table 3:

[0047] Based on the test results in Table 3 above, the healing time in the blank test was 14 days, the average healing time of commercially available dressings was 10 days, while the dressing in Example 11 significantly shortened the wound healing time, with an average healing time of 7 days. In Examples 6-7, the healing time was longer when the amount of guaiac extract added was lower than that in Example 11. In Example 8, the amount of guaiac extract added was lower than that in Example 11, while the healing time was longer when the amount of sodium guaiac sulfonate added was higher than that in Example 1. The healing time was also longer in Example 9 compared to Example 11 when the amount of guaiac extract added was less. Similarly, the healing time was longer in Example 10 compared to Example 11 when the amount of sodium guaiac sulfonate added was more. This shows that controlling the amount of guaiac extract and sodium guaiac sulfonate added in the formula has a greater impact on the healing effect. When the amount of guaiac extract added is more and the amount of sodium guaiac sulfonate added is less, the combination of the two results in a better healing effect.

[0048] Combining the test results of Comparative Examples 1-3, the healing effect was significantly reduced when no comfrey extract, eucommia extract, or comfrey extract was added to the raw materials. Combining the test results of Example 11 and Examples 1-3, the healing effect was even better when guaiac blue oleane and vitamin E were added to the raw materials.

[0049] Finally, the antibacterial properties of the dressings prepared in Examples 1-3 and 9-11 of this application, commercially available dressings, and a blank control group were tested. Specific implementation method: The in vitro antibacterial activity of the dressings was determined using the plate coating diffusion method. Culture media containing Staphylococcus aureus, Escherichia coli, and Candida albicans were used as control groups to evaluate the antibacterial activity of the dressings against Staphylococcus aureus, Escherichia coli, and Candida albicans, respectively. Each test bacterium was cultured in a shaker at 37°C for 24 hours, subcultured once, and prepared with physiological saline to contain bacterial counts of 10⁷–10⁶. 8 Prepare a bacterial suspension of CFU / ml. Cut the dressing into 5×5cm cubes, wrap the cut dressings and experimental items separately, and autoclave at 121℃ for 20 minutes. Remove the dressings and place them in petri dishes, add 10ml of phosphate-buffered saline (PBS) to fully soak them, and then add 100μL of each of the three bacterial suspensions (approximately 10⁷-10⁻¹⁰). 8 (CFU / ml) Incubate at 37℃ for 5 h. Use a pipette to evenly spread 60 μL of the infusion onto a standard nutrient agar plate and incubate at 37℃ for 24 h. Count the colonies on the agar plate using the colony counting method. The statistical results of the antibacterial activity of the dressing are shown in Table 4 below.

[0050] Table 4:

[0051] Based on Table 4 above, it can be seen that Examples 1-3 and Example 11 showed better inhibition rates against Staphylococcus aureus, Escherichia coli, and Candida albicans, while the blank control group showed no antibacterial effect.

[0052] Finally, the breathability of the wet functional dressing, commercially available dressing, and blank control group in Examples 1 and 11 of this application was measured using a standard breathability tester, and the results are shown in Table 5 below: Table 5:

[0053] Referring to the test results in Table 5 above, the dressing prepared in this embodiment has excellent breathability.

[0054] To further enhance the healing effect of dressings on chronic wounds, this application microencapsulates the comfrey extract. In particular, infected wounds such as bedsores can cause local temperature increases due to inflammatory reactions. Therefore, this application microencapsulates the comfrey extract to allow it to be rapidly released under the acidic pH and inflammatory temperature conditions of the wound, resulting in faster healing. At the same time, it better protects the comfrey extract and reduces its activity loss during subsequent heat treatment.

[0055] Example 12

[0056] A method for preparing a wet dressing based on fat emulsion technology is carried out according to the method in Example 1, except that the comfrey extract is added after microencapsulation. The specific operation of microencapsulation is as follows: 1) Add the extract of Lithospermum erythrorhizon to the sodium alginate-PNIPAM-acrylic acid copolymer solution, stir to form an emulsion, then add the emulsion dropwise to the calcium chloride solution, react for 45 min to form gel microspheres, filter and wash with water to obtain sodium alginate microspheres; The sodium alginate-PNIPAM-acrylic acid copolymer solution was prepared by dissolving the sodium alginate-PNIPAM-acrylic acid copolymer in 12 times its mass of water. The mass ratio of the added Lithospermum erythrorhizon extract to the sodium alginate-PNIPAM-acrylic acid copolymer was 1:1.3. The mass concentration of the calcium chloride solution was 2.5%, and the mass ratio of the added calcium chloride to the sodium alginate-PNIPAM-acrylic acid copolymer was 1:1.6. 2) After washing the sodium alginate microspheres with water, they were added to PNIPAM-acrylic acid solution. Under a nitrogen atmosphere, ammonium persulfate was added and the reaction was carried out at 65°C for 2.5 h. After the reaction was completed, the microcapsules were collected by centrifugation, washed with water until neutral, and then freeze-dried to obtain microcapsule comfrey extract. In step 2), the PNIPAM-acrylic acid solution is prepared by dissolving acrylic acid-PNIPAM prepolymer in 12 times the mass of water. The mass ratio of sodium alginate microspheres to PNIPAM-acrylic acid prepolymer is 1:1.6, and the amount of ammonium persulfate added is 4 wt% of sodium alginate microspheres.

[0057] The PNIPAM-acrylic acid prepolymer in step 2) above is prepared by the following method: In a nitrogen atmosphere, N-isopropylacrylamide and acrylic acid were mixed at a molar ratio of 8.5:1 and dissolved in water. Then, N,N'-methylenebisacrylamide and sodium dodecyl sulfonate were added, followed by PEG 2000. After ultrasonic dispersion, the initial reaction solution was prepared. The temperature was raised to 70℃, ammonium persulfate was added dropwise, and the reaction was carried out for 2.5 hours. After cooling, the product was subjected to dialysis with a molecular weight cutoff of 10 kDa and then freeze-dried to obtain acrylic acid-PNIPAM prepolymer. The initial reaction solution contained 0.8 wt% N,N'-methylenebisacrylamide, 0.4 wt% sodium dodecyl sulfonate, 5 wt% PEG 2000, 25 wt% N-isopropylacrylamide, and 0.4 wt% ammonium persulfate.

[0058] The sodium alginate-PNIPAM-acrylic acid copolymer in step 1) is prepared by the following method: Sodium alginate was dissolved in water to prepare a sodium alginate solution with a mass concentration of 2wt%. Then, acrylic acid-PNIPAM prepolymer and PEG 2000 prepared by the method in step 2) above were added. After ultrasonic dispersion for 20 min, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide were added. After stirring at room temperature for 21 h, the mixture was subjected to dialysis treatment with a molecular weight cutoff of 10 kDa and then freeze-dried to obtain sodium alginate-PNIPAM-acrylic acid copolymer. The mass ratio of acrylic acid-PNIPAM prepolymer to sodium alginate is 1:2, the amount of PEG 2000 added is 6 wt% of sodium alginate, the amount of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride added is 2% of acrylic acid-PNIPAM prepolymer, and the amount of N-hydroxysuccinimide added is 0.8 wt% of acrylic acid-PNIPAM prepolymer.

[0059] Example 13

[0060] A method for preparing a wet dressing based on fat emulsion technology is carried out according to the method in Example 1, except that the comfrey extract is added after microencapsulation. The specific operation of microencapsulation is as follows: 1) Add the extract of Lithospermum erythrorhizon to the sodium alginate-PNIPAM-acrylic acid copolymer solution, stir to form an emulsion, then add the emulsion dropwise to the calcium chloride solution, react for 30 minutes to form gel microspheres, filter and wash with water to obtain sodium alginate microspheres; The sodium alginate-PNIPAM-acrylic acid copolymer solution was prepared by dissolving the sodium alginate-PNIPAM-acrylic acid copolymer in 10 times its mass of water. The mass ratio of the added Lithospermum erythrorhizon extract to the sodium alginate-PNIPAM-acrylic acid copolymer was 1:1.2. The mass concentration of the calcium chloride solution was 2%, and the mass ratio of the added calcium chloride to the sodium alginate-PNIPAM-acrylic acid copolymer was 1:1.5. 2) After washing the sodium alginate microspheres with water, they were added to PNIPAM-acrylic acid solution. Under a nitrogen atmosphere, ammonium persulfate was added and the reaction was carried out at 60°C for 3 hours. After the reaction was completed, the microcapsules were collected by centrifugation, washed with water until neutral, and then freeze-dried to obtain microcapsule comfrey extract. In step 2), the PNIPAM-acrylic acid solution is prepared by dissolving acrylic acid-PNIPAM prepolymer in 10 times the mass of water, the mass ratio of sodium alginate microspheres to PNIPAM-acrylic acid prepolymer is 1:1.5, and the amount of ammonium persulfate added is 3 wt% of sodium alginate microspheres.

[0061] The PNIPAM-acrylic acid prepolymer in step 2) above is prepared by the following method: In a nitrogen atmosphere, N-isopropylacrylamide and acrylic acid were mixed in a molar ratio of 8:1 and dissolved in water. Then, N,N'-methylenebisacrylamide and sodium dodecyl sulfonate were added, followed by PEG 2000. After ultrasonic dispersion, the initial reaction solution was prepared. The temperature was raised to 65℃, ammonium persulfate was added dropwise, and the reaction was carried out for 3 hours. After cooling, the mixture was subjected to dialysis with a molecular weight cutoff of 10 kDa and then freeze-dried to obtain acrylic acid-PNIPAM prepolymer. The initial reaction solution contained 0.5 wt% N,N'-methylenebisacrylamide, 0.3 wt% sodium dodecyl sulfonate, 4 wt% PEG 2000, 20 wt% N-isopropylacrylamide, and 0.3 wt% ammonium persulfate.

[0062] The sodium alginate-PNIPAM-acrylic acid copolymer in step 1) is prepared by the following method: Sodium alginate was dissolved in water to prepare a sodium alginate solution with a mass concentration of 1 wt%. Then, acrylic acid-PNIPAM prepolymer and PEG 2000 prepared by the method in step 3) above were added. After ultrasonic dispersion for 20 min, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide were added. After stirring at room temperature for 20 h, the mixture was subjected to dialysis treatment with a molecular weight cutoff of 10 kDa and then freeze-dried to obtain sodium alginate-PNIPAM-acrylic acid copolymer. The mass ratio of acrylic acid-PNIPAM prepolymer to sodium alginate is 1:1.8, the amount of PEG 2000 added is 5 wt% of sodium alginate, the amount of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride added is 1% of acrylic acid-PNIPAM prepolymer, and the amount of N-hydroxysuccinimide added is 0.5 wt% of acrylic acid-PNIPAM prepolymer.

[0063] Example 14

[0064] A method for preparing a wet dressing based on fat emulsion technology is carried out according to the method in Example 1, except that the comfrey extract is added after microencapsulation. The specific operation of microencapsulation is as follows: 1) Add the extract of Lithospermum erythrorhizon to the sodium alginate-PNIPAM-acrylic acid copolymer solution, stir to form an emulsion, then add the emulsion dropwise to the calcium chloride solution, react for 60 min to form gel microspheres, filter and wash with water to obtain sodium alginate microspheres; The sodium alginate-PNIPAM-acrylic acid copolymer solution was prepared by dissolving the sodium alginate-PNIPAM-acrylic acid copolymer in 15 times its mass of water. The mass ratio of the added comfrey extract to the sodium alginate-PNIPAM-acrylic acid copolymer was 1:1.5. The mass concentration of the calcium chloride solution was 3%, and the mass ratio of the added calcium chloride to the sodium alginate-PNIPAM-acrylic acid copolymer was 1:1.8. 2) Sodium alginate microspheres were washed with water and added to PNIPAM-acrylic acid solution. Ammonium persulfate was added under nitrogen atmosphere and the reaction was carried out at 70°C for 2 hours. After the reaction was completed, the microcapsules were collected by centrifugation, washed with water until neutral, and then freeze-dried to obtain the microcapsule transdermal penetration enhancer. In step 2), the PNIPAM-acrylic acid solution is prepared by dissolving acrylic acid-PNIPAM prepolymer in 15 times the mass of water. The mass ratio of sodium alginate microspheres to PNIPAM-acrylic acid prepolymer is 1:1.8, and the amount of ammonium persulfate added is 5 wt% of sodium alginate microspheres.

[0065] The PNIPAM-acrylic acid prepolymer in step 2) above is prepared by the following method: In a nitrogen atmosphere, N-isopropylacrylamide and acrylic acid were mixed in a molar ratio of 9:1 and dissolved in water. Then, N,N'-methylenebisacrylamide and sodium dodecyl sulfonate were added, followed by PEG 2000. After ultrasonic dispersion, the initial reaction solution was prepared. The temperature was raised to 75℃, ammonium persulfate was added dropwise, and the reaction was carried out for 2 hours. After cooling, the mixture was subjected to dialysis with a molecular weight cutoff of 10 kDa and then freeze-dried to obtain acrylic acid-PNIPAM prepolymer. The initial reaction solution contained 1 wt% N,N'-methylenebisacrylamide, 0.5% sodium dodecyl sulfonate, 6% PEG 2000, 30% N-isopropylacrylamide, and 0.5 wt% ammonium persulfate.

[0066] The sodium alginate-PNIPAM-acrylic acid copolymer in step 1) is prepared by the following method: Sodium alginate was dissolved in water to prepare a sodium alginate solution with a mass concentration of 3wt%. Then, acrylic acid-PNIPAM prepolymer and PEG 2000 prepared by the method in step 3) above were added. After ultrasonic dispersion for 20 min, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide were added. After stirring at room temperature for 22 h, the mixture was subjected to dialysis treatment with a molecular weight cutoff of 10 kDa and then freeze-dried to obtain sodium alginate-PNIPAM-acrylic acid copolymer. The mass ratio of acrylic acid-PNIPAM prepolymer to sodium alginate is 1:2.2, the amount of PEG 2000 added is 8 wt% of sodium alginate, the amount of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride added is 3% of acrylic acid-PNIPAM prepolymer, and the amount of N-hydroxysuccinimide added is 1 wt% of acrylic acid-PNIPAM prepolymer.

[0067] The dressings prepared in Examples 12-14 above were tested for wound healing effect, and the results are shown in Table 6 below.

[0068] Table 6:

[0069] Based on the test results in Table 6 above, the microencapsulated extract of Lithospermum erythrorhizon promotes faster wound healing.

[0070] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for preparing a wet dressing based on fat emulsion technology, characterized in that, Includes the following steps: S1. Dissolve sodium guaiac sulfonate, phospholipid A, astragalus extract and euphorbia extract in water to prepare an aqueous solution; S2. Mix olive oil, phospholipid B, and comfrey extract, and heat and stir to obtain an oil phase solution; S3. Add the oil phase solution to the aqueous phase solution and shear to obtain the primary emulsion solution; S4. Homogenize the colostrum solution to obtain a fat emulsion solution; S5. After soaking the sponge carrier in the fat emulsion solution, dry it to obtain a wet dressing.

2. The method for preparing a wet dressing based on fat emulsion technology according to claim 1, characterized in that: The colostrum solution contains the following percentages by weight: 0.8-1.2% Astragalus membranaceus extract, 1.0-3.0% Citrus aurantium extract, 0.6-1.0% phospholipid A, 0.02-0.05% sodium guaiac sulfonate, 9-12% olive oil, 0.7-0.9% phospholipid B, 2.5-3% Lithospermum erythrorhizon extract, and the remainder water.

3. The method for preparing a wet dressing based on fat emulsion technology according to claim 1, characterized in that: In step S2, olive oil is added along with guaiac blue hydrocarbons, and the mass percentage of guaiac blue hydrocarbons in the colostrum solution is 0.2-0.3%.

4. The method for preparing a wet dressing based on fat emulsion technology according to claim 1, characterized in that: In step S2, olive oil and vitamin E are added together, and the mass percentage of vitamin E in the colostrum solution is 0.01-0.03%.

5. The method for preparing a wet dressing based on fat emulsion technology according to claim 1, characterized in that: In step S4, the homogenization pressure is 100-200 MPa, and the homogenization is performed 3-5 times.

6. The method for preparing a wet dressing based on fat emulsion technology according to claim 1, characterized in that: In step S2, the mixture is heated to 60-80℃ and stirred to obtain an oil phase solution.

7. The method for preparing a wet dressing based on fat emulsion technology according to claim 1, characterized in that: The comfrey extract in step S2 is added after microencapsulation. The specific operation is as follows: 1) Add the extract of Lithospermum erythrorhizon to a copolymer solution of sodium alginate-PNIPAM-acrylic acid containing PEG 2000, stir to form an emulsion, then add the emulsion dropwise to a calcium chloride solution, react for 30-60 minutes to form gel microspheres, filter and wash with water to obtain sodium alginate microspheres; 2) After washing the sodium alginate microspheres with water, add them to a PNIPAM-acrylic acid solution containing PEG 2000. Under a nitrogen atmosphere, add ammonium persulfate and react at 60-70℃ for 2-3 hours. After the reaction is completed, centrifuge to collect the microcapsules, wash with water until neutral, and freeze-dry to obtain microcapsule comfrey extract.

8. A method for preparing a wet dressing based on fat emulsion technology according to claim 7, characterized in that: In step 1), the sodium alginate-PNIPAM-acrylic acid copolymer solution is prepared by dissolving the sodium alginate-PNIPAM-acrylic acid copolymer in 10-15 times the mass of water. The mass ratio of the added comfrey extract to the sodium alginate-PNIPAM-acrylic acid copolymer is 1:(1.2-1.5). The mass concentration of the calcium chloride solution is 2-3%, and the mass ratio of the added calcium chloride to the sodium alginate-PNIPAM-acrylic acid copolymer is 1:(1.5-1.8). In step 2), the PNIPAM-acrylic acid solution is prepared by dissolving acrylic acid-PNIPAM prepolymer in 10-15 times the mass of water. The mass ratio of sodium alginate microspheres to PNIPAM-acrylic acid prepolymer is 1:(1.5-1.8), and the amount of ammonium persulfate added is 3-5 wt% of sodium alginate microspheres.

9. A method for preparing a wet dressing based on fat emulsion technology according to claim 8, characterized in that: In step 2), the PNIPAM-acrylic acid prepolymer is prepared by the following method: In a nitrogen atmosphere, N-isopropylacrylamide and acrylic acid were mixed in a molar ratio of (8-9):1 and dissolved in water. Then, N,N'-methylenebisacrylamide and sodium dodecyl sulfonate were added, followed by PEG 2000. After ultrasonic dispersion, the initial reaction solution was prepared. The temperature was raised to 65-75℃, ammonium persulfate was added dropwise, and the reaction was carried out for 2-3 hours. After cooling, the mixture was subjected to dialysis with a molecular weight cutoff of 10kDa and then freeze-dried to obtain acrylic acid-PNIPAM prepolymer. The initial reaction solution contained 0.5-1 wt% N,N'-methylenebisacrylamide, 0.3-0.5% sodium dodecyl sulfonate, 4-6% PEG 2000, and 20-30% N-isopropylacrylamide. Ammonium persulfate was added at 0.3-0.5 wt% of the initial reaction solution. The sodium alginate-PNIPAM-acrylic acid copolymer in step 1) is prepared by the following method: Sodium alginate was dissolved in water to prepare a sodium alginate solution with a mass concentration of 1-3 wt%. Then, acrylic acid-PNIPAM prepolymer and PEG 2000 were added. After ultrasonic dispersion, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and N-hydroxysuccinimide were added. After stirring at room temperature for 20-22 h, the solution was subjected to dialysis treatment with a molecular weight cutoff of 10 kDa and then freeze-dried to obtain sodium alginate-PNIPAM-acrylic acid copolymer. The mass ratio of acrylic acid-PNIPAM prepolymer to sodium alginate is 1:(1.8-2.2), the amount of PEG 2000 added is 5-8 wt% of sodium alginate, the amount of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride added is 1-3% of acrylic acid-PNIPAM prepolymer, and the amount of N-hydroxysuccinimide added is 0.5-1 wt% of acrylic acid-PNIPAM prepolymer.

10. A wet dressing prepared by the method described in any one of claims 1-9.

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