A method for preparing a stable carboxymethyl chitosan wound dressing
By introducing a passivating stabilizer into carboxymethyl chitosan wound dressing, the problem of pH-dependent structural instability was solved, achieving stability and structural integrity under acidic and alkaline environments, and improving the dressing's effectiveness.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HAERBIN FUERSITE BIOLOGY ENG CO LTD
- Filing Date
- 2025-08-05
- Publication Date
- 2026-06-12
Abstract
Description
Technical Field
[0001] This invention belongs to the field of medical dressing technology, specifically, it relates to a method for preparing a stable carboxymethyl chitosan wound dressing. Background Technology
[0002] Carboxymethyl chitosan is a water-soluble derivative of chitosan obtained by carboxymethylation modification. It combines the biocompatibility and antibacterial properties of chitosan with the hydrophilicity of carboxyl groups, and is widely used in wound dressings.
[0003] However, CMCS dressings have significant drawbacks: carboxymethyl chitosan is an amphoteric polyelectrolyte containing both amino and carboxyl groups in its molecule. In acidic environments, amino protonation dominates, intermolecular hydrogen bonding is enhanced, the gel network shrinks and hardens, and it becomes brittle and granular. In alkaline environments, carboxyl ionization leads to electrostatic repulsion, causing excessive swelling and disintegration of the gel. This pH dependence makes the dressing prone to transforming into a jelly-like, brittle gel when in contact with wound exudate or drug-loaded fluids, resulting in a granular texture and structural instability, significantly reducing user experience and healing effectiveness. Existing technologies attempt to improve pH resistance through composites of sodium alginate and silicone oil, but these methods rely on their own pH resistance for buffering and cannot suppress the protonation / deprotonation nature of the carboxymethyl chitosan chains, resulting in limited improvement and severely restricting the application of carboxymethyl chitosan dressings. Summary of the Invention
[0004] In order to solve the technical problems mentioned in the background art, the purpose of this invention is to provide a method for preparing a stable carboxymethyl chitosan wound dressing.
[0005] The objective of this invention can be achieved through the following technical solutions:
[0006] A stable carboxymethyl chitosan wound dressing comprises: 3.2-4.5 wt% carboxymethyl chitosan, 1.1-1.6 wt% passivating stabilizer, 0.15-0.2 wt% crosslinking agent, 1.6-2.0 wt% wetting agent, and 0.7-0.9 wt% moisturizing agent, with the balance being PBS buffer.
[0007] Preferably, the crosslinking agent is genipin, which is a natural crosslinking material that is non-toxic and highly biocompatible, effectively regulating the dressing's condition.
[0008] Preferably, the wetting agent is polyethylene glycol and the moisturizing agent is glycerin, which have high biocompatibility. The two work together to adjust the dressing state, making it easy to infiltrate the wound and keep the wound moist.
[0009] A method for preparing a stable carboxymethyl chitosan wound dressing is as follows: carboxymethyl chitosan, a passivating stabilizer and PBS buffer are ultrasonically dispersed, homogenized in a water bath, and then the remaining components are added and mixed. Afterwards, the mixture is vacuum degassed and sterilized with ultraviolet light to obtain the carboxymethyl chitosan wound dressing.
[0010] Preferably, the water bath homogenization temperature is 40-50℃ and the time is 2-3 hours. Under this environment, carboxymethyl chitosan and passivating stabilizer can interact effectively, while having a low impact on the state of the dressing.
[0011] The passivation stabilizer is prepared by the following method:
[0012] Step A1: Mix ethylene glycol diallyl ether, platinum catalyst and anhydrous toluene, purge with nitrogen, preheat to 50-60℃, slowly add octamethyltetrasiloxane and stir for 1.2-1.6h, then heat to 80-90℃ and continue the reaction for 2.5-3.2h. After the reaction is complete, remove toluene and excess ethylene glycol diallyl ether by rotary evaporation under reduced pressure to obtain the silyl ether intermediate.
[0013] Furthermore, the ratio of octamethyltetrasiloxane, ethylene glycol diallyl ether, platinum catalyst, and anhydrous toluene is 0.1 mol: 0.13-0.15 mol: 0.06-0.08 g: 150-180 mL. Under catalysis, excess ethylene glycol diallyl ether undergoes hydrosilylation with octamethyltetrasiloxane to form a chain compound with allyl end-capped segments and alternating silicon and ether segments in the chain.
[0014] Step A2: Mix mercaptoethylamine and acetone under nitrogen protection, then add the silyl ether intermediate and photosensitizer and mix thoroughly at room temperature at 35-45 mW / cm². 2 Irradiate with ultraviolet light and stir for 4-5 hours. After the reaction is complete, remove acetone by rotary evaporation. Wash the substrate with water and dry it to obtain the amination monomer.
[0015] Furthermore, the ratio of the silyl ether intermediate, mercaptoethylamine, photosensitizer, and acetone is 50g:60-80mmol:0.15-0.2g:120-160mL. Under photoinitiation, mercaptoethylamine undergoes click addition to the terminal double bond of the silyl ether intermediate, introducing terminal amino modification.
[0016] Step A3: Mix the amination monomer, propylene glycol alginate, tetrabutyl titanate and acidic dioxane aqueous solution, purge with nitrogen for protection, heat to 90-100℃ and stir under reflux for 10-13 hours. After the reaction is complete, remove dioxane by rotary evaporation. Wash the substrate with citric acid solution and water in sequence, freeze dry and then pulverize to obtain the passivation stabilizer.
[0017] Furthermore, the ratio of propylene glycol alginate, amination monomer, tetrabutyl titanate, and acidic dioxane aqueous solution is 50g:13-17g:0.08-0.1g:250-330mL. Propylene glycol alginate and amination monomer undergo amine-ester exchange to introduce a block structure of the amination monomer.
[0018] The beneficial effects of this invention are:
[0019] This invention, based on the existing carboxymethyl chitosan dressing system, introduces a passivation stabilizer mixture. This mixture is formed by hydrosilylation of excess ethylene glycol diallyl ether and octamethyltetrasiloxane to create a chain-like compound with allyl ends and alternating silicon and ether segments—a silyl ether intermediate. Then, mercaptoethylamine and the silyl ether intermediate undergo photoinitiated addition to form a terminal amino group, producing an amination monomer. Finally, the amination monomer undergoes an amino-ester exchange with propylene glycol alginate to introduce a block structure, thus obtaining the passivation stabilizer. Compared to existing technologies, the alginate segment in the passivation stabilizer molecular chain has a similar affinity to carboxymethyl chitosan. The polysaccharide-like structure, through compatibility and dispersion and interactions between polysaccharide units, allows the passivating stabilizer molecular chains to become entangled with carboxymethyl chitosan. An alternating structure of ether fragments and organosilicon fragments is introduced onto the carboxymethyl chitosan molecular chains. In acidic environments, when the carboxyl groups of carboxymethyl chitosan undergo carboxylation and shrinkage, the organosilicon fragments prevent excessive water molecule penetration, reducing gel network collapse. In alkaline environments, the organosilicon fragments inhibit excessive chain extension through steric hindrance, preventing gel swelling and rupture, and ensuring the stability of the initial gel. Furthermore, the ether fragments form a hydration layer, encapsulating the amino and carboxyl groups of carboxymethyl chitosan, buffering H+ during sudden pH changes. + Or the impact of OH-, under acidic conditions, the ether chain reacts with H. + A stable solvation layer is formed, slowing down the protonation rate of carboxymethyl chitosan. In an alkaline environment, the hydrogen bonds between the ether chain and water molecules are enhanced, counteracting the damage of electrostatic crosslinking by OH-, thus buffering the direct effect of external pH changes on the carboxymethyl chitosan chains. The introduction of passivating stabilizers significantly improves the pH resistance of dressings, and has important application value in drug loading and long-term storage. Detailed Implementation
[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0021] Example 1: Preparation of a stable carboxymethyl chitosan wound dressing. The specific implementation process is as follows:
[0022] (1) Preparation of passivation stabilizer
[0023] Step A1: Mix ethylene glycol diallyl ether, platinum catalyst, and anhydrous toluene, purge with nitrogen for protection, preheat to 60°C, slowly add octamethyltetrasiloxane and stir for 1.2 h, then heat to 90°C and continue the reaction for 2.5 h. The platinum catalyst used is a Castrol catalyst with a platinum content of 5000 ppm. The molar ratio of octamethyltetrasiloxane, ethylene glycol diallyl ether, platinum catalyst, and anhydrous toluene is 0.1 mol: 0.15 mol: 0.08 g: 180 mL. After the reaction is complete, remove toluene and excess ethylene glycol diallyl ether by rotary evaporation under reduced pressure to obtain the silyl ether intermediate.
[0024] Step A2: Mix mercaptoethylamine and acetone under nitrogen protection, then add the silyl ether intermediate and photosensitizer and mix well. Incubate at room temperature at 45 mW / cm². 2 The reaction was subjected to ultraviolet irradiation and stirred for 4 hours. The photosensitizer used was photosensitizer 1173. The ratio of silyl ether intermediate, mercaptoethylamine, photosensitizer and acetone was 50 g: 80 mmol: 0.2 g: 160 mL. After the reaction was completed, the acetone was removed by rotary evaporation. The substrate was washed with water and dried to obtain the amination monomer.
[0025] Step A3: Mix the amination monomer, propylene glycol alginate, tetrabutyl titanate, and acidic dioxane aqueous solution, purge with nitrogen for protection, heat to 100℃ and reflux for 10 hours. The degree of esterification of propylene glycol alginate is ≥80%, the mass fraction of acidic dioxane aqueous solution is 60%, the pH value of acetic acid is 4, and the ratio of propylene glycol alginate, amination monomer, tetrabutyl titanate, and acidic dioxane aqueous solution is 50g:17g:0.1g:330mL. After the reaction is complete, remove dioxane by rotary evaporation. Wash the substrate sequentially with citric acid solution and water, freeze-dry, and then pulverize to obtain the passivation stabilizer.
[0026] (2) Preparation of wound dressings
[0027] The raw materials were prepared according to the following proportions: 3.2 wt% carboxymethyl chitosan (commercially available medical grade); 1.1 wt% passivating stabilizer (prepared in-house); 0.15 wt% crosslinking agent (commercially available medical grade genipin); 1.6 wt% wetting agent (polyethylene glycol 400); 0.9 wt% humectant (glycerol); and the remainder was PBS buffer.
[0028] Carboxymethyl chitosan, passivation stabilizer and PBS buffer were ultrasonically dispersed and placed in a water bath at 50°C for 2 hours for homogenization. Then the remaining components were added and stirred until well mixed. After vacuum degassing and UV sterilization, carboxymethyl chitosan wound dressing was obtained.
[0029] Example 2: Preparation of a stable carboxymethyl chitosan wound dressing. The specific implementation process is as follows:
[0030] (1) Preparation of passivation stabilizer
[0031] Step A1: Mix ethylene glycol diallyl ether, platinum catalyst, and anhydrous toluene, purge with nitrogen for protection, preheat to 50°C, slowly add octamethyltetrasiloxane and stir for 1.6 h, then raise the temperature to 80°C and continue the reaction for 3.2 h. The platinum catalyst used is a Castrol catalyst with a platinum content of 5000 ppm. The ratio of octamethyltetrasiloxane, ethylene glycol diallyl ether, platinum catalyst, and anhydrous toluene is 0.1 mol: 0.13 mol: 0.06 g: 150 mL. After the reaction is complete, remove toluene and excess ethylene glycol diallyl ether by rotary evaporation under reduced pressure to obtain the silyl ether intermediate.
[0032] Step A2: Mix mercaptoethylamine and acetone under nitrogen protection, then add the silyl ether intermediate and photosensitizer and mix well. Incubate at room temperature at 35 mW / cm 2 The reaction was subjected to ultraviolet irradiation and stirred for 5 hours. The photosensitizer used was photosensitizer 1173. The ratio of silyl ether intermediate, mercaptoethylamine, photosensitizer and acetone was 50 g: 60 mmol: 0.15 g: 120 mL. After the reaction was completed, the acetone was removed by rotary evaporation. The substrate was washed with water and dried to obtain the amination monomer.
[0033] Step A3: Mix the amination monomer, propylene glycol alginate, tetrabutyl titanate, and acidic dioxane aqueous solution, purge with nitrogen for protection, heat to 90℃ and reflux for 13 hours. The degree of esterification of propylene glycol alginate is ≥80%, the mass fraction of acidic dioxane aqueous solution is 60%, the pH value of acetic acid acidification is 4, and the ratio of propylene glycol alginate, amination monomer, tetrabutyl titanate, and acidic dioxane aqueous solution is 50g:13g:0.08g:250mL. After the reaction is complete, remove dioxane by rotary evaporation. Wash the substrate sequentially with citric acid solution and water, freeze-dry, and then pulverize to obtain the passivation stabilizer.
[0034] (2) Preparation of wound dressings
[0035] The raw materials were prepared according to the following proportions: 4.5 wt% carboxymethyl chitosan (commercially available medical grade); 1.6 wt% passivating stabilizer (prepared in this embodiment); 0.2 wt% crosslinking agent (commercially available medical grade genipin); 2.0 wt% wetting agent (polyethylene glycol 400); 0.7 wt% humectant (glycerol); and the remainder was PBS buffer.
[0036] Carboxymethyl chitosan, passivation stabilizer and PBS buffer were ultrasonically dispersed and placed in a water bath at 40°C for 3 hours for homogenization. Then the remaining components were added and stirred until well mixed. After vacuum degassing and UV sterilization, carboxymethyl chitosan wound dressing was obtained.
[0037] Example 3: Preparation of a stable carboxymethyl chitosan wound dressing. The specific implementation process is as follows:
[0038] (1) Preparation of passivation stabilizer
[0039] Step A1: Mix ethylene glycol diallyl ether, platinum catalyst, and anhydrous toluene, purge with nitrogen for protection, preheat to 55°C, slowly add octamethyltetrasiloxane and stir for 1.4 h, then raise the temperature to 85°C and continue the reaction for 2.8 h. The platinum catalyst used is a Castrol catalyst with a platinum content of 5000 ppm. The molar ratio of octamethyltetrasiloxane, ethylene glycol diallyl ether, platinum catalyst, and anhydrous toluene is 0.1 mol: 0.14 mol: 0.07 g: 160 mL. After the reaction is complete, remove toluene and excess ethylene glycol diallyl ether by rotary evaporation under reduced pressure to obtain the silyl ether intermediate.
[0040] Step A2: Mix mercaptoethylamine and acetone under nitrogen protection, then add the silyl ether intermediate and photosensitizer and mix well. Incubate at room temperature at 40 mW / cm 2 The reaction was subjected to ultraviolet irradiation and stirred for 4.5 h. The photosensitizer used was photosensitizer 1173. The ratio of silyl ether intermediate, mercaptoethylamine, photosensitizer and acetone was 50 g: 70 mmol: 0.18 g: 140 mL. After the reaction was completed, the acetone was removed by rotary evaporation. The substrate was washed with water and dried to obtain the amination monomer.
[0041] Step A3: Mix the amination monomer, propylene glycol alginate, tetrabutyl titanate, and acidic dioxane aqueous solution, purge with nitrogen for protection, heat to 95°C, and reflux for 12 hours with stirring. The degree of esterification of propylene glycol alginate is ≥80%, the mass fraction of acidic dioxane aqueous solution is 60%, the pH value of acetic acid is 4, and the ratio of propylene glycol alginate, amination monomer, tetrabutyl titanate, and acidic dioxane aqueous solution is 50g:15g:0.09g:280mL. After the reaction is complete, remove dioxane by rotary evaporation. Wash the substrate sequentially with citric acid solution and water, freeze-dry, and then pulverize to obtain the passivation stabilizer.
[0042] (2) Preparation of wound dressings
[0043] The raw materials were prepared according to the following proportions: 4.0 wt% carboxymethyl chitosan (commercially available medical grade); 1.4 wt% passivating stabilizer (prepared in this embodiment); 0.17 wt% crosslinking agent (commercially available medical grade genipin); 1.9 wt% wetting agent (polyethylene glycol 400); 0.8 wt% humectant (glycerol); and the remainder was PBS buffer.
[0044] Carboxymethyl chitosan, passivation stabilizer and PBS buffer were ultrasonically dispersed and placed in a water bath at 45°C for 2.5 hours for homogenization. Then the remaining components were added and stirred until well mixed. The mixture was then vacuum degassed and sterilized with ultraviolet light to obtain carboxymethyl chitosan wound dressing.
[0045] Example 4: Preparation of a stable carboxymethyl chitosan wound dressing. The specific implementation process is as follows:
[0046] (1) Preparation of passivation stabilizer
[0047] Step A1: Mix ethylene glycol diallyl ether, platinum catalyst, and anhydrous toluene, purge with nitrogen for protection, preheat to 60°C, slowly add octamethyltetrasiloxane and stir for 1.3 h, then raise the temperature to 85°C and continue the reaction for 3 h. The platinum catalyst used is a caster catalyst with a platinum content of 5000 ppm. The molar ratio of octamethyltetrasiloxane, ethylene glycol diallyl ether, platinum catalyst, and anhydrous toluene is 0.1 mol: 0.14 mol: 0.08 g: 170 mL. After the reaction is complete, remove toluene and excess ethylene glycol diallyl ether by rotary evaporation under reduced pressure to obtain the silyl ether intermediate.
[0048] Step A2: Mix mercaptoethylamine and acetone under nitrogen protection, then add the silyl ether intermediate and photosensitizer and mix well. Incubate at room temperature at 40 mW / cm 2 The reaction was subjected to ultraviolet irradiation and stirred for 4.8 h. The photosensitizer used was photosensitizer 1173. The ratio of silyl ether intermediate, mercaptoethylamine, photosensitizer and acetone was 50 g: 75 mmol: 0.18 g: 150 mL. After the reaction was completed, the acetone was removed by rotary evaporation. The substrate was washed with water and dried to obtain the amination monomer.
[0049] Step A3: Mix the amination monomer, propylene glycol alginate, tetrabutyl titanate, and acidic dioxane aqueous solution, purge with nitrogen for protection, heat to 100℃ and reflux for 12 hours. The degree of esterification of propylene glycol alginate is ≥80%, the mass fraction of acidic dioxane aqueous solution is 60%, the pH value of acetic acid acidification is 4, and the ratio of propylene glycol alginate, amination monomer, tetrabutyl titanate, and acidic dioxane aqueous solution is 50g:16g:0.1g:300mL. After the reaction is complete, remove dioxane by rotary evaporation. Wash the substrate sequentially with citric acid solution and water, freeze-dry, and then pulverize to obtain the passivation stabilizer.
[0050] (2) Preparation of wound dressings
[0051] The raw materials were prepared according to the following proportions: 3.8 wt% carboxymethyl chitosan (commercially available medical grade); 1.3 wt% passivating stabilizer (prepared in this embodiment); 0.17 wt% crosslinking agent (commercially available medical grade genipin); 1.8 wt% wetting agent (polyethylene glycol 400); 0.5 wt% humectant (glycerol); and the remainder was PBS buffer.
[0052] Carboxymethyl chitosan, passivation stabilizer and PBS buffer were ultrasonically dispersed and placed in a water bath at 40°C for 2.7 h for homogenization. Then the remaining components were added and stirred until well mixed. The mixture was then vacuum degassed and sterilized with ultraviolet light to obtain carboxymethyl chitosan wound dressing.
[0053] In the comparative example, referring to Example 4, the passivation stabilizer was replaced with 1.0 wt% medical-grade sodium alginate and 0.3 wt% Liveo. TM The 360-type medical silicone oil is used, and the rest of the implementation process is exactly the same.
[0054] Dressing stability test: The viscous modulus of the dressing was measured using a DHR-2 rheometer. Acetic acid solution with pH 2 and sodium carbonate solution with pH 10 were prepared and added to the dressing at 30 wt%, respectively. The rate of change in viscous modulus was measured and recorded as ΔG1 and ΔG2, respectively. Specific test results are shown in Table 1.
[0055] Table 1
[0056] Example 1 Example 2 Example 3 Example 4 Comparative Example <![CDATA[ΔG1 / %]]> 12.47 16.51 14.25 10.06 41.72 <![CDATA[ΔG2 / %]]> 9.55 10.63 9.08 7.14 29.58
[0057] As can be seen from the test results in Table 1, the dressing prepared in the example showed little change in state under varying acidity and alkalinity, and maintained its initial delicate skin feel.
[0058] Medical performance testing of dressings: The antibacterial properties of the dressings were tested according to ASTM E2149-20 standard, using Staphylococcus aureus as the test bacterium; the viability of L929 fibroblasts was tested using the MTT assay according to ISO 10993-5:2009 standard. Specific test results are shown in Table 2.
[0059] Table 2
[0060] Example 1 Example 2 Example 3 Example 4 Comparative Example Antibacterial rate / % 97.4 99.1 98.5 97.9 98.1 Survival rate / % 91.6 87.5 89.4 90.8 85.6
[0061] As shown in Table 2, the introduction of the passivation stabilizer in the examples had almost no statistically significant effect on the antibacterial and cytotoxic properties of the dressing.
[0062] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0063] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.
Claims
1. A method for preparing a stable carboxymethyl chitosan wound dressing, characterized by, Specifically, carboxymethyl chitosan, passivation stabilizer and PBS buffer are ultrasonically dispersed, homogenized in a water bath, and then crosslinking agent, wetting agent and moisturizing agent are added and mixed. After vacuum degassing and ultraviolet sterilization, carboxymethyl chitosan wound dressing is obtained. The passivation stabilizer is prepared by the following method: Step A1: Mix ethylene glycol diallyl ether, platinum catalyst and anhydrous toluene, purge with nitrogen for protection, preheat to 50-60℃, slowly add octamethyltetrasiloxane and stir for 1.2-1.6h, then heat to 80-90℃ and continue the reaction for 2.5-3.2h to prepare silane intermediate; Step A2: Thioethylamine and acetone were mixed under nitrogen protection, then the siloxane intermediate and photosensitizer were added and mixed, and irradiation was carried out at 35-45 mW / cm 2 UV intensity, and the reaction was irradiated and stirred for 4-5 h to prepare the aminated monomer; Step A3: Mix the amination monomer, propylene glycol alginate, tetrabutyl titanate and acidic dioxane aqueous solution, purge with nitrogen for protection, heat to 90-100℃ and stir under reflux for 10-13 hours to prepare a passivation stabilizer.
2. The method for preparing a stable carboxymethyl chitosan wound dressing according to claim 1, characterized in that, The ratio of octamethyltetrasiloxane, ethylene glycol diallyl ether, platinum catalyst, and anhydrous toluene is 0.1 mol: 0.13-0.15 mol: 0.06-0.08 g: 150-180 mL.
3. The method for preparing a stable carboxymethyl chitosan wound dressing according to claim 2, characterized in that, The ratio of the amount of silyl ether intermediate, mercaptoethylamine, photosensitizer and acetone is 50g: 60-80mmol: 0.15-0.2g: 120-160mL.
4. The method for preparing a stable carboxymethyl chitosan wound dressing according to claim 3, characterized in that, The ratio of propylene glycol alginate, amination monomer, tetrabutyl titanate, and acidic dioxane aqueous solution is 50g: 13-17g: 0.08-0.1g: 250-330mL.
5. The method for preparing a stable carboxymethyl chitosan wound dressing according to claim 4, characterized in that, The dressing consists of the following components: 3.2-4.5 wt% carboxymethyl chitosan, 1.1-1.6 wt% passivating stabilizer, 0.15-0.2 wt% crosslinking agent, 1.6-2.0 wt% wetting agent, and 0.7-0.9 wt% humectant, with the balance being PBS buffer.
6. The method for preparing a stable carboxymethyl chitosan wound dressing according to claim 5, characterized in that, The crosslinking agent is genipin.
7. The method for preparing a stable carboxymethyl chitosan wound dressing according to claim 1, characterized in that, The wetting agent is polyethylene glycol, and the humectant is glycerin.
8. The method for preparing a stable carboxymethyl chitosan wound dressing according to claim 1, characterized in that, The water bath homogenization temperature is 40-50℃, and the time is 2-3 hours.