Medical sodium hyaluronate dressing and preparation method thereof

Abstract

The invention discloses a medical sodium hyaluronate dressing which comprises the following components in percentage by weight: 0.15-0.5% of sodium hyaluronate, 0.1-0.5% of sodium hyaluronate, 0.1-0.5% of sodium hyaluronate and the balance of water. 0.1 to 1.0 percent of carbomer; 5.0 to 8.0% of glycerin; 0.1 to 1.0 percent of arginine; 0.2 to 0.7% of sodium benzoate; 0.3 to 0.8 percent of potassium sorbate; and the balance of water. The invention also discloses a preparation method of the medical sodium hyaluronate dressing, which comprises the following steps: putting the sodium hyaluronate, the carbomer, the glycerol and the water into a water phase pot, and stirring to obtain a first mixed solution; continuously stirring the first mixed solution; adding arginine, sodium benzoate and potassium sorbate into the first mixed solution, and stirring to obtain a second mixed solution; adding auxiliary materials into the second mixed solution, and stirring to obtain a third mixed solution; continuously stirring the third mixed solution to obtain the medical sodium hyaluronate dressing; the medical sodium hyaluronate dressing has excellent antibacterial performance, corrosion resistance, mechanical performance and water retention performance, and the preparation method of the medical sodium hyaluronate dressing is simple and convenient to operate.

Description

Technical Field

[0001] The invention belongs to the technical field of dressings, and in particular relates to a medical sodium hyaluronate dressing and a preparation method thereof. Background Art

[0002] With the development of medical technology, medical dressings play an important role in promoting wound healing, preventing infection, and alleviating pain. Traditional medical dressings are mostly made of single materials, such as gauze and non-woven fabrics. Although they can provide basic protection and absorption functions, they have limitations in terms of moisture retention, antibacterial properties, and biocompatibility.

[0003] In recent years, sodium hyaluronate, as a natural polysaccharide, has been widely used in the field of medical dressings due to its excellent biocompatibility, water retention and ability to promote wound repair.

[0004] However, the sodium hyaluronate dressing currently used has poor antibacterial properties and is prone to breeding microorganisms and bacteria, which limits its application in clinical practice and is not conducive to patient use.

[0005] Based on this, it is necessary to provide a medical sodium hyaluronate dressing that can be widely used clinically and a preparation method thereof. Summary of the Invention

[0006] One object of the present invention is to provide a medical sodium hyaluronate dressing, and another object of the present invention is to provide a method for preparing the medical sodium hyaluronate dressing.

[0007] In order to achieve the first object of the present invention, the following technical solution is adopted:

[0008] A medical sodium hyaluronate dressing, comprising the following components by weight percentage:

[0009] Sodium hyaluronate 0.15-0.5%; carbomer 0.1-1.0%; glycerin 5.0-8.0%; arginine 0.1-1.0%; sodium benzoate 0.2-0.7%; potassium sorbate 0.3-0.8%; the balance is water.

[0010] In the medical sodium hyaluronate dressing of the present invention, the carboxyl group (-COO-) and hydroxyl group (-OH) in sodium hyaluronate can bind to a large number of water molecules, greatly enhancing its water retention capacity. Therefore, in the present invention, sodium hyaluronate is used as a moisturizer. In order to enable the medical sodium hyaluronate dressing of the present invention to quickly penetrate the stratum corneum and form an internal water film, sodium hyaluronate is selected to have a low molecular weight. Preferably, the molecular weight of sodium hyaluronate is 100,000-500,000 Da.

[0011] In the medical sodium hyaluronate dressing of the present invention, carbomer is an acrylic resin, which is a polyacrylic acid cross-linked polymer and contains a large number of carboxyl groups (-COO-). Therefore, carbomer can lock free water with the hydrogen bond network in sodium hyaluronate, thereby enhancing the viscosity of the medical sodium hyaluronate dressing. Therefore, in the present invention, carbomer is used as a thickener.

[0012] In the medical sodium hyaluronate dressing of the present invention, in order to further enhance the maintenance of the moist microenvironment of the wound, promote wound healing, increase the migration rate of keratinocytes, promote epithelial migration on the wound, and reduce inflammatory response, glycerol is added as a moisturizer in the present invention to achieve the above effects.

[0013] In the medical sodium hyaluronate dressing of the present invention, the pH of the dressing is 5.0-7.0. Since this range is the best environment for wound healing, a neutralizer needs to be added to adjust the pH of the dressing. In the present invention, arginine is used as the preferred neutralizer. On the other hand, arginine also has antimicrobial functions. For example, arginine can inhibit the growth of Staphylococcus aureus.

[0014] In the medical sodium hyaluronate dressing of the present invention, sodium benzoate and potassium sorbate are used as preservatives to inhibit the growth of microorganisms such as heat-resistant Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, thereby preventing the dressing from being infected by microorganisms and affecting its efficacy and service life.

[0015] Among them, sodium benzoate penetrates the microbial cell membrane through its undissociated benzoic acid molecules, inhibits enzyme activity, and thus inhibits the growth of microorganisms. Since if the content of sodium benzoate exceeds a certain range, it will cause delayed wound healing. Therefore, the content of sodium benzoate is preferably 0.01-0.1wt%, and more preferably 0.05-0.08wt%.

[0016] Among them, potassium sorbate inhibits microbial dehydrogenase, blocks energy metabolism, and thus inhibits the growth of microorganisms.

[0017] In the medical sodium hyaluronate dressing of the present invention, water is used as a solvent.

[0018] Preferably, the following components are included in percentage by weight:

[0019] Sodium hyaluronate 0.3%; Carbomer 0.55%; Glycerin 6.5%; Arginine 0.5%; Sodium benzoate 0.45%; Potassium sorbate 0.6%; Water 91.1%.

[0020] Preferably, other acceptable excipients are also included, and the excipients are added in the form of external admixtures, and the amount of the excipients added is 0.1 to 0.5% of the total amount. In the medical sodium hyaluronate dressing of the present invention, other acceptable excipients will not have a negative effect on the dressing and will not affect the performance of other components. Therefore, the excipients are added in the form of external admixtures, and the excipients are added after the other components are added. In the present invention, the added excipients are cross-linking agents. One of the functions of the cross-linking agent in the medical sodium hyaluronate dressing of the present invention is to improve the mechanical strength of the dressing, and to cross-link the linear sodium hyaluronate molecular chains into a network structure through chemical bonds or physical effects, so that the tensile strength of the dressing is improved; the second function of the cross-linking agent in the medical sodium hyaluronate dressing of the present invention is to enhance the degradation resistance. After cross-linking, it can resist the degradation of hyaluronidase and extend the service life of the dressing. Furthermore, in order to avoid the increased brittleness of the medical sodium hyaluronate dressing of the present invention due to excessive addition of the cross-linking agent, the amount of the cross-linking agent added should be controlled within an appropriate range. After several experiments, it was demonstrated that the best effect was achieved when the amount of the cross-linking agent added was 0.1 to 0.5% of the total amount, i.e., the total amount after all other components were added.

[0021] Preferably, the auxiliary material is genipin. Genipin is a natural cross-linking agent, and the strength of the dressing gel after cross-linking can be improved to a certain extent. In addition, genipin has very low toxicity and high cell survival rate, which is beneficial to the healing and recovery of the wound.

[0022] In order to achieve the second purpose of the present invention, the following technical solution is adopted:

[0023] A method for preparing the medical sodium hyaluronate dressing as described herein comprises the following steps:

[0024] S1. Place sodium hyaluronate, carbomer, glycerin, and water in an aqueous phase pot at a temperature of 80-85° C. and stir at a speed of 20-30 rpm to obtain a uniformly dispersed first mixed solution;

[0025] S2. Continue stirring the first mixed solution for 20-30 minutes at a temperature of 80-85° C. in the water phase pot;

[0026] S3, stirring the first mixed solution at a speed of 15-25 rpm to reduce the temperature in the aqueous phase pot, adding arginine, sodium benzoate and potassium sorbate to the first mixed solution after the temperature is reduced and stirring at a speed of 15-20 rpm for 15-20 minutes to obtain a uniformly dispersed second mixed solution;

[0027] S4, adding auxiliary materials to the second mixed solution and stirring for 30-40 minutes to obtain a third mixed solution;

[0028] S5. Stir the third mixed liquid at a speed of 15-20 rpm to lower the temperature in the water phase pot. Continue stirring for 15-25 minutes after the temperature is lowered to obtain a gel-like medical sodium hyaluronate dressing.

[0029] The medical sodium hyaluronate dressing prepared by the invention is odorless, colorless, transparent and in a gel-like state.

[0030] Preferably, in said S3, the temperature in the aqueous phase pot after the temperature is lowered is 45-50°C. Since the solubility of arginine is large at a temperature of 50°C, when the temperature is greater than 50°C, the guanidine group of arginine will be oxidized, thereby reducing the NO generation efficiency. On the contrary, when the temperature is 45-50°C, the molecular chain of sodium hyaluronate is moderately stretched, which facilitates the formation of ionic bonds between the guanidine group (-NH-C(=NH)-NH2) of arginine and the carboxyl group (-COO-) in sodium hyaluronate, thereby enhancing the stability of the dressing. Since sodium benzoate has a high solubility at a temperature of 45- At 50°C, the proportion of undissociated benzoic acid molecules can achieve the best antibacterial effect, while when the temperature is greater than 50°C, the hydrolysis of sodium benzoate into invalid benzoate will be accelerated, and if the temperature is greater than 50°C, it may cause the sodium hyaluronate molecular chain to break; since potassium sorbate has good stability at temperatures below 50°C, and decarboxylation reaction will occur at temperatures greater than 50°C, causing potassium sorbate to be inactivated and have no preservative effect; therefore, in summary, the temperature in the aqueous phase pot needs to be reduced to 45-50°C before adding arginine, sodium benzoate and potassium sorbate.

[0031] In S5, the temperature in the water phase pot after the temperature is lowered is 40°C. When the temperature is greater than 40°C, the hydrolysis of the sodium hyaluronate molecular chain is accelerated, and when the temperature is 40°C, the hydrolysis rate of the sodium hyaluronate molecular chain decreases significantly. When the temperature is greater than 40°C, the viscosity of the dressing will continue to decrease. When the temperature is 40°C, the viscosity of the dressing will fluctuate stably within the range.

[0032] Preferably, in S4, the stirring speed after adding the auxiliary materials is 50-80 rpm, and such a stirring speed will not destroy the molecular chain of sodium hyaluronate.

[0033] In the present invention, the medical sodium hyaluronate dressing prepared by the above-mentioned preparation method is tested for the contents of mercury, lead, arsenic and cadmium in the sanitary chemical indicators, and the total colony count, total mold and yeast count, and microbial content including heat-resistant Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa in the medical sodium hyaluronate dressing are tested to ensure that the prepared medical sodium hyaluronate dressing meets the requirements of clinical application.

[0034] Beneficial effects of the present invention:

[0035] The medical sodium hyaluronate dressing of the present invention has excellent antibacterial and antiseptic properties, mechanical properties, and water retention. The preparation method of the medical sodium hyaluronate dressing of the present invention is simple and easy to operate. The medical sodium hyaluronate dressing of the present invention has low levels of mercury, lead, arsenic, and cadmium. The medical sodium hyaluronate dressing of the present invention has low total bacterial counts and total mold and yeast counts. The medical sodium hyaluronate dressing of the present invention does not contain microorganisms such as heat-resistant Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa. DETAILED DESCRIPTION

[0036] The present invention can be further understood through the specific examples of the present invention given below, but they are not intended to limit the present invention.

[0037] Example 1

[0038] A medical sodium hyaluronate dressing, comprising the following components by weight percentage:

[0039] Sodium hyaluronate 0.3%; Carbomer 0.55%; Glycerin 6.5%; Arginine 0.5%; Sodium benzoate 0.45%; Potassium sorbate 0.6%; Water 91.1%.

[0040] The preparation method of the medical sodium hyaluronate dressing of Example 1 comprises the following steps:

[0041] S1. Place 0.3 parts of sodium hyaluronate with a molecular weight of 100,000-500,000 Da, 0.55 parts of carbomer, 6.5 parts of glycerin, and 91.1 parts of water in an aqueous phase pot at a temperature of 80-85° C. and stir at a speed of 20-30 rpm to obtain a uniformly dispersed first mixed solution;

[0042] S2. Continue stirring the first mixed solution at a temperature of 80-85°C in the water phase pot for 20-30 minutes;

[0043] S3, stirring the first mixed solution at a speed of 15-25 rpm to reduce the temperature in the aqueous phase pot to 48° C. After the temperature is reduced, 0.5 parts of arginine, 0.45 parts of 0.07 wt% sodium benzoate and 0.6 parts of potassium sorbate are added to the first mixed solution and stirred at a speed of 15-20 rpm for 15-20 minutes to obtain a uniformly dispersed second mixed solution;

[0044] S4, adding 0.3 parts of genipin to the second mixed solution and stirring at a speed of 65 rpm for 30-40 minutes to obtain a third mixed solution;

[0045] S5. Stir the third mixed liquid at a speed of 15-20 rpm to reduce the temperature in the water phase pot to 40° C. After the temperature is reduced, continue stirring for 15-25 minutes to obtain a gel-like medical sodium hyaluronate dressing.

[0046] Example 2

[0047] A medical sodium hyaluronate dressing, comprising the following components by weight percentage:

[0048] Sodium hyaluronate 0.15%; Carbomer 0.1%; Glycerin 8%; Arginine 0.1%; Sodium benzoate 0.2%; Potassium sorbate 0.3%; Water 91.15%.

[0049] The preparation method of the medical sodium hyaluronate dressing of Example 2 comprises the following steps:

[0050] S1. Place 0.15 parts of sodium hyaluronate with a molecular weight of 100,000-500,000 Da, 0.1 parts of carbomer, 8 parts of glycerin, and 91.15 parts of water in an aqueous phase pot at a temperature of 80-85° C. and stir at a speed of 20-30 rpm to obtain a uniformly dispersed first mixed solution;

[0051] S2. Continue stirring the first mixed solution at a temperature of 80-85°C in the water phase pot for 20-30 minutes;

[0052] S3, stirring the first mixed solution at a speed of 15-25 rpm to reduce the temperature in the aqueous phase pot to 45° C. After the temperature is reduced, 0.1 parts of arginine, 0.2 parts of 0.05 wt% sodium benzoate and 0.3 parts of potassium sorbate are added to the first mixed solution and stirred at a speed of 15-20 rpm for 15-20 minutes to obtain a uniformly dispersed second mixed solution;

[0053] S4, adding 0.1 parts of genipin to the second mixed solution and stirring at a speed of 50 rpm for 30-40 minutes to obtain a third mixed solution;

[0054] S5. Stir the third mixed liquid at a speed of 15-20 rpm to reduce the temperature in the water phase pot to 40° C. After the temperature is reduced, continue stirring for 15-25 minutes to obtain a gel-like medical sodium hyaluronate dressing.

[0055] Example 3

[0056] A medical sodium hyaluronate dressing, comprising the following components by weight percentage:

[0057] Sodium hyaluronate 0.5%; Carbomer 1.0%; Glycerin 5%; Arginine 1.0%; Sodium benzoate 0.7%; Potassium sorbate 0.8%; Water 91%.

[0058] The preparation method of the medical sodium hyaluronate dressing of Example 3 comprises the following steps:

[0059] S1. Place 0.5 parts of sodium hyaluronate with a molecular weight of 100,000-500,000 Da, 1 part of carbomer, 5 parts of glycerin, and 91 parts of water in an aqueous phase pot at a temperature of 80-85°C and stir at a speed of 20-30 rpm to obtain a uniformly dispersed first mixed solution;

[0060] S2. Continue stirring the first mixed solution at a temperature of 80-85°C in the water phase pot for 20-30 minutes;

[0061] S3, stirring the first mixed solution at a speed of 15-25 rpm to reduce the temperature in the aqueous phase pot to 50° C. After the temperature is reduced, 1 part of arginine, 0.7 parts of 0.08 wt% sodium benzoate and 0.8 parts of potassium sorbate are added to the first mixed solution and stirred at a speed of 15-20 rpm for 15-20 minutes to obtain a uniformly dispersed second mixed solution;

[0062] S4, adding 0.5 parts of genipin to the second mixed solution and stirring at a speed of 80 rpm for 30-40 minutes to obtain a third mixed solution;

[0063] S5. Stir the third mixed liquid at a speed of 15-20 rpm to reduce the temperature in the water phase pot to 40° C. After the temperature is reduced, continue stirring for 15-25 minutes to obtain a gel-like medical sodium hyaluronate dressing.

[0064] Comparative Example 1

[0065] The difference between this comparative example 1 and Example 1 is that no genipin is added in this comparative example 1, and the rest is the same as Example 1, which will not be repeated here.

[0066] Comparative Example 2

[0067] The difference between this comparative example 2 and Example 2 is that no genipin is added in this comparative example 2, and the rest is the same as Example 2, which will not be repeated here.

[0068] Comparative Example 3

[0069] The difference between this comparative example 3 and Example 3 is that no genipin is added in this comparative example 3, and the rest is the same as Example 3, which will not be repeated here.

[0070] Test Case

[0071] Mechanical strength test

[0072] 1. Tensile performance test

[0073] The medical sodium hyaluronate dressings prepared in Examples 1-3 and Comparative Examples 1-3 were cut into dumbbell-shaped specimens (length ≥50 mm, width 10 mm, thickness 2±0.2 mm) according to the requirements of the ISO 527-3 standard test method. Tensile testing was performed at a tensile speed of 10 mm / min and a clamp spacing of 30 mm. The test items included tensile strength (MPa), elongation at break (%), and elastic modulus (MPa). The test results are shown in Table 1:

[0074] Table 1 Tensile properties test results

[0075] Test samples Tensile strength (MPa) Elongation at break (%) Elastic modulus (MPa) Example 1 0.50 165 0.15 Example 2 0.48 162 0.13 Example 3 0.46 158 0.12 Comparative Example 1 0.40 155 0.12 Comparative Example 2 0.41 156 0.09 Comparative Example 3 0.39 150 0.10

[0076] From the test results of the tensile performance test in Table 1, it can be seen that the tensile strength, elongation at break and elastic modulus of Examples 1-3 all performed excellently; compared with Example 1, Example 2 and Comparative Example 2, and Example 3 and Comparative Example 3, the tensile properties of the former were better than those of the latter. The difference between the former and the latter is that the former is doped with a cross-linking agent (genipin), which shows that genipin can improve the tensile properties of the dressing.

[0077] 2. Compression performance test

[0078] The medical sodium hyaluronate dressings prepared in Examples 1-3 and Comparative Examples 1-3 were cut into cylindrical specimens (10 mm in diameter and 5 mm in height) according to the requirements of the ISO 604 standard test method. Compression performance tests were performed at a compression rate of 1 mm / min and a deformation of 50% of the thickness. The test items included compressive strength (kPa) and rebound rate (%). The test results are shown in Table 2:

[0079] Table 2 Compression performance test results

[0080] Test samples Compression strength (kPa) Rebound rate (%) Example 1 27.2 97.2 Example 2 26.1 96.6 Example 3 26.5 96.1 Comparative Example 1 7.8 77.3 Comparative Example 2 6.8 74.2 Comparative Example 3 7.3 75.9

[0081] From the test results of the tensile performance test in Table 2, it can be seen that the compressive strength and rebound rate of Examples 1-3 are excellent; compared with Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, and Example 3 and Comparative Example 3, the compression performance of the former is better than that of the latter. The difference between the former and the latter is that the former is doped with a cross-linking agent (genipin), which shows that genipin can improve the compression performance of the dressing.

[0082] 3. Shear test

[0083] The medical sodium hyaluronate dressings prepared in Examples 1-3 and Comparative Examples 1-3 were cut into square specimens (length 25 mm, width 25 mm) according to the requirements of the ASTM F2458 standard test method, and the adhesion area with the simulated wound surface was ≥12.5 mm×25 mm. Shear tests were performed on the above dressings and simulated skin (ex vivo pig skin) under environmental conditions of temperature 32±1°C and humidity 50±5%, at a shear rate of 1.0±0.1 mm / s and a loading force until the specimen failed. The test items included shear strength (kPa) and strength retention rate after cycle (%). The test results are shown in Table 3:

[0084] Table 3 Shear test results

[0085] Test samples Shear strength (kPa) Strength retention rate after cycle (%) Example 1 31.8 89.2 Example 2 31.4 87.5 Example 3 30.5 86.8 Comparative Example 1 26.8 78.9 Comparative Example 2 27.5 75.4 Comparative Example 3 25.9 77.1

[0086] From the test results of the tensile performance test in Table 3, it can be seen that the shear strength and strength retention rate after cycling of Examples 1-3 are excellent; compared with each group of Example 1 and Comparative Example 1, Example 2 and Comparative Example 2, and Example 3 and Comparative Example 3, the shear test effects of the former are better than those of the latter. The difference between the former and the latter is that the former is doped with a cross-linking agent (genipin), which shows that genipin can improve the shear effect of the dressing.

[0087] Test Example

[0088] Testing for mercury, lead, arsenic, and cadmium

[0089] The contents of mercury, lead, arsenic, and cadmium in the medical sodium hyaluronate dressings prepared in Examples 1-3 and Comparative Examples 1-3 were tested according to the test methods in the Chinese Standard (YY / T 1293.4-2020). The test results are shown in Table 4:

[0090] Table 4 Test results of mercury, lead, arsenic and cadmium

[0091] Inspection samples Mercury (ppm) Lead (ppm) Arsenic (ppm) Cadmium (ppm) Example 1 0.21 3.1 0.89 0.2 Example 2 0.43 3.4 1.10 0.5 Example 3 0.55 3.8 0.95 0.4 Comparative Example 1 0.27 4.6 1.03 0.5 Comparative Example 2 0.48 4.7 1.35 0.6 Comparative Example 3 0.64 4.5 1.12 0.7

[0092] According to the relevant standards for medical devices (GB / T 16886.17), the content standards for mercury, lead, arsenic, and cadmium are "mercury ≤ 1 ppm", "lead ≤ 5 ppm", "arsenic ≤ 2 ppm", and "cadmium ≤ 1 ppm", respectively. As can be seen from the results in Table 4, the contents of mercury, lead, arsenic, and cadmium in the dressings of Examples 1-3 and Comparative Examples 1-3 all meet the requirements of the standards.

[0093] Testing of microbial indicators

[0094] According to the test method for total colony count, total mold and yeast count, heat-resistant coliform group, Staphylococcus aureus, and Pseudomonas aeruginosa in the "Standard Test Methods" in the Chinese Standard (YY / T 1477-2016), the total colony count, total mold and yeast count, heat-resistant coliform group, Staphylococcus aureus, and Pseudomonas aeruginosa in the medical sodium hyaluronate dressings prepared in Examples 1-3 and Comparative Examples 1-3 were tested, respectively. The test results are shown in Table 5:

[0095] Table 5 Test results of microbial indicators

[0096]

[0097] The content standards of the total colony count, total mold and total yeast count in the microbial indicators are "total colony count ≤ 1000 CFU / g" and "total mold and yeast count ≤ 100 CFU / g", respectively. From the results in Table 5, it can be seen that the total colony count, total mold and total yeast count in the dressings of Examples 1-3 and Comparative Examples 1-3 all meet the requirements of the standards, and no heat-resistant coliform bacteria, Staphylococcus aureus and Pseudomonas aeruginosa were detected in the dressings of Examples 1-3 and Comparative Examples 1-3. It can be seen that the medical sodium hyaluronate dressing prepared by the present invention has a good antibacterial effect.

[0098] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiment. All technical solutions based on the concept of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A medical sodium hyaluronate dressing, characterized in that: Calculated by weight percentage, it includes the following components: Sodium hyaluronate 0.15-0.5%; carbomer 0.1-1.0%; glycerin 5.0-8.0%; arginine 0.1-1.0%; sodium benzoate 0.2-0.7%; potassium sorbate 0.3-0.8%; the balance is water.

2. The medical sodium hyaluronate dressing according to claim 1, characterized in that Calculated by weight percentage, it includes the following components: Sodium hyaluronate 0.3%; Carbomer 0.55%; Glycerin 6.5%; Arginine 0.5%; Sodium benzoate 0.45%; Potassium sorbate 0.6%; Water 91.1%.

3. The medical sodium hyaluronate dressing according to claim 1 or 2, characterized in that The molecular weight of the sodium hyaluronate is 100,000-500,000 Da.

4. The medical sodium hyaluronate dressing according to claim 1 or 2, characterized in that The content of the sodium benzoate is 0.01-0.1 wt %.

5. The medical sodium hyaluronate dressing according to claim 4, characterized in that The content of the sodium benzoate is 0.05-0.08 wt%.

6. The medical sodium hyaluronate dressing according to claim 1 or 2, characterized in that: It also includes other acceptable auxiliary materials, which are added in the form of external admixtures, and the amount of the auxiliary materials added is 0.1-0.5% of the total amount.

7. The medical sodium hyaluronate dressing according to claim 6, characterized in that The auxiliary material is genipin.

8. A method for preparing the medical sodium hyaluronate dressing according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: S1. Place sodium hyaluronate, carbomer, glycerin, and water in an aqueous phase pot at a temperature of 80-85° C. and stir at a speed of 20-30 rpm to obtain a uniformly dispersed first mixed solution; S2. Continue stirring the first mixed solution for 20-30 minutes at a temperature of 80-85° C. in the water phase pot; S3, stirring the first mixed solution at a speed of 15-25 rpm to reduce the temperature in the aqueous phase pot, adding arginine, sodium benzoate and potassium sorbate to the first mixed solution after the temperature is reduced and stirring at a speed of 15-20 rpm for 15-20 minutes to obtain a uniformly dispersed second mixed solution; S4, adding auxiliary materials to the second mixed solution and stirring for 30-40 minutes to obtain a third mixed solution; S5. Stir the third mixed liquid at a speed of 15-20 rpm to lower the temperature in the water phase pot. Continue stirring for 15-25 minutes after the temperature is lowered to obtain a gel-like medical sodium hyaluronate dressing.

9. The method for preparing the medical sodium hyaluronate dressing according to claim 8, wherein: In the step S3, the temperature in the water phase pot after the temperature is lowered is 45-50°C; in the step S5, the temperature in the water phase pot after the temperature is lowered is 40°C.

10. The method for preparing the medical sodium hyaluronate dressing according to claim 8, wherein: In S4, the stirring speed after adding the auxiliary materials is 50-80 rpm.

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