A hydrophilic hydrogel patch and its preparation method

Abstract

The present invention belongs to the field of healthcare products, and particularly relates to a hydrogel patch and a preparation method thereof. The present invention adopts a method of thermosensitive polymer thermally initiated curing, which effectively shortens the curing process time, reduces the time interval with the workshop blanking process, and effectively improves the production efficiency of the hydrogel patch. In addition, the thermosensitive polymer used in the present invention can not only effectively shorten the curing time, but also has no charge in the solution and will not chemically react with other components in the hydrogel patch formula. By adding polyacrylamide, the swelling performance of the gel is effectively improved.

Description

Technical Field

[0001] The present invention belongs to the field of healthcare products, and particularly relates to a hydrophilic gel patch and a preparation method thereof. Background Art

[0002] A hydrogel patch is a transdermal drug delivery preparation for external use, which is made of a water-soluble polymer material as the main matrix, added with drugs, and processed through processes such as coating, curing, and blanking. In recent years, because the unique structure of the hydrogel can provide an extracellular environment similar to human tissues and has good biocompatibility, hydrogel patches have been widely used in fields such as drug loading and sustained release, surgical dressings, antipyretic temperature control, etc., and have good clinical efficacy and market prospects.

[0003] The production and preparation process of the hydrogel patch is divided into five major steps: oil-water mixing, stirring, coating, curing, and blanking. Curing is the rate-determining step. In current production, it needs to be cured at room temperature for a long time before the next blanking process can be carried out. The process time interval is large and the production efficiency is low. If the time interval between the curing process and the blanking process can be reduced, the production efficiency of the hydrogel patch will be greatly improved.

[0004] The patent text with the patent publication number CN115006337A discloses a preparation method of a double-layer hydrophilic gel patch. The preparation steps are as follows: after obtaining a hydrophobic isolation layer, pour liquid A into a mold containing the hydrophobic isolation layer, cool it to solidify at room temperature, attach a drug-containing hydrophilic gel layer on the isolation layer, and demold to obtain the double-layer hydrophilic gel patch. The patent text with the patent publication number CN111494348A discloses a preparation method of a traditional Chinese medicine hydrogel eye patch. The preparation steps are as follows: a) reflux extract pearls, shexiang, bezoar, buddleja officinalis, radix stephaniae cepharanthae, and saffron in an ethanol aqueous solution to obtain a traditional Chinese medicine extract; b) dissolve hyaluronic acid and polyvinyl alcohol in deionized water for gelation treatment to obtain a colloid; c) mix the traditional Chinese medicine extract and the colloid evenly, and then process to obtain a traditional Chinese medicine hydrogel; d) coat the traditional Chinese medicine hydrogel on the drug area of the eye patch body to obtain the traditional Chinese medicine hydrogel eye patch. The preparation methods of the hydrophilic gel patches provided by the above-mentioned prior arts all adopt process steps such as mixing, stirring, coating, and curing, with a long production cycle and low efficiency.

[0005] In summary, there are common technical problems in the prior art such as long curing time, long production cycle, and low production efficiency in hydrogel production. Summary of the Invention

[0006] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a hydrophilic gel patch and a preparation method thereof. The hydrophilic gel patch provided by the present invention adds a thermosensitive polymer to the hydrophilic gel patch, raises the curing temperature by heating, and uses a thermal initiation curing method to enable the hydrophilic gel patch system to quickly achieve a curing effect in a short time, thereby shortening the curing time and improving the production efficiency of the hydrophilic gel patch.

[0007] In order to achieve the above object, the technical solution of the present invention is as follows:

[0008] A preparation method of a hydrophilic gel patch, comprising the following steps:

[0009] S1. Mix the oil-phase components in the hydrogel formula evenly to obtain an oil-phase mixture A;

[0010] S2. Mix the water-phase components in the hydrogel formula evenly to obtain a water-phase mixture B;

[0011] S3. Weigh a small amount of deionized water, add a thermosensitive polymer and polyacrylamide, and stir until completely dissolved to obtain a homogeneous solution C;

[0012] S4. At a certain temperature, mix the oil-phase mixture A prepared in step S1, the water-phase mixture B prepared in step S2, and the homogeneous solution C prepared in step S3, and stir to make the glue, requiring uniformity and no lack of glue, to obtain a hydrogel;

[0013] S5. Coat the hydrogel prepared in step S4 on a non-woven fabric to form a hydrogel sheet;

[0014] S6. Install a heating device in the blanking equipment, and heat and blank the hydrogel sheet prepared in step S5 to obtain the product.

[0015] Further, the thermosensitive polymer in step S3 of the preparation method of the hydrophilic gel patch is composed of hydroxypropyl methylcellulose and methylcellulose in a mass ratio of 33-37:7-11.

[0016] Further, the dosage of the thermosensitive polymer in step S3 of the preparation method of the hydrophilic gel patch is 0.5-5% of the mass of the hydrogel formula.

[0017] Further, the dosage of polyacrylamide in step S3 of the preparation method of the hydrophilic gel patch is 2-4% of the mass of the hydrogel formula.

[0018] Further, the certain temperature in step S4 of the preparation method of the hydrophilic gel patch is 25-35°C.

[0019] Further, the temperature of the heating device in step S6 of the preparation method of the hydrophilic gel patch is set to 50-80°C.

[0020] The present invention also provides a hydrogel patch prepared by using the preparation method of the above-mentioned hydrogel patch.

[0021] The present invention adopts the method of thermosensitive polymer thermally initiated curing, which effectively shortens the curing process time, reduces the time interval with the workshop blanking process, and effectively improves the production efficiency of the hydrogel patch. In addition, the thermosensitive polymer used in the present invention can not only effectively shorten the curing time, but also has no charge in the solution and will not chemically react with other components in the hydrogel patch formula, and also plays the roles of prepolymerization, emulsification and thickening in the hydrogel patch formula.

[0022] The thermosensitive polymer has water solubility within a certain temperature range. When the temperature of its aqueous solution rises to a certain temperature, the solution will undergo a completely reversible solution-gel phase transition. In the coating process of the present invention, the thermosensitive polymer is in a dissolved state in the existing gel system, which is convenient for coating. After coating, the temperature of the gel patch is raised to gelate the thermosensitive polymer, increasing the cohesion (crosslinking strength) of the gel system, so that the hydrogel patch can be directly blanked without waiting for the static curing time of 10-24 hours, thus greatly improving the production efficiency. After blanking, the temperature of the gel patch drops, and the thermosensitive polymer returns to the dissolved state, which can further improve the viscosity of the hydrogel patch. During the research process, the applicant found that when the addition amount of the thermosensitive polymer is too low, the effect of thermally initiated curing is not obvious, while when the addition amount is too high, it will affect the formation of the hydrogel patch. When the addition amount of the thermosensitive polymer is 0.5-5%, the effect of thermally initiated curing and the forming performance of the hydrogel patch are the best.

[0023] However, during the research process, the inventor found that the addition of the thermosensitive polymer will cause phase separation inside the hydrogel, and the swelling ratio of the hydrogel will increase significantly, so that the gel is prone to break due to cracks inside after swelling. The addition of polyacrylamide can effectively reduce the significant increase in the swelling ratio of the hydrogel in a short time, avoid cracks inside the gel, and effectively improve the swelling performance of the hydrogel.

[0024] Compared with the prior art, the hydrogel patch and its preparation method provided by the present invention have the following technical advantages:

[0025] (1) The preparation method of the hydrogel patch provided by the present invention adopts the method of introducing thermosensitive polymer thermally initiated curing, shortens the curing process time, reduces the time interval with the blanking process, improves the production efficiency of the hydrogel patch, and reduces the production cost;

[0026] (2) The hydrogel patch provided by the present invention not only shortens the gel curing time, but also effectively improves the swelling performance of the gel by adding polyacrylamide. Detailed embodiments

[0027] The present invention will be further described below through the description of specific embodiments. However, this is not a limitation of the present invention. Those skilled in the art can make various modifications or improvements based on the basic idea of the present invention. As long as they do not depart from the basic idea of the present invention, they are within the scope of the present invention.

[0028] In the specific embodiments, the raw materials used are all conventional commercially available products without special instructions, and the animal and plant extracts used are all purchased from Xi'an Hejian Biotechnology Co., Ltd.

[0029] Example 1: A hydrophilic hydrogel patch and its preparation method

[0030] The hydrogel formulation comprises the following components and their mass percentages: aloe extract 0.01%, lavender essential oil 0.01%, dipotassium glycyrrhizinate 0.005%, glycerol 10%, imidazolidinyl urea 0.01%, polyvinylpyrrolidone 0.5%, essence 0.0001%, pigment 0.0001%, sodium polyacrylate with an average molecular weight of 2-3 million 0.5%, sodium polyacrylate with an average molecular weight of 0.8-1 million 0.5%, calcium sulfate 0.01%, thermosensitive polymer 0.5%, polyacrylamide 2% and the balance deionized water. The thermosensitive polymer is composed of hydroxypropyl methylcellulose and methylcellulose in a mass ratio of 33:7.

[0031] The preparation method of the hydrophilic hydrogel patch comprises the following steps:

[0032] S1. Mix the aloe extract, lavender essential oil, dipotassium glycyrrhizinate, glycerol, imidazolidinyl urea, polyvinylpyrrolidone, essence and pigment (oil phase components) in the hydrogel formulation evenly to obtain an oil phase mixture A;

[0033] S2. Mix the sodium polyacrylate with an average molecular weight of 2-3 million, the sodium polyacrylate with an average molecular weight of 0.8-1 million and calcium sulfate (water phase components) in the hydrogel formulation evenly to obtain a water phase mixture B;

[0034] S3. Weigh 10% of the deionized water in the hydrogel formulation amount, add the thermosensitive polymer and polyacrylamide, and stir until completely dissolved to obtain a homogeneous solution C;

[0035] S4. At 25°C, mix the oil phase mixture A prepared in step S1, the water phase mixture B prepared in step S2 and the homogeneous solution C prepared in step S3, and stir to make the gel, requiring uniformity and no lack of gel, to obtain a hydrogel with a pH value of 7.5;

[0036] S5. Coat the hydrogel prepared in step S4 on the non-woven fabric to form a hydrogel sheet;

[0037] S6. Install a heating device in the blanking equipment, set the temperature of the heating device to 50 °C, and perform heating blanking on the hydrogel sheet obtained in step S5 to obtain the product.

[0038] Example 2. A hydrophilic gel patch and its preparation method

[0039] The hydrogel formula includes the following components and their mass percentages: aloe vera extract 0.01%, lavender essential oil 0.01%, dipotassium glycyrrhizinate 0.005%, glycerol 10%, imidazolidinyl urea 0.01%, polyvinylpyrrolidone 0.5%, essence 0.0001%, pigment 0.0001%, sodium polyacrylate with an average molecular weight of 2 million - 3 million 0.5%, sodium polyacrylate with an average molecular weight of 800,000 - 1 million 0.5%, calcium sulfate 0.01%, thermosensitive polymer 5%, polyacrylamide 4%, and the balance deionized water. The thermosensitive polymer is composed of hydroxypropyl methylcellulose and methylcellulose in a mass ratio of 37:11.

[0040] The preparation method of the hydrophilic gel patch includes the following steps:

[0041] S1. Mix the aloe vera extract, lavender essential oil, dipotassium glycyrrhizinate, glycerol, imidazolidinyl urea, polyvinylpyrrolidone, essence, and pigment (oil phase components) in the hydrogel formula evenly to obtain an oil phase mixture A.

[0042] S2. Mix the sodium polyacrylate with an average molecular weight of 2 million - 3 million, sodium polyacrylate with an average molecular weight of 800,000 - 1 million, and calcium sulfate (water phase components) in the hydrogel formula evenly to obtain a water phase mixture B.

[0043] S3. Weigh 10% of the deionized water in the hydrogel formula, add the thermosensitive polymer and polyacrylamide, and stir until completely dissolved to obtain a homogeneous solution C.

[0044] S4. At 35 °C, mix the oil phase mixture A obtained in step S1, the water phase mixture B obtained in step S2, and the homogeneous solution C obtained in step S3, and stir to make the gel, requiring it to be uniform without lack of gel, to obtain a hydrogel with a pH value of 7.5.

[0045] S5. Coat the hydrogel obtained in step S4 on the non - woven fabric to form a hydrogel sheet.

[0046] S6. Install a heating device in the blanking equipment, set the temperature of the heating device to 80 °C, and perform heating blanking on the hydrogel sheet obtained in step S5 to obtain the product.

[0047] Example 3. A hydrophilic gel patch and its preparation method

[0048] The hydrogel formulation comprises the following components and their mass percentages: aloe extract 0.01%, lavender essential oil 0.01%, dipotassium glycyrrhizinate 0.005%, glycerol 10%, imidazolidinyl urea 0.01%, polyvinylpyrrolidone 0.5%, essence 0.0001%, pigment 0.0001%, sodium polyacrylate with an average molecular weight of 2 million - 3 million 0.5%, sodium polyacrylate with an average molecular weight of 0.8 million - 1 million 0.5%, calcium sulfate 0.01%, thermosensitive polymer 2.6%, polyacrylamide 3.1%, and the balance deionized water. The thermosensitive polymer is composed of hydroxypropyl methylcellulose and methylcellulose in a mass ratio of 35:9.

[0049] The preparation method of the hydrophilic hydrogel patch comprises the following steps:

[0050] S1. Mix the aloe extract, lavender essential oil, dipotassium glycyrrhizinate, glycerol, imidazolidinyl urea, polyvinylpyrrolidone, essence, and pigment (oil-phase components) in the hydrogel formulation evenly to obtain an oil-phase mixture A;

[0051] S2. Mix the sodium polyacrylate with an average molecular weight of 2 million - 3 million, sodium polyacrylate with an average molecular weight of 0.8 million - 1 million, and calcium sulfate (water-phase components) in the hydrogel formulation evenly to obtain a water-phase mixture B;

[0052] S3. Weigh 10% of the deionized water in the hydrogel formulation, add the thermosensitive polymer and polyacrylamide, and stir until completely dissolved to obtain a homogeneous solution C;

[0053] S4. At 30°C, mix the oil-phase mixture A prepared in step S1, the water-phase mixture B prepared in step S2, and the homogeneous solution C prepared in step S3, and stir to make the gel, ensuring uniformity and no lack of gel, to obtain a hydrogel with a pH value of 7.5;

[0054] S5. Coat the hydrogel obtained in step S4 on the non-woven fabric to form a hydrogel sheet;

[0055] S6. Install a heating device in the blanking equipment, set the temperature of the heating device to 73°C, and perform heating blanking on the hydrogel sheet prepared in step S5 to obtain the product.

[0056] Comparative Example 1. A gel patch and its preparation method

[0057] In this comparative example, the formulation and preparation method of the gel patch are similar to those of Example 3. The difference between this comparative example and Example 3 is that in this comparative example, an equal amount of deionized water is used to replace the thermosensitive polymer in the hydrogel formulation.

[0058] Comparative Example 2. A gel patch and its preparation method

[0059] The formulation and preparation method of the gel patch described in this comparative example are similar to those in Example 3. The difference between this comparative example and Example 3 is that the addition amount of the thermosensitive polymer in this comparative example is 0.05%.

[0060] Comparative Example 3: A gel patch and its preparation method

[0061] The formulation and preparation method of the gel patch described in this comparative example are similar to those in Example 3. The difference between this comparative example and Example 3 is that the addition amount of the thermosensitive polymer in this comparative example is 8%.

[0062] Comparative Example 4: A gel patch and its preparation method

[0063] The formulation and preparation method of the gel patch described in this comparative example are similar to those in Example 3. The difference between this comparative example and Example 3 is that in this comparative example, the thermosensitive polymer poly(N-vinylformamide) is used instead of hydroxypropyl methylcellulose.

[0064] Comparative Example 5: A gel patch and its preparation method

[0065] The formulation and preparation method of the gel patch described in this comparative example are similar to those in Example 3. The difference between this comparative example and Example 3 is that in this comparative example, the thermosensitive water-soluble polymer material prepared in Example 1 of Patent No. ZL01145646.9 is used instead of hydroxypropyl methylcellulose.

[0066] Comparative Example 6: A gel patch and its preparation method

[0067] The formulation and preparation method of the gel patch described in this comparative example are similar to those in Example 3. The difference between this comparative example and Example 3 is that in this comparative example, an equal amount of deionized water is used instead of polyacrylamide.

[0068] Comparative Example 7: A gel patch and its preparation method

[0069] The formulation and preparation method of the gel patch described in this comparative example are similar to those in Example 3. The difference between this comparative example and Example 3 is that in this comparative example, the superabsorbent resin prepared by the preparation method of the superabsorbent resin provided in Example 1 of Patent Publication No. CN114369322A is used instead of polyacrylamide.

[0070] Test Example 1: Mechanical property test

[0071] The blanking process in the production of hydrogel patches needs to meet the blanking standard - the patches can be cut and there is no colloid residue on the cutting tool, which requires the gel to have a certain degree of curing, and in terms of mechanical properties, it is manifested as cohesion and shear resistance. Tensile strength and elongation at break were used in the experiment to characterize the curing degree of the hydrogel. Tensile strength refers to the stress at which the material produces the maximum uniform plastic deformation, which is determined by the mechanical strength of the molecular chain and reflects the cohesion of the hydrogel. The elongation at break macroscopically manifests as the "toughness" of the material and reflects the shear resistance of the hydrogel.

[0072] Test samples: Gel patches prepared in Examples 1-3 and Comparative Examples 1-5;

[0073] Test method: Use a GBS electronic tensile machine with a probe in the shape of a clamp to conduct a vertical tensile test on the hydrogel. Fix the sample with the probe, input the size of the sample and the distance between the clamps, and the tensile machine stretches the hydrogel sample at a tensile rate of 100 mm / min, and then the tensile strength and elongation at break of the material can be obtained.

[0074] Test results: See Table 1.

[0075] Table 1 Test results of mechanical properties

[0076] Group Tensile strength / MPa Elongation at break / % Example 1 1.5 444 Example 2 1.3 405 Example 3 1.9 521 Comparative Example 1 0.05 20 Comparative Example 2 0.1 80 Comparative Example 3 0.3 135 Comparative Example 4 1.0 353 Comparative Example 5 1.2 394

[0077] As can be seen from Table 1, the tensile strength of the hydrophilic gel patch provided by the present invention is 1.3 - 1.9 MPa, and the elongation at break is 405 - 521%, which fully proves that the hydrophilic gel patch provided by the present invention has good cohesion and shear resistance. When combined with the blanking in the workshop, there is no adhesion of the antipyretic patch and no residue on the blanking tool of the hydrophilic gel patches prepared in Examples 1-3 of the present invention, indicating that the hydrophilic gel has good blanking performance and meets the workshop blanking standard. Among them, the hydrophilic gel patch prepared in Example 3 has the best blanking performance and is the best embodiment of the present invention.

[0078] Compared with Example 3, the tensile strength and elongation at break of the gel patch prepared in Comparative Example 1 are extremely low and it cannot be blanked immediately, which fully shows that the addition of the thermosensitive polymer can effectively shorten the curing time and improve the production efficiency; in Comparative Examples 2 and 3, the addition amount of the thermosensitive polymer was changed, but the tensile strength and elongation at break of the prepared gel patch were significantly reduced, which indicates that the dosage of the thermosensitive polymer in the present invention has reached optimization; in Comparative Examples 4 and 5, common thermosensitive polymers were selected to replace the thermosensitive polymer in the present application, but the tensile strength and elongation at break of the prepared gel patch were slightly reduced, which shows that not all thermosensitive polymers can achieve the technical effects of the present invention. The use of hydroxypropyl methylcellulose and methylcellulose in a certain mass ratio to jointly form a thermosensitive polymer in the present invention can effectively improve the blanking performance of the hydrophilic gel patch.

[0079] Test Example II. Adhesion Force Test

[0080] Test Samples: Gel patches prepared in Examples 1-3 and Comparative Example 1;

[0081] Test Method: The test samples together with the intact packaging were pre-treated by placing them at 18°C to 25°C and a relative humidity of 40% to 70% for more than 2 h. According to the test method under the first method (determination of initial adhesion force) of the adhesion force determination method in Part IV of the Chinese Pharmacopoeia (2020 Edition), the adhesion force of the hydrogel patch was detected, and the size of its initial adhesion was evaluated according to the largest ball number steel ball that the sticky surface of the test sample could adhere to.

[0082] Test Results: See Table 2.

[0083] Table 2 Adhesion Force Test Results

[0084] Group The largest steel ball number that can adhere Example 1 25 Example 2 22 Example 3 29 Comparative Example 1 19

[0085] As can be seen from Table 2, the ball numbers of the largest steel balls that the hydrophilic gel patches prepared in Examples 1-3 could adhere to were 22-29, and they had good adhesion force, indicating that the addition of the thermosensitive polymer in the present invention can further improve the viscosity of the hydrogel patch at room temperature. The ball number of the largest steel ball that the gel patch prepared in Comparative Example 1 could adhere to was 19, which was greatly reduced compared with Example 3, indicating that the adhesion of the ordinary gel patch was poor.

[0086] Test Example III. Swelling Performance Test

[0087] Test Samples: Hydrogels prepared in Step S4 of the preparation methods in Example 3, Comparative Example 6, and Comparative Example 7;

[0088] Test method: The test samples were dried to constant weight in a forced-air drying oven. The dried hydrogel was placed in a constant-temperature water bath at 30 ± 1 °C for water absorption and swelling. At regular intervals, the hydrogel was taken out, the surface moisture was blotted dry with filter paper, and then weighed. Step S3 was repeated until the swelling equilibrium was reached.

[0089] The swelling ratio (SR) and equilibrium swelling ratio (q) are defined as:

[0090] SR = (w t - w d ) / w d

[0091] q = w e / w d

[0092] In the formula: w d —The mass of the dried hydrogel matrix; w t —The mass of the swollen hydrogel matrix at different times; w e —The mass of the hydrogel at swelling equilibrium.

[0093] Test results: The test results are shown in Table 3.

[0094] Table 3 Swelling ratio test results

[0095]

[0096] As can be seen from Table 3, the swelling ratio of the hydrophilic gel prepared in Example 3 of the present invention is greater than that of the hydrophilic gels prepared in Comparative Example 6 and Comparative Example 7, indicating that the swelling performance of the hydrophilic gel prepared in Example 3 is better. Moreover, the increase in the swelling ratio of the hydrophilic gel prepared in Example 3 is uniform, without a large increase in a short period of time. In contrast, the swelling ratios of the hydrophilic gels prepared in Comparative Example 6 and Comparative Example 7 increase significantly. Among them, the swelling ratio of the gel in Comparative Example 6 shows a trend of first increasing and then decreasing, which indicates that the addition of the thermosensitive polymer will cause phase separation inside the hydrophilic gel, resulting in a significant increase in the swelling ratio of the hydrogel, and thus the gel is prone to breakage due to cracks inside after swelling.

[0097] The above embodiments only exemplarily illustrate the preparation method of the present invention and are not intended to limit the present invention. Any person skilled in the art cannot modify the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the relevant technical field without departing from the technical idea provided by the present invention are still covered by the claims of the present invention.

Claims

1. A preparation method of a hydrophilic gel patch, characterized in that, It includes the following steps: S1. Mix the oil-phase components evenly to obtain the oil-phase mixture A; S2. Mix the water-phase components evenly to obtain the water-phase mixture B; S3. Weigh a small amount of deionized water, add the thermosensitive polymer and polyacrylamide, and stir until completely dissolved to obtain the homogeneous solution C; S4. At a certain temperature, mix the oil-phase mixture A prepared in step S1, the water-phase mixture B prepared in step S2, and the homogeneous solution C prepared in step S3, and stir to make the gel, requiring uniformity without missing gel to obtain the hydrogel; S5. Coat the hydrogel prepared in step S4 on the non-woven fabric to form a hydrogel sheet; S6. Install a heating device in the blanking equipment, and heat up and blank the hydrogel sheet prepared in step S5 to obtain the product; The hydrogel formula consists of oil-phase components, water-phase components, thermosensitive polymer, polyacrylamide, and deionized water; The oil-phase components consist of aloe extract, lavender essential oil, dipotassium glycyrrhizinate, glycerin, imidazolidinyl urea, polyvinylpyrrolidone, essence, and pigment; The water-phase components consist of sodium polyacrylate with an average molecular weight of 2 million - 3 million, sodium polyacrylate with an average molecular weight of 0.8 million - 1 million, and calcium sulfate; The thermosensitive polymer in step S3 is composed of hydroxypropyl methylcellulose and methylcellulose in a mass ratio of 33 - 37:7 - 11; The dosage of the thermosensitive polymer in step S3 is 0.5% - 5% of the mass of the hydrogel formula.

2. The preparation method of the hydrophilic gel patch according to claim 1, characterized in that, The thermosensitive polymer in step S3 is composed of hydroxypropyl methylcellulose and methylcellulose in a mass ratio of 35:

9.

3. The preparation method of the hydrophilic hydrogel patch according to claim 1, wherein The dosage of the thermosensitive polymer in step S3 is 2.6% of the mass of the hydrogel formula.

4. The preparation method of the hydrophilic hydrogel patch according to claim 1, characterized in that, The dosage of polyacrylamide in step S3 is 2% - 4% of the mass of the hydrogel formula.

5. The preparation method of the hydrophilic hydrogel patch according to claim 1, characterized in that, The certain temperature in step S4 is 25 - 35 °C.

6. The preparation method of the hydrophilic hydrogel patch according to claim 1, characterized in that The temperature of the heating device in step S6 is set to 50 - 80 °C.

7. The preparation method of the hydrophilic hydrogel patch according to claim 6, characterized in that, The temperature of the heating device in step S6 is set to 73 °C.

8. The hydrophilic gel patch prepared by the preparation method of the hydrophilic gel patch according to any one of claims 1 - 7.

Images