A plaster patch with long-term one-way moisture conducting performance and a preparation method thereof

Abstract

The present application belongs to the technical field of plaster, and particularly relates to a plaster with long-term one-way wetting performance and a preparation method thereof. After a backing layer of a raw plaster is punched and treated by oxygen / air plasma, a hydrophilic film on an inner surface of a hole of a drug matrix layer is constructed in situ by applying a combination of a macromolecular polymer and a small-molecular-weight hydrophilic liquid reagent in sequence and cooperating with super-hydrophilic modification of the backing layer. The plaster can obtain long-term and efficient one-way wetting and one-way sweat releasing functions without affecting drug efficacy, and can avoid skin discomfort and allergy problems.

Description

Technical Field

[0001] This invention belongs to the field of plaster technology, specifically relating to a plaster with long-lasting unidirectional moisture-wicking properties and its preparation method. Background Technology

[0002] Traditional medicated plasters (such as those from Yunnan Baiyao, Lingrui, Tongrentang, Wantong, and Jiuguang) typically employ a three-layer structure: an outermost backing layer, a middle drug matrix layer, and an innermost anti-adhesive layer. The method of use involves removing the anti-adhesive layer beforehand, applying the exposed drug matrix layer to the affected skin, and securing it with adhesive to ensure prolonged contact between the medication and the skin for continuous treatment. However, traditional plasters generally have poor breathability and moisture permeability, lacking active perspiration capabilities. Prolonged application leads to a buildup of sweat on the skin surface, weakening the plaster's adhesion, causing it to detach and become wasteful, thus negating the therapeutic effect. Furthermore, the prolonged dampness in the local skin microenvironment can cause more serious health problems such as irritant dermatitis, folliculitis, fungal or bacterial infections, and skin allergies. Summary of the Invention

[0003] This invention primarily provides a medicated plaster that possesses long-lasting unidirectional moisture-wicking capability and wet adhesion performance in an open state, thereby solving the problems of poor breathability, sweat accumulation due to the inability to wick away perspiration after application, resulting in poor comfort, and decreased adhesiveness or even detachment of the plaster in existing technologies. The technical solution is as follows:

[0004] A medicated plaster with long-lasting unidirectional moisture-wicking properties includes a matrix layer containing a drug and a backing layer that adheres closely to the matrix layer; the matrix layer is hydrophobic and the backing layer is hydrophilic; a plurality of interconnected pores are evenly distributed between the matrix layer and the backing layer; the side of the backing layer away from the matrix layer is provided with a hydrophilic film layer formed by a solid hydrophilic film-forming agent and a non-volatile liquid hydrophilic reagent.

[0005] Furthermore, the solid hydrophilic film-forming agent includes one or more of the following: polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropyl cellulose, sodium carboxymethyl cellulose, hydroxypropyl starch, chitosan, carboxymethyl chitosan, or polyacrylic acid, with a molecular weight of not less than 2000.

[0006] Furthermore, the liquid hydrophilic reagent includes one or more of polyethylene glycol, glycerol, diethylene glycol, propylene glycol, polyglycerol, sorbitol, N-methylpyrrolidone, or dimethyl sulfoxide with a molecular weight not greater than 600.

[0007] Furthermore, the backing layer is made of fabric.

[0008] Furthermore, the diameter of the through hole is 0.1~2mm; the spacing between the through holes is 0.2~5mm.

[0009] Furthermore, the contact angle of the backing layer is <30°.

[0010] A method for preparing the above-mentioned plaster with long-lasting unidirectional moisture-wicking properties includes the following steps: dissolving a solid hydrophilic film-forming agent to obtain a film-forming agent solution with a mass concentration of 1-70%; coating the film-forming agent solution onto the surface of a backing layer with uniformly distributed through holes; and coating a liquid hydrophilic reagent after drying.

[0011] Furthermore, the through-hole can be obtained by one or more of the following methods: laser drilling, mechanical stamping, water jet drilling, thermal drilling, and chemical drilling.

[0012] Furthermore, the backing layer is hydrophilically modified before the film-forming agent is applied.

[0013] Furthermore, the backing layer is treated with oxygen-containing gas at a power of 50~200W for 0.5~3.5 minutes using a plasma machine.

[0014] By adopting the above scheme, the method of the present invention has the following advantages:

[0015] 1. Compared to traditional unidirectional moisture-wicking fabrics prepared using only plasma hydrophilic processing methods, which have a shelf life of no more than one day, the medicated plaster of this invention can achieve long-term unidirectional moisture wicking (storage time in air > 70 days). Compared to traditional medicated plasters, the medicated plaster of this invention has better breathability and excellent long-term unidirectional moisture wicking performance, so it can be firmly adhered to the skin for a longer period of time, ensuring long-term skin comfort in sweating situations. It helps to improve the problem of excessive sweat accumulation caused by prolonged plaster application, and at the same time, it indirectly enhances wet adhesion, so that the medicated plaster can still adhere firmly to the skin after sweating and is not easy to fall off.

[0016] 2. The drug matrix layer of the medicated plaster of the present invention is hydrophobic, and the backing layer is modified to have superhydrophilic properties, forming a hydrophobic-superhydrophilic wetting gradient. Due to the different wettability on both sides of the film, the sweat secreted by the skin during the application process will be spontaneously transported from the drug matrix layer on the skin to the backing layer on the outside, keeping the skin relatively dry, thereby indirectly improving the wet adhesion and achieving the purpose of not easily falling off after sweating.

[0017] 3. The solid hydrophilic film-forming agent of the present invention forms a water-soluble polymer film on the drug matrix layer inside the pores of the unidirectional hygroscopic plaster. The small-molecule hydrophilic liquid reagent penetrates and wets the hydrophilic film layer. In the through-holes where there is no fabric influence, the two form a uniform mixture, so that the pores of the unidirectional hygroscopic plaster remain continuously moist. The small-molecule hydrophilic reagent in the through-holes can directly contact the high-humidity liquid passing through the through-holes. After the water-based liquid penetrates the plaster of the present invention, it will skip the wetting process and directly carry out the transport and absorption process, so that the unidirectional hygroscopic plaster has an ultra-fast unidirectional moisture-wicking ability (the initial unidirectional transport time of 50 microliter water droplets is <0.5s).

[0018] 4. Due to the capillary effect formed by the pores of the fabric, small-molecule hydrophilic liquid reagents tend to move inward, while large-molecule polymers, due to tension, can mostly remain near the surface of the fabric, forming a seal for the internal hydrophilic liquid reagents. This protects the hydrophilic liquid reagents in the fabric layer, reduces their direct contact with air, and greatly slows down the rate of loss of hydrophilic liquid reagents.

[0019] 5. Due to the fabric, the concentration of small-molecule hydrophilic liquid reagents is higher inside the backing layer, while the content of high-molecular-weight hydrophilic polymers is higher near the surface. The hydrophilic liquid reagents lost in the pores due to moisture transport can be replenished by the more fluid hydrophilic liquid reagents in the backing layer. At the junction of the pores and the fabric, the concentration of hydrophilic liquid reagents reaches a relative equilibrium, ensuring that the content of hydrophilic liquid reagents transporting water-based liquids in the pores remains at a relatively stable level. This allows the plaster of this invention to maintain outstanding wettability and moisture-wicking properties for an extremely long period. Attached Figure Description

[0020] Figure 1 This is a diagram showing the change in contact angle on different sides of the plaster patch in Example 1;

[0021] Figure 2 This is a comparison diagram of the absorption peaks of the extracts from Example 1 and traditional plaster patches in a spectrophotometer;

[0022] Figure 3 This is a comparison chart of the water vapor transmission rate between Example 1 and traditional plaster patches;

[0023] Figure 4 This is a comparison chart of the perspiration effects of Example 1 and traditional medicated plasters;

[0024] Figure 5 This is a comparison diagram of the wet adhesion and holding power of Example 1 and traditional plasters;

[0025] Figure 6 This is a graph showing the change in unidirectional transportation time of the plaster patch in Example 1 over storage time;

[0026] Figure 7 This is a graph showing the change in unidirectional transportation time of the plaster patches as a function of storage time in Examples 2-11;

[0027] Figure 8 This is a graph showing the change in unidirectional transportation time of the plaster in Examples 1 and 12-18 over storage time;

[0028] Figure 9 This is a comparison chart of the unidirectional transport time of the plaster patches in Examples 1 and 19-23;

[0029] Figure 10 This is a comparison diagram of the unidirectional transport mechanism of the plasters stored for different times in Comparative Example 1 and Comparative Example 2.

[0030] Figure 11 This is a comparison diagram of the unidirectional transport mechanism of the plaster patch of the present invention and the unidirectional moisture-wicking fabric that has only undergone plasma hydrophilic modification;

[0031] Figure 12 This is a schematic diagram showing the distribution of solid hydrophilic film-forming agent and hydrophilic liquid reagent in the plaster patch of the present invention. Detailed Implementation

[0032] Example 1: A one-way hygroscopic plaster was constructed using commercially available Sunflower brand pain relief and muscle tonic. First, with the backing layer facing upward, an array of 0.5 mm pores with a pore spacing of 1.5 mm was constructed using a CO2 laser. Then, with the backing layer facing upward, the plaster was placed in an oxygen plasma machine for hydrophilic modification (time 1.5 min, power 150 W). Subsequently, a 33% (w / w) PEG-4000 aqueous solution was coated on the backing layer. After drying, PEG-200 was coated on the backing layer, finally forming a one-way hygroscopic plaster.

[0033] Example 2: The difference from Example 1 is as follows:

[0034] An aqueous solution of PEG-6000 is coated onto the backing layer of the plaster. After drying, dimethyl sulfoxide is coated onto the backing layer of the plaster, thus forming a one-way moisture-wicking plaster.

[0035] Example 3: The difference from Example 1 is as follows:

[0036] An aqueous solution of PEG-3000 is coated onto the backing layer of the plaster. After drying, glycerin is coated onto the backing layer of the plaster, thus forming a one-way moisture-wicking plaster.

[0037] Example 4: The difference from Example 1 is as follows:

[0038] An aqueous solution of polyvinylpyrrolidone is coated onto the backing layer of the plaster. After drying, PEG-300 is coated onto the backing layer of the plaster, finally forming a one-way moisture-wicking plaster.

[0039] Example 5: The difference from Example 1 is as follows:

[0040] An aqueous solution of polyvinyl alcohol is coated onto the backing layer of the plaster. After drying, propylene glycol is coated onto the backing layer of the plaster, thus forming a one-way moisture-wicking plaster.

[0041] Example 6: The difference from Example 1 is as follows:

[0042] An aqueous solution of PEG-6000 is coated onto the backing layer of the plaster. After drying, PEG-400 is coated onto the backing layer of the plaster, finally forming a one-way moisture-wicking plaster.

[0043] Example 7: The difference from Example 1 is as follows:

[0044] An aqueous solution of polyvinylpyrrolidone is coated onto the backing layer of the plaster. After drying, dimethyl sulfoxide is coated onto the backing layer of the plaster, thus forming a one-way moisture-wicking plaster.

[0045] Example 8: The difference from Example 1 is as follows:

[0046] An aqueous solution of PEG-3000 is coated onto the backing layer of the plaster. After drying, propylene glycol is coated onto the backing layer of the plaster, thus forming a one-way moisture-wicking plaster.

[0047] Example 9: The difference from Example 1 is as follows:

[0048] An aqueous solution of polyvinyl alcohol is coated onto the backing layer of the plaster. After drying, glycerin is coated onto the backing layer of the plaster, thus forming a one-way moisture-wicking plaster.

[0049] Example 10: The difference from Example 1 is as follows:

[0050] An aqueous solution of PEG-6000 is coated onto the backing layer of the plaster. After drying, PEG-300 is coated onto the backing layer of the plaster, finally forming a one-way moisture-wicking plaster.

[0051] Example 11: The difference from Example 1 is as follows:

[0052] An aqueous solution of PEG-3000 is coated onto the backing layer of the plaster. After drying, PEG-400 is coated onto the backing layer of the plaster, finally forming a one-way moisture-wicking plaster.

[0053] Example 12: The difference from Example 1 is as follows:

[0054] An aqueous solution of PEG-4000 is coated onto the backing layer of the plaster. After drying, PEG-300 is coated onto the backing layer of the plaster, thus forming a one-way moisture-wicking plaster.

[0055] Example 13: The difference from Example 1 is as follows:

[0056] An aqueous solution of PEG-4000 is coated onto the backing layer of the plaster. After drying, PEG-600 is coated onto the backing layer of the plaster, finally forming a one-way moisture-wicking plaster.

[0057] Example 14: The difference from Example 1 is as follows:

[0058] An aqueous solution of PEG-2000 is coated onto the backing layer of the plaster. After drying, PEG-200 is coated onto the backing layer of the plaster, finally forming a one-way moisture-wicking plaster.

[0059] Example 15: The difference from Example 1 is as follows:

[0060] An aqueous solution of PEG-8000 is coated onto the backing layer of the plaster. After drying, PEG-200 is coated onto the backing layer of the plaster, finally forming a one-way moisture-wicking plaster.

[0061] Example 16: The difference from Example 1 is as follows:

[0062] An aqueous solution of PEG-2000 is coated onto the backing layer of the plaster. After drying, PEG-600 is coated onto the backing layer of the plaster, finally forming a one-way moisture-wicking plaster.

[0063] Example 17: The difference from Example 1 is as follows:

[0064] An aqueous solution of PEG-4000 is coated onto the backing layer of the plaster. After drying, PEG-300 is coated onto the backing layer of the plaster, thus forming a one-way moisture-wicking plaster.

[0065] Example 18: The difference from Example 1 is as follows:

[0066] An aqueous solution of PEG-6000 is coated onto the backing layer of the plaster. After drying, PEG-200 is coated onto the backing layer of the plaster, thus forming a one-way moisture-wicking plaster.

[0067] Example 19: The difference from Example 1 is as follows:

[0068] A one-way diaphoretic plaster was constructed using commercially available Yunnan Baiyao plaster.

[0069] Example 20: The difference from Example 1 is as follows:

[0070] A commercially available antelope dermatitis patch was constructed using antelope dermatitis patch.

[0071] Example 21: The difference from Example 1 is as follows:

[0072] The commercially available Tongrentang plaster was used to construct a one-way diaphoretic plaster.

[0073] Example 22: The difference from Example 1 is as follows:

[0074] A one-way diaphoretic plaster was constructed using commercially available Wantong plaster.

[0075] Example 23: The difference from Example 1 is as follows:

[0076] Commercially available Hisamitsu plaster was used to construct a one-way diaphoretic plaster.

[0077] Comparative Example 1: The difference from Example 1 is that:

[0078] The PEG-4000 aqueous solution is coated onto the backing layer and dried to obtain the final product.

[0079] Comparative Example 2: The difference from Example 1 is that:

[0080] The product is obtained by coating PEG-200 onto the backing layer.

[0081] Example and Comparative Performance Tests:

[0082] Contact angle measurement: Results of contact angle changes on different sides are as follows Figure 1 As shown, the results indicate that the contact angle of the backing layer of the one-way hygroscopic plaster is 0°, exhibiting superhydrophilic properties; while the contact angle of the drug matrix layer is >90°, exhibiting hydrophobic properties.

[0083] Drug property comparison experiment: 2×3.5cm 2 After removing the anti-adhesive layer, the unidirectional hygroscopic plaster of Example 1 and the corresponding commercially available plaster were placed in 5 mL of alcohol for 30 min. Then, the extracts of the plaster from Example 1, the commercially available plaster extract, and the alcohol were placed in a spectrophotometer to observe the differences in absorption peaks. The results are as follows: Figure 2 As shown in the experimental results, the absorption peaks are very close, proving that our preparation method does not affect the medicinal properties of the drug matrix layer of the plaster.

[0084] Water vapor transmission rate experiment: The difference in air permeability was evaluated by the water vapor transmission rate. First, test tubes containing 5 mL of water were preheated in a 40℃ oven. Then, one-way hygroscopic plaster with the anti-adhesive layer removed and a traditional plaster were respectively placed over the mouth of the test tubes, and the weight of the samples was measured. Subsequently, the samples were placed back into the 40℃ oven, and the weight was measured every 5 hours. The experimental results are as follows: Figure 3 As shown, the results indicate that the plaster patch of Example 1 (68 gm) -2 h -1 The water vapor throughput of 14 gm is approximately the same as that of traditional medicated plasters. -2 h -1 The breathability of the plaster prepared by the method of the present invention is significantly improved by 5 times, which proves that the breathability of the plaster is significantly improved.

[0085] Simulated sweating experiment: The difference in sweating effect between the plaster of this invention and traditional plasters was evaluated through a simulated experiment. Nine holes (radius: 2mm) were punched in the prosthetic hand to simulate sweat glands (total area 36πmm²). 2 Simulated sweat (blue water) was pumped using a flow pump. One-way moisture-wicking plasters with the anti-adhesive layer removed and traditional plasters were applied to the simulated sweat gland locations, respectively. To simulate daily light sweating, the flow rate was set to 1 mL / h. After 6 hours, the plasters from Example 1 and their corresponding commercially available plasters were removed for observation. To simulate sweating during strenuous exercise, the flow rate was set to 24 mL / h. After 0.5 hours, the plasters from Example 1 and their corresponding commercially available plasters were removed for observation. The experimental results are as follows: Figure 4 As shown, Figure 4 The results clearly show that, under simulated sweating conditions, the amount of simulated sweat remaining on the prosthetic hand covered by the plaster patch of Example 1 is significantly less than that covered by the corresponding commercially available plaster patch, proving that the wicking effect of the plaster patch prepared by the present invention is far better than that of traditional plaster patches.

[0086] Wet adhesion test: A wet adhesion test was conducted using holding power as the standard to evaluate the difference in wet adhesion between the plaster of this invention and traditional plasters. First, 50 μL of water was dropped onto a stainless steel test plate, and 2×2 cm samples were taken from each plate. 2 One-way moisture-wicking plasters and traditional plasters were applied to the surface of a stainless steel test plate after removing the anti-adhesive layer. After 5 minutes, the plasters and the stainless steel test plate were rolled three times with a 2000g roller. The plates were then left to stand at room temperature for 15 minutes, and finally suspended horizontally on a test frame with a 200g weight. The adhesion time was recorded. The experimental results are as follows: Figure 5 As shown in the figure, the adhesion time of the plaster in Example 1 is more than twice that of the corresponding commercially available plaster, proving that the plaster prepared by the present invention has stronger wet adhesion.

[0087] Unidirectional moisture-wicking and durability testing: Durability testing was conducted using unidirectional transport time as the standard. The unidirectional moisture-wicking plaster of Example 1 was divided into two groups: sealed storage and unsealed (air-exposed) storage. Three samples were taken at regular intervals, and 50 μL of water was dropped onto the drug matrix layer of the sample after the anti-adhesive layer was removed. The unidirectional transport time of Example 1 was measured, and the average value was recorded. The results are as follows: Figure 6 As shown, by Figure 6 It can be seen that, whether stored in a sealed container or in the air without being sealed, the plaster of Example 1 can maintain an average unidirectional transport time of less than 2 seconds for 50 microliters of water droplets even after being stored for up to 70 days.

[0088] Unidirectional moisture wicking and durability tests were conducted using plasters from Comparative Examples 1 and 2. The experiments revealed that the plaster prepared in Comparative Example 1 lost its long-lasting and highly efficient unidirectional moisture wicking function: initially, its unidirectional transport time was greater than 10 seconds; with prolonged storage (after 3 days), the unidirectional transport time gradually increased until it lost its unidirectional moisture wicking function (unidirectional transport time > 2 minutes). Figure 10 The mechanism diagram shows that after the PEG-4000 solution is initially dried, a PEG-4000 film forms on the drug matrix layer within the pores of the unidirectional hygroscopic plaster. At this point, the PEG-4000 film is not wetted, requiring a wetting process for unidirectional transport, thus increasing the unidirectional transport time. Although the PEG-4000 solution loses free water and becomes solid, bound water still exists within PEG-4000, making the PEG-4000 film more easily wetted. As the bound water within PEG-4000 gradually disappears until a dense PEG-4000 film is formed, the unidirectional transport time gradually increases until the unidirectional hygroscopic function is lost. When PEG-200 is used alone, although the plaster prepared in Comparative Example 2 maintains a highly efficient unidirectional hygroscopic function, it loses its longevity: initially, it has highly efficient unidirectional transport performance, but after storage for a period of time (3-5 days), it loses its unidirectional hygroscopic ability. Furthermore, our study found that PEG-200 liquid cannot be effectively preserved on the drug matrix layer of the plaster for a long period. In the initial stage, due to the presence of the PEG-200 liquid film, unidirectional transport will skip the pipeline wetting stage, allowing the unidirectional moisture-wicking plaster to maintain its efficient unidirectional moisture-wicking function; however, as time goes on, the PEG-200 liquid film will disappear, causing it to lose its unidirectional moisture-wicking ability.

[0089] Examples 2-18 were sealed and stored, and longevity tests were conducted. The results are as follows: Figure 7 and Figure 8 As shown, combined with Figure 6 and Figure 7 , Figure 8 It can be seen that the plasters prepared by the method of the present invention can maintain efficient unidirectional liquid transport performance even after long-term storage. Comparative examples 1 and 6, 10, and 11 are provided. Figure 7 In the examples, the unidirectional transport time of Example 11, which uses PEG-3000 and PEG-400 with relatively close molecular weights, was consistently higher than that of Examples 1, 6, and 10. In contrast, the unidirectional transport time of Example 10, which has the largest difference in molecular weight, was also higher than that of Examples 1 and 6. This indicates that the difference in molecular weight can directly affect the unidirectional moisture-wicking properties and durability of the plaster patch of the present invention. Examples 15, 16, and 18, which have relatively poor effects, also prove this point.

[0090] The experimental results of Examples 12 to 18 further demonstrate that since the smaller the molecular weight of small PEG molecules, the better the hydrophilicity, the smaller the molecular weight, the better the effect; since the higher the molecular weight of large PEG molecules, the higher the mechanical strength of the film formed, but at the same time it may become harder and more brittle, so it is necessary to select an appropriate molecular weight to make the efficient one-way moisture wicking ability last longer.

[0091] Combination Figure 11 and Figure 12 As can be seen from the mechanism diagram, the closer the molecular weights are, the less significant the separation effect of the backing fabric on the polymer and the hydrophilic liquid reagent; the two tend to mix more, resulting in more contact between the hydrophilic liquid reagent and the air, thus weakening the polymer's covering and protective effect on the hydrophilic liquid reagent. However, if the molecular weights differ too much, it becomes more difficult for the polymer and hydrophilic liquid to mix uniformly at the pore walls, and the polymer's binding effect on the hydrophilic liquid reagent is stronger, further restricting the movement of the hydrophilic liquid reagent and affecting the sweat transport effect. Therefore, the polymer of this invention needs to be selected with an appropriate degree of polymerization, and the molecular weights of the polymer and the hydrophilic liquid reagent need to be controlled within a suitable range to ensure the generation of the most suitable intermolecular forces.

[0092] The medicated plasters from Examples 19-23 were used for unidirectional moisture conduction and durability testing. These plasters were grouped by brand, and three samples were taken from each group. 50 μL of water was dropped onto the drug matrix layer of the sample after the anti-adhesive layer was removed. The unidirectional transport time was measured, and the average value was recorded. The results are as follows: Figure 9 As shown, combined with Figure 6 Example 1 and Figure 9 It can be seen that the plasters prepared by the method of the present invention from different brands all have unidirectional liquid transport performance, and the unidirectional transport time is less than 2 seconds, which proves that the method of the present invention can be universally applied to commercially available ordinary plasters.

[0093] For those skilled in the art, various other corresponding changes and modifications can be made based on the technical solutions and concepts described above, and all such changes and modifications should fall within the protection scope of the claims of this invention.

Claims

1. A plaster patch having a long-term one-way moisture conducting property, characterized by, It includes a matrix layer containing a drug and a backing layer closely adhering to the matrix layer; the matrix layer is hydrophobic, and the backing layer is hydrophilic; the matrix layer and the backing layer are evenly distributed with multiple through-holes; the pore diameter of the through-holes is 0.1~2mm; the spacing between the through-holes is 0.2~5mm; the side of the backing layer away from the matrix layer is provided with a hydrophilic film layer formed by a solid hydrophilic film-forming agent and a liquid hydrophilic reagent; The solid hydrophilic film-forming agent includes one or more of the following: polyethylene glycol, polyvinyl alcohol, polyvinylpyrrolidone, hydroxypropyl cellulose, sodium carboxymethyl cellulose, hydroxypropyl starch, chitosan, carboxymethyl chitosan, or polyacrylic acid, with a molecular weight of not less than 2000; the liquid hydrophilic reagent includes one or more of the following: polyethylene glycol, glycerol, diethylene glycol, propylene glycol, polyglycerol, sorbitol, N-methylpyrrolidone, or dimethyl sulfoxide, with a molecular weight of not more than 600.

2. The plaster patch having a long-term one-way moisture conducting property according to claim 1, characterized by, The backing layer is made of fabric.

3. The plaster patch having a long-term one-way moisture conducting property according to claim 1, characterized by, The contact angle of the backing layer is <30°.

4. A method of producing the plaster patch having a long-term one-way moisture conducting property according to any one of claims 1 to 3, characterized by, Includes the following steps: Dissolve the solid hydrophilic film-forming agent to obtain a film-forming agent solution with a mass concentration of 1-70%; The film-forming agent solution is applied to the surface of the backing layer with uniformly distributed through holes; after drying, a liquid hydrophilic reagent is applied.

5. The method of claim 4, wherein the plaster patch having a long-term one-way moisture conducting property is prepared by applying a pressure to the adhesive layer of the plaster patch having a long-term one-way moisture conducting property, and then cutting the plaster patch having a long-term one-way moisture conducting property. The through-holes are obtained by one or more of the following methods: laser drilling, mechanical stamping, water jet drilling, thermal drilling, and chemical drilling.

6. The method for preparing a medicated plaster with long-lasting unidirectional moisture-wicking properties according to claim 4, characterized in that, A backing layer with a hydrophilic surface was obtained through hydrophilic modification.

7. The method for preparing a medicated plaster with long-lasting unidirectional moisture-wicking properties according to claim 6, characterized in that, The backing layer is treated with oxygen-containing gas at a power of 50~200W for 0.5~3.5min using a plasma machine to complete the hydrophilic modification.

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