A quick and continuous liquid absorbing hydrocolloid dressing and a method for preparing the same

Abstract

The application provides a water glue dressing capable of quickly and continuously absorbing liquid and a preparation method thereof. A core layer of the water glue dressing comprises the following raw materials by weight: 40-50% of medical hot melt pressure sensitive adhesive, 3-10% of softening agent, 20-44% of sodium carboxymethyl cellulose, 10-25% of carboxymethyl chitosan and 3-10% of super absorbent resin. The water glue dressing prepared from the core layer components can quickly and continuously absorb wound exudate, effectively prevents the wound from being soaked and maintains appropriate humidity of the wound, thereby reducing the replacement frequency. The water glue dressing has appropriate peel strength, good adhesion and comfort for the skin, is painless to replace, is durable to adhere and is simple and environmentally friendly in material and preparation process.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of medical wound dressings, and particularly relates to a hydrogel dressing capable of rapidly and continuously absorbing liquid and a preparation method thereof. BACKGROUND

[0002] As a high-end medical dressing, the hydrogel can durably absorb wound exudates and maintain a moist wound environment, thereby accelerating the healing process of the wound. Compared with traditional dressings, the hydrogel dressing has the following advantages: (1) absorbing wound exudates to create a moist healing environment; (2) forming a closed environment conducive to the removal of necrotic tissue by macrophages; and (3) having adhesiveness to promote the proliferation of microvessels and the formation of granulation tissue.

[0003] Wound exudate management capability and peel strength are two important indicators of a hydrogel dressing. Wound exudate is essential for moist healing. However, when there is too much or too little wound exudate, or when bacteria are infected due to improper management, it will delay wound healing, reduce the quality of life of patients, and consume a large amount of health resources, ultimately reducing the overall treatment efficiency. Therefore, the key to solving the problem is to ensure that the wound is in a moist environment while timely absorbing excess exudate. Peel strength refers to the ease of removing the dressing from the body when the dressing is applied to the body, which represents the adhesiveness. A suitable peel strength can produce good adhesion to the skin, and when removed, it does not excessively adhere to the wound, and when applied, it does not easily fall off, and has good comfort. If the peel strength is too small, the dressing is easy to fall off from the wound when applied; if the peel strength is too large, there is a pain when removed, which can easily enlarge the wound area and cause further deterioration of the wound. According to the Pressure Sensitive Adhesive Products Technology Manual written by Yang Yukun et al., it is known that the peel strength of the hydrogel dressing is preferably controlled at about 3N / cm.

[0004] At present, the existing hydrogel dressing products on the market still need to be improved in promoting wound healing and patient use experience. Most of the products have slow liquid absorption rate, small liquid absorption capacity, and are prone to wound immersion. Moreover, the peel strength of most hydrogel dressings is not suitable for application to the skin of the wound, affecting the wound healing and use experience of patients. For example, CN 115089761 A discloses a preparation method of a high-liquid-absorption natural polysaccharide-based medical hydrogel dressing, which uses sodium alginate, carboxymethyl cellulose and cross-linked carboxymethyl cellulose to synergistically ensure good liquid absorption capacity of the dressing. The peel strength of the hydrogel dressing prepared thereby is 0.10-0.32N / cm. According to the peel strength of the existing products on the market, it can be judged that the dressing is prone to falling off during use, and does not meet the requirement of the domestic industry standard YY / T 1293.4-2016 that the peel strength of a hydrogel dressing should be greater than or equal to 1N / cm. SUMMARY

[0005] The application provides a water gel dressing capable of quickly and continuously absorbing liquid and a preparation method thereof, and has the advantages of fast liquid absorption rate, large liquid absorption amount, moderate peeling strength, simple and environment-friendly preparation process, and the like, and can accelerate wound healing of a patient and improve use experience.

[0006] The technical scheme of the application is a water gel dressing capable of quickly and continuously absorbing liquid, and a core layer of the water gel dressing comprises the following raw materials by weight: 40-50% of medical hot melt pressure-sensitive adhesive, 3-10% of softening agent, 20-44% of sodium carboxymethyl cellulose, 10-25% of carboxymethyl chitosan, and 3-10% of superabsorbent resin.

[0007] Further, the effective component in the medical hot melt pressure-sensitive adhesive is styrene-isoprene-styrene block copolymer (SIS) and / or styrene-butadiene-styrene block copolymer (SBS).

[0008] Further, the softening agent is at least one of paraffin oil, naphthenic oil, mineral oil or dibutyl phthalate.

[0009] Further, the viscosity of the sodium carboxymethyl cellulose is 300-3000 mpa.s.

[0010] Further, the degree of substitution of the carboxymethyl chitosan is above 80%, and the particle size is 40-250 mesh.

[0011] Further, the superabsorbent resin is one or several of polyacrylic acid, polyacrylamide or acrylamide-acrylonitrile-acrylic acid terpolymer; and the particle size is 40-250 mesh.

[0012] The application also relates to a preparation method of the water gel dressing, comprising the following steps:

[0013] S1: melt-blending the medical hot melt pressure-sensitive adhesive and the softening agent in proportion to obtain component A;

[0014] S2: weighing the sodium carboxymethyl cellulose, the carboxymethyl chitosan and the superabsorbent resin in proportion, and physically blending them at room temperature to obtain component B;

[0015] S3: adding the component B in step S2 into the component A in step S1 for blending to obtain a core layer gel; the core layer gel is pressed and formed into a sheet, and then is combined with a PU film to obtain a sheet-shaped water gel dressing;

[0016] S4: placing the sheet-shaped water gel dressing in step S3 in a mold for mold pressing and forming, and then performing die cutting, packaging and sterilization to obtain a water gel dressing product.

[0017] Further, the blending temperature in S1 is 130-170 DEG C, and the blending time is 5-40 min.

[0018] Further, the blending temperature in S3 is 130-160 DEG C, and the blending time is 5-30 min.

[0019] Further, a flat vulcanization instrument is used in the tablet forming, and the upper and lower parts of the gel are provided with release paper, the tablet thickness is 0.4-0.7 mm, the tablet temperature is 80-110 DEG C, and the tablet is transferred to a doctor coater to be combined with the PU film after the temperature is reduced to 80 DEG C.

[0020] The present application has the following beneficial effects:

[0021] (1) The water gel dressing preparation process is simple, environmentally friendly and non-polluting, the production process has low energy consumption, the cost is low, and it is suitable for industrialized production; the components are simple, each component has good biocompatibility, stable performance and is easy to obtain.

[0022] (2) The water gel dressing core layer contains sodium carboxymethyl cellulose, carboxymethyl chitosan and superabsorbent resin three kinds of functional polymers. Among them, sodium carboxymethyl cellulose and carboxymethyl chitosan are both natural polysaccharide polymers, which have excellent biocompatibility and good sustained water absorption performance, and carboxymethyl chitosan has good antibacterial activity, but the liquid absorption rate of both is relatively low, and the liquid absorption capacity of each is limited. When sodium carboxymethyl cellulose and carboxymethyl chitosan absorb liquid, they interact with each other, synergistically enhancing the water retention of the water gel core layer, and also enhancing its sustained liquid absorption capacity; and through experiments, it can be seen that the addition of carboxymethyl chitosan can increase the viscosity of the water gel core layer and increase its peel strength. The superabsorbent resin is a functional polymer material containing hydrophilic groups and having a certain crosslinking degree, which has excellent water retention, high water absorption rate and certain deodorization effect, and is non-toxic, harmless and pollution-free. By adjusting the proportion of the three kinds of functional polymers, a water gel dressing with fast and sustained liquid absorption, adhesion and easy peeling can be prepared, which can effectively avoid liquid immersion of the wound and frequent replacement of the dressing, thereby promoting wound repair.

[0023] (3) The water gel dressing has a fast liquid absorption rate, and the liquid absorption amount of 2h can reach 0.3-0.4g / cm 2 , the liquid absorption amount of 6h can reach 0.35-0.5g / cm 2 , which is 3.6-6.6 times that of some foreign products; and the liquid absorption amount of the dressing is large, and the liquid absorption amount of 24h can reach 0.6-0.8g / cm 2 , which is 3-5 times that of some foreign products; in the process of wound care, it can timely absorb exudate and effectively reduce the replacement frequency of the dressing, promote faster and better healing of the wound, and reduce inflammation, scar formation and the like caused by frequent replacement. The water gel has good air permeability, and the water vapor transmission rate is >150g / m 224h. The dressing has suitable peel strength, good adhesion to the skin, and is not easy to fall off when attached, and does not cause further deterioration of the skin of the wound when removed, and has good comfort and painless replacement. Therefore, the hydrocolloid dressing in the application has positive significance in protecting and promoting wound healing, improving user experience and improving treatment efficiency, and breaks the application limitation of traditional hydrocolloid dressings. DETAILED DESCRIPTION

[0024] The embodiments of the application will be described in detail below with reference to examples, but those skilled in the art will understand that the following examples are only for illustration of the application and should not be regarded as limiting the scope of the application.

[0025] Example 1

[0026] The preparation method of the hydrocolloid dressing described in this embodiment is as follows:

[0027] 1. Take 40wt% of medical hot melt pressure sensitive adhesive with styrene-isoprene-styrene block copolymer (SIS) as the main component and 3.5wt% of naphthenic oil in sequence, and add them into a stirrer at 150℃ for fully melting and blending for 25min;

[0028] 2. Mix 36wt% of sodium carboxymethyl cellulose (viscosity of 300-800mpa.s), 15wt% of carboxymethyl chitosan (degree of substitution of 90% or more, 40-80 mesh) and 5.5wt% of polyacrylamide superabsorbent resin (100-200 mesh) uniformly at room temperature;

[0029] 3. Adjust the temperature of the stirrer to 140℃, add the blended powder in step 2 into the glue solution in step 1 for fully stirring for 25min, and then mix uniformly to obtain the core layer glue after cooling to 80℃, and then transfer to a doctor blade coater to be compounded with a PU film, and then obtain the finished product of the hydrocolloid dressing after molding, die cutting, packaging and sterilization.

[0030] 4. Take an appropriate amount of core layer glue and place it between two release papers for tabletting and shaping at 105℃ on a flat plate vulcanizing instrument to 0.5mm, and then cool to 80℃, and then transfer to a doctor blade coater to be compounded with a PU film, and then obtain the finished product of the hydrocolloid dressing after molding, die cutting, packaging and sterilization.

[0031] Example 2

[0032] The preparation method of the hydrocolloid dressing described in this embodiment is as follows:

[0033] 1. Take 40wt% of medical hot melt pressure sensitive adhesive with styrene-isoprene-styrene block copolymer (SIS) as the main component and 3.5wt% of naphthenic oil in sequence, and add them into a stirrer at 150℃ for fully melting and blending for 25min;

[0034] 2. Take 36wt% sodium carboxymethyl cellulose (viscosity of 600-1000), 15wt% carboxymethyl chitosan (degree of substitution ≥95%, 80-120 mesh) and 5wt% polyacrylic acid-based superabsorbent resin (150-250 mesh) and mix them uniformly at room temperature;

[0035] 3. Adjust the temperature of the stirrer to 150°C, add the blended powder in step 2 to the glue solution in step 1 and stir for 20 minutes, mix uniformly and then cool to obtain the core layer glue;

[0036] 4. Take an appropriate amount of core layer glue and place it between two layers of release paper, press and shape it into a 0.5mm sheet in a flat vulcanizing instrument at 95°C, cool it to 80°C, then transfer it to a draw coater and compound it with a PU film, and then mold, cut, package and sterilize to obtain the finished product of the hydrogel dressing.

[0037] Example 3

[0038] The preparation method of the hydrogel dressing described in this example is as follows:

[0039] 1. Take 42wt% medical hot melt pressure sensitive adhesive with styrene-isoprene-styrene block copolymer (SIS) as the main component and 4.2wt% mineral oil, add them to a stirrer at 160°C and melt and blend them for 30 minutes;

[0040] 2. Take 43wt% sodium carboxymethyl cellulose (viscosity of 600-1000mpa.s), 7.5wt% carboxymethyl chitosan (degree of substitution ≥90%, 80-120 mesh) and 5.1wt% polyacrylamide-based superabsorbent resin (150-200 mesh) and mix them uniformly at room temperature;

[0041] 3. Adjust the temperature of the stirrer to 130°C, add the blended powder in step 2 to the glue solution in step 1 and stir for 30 minutes, mix uniformly and then cool to obtain the core layer glue;

[0042] 4. Take an appropriate amount of core layer glue and place it between two layers of release paper, press and shape it into a 0.4mm sheet in a flat vulcanizing instrument at 90°C, cool it to 80°C, then transfer it to a draw coater and compound it with a PU film, and then mold, cut, package and sterilize to obtain the finished product of the hydrogel dressing.

[0043] Comparative Example 1

[0044] The preparation method of the hydrogel dressing described in this example is as follows:

[0045] 1. Take 42wt% medical hot melt pressure sensitive adhesive with styrene-isoprene-styrene block copolymer (SIS) as the main component and 4.2wt% mineral oil, add them to a stirrer at 160°C and melt and blend them for 30 minutes;

[0046] 2. Take 38wt% sodium carboxymethyl cellulose (viscosity 300-800 mpa.s) and 16wt% carboxymethyl chitosan (degree of substitution ≥ 90%, 40-80 mesh) and mix uniformly at room temperature;

[0047] 3. Adjust the temperature of the stirrer to 140°C, add the blended powder in step 2 to the glue solution in step 1 and stir for 25 min, mix uniformly and cool to obtain the core layer glue;

[0048] 4. Take the appropriate amount of core layer glue and place it between two layers of release paper in a flat plate vulcanizing instrument at 105°C to press and shape 0.5 mm, cool to 80°C, then transfer to a doctor blade coater and composite with a PU film, then mold, cut, package and sterilize to obtain the finished product of the hydrogel dressing.

[0049] Comparative Example 2

[0050] 1. Take 40wt% medical hot melt pressure sensitive adhesive with styrene-butadiene-styrene block copolymer (SBS) as the main component and 4wt% paraffin oil in sequence, add to a stirrer at 170°C and melt blend for 20 min;

[0051] 2. Mix 51wt% carboxymethyl chitosan (degree of substitution ≥ 95%, 80-120 mesh) and 5wt% polyacrylic acid-based superabsorbent resin (150-250 mesh) uniformly at room temperature;

[0052] 3. Adjust the temperature of the stirrer to 150°C, add the blended powder in step 2 to the glue solution in step 1 and stir for 20 min, mix uniformly and cool to obtain the core layer glue;

[0053] 4. Take the appropriate amount of core layer glue and place it between two layers of release paper in a flat plate vulcanizing instrument at 95°C to press and shape 0.5 mm, cool to 80°C, then transfer to a doctor blade coater and composite with a PU film, then mold, cut, package and sterilize to obtain the finished product of the hydrogel dressing.

[0054] Comparative Example 3

[0055] 1. Take 40wt% medical hot melt pressure sensitive adhesive with styrene-butadiene-styrene block copolymer (SBS) as the main component and 4wt% paraffin oil in sequence, add to a stirrer at 170°C and melt blend for 20 min;

[0056] 2. Mix 51wt% sodium carboxymethyl cellulose (viscosity 600-1000) and 5wt% polyacrylic acid-based superabsorbent resin (150-250 mesh) uniformly at room temperature;

[0057] 3. Adjust the temperature of the stirrer to 150℃, add the blended powder in step 2 into the glue solution in step 1 and stir for 20 min, then cool down to obtain the core layer glue;

[0058] 4. Take an appropriate amount of core layer glue and place it between two layers of release paper, then press it into a 0.5 mm thick sheet in a flat plate vulcanizing instrument at 95℃, cool it down to 80℃, then transfer it to a draw coater and compound it with a PU film, then mold, cut, package and sterilize it to obtain the finished hydrogel dressing product.

[0059] Table 1 shows the comparison of the liquid absorption and peeling strength of the hydrogel dressings of Examples 1-3, Comparative Examples 1-3 and three commercially available hydrogel products at different time points.

[0060] Table 1 Comparison of the properties of the hydrogel dressing

[0061]

[0062] In summary, it can be seen that:

[0063] (1) Compared with Example 1, Comparative Example 1 does not add high water-absorbing resin, and the prepared hydrogel dressing has a significant decrease in liquid absorption rate and liquid absorption amount, which shows that the added high water-absorbing resin can significantly improve the liquid absorption rate of the glue, and at the same time, it complements other raw materials to give the glue a stronger sustained liquid absorption capacity.

[0064] (2) In addition to adding the same amount of high water-absorbing resin SAP, Example 2 also adds sodium carboxymethyl cellulose and carboxymethyl chitosan (51wt%), Comparative Example 2 adds carboxymethyl chitosan (51wt%), and Comparative Example 3 adds sodium carboxymethyl cellulose (51wt%). Comparison of the three sets of data shows that the liquid absorption amount of Example 2 at each time point is higher than that of Comparative Examples 2 and 3, which shows that the liquid absorption capacity of the glue with only carboxymethyl chitosan or sodium carboxymethyl cellulose is lower than that of the glue with carboxymethyl chitosan and sodium carboxymethyl cellulose at each time point, proving that carboxymethyl chitosan and sodium carboxymethyl cellulose have a synergistic effect on liquid absorption performance. It can also be seen that the peeling strength relationship is: Comparative Example 3 < Example 2 < Comparative Example 2, which shows that as the amount of carboxymethyl chitosan increases, the peeling strength of the glue also increases, i.e. carboxymethyl chitosan can increase the adhesion of the glue.

[0065] (3) As can be seen from the data in Table 1, the liquid absorption amount of the hydrogel dressings of Examples 1-3 at each time point is higher than that of the existing similar products on the market, which has the advantages of fast and sustained liquid absorption and high liquid absorption amount, and can effectively prevent the occurrence of wound immersion phenomenon; by adjusting the ratio of each component, a hydrogel dressing with fast liquid absorption rate, high liquid absorption amount and easy to peel off under the condition of ensuring not easy to fall off can be prepared, which can effectively improve the use experience while reducing the treatment cost of patients.

[0066] The above embodiments are only for illustrating the technical ideas and characteristics of the present application, and the content is only the preferred embodiments of the present application, but the protection scope of the present application is not limited to this. Within the technical scope disclosed by the present application, equivalent changes or improvements according to the technical solutions and inventive concepts of the present application should be covered in the protection scope of the present application.

Claims

1. A hydrocolloid dressing that provides rapid and continuous liquid absorption, characterized in that, Its core layer comprises the following raw materials by weight: 40-50% medical hot melt pressure-sensitive adhesive, 3-10% softener, 20-44% sodium carboxymethyl cellulose, 10-25% carboxymethyl chitosan, and 3-10% superabsorbent resin; the viscosity of the sodium carboxymethyl cellulose is 300-3000 mPa·s; the degree of substitution of the carboxymethyl chitosan is above 80%, and the particle size is 40-250 mesh; the effective component in the medical hot melt pressure-sensitive adhesive is styrene-isoprene-styrene block copolymer SIS and / or styrene-butadiene-styrene block copolymer SBS; the superabsorbent resin is polyacrylic acid based and / or polyacrylamide based. The preparation method of this dressing includes the following steps: S1: Medical hot melt pressure-sensitive adhesive and softener are melt-blended in a certain proportion to obtain component A; S2: Weigh out sodium carboxymethyl cellulose, carboxymethyl chitosan and superabsorbent resin in proportion, and physically blend them at room temperature to obtain component B; S3: Add component B from step S2 to component A from step S1 and blend to obtain a core layer colloid; compress the core layer colloid into a sheet, and then laminate it with a PU film to obtain a sheet-like hydrocolloid dressing. S4: Place the sheet-like hydrocolloid dressing from step S3 into a mold and mold it into shape, then perform die cutting, packaging, and sterilization to obtain the finished hydrocolloid dressing.

2. The hydrocolloid dressing according to claim 1, characterized in that: The softener is at least one of mineral oil or dibutyl phthalate.

3. The hydrocolloid dressing according to claim 1, characterized in that: The softener is at least one of paraffin oil or naphthenic oil.

4. The hydrocolloid dressing according to claim 1, characterized in that: The superabsorbent resin has a particle size of 40~250 mesh.

5. The hydrocolloid dressing according to claim 1, characterized in that: The blending temperature in S1 is 130~170℃, and the blending time is 5~40min.

6. The hydrocolloid dressing according to claim 1, characterized in that: The blending temperature in S3 is 130~160℃, and the blending time is 5~30min.

7. The hydrocolloid dressing according to claim 1, characterized in that: The tableting process uses a flat vulcanizing apparatus. Release paper is placed on both the top and bottom of the colloid. The tablet thickness is 0.4~0.7mm, and the tableting temperature is 80~110℃. After the tableting is completed, the temperature is reduced to 80℃ and then transferred to a coating machine to be laminated with PU film.

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