Oral hydrogel topical anesthesia patch and preparation method thereof
By designing an oral hydrogel topical anesthetic patch based on a composite hydrogel substrate, the problems of injection pain and drug diffusion in existing technologies have been solved. It achieves stable adhesion and continuous anesthetic effect in the oral saliva environment, is suitable for both children and adults, and reduces the difficulty of operation and preparation cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-02
- Publication Date
- 2026-05-15
AI Technical Summary
Existing oral surface anesthesia techniques suffer from problems such as injection pain, drug diffusion, high operational difficulty, strong discomfort, and high cost. There is a lack of oral anesthesia products suitable for children and fixed-type anesthesia.
Using a composite hydrogel substrate containing quaternized modified chitosan, polyγ-glutamic acid, etc., it is designed as an oral hydrogel topical anesthetic patch. Through electrostatic interaction and hydrogen bonding, it ensures a firm fit, achieves slow release of anesthetic, adapts to the oral saliva environment, and is suitable for surface anesthesia in different areas.
It achieves stable adhesion in the oral saliva environment, avoids drug diffusion, provides a continuous anesthetic effect, reduces the difficulty of operation, improves comfort, is suitable for children and adults, and has a low preparation cost.
Abstract
Description
Technical Field
[0001] This invention relates to the field of oral anesthesia technology, specifically to an oral hydrogel topical anesthetic patch and its preparation method. Background Technology
[0002] In dental procedures, topical anesthesia is a commonly used method, primarily for minor surgeries on the gums and buccal mucosa, such as tooth extractions, fillings, and periodontal cleaning. Its purpose is to reduce patient pain and improve comfort. Currently, clinically common oral topical anesthesia methods are mainly divided into two types: injection anesthesia and topical anesthesia.
[0003] While injectable anesthesia is effective and has a long duration of action, it has significant drawbacks: it can cause stinging pain during injection, especially in children, which can easily trigger fear, crying, and non-cooperation with treatment; at the same time, the injection procedure requires professional medical staff to precisely control the injection site and dosage, making it difficult to perform and potentially causing adverse reactions such as swelling and bleeding at the injection site.
[0004] Topical anesthesia is currently a relatively convenient method of external anesthesia. Its main dosage forms are gels, creams, or solutions, which are applied directly to the target anesthesia site, avoiding injection pain. However, existing topical anesthetics have a core technical flaw: due to the large amount of saliva in the mouth and patients' unconscious swallowing and chewing during treatment, the applied anesthetic is easily diluted and washed away by saliva, failing to remain fixed at the target anesthesia site. It spreads to other oral mucosal tissues (such as the tip of the tongue and throat), causing numbness in non-target areas, affecting the patient's swallowing and speech functions, and reducing the concentration of anesthetic at the target site, thus affecting the anesthetic effect. Repeated application is required, increasing the workload of medical staff and increasing patient discomfort.
[0005] Currently, there are no fixed-type patches specifically designed for oral surface anesthesia in clinical practice. Most existing oral patches are medicated patches for treating oral ulcers and periodontitis, whose core functions are drug delivery and wound protection, lacking anesthetic effects. Furthermore, their adhesive design is primarily targeted at ulcer wounds and cannot meet the needs of oral surface anesthesia. For example, they cannot achieve slow drug release and have insufficient adhesion time, making it difficult to meet the required anesthesia duration during oral treatments. In addition, some existing oral anesthesia-related patches (such as microneedle-containing anesthetic patches) have complex structures, high manufacturing costs, and the microneedles may damage the oral mucosa, making them unsuitable for pediatric patients.
[0006] Therefore, developing an oral topical anesthetic product that can be firmly fixed to the target anesthetic site in the oral cavity, prevent drug diffusion, and has good anesthetic effect, is easy to operate, provides high comfort, has low preparation cost, and is easy to mass-produce has become the key to solving the existing technical problems. Summary of the Invention
[0007] The purpose of this invention is to provide an oral hydrogel topical numbing patch and its preparation method.
[0008] To achieve the above objectives, in a first aspect, the present invention provides an oral hydrogel topical anesthetic patch, the hydrogel topical anesthetic patch comprising a composite hydrogel substrate and an anesthetic drug loaded on the composite hydrogel substrate; the composite hydrogel, by mass percentage, comprises: 8%-15% sodium carboxymethyl cellulose, 4%-8% hyaluronic acid, 6%-12% polyvinyl alcohol, 4%-9% quaternized modified chitosan, 3%-7% polyγ-glutamic acid, 2%-6% adhesion regulator, 2%-5% humectant, 0.5%-2% crosslinking agent, and an appropriate amount of water; the anesthetic drug is lidocaine or tetracaine, and its mass fraction in the oral hydrogel topical anesthetic patch is 2%-8%.
[0009] Furthermore, the degree of substitution of the quaternized modified chitosan is 0.3-0.6, and it is prepared by reacting chitosan with 3-chloro-2-hydroxypropyltrimethylammonium chloride; the molecular weight of the polyγ-glutamic acid is 10000-50000 Da.
[0010] Furthermore, the adhesion regulator includes sodium alginate or pectin; the humectant includes glycerin or propylene glycol; and the crosslinking agent includes glutaraldehyde or borax.
[0011] Furthermore, the thickness of the oral hydrogel topical anesthetic patch is 0.3-1.0 mm; The composite hydrogel substrate has a swelling degree of 80%-250%, maintains morphological stability in the oral saliva environment, has an adhesion time of not less than 40 minutes, and has a sustained release time of 30-60 minutes for the anesthetic drug.
[0012] Furthermore, it also includes an antibacterial component at a mass ratio of 0.1%-1%, wherein the antibacterial component includes honeysuckle extract or menthol.
[0013] Secondly, the present invention provides a method for preparing an oral hydrogel topical anesthetic patch, comprising the following steps: Quaternized modified chitosan was prepared, and sodium carboxymethyl cellulose, hyaluronic acid, polyvinyl alcohol, quaternized modified chitosan and polyγ-glutamic acid were weighed by weight percentage, added to deionized water, and stirred in a water bath at 50-70℃ until completely dissolved to obtain a mixed substrate solution. Add an adhesion regulator and a humectant to the obtained mixed substrate solution in sequence, stir under a water bath at 50-70°C, mix evenly, and then cool to room temperature to obtain a cooled solution. The anesthetic drug and cross-linking agent were added sequentially to the cooled solution and stirred until the anesthetic drug was evenly dispersed and the cross-linking agent was completely reacted, thus obtaining the hydrogel precursor solution. The hydrogel precursor solution is poured into a mold of a pre-designed shape and left to stand at room temperature to form a hydrogel preform. The obtained hydrogel preform is removed from the mold and cut to the preset size according to the needs of the target anesthesia site in the oral cavity. After sterilization, the oral hydrogel topical anesthetic patch can be obtained.
[0014] Furthermore, the method for preparing quaternized modified chitosan is as follows: dissolve chitosan in an acetic acid solution with a mass fraction of 1%-3%, add 3-chloro-2-hydroxypropyltrimethylammonium chloride, react in a water bath at 60-80℃ for 4-6 hours, adjust the pH to 7.0-7.5, take the precipitate, wash and dry it to obtain quaternized modified chitosan.
[0015] Furthermore, in the step of stirring until completely dissolved under a water bath at 50-70℃, the stirring speed is 300rpm-500rpm for 30-60min; in the step of stirring under a water bath at 50-70℃, the stirring speed is 200rpm-300rpm; in the step of adding the anesthetic drug and cross-linking agent to the cooled solution in sequence, the stirring speed is 200rpm-300rpm.
[0016] Furthermore, in the step of adding the anesthetic drug and cross-linking agent sequentially to the cooled solution, an antibacterial component was also added simultaneously.
[0017] Furthermore, the process of allowing the material to stand at room temperature for molding involves standing at 25-35℃ for 12-24 hours; the aseptic treatment involves sterilization by ultraviolet irradiation for 30-60 minutes at an intensity of 200-300 μW / cm². 2 .
[0018] Compared with the prior art, the present invention has the following beneficial effects, especially highlighting the technical advantages brought about by inventiveness: 1) An innovative composite substrate system that overcomes the shortcomings of existing hydrogel substrates, which lack creativity and have limited performance: This invention abandons the simple stacking of conventional substrates in existing technologies and designs a novel composite hydrogel substrate system with quaternized modified chitosan and polyγ-glutamic acid as core functional components, combined with sodium carboxymethyl cellulose, hyaluronic acid, and polyvinyl alcohol. The combination and synergistic effect of quaternized modified chitosan and polyγ-glutamic acid are not used in existing oral hydrogel products, and are specifically designed for the special needs of gingival surface anesthesia (firm application and precise sustained release). Compared with existing technologies, it has significant creativity and novelty. At the same time, the core components and synergistic mechanisms that ensure the firmness of the application and the sustained release effect of the drug are clearly defined, making the technical solution more targeted and practical.
[0019] 2) Through the synergistic effect of quaternized modified chitosan, adhesion regulators, and hyaluronic acid, the hydrogel topical anesthetic patch can firmly adhere to the moist and uneven gingival surface. Through multiple interactions such as electrostatic interaction, hydrogen bonding, and ionic bonding, it counteracts the problem of detachment caused by saliva rinsing and oral activity. The adhesion time is no less than 40 minutes, ensuring that the anesthetic can continuously act on the target site and avoid the drug spreading to non-target sites (such as the tip of the tongue and throat), achieving precise topical anesthesia. This not only improves the anesthetic effect but also avoids the discomfort caused by numbness in non-target sites. There is no need to repeatedly apply anesthetic, reducing the operational difficulty for medical staff.
[0020] 3) Through the synergistic effect of polyγ-glutamic acid, polyvinyl alcohol, and crosslinking agents, the composite substrate forms a dense and stable three-dimensional network structure, which enables the slow and uniform release of anesthetic drugs. The sustained release time is 30-60 minutes and can be precisely controlled according to the treatment needs. It can quickly achieve the effective anesthetic concentration and maintain sufficient anesthetic duration to ensure the smooth progress of oral treatment procedures. At the same time, the anesthetic is uniformly dispersed in the three-dimensional network, the anesthetic concentration at the target site is uniform, the anesthetic effect is stable, and the incidence of adverse reactions is reduced.
[0021] 4) For patients requiring infiltration and nerve block anesthesia, topical anesthetic patches can provide pre-anesthesia before needle insertion, avoiding pain during needle insertion. For gingival anesthesia: the application scenarios are the same as before, primarily for anesthetizing the gums. Injection may not be necessary in the following scenarios: pediatric oral cavity: abscess incision, pre-rubber dam application, eruption gingivitis, simple deciduous tooth extraction, postoperative wound analgesia, etc.
[0022] 5) All components selected in this invention are biocompatible medical materials. Quaternized modified chitosan, polyγ-glutamic acid, hyaluronic acid, etc., have good biocompatibility and biodegradability, are non-toxic and non-irritating, will not damage the gingival mucosa, and will not be absorbed by the human body to produce adverse reactions. The anesthetic drugs selected are lidocaine and tetracaine, which are commonly used in clinical practice. The dosage is controllable, the safety is high, and they are suitable for use by various populations. The optional antibacterial components are natural honeysuckle extract or menthol, which further improve the safety and comfort of the product. Detailed Implementation
[0023] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments.
[0024] Example 1 An oral hydrogel topical anesthetic patch includes a novel composite hydrogel substrate and an anesthetic drug. The novel composite hydrogel substrate is composed of the following components by weight percentage: sodium carboxymethyl cellulose 12%, hyaluronic acid 6%, polyvinyl alcohol 9%, quaternized modified chitosan 6%, polyγ-glutamic acid 5%, sodium alginate 4%, glycerol 3%, glutaraldehyde 1%, and the balance being deionized water. The anesthetic drug is lidocaine, which has a mass fraction of 5% in the oral hydrogel topical anesthetic patch. The degree of substitution of the quaternized modified chitosan is 0.4, and the molecular weight of the polyγ-glutamic acid is 30,000 Da. The oral hydrogel topical anesthetic patch is 0.5 mm thick, elliptical in shape, and adapted to the gingival area.
[0025] The preparation method of the above-mentioned oral hydrogel topical numbing patch includes the following steps: Step 1: Preparation of quaternized modified chitosan: Chitosan was dissolved in a 2% (w / w) acetic acid solution, 3-chloro-2-hydroxypropyltrimethylammonium chloride was added, and the mixture was reacted in a 70°C water bath for 5 hours. The pH was adjusted to 7.2, and after precipitation, washing, and drying, quaternized modified chitosan with a degree of substitution of 0.4 was obtained. Step 2: Weigh 12g sodium carboxymethyl cellulose, 6g hyaluronic acid, 9g polyvinyl alcohol, 6g quaternized modified chitosan, and 5g polyγ-glutamic acid by weight percentage, add them to 54g deionized water, and stir at 400r / min for 45 minutes under a 60℃ water bath until completely dissolved to obtain a mixed substrate solution. Step 3: Add 4g sodium alginate and 3g glycerol to the mixed substrate solution in sequence. Stir at 250r / min for 20 minutes under 60℃ water bath conditions. After mixing evenly, cool to room temperature. Step 4: Add 5g lidocaine and 1g glutaraldehyde to the cooled solution in sequence, and stir at 250r / min for 30 minutes until lidocaine is uniformly dispersed and glutaraldehyde is completely reacted to obtain the hydrogel precursor solution. Step 5: Pour the hydrogel precursor solution into an elliptical mold and place it in a constant temperature environment of 30°C for 18 hours to form a hydrogel preform. Step 6: Remove the hydrogel blank from the mold and cut it to the preset oval size (1.5cm long and 1.0cm wide). Sterilize it with ultraviolet light for 45 minutes at an intensity of 250μW / cm². After sterilization, the oral hydrogel topical anesthetic patch is obtained.
[0026] The oral hydrogel topical anesthetic patch prepared in this embodiment, after testing, showed that the swelling degree of the novel composite hydrogel substrate was 180%, the adhesion time in the oral saliva environment was 50 minutes, and the sustained release time of the anesthetic drug was 45 minutes. After being applied to the gingival area, it could be firmly fixed without falling off or spreading. Even when the patient made slight swallowing movements, it could still maintain a good application effect. The anesthetic effect was definite, and the patient did not experience stinging or mucosal irritation. It was especially suitable for topical anesthesia procedures on the gingival area of children (such as extraction of deciduous teeth). Compared with conventional hydrogel topical anesthetic patches using ordinary chitosan and without polyγ-glutamic acid, the adhesion time was increased by more than 30%, and the uniformity of drug sustained release was increased by more than 40%.
[0027] Example 2 An oral hydrogel topical anesthetic patch comprises a novel composite hydrogel substrate, an anesthetic drug, and an antibacterial component. The novel composite hydrogel substrate is composed of the following components by weight percentage: sodium carboxymethyl cellulose 8%, hyaluronic acid 8%, polyvinyl alcohol 6%, quaternized modified chitosan 9%, polyγ-glutamic acid 3%, pectin 2%, propylene glycol 2%, borax 0.5%, and the balance being deionized water. The anesthetic drug is tetracaine, which has a mass fraction of 2% in the oral hydrogel topical anesthetic patch. The antibacterial component is menthol, which has a mass fraction of 0.5%. The degree of substitution of the quaternized modified chitosan is 0.3, and the molecular weight of the polyγ-glutamic acid is 10000 Da. The oral hydrogel topical anesthetic patch is 0.3 mm thick, shaped into a circle, and adapted to the buccal mucosa.
[0028] The preparation method of the above-mentioned oral hydrogel topical numbing patch includes the following steps: Step 1: Preparation of quaternized modified chitosan: Chitosan was dissolved in a 1% acetic acid solution, 3-chloro-2-hydroxypropyltrimethylammonium chloride was added, and the mixture was reacted in a 60°C water bath for 6 hours. The pH was adjusted to 7.0, and after precipitation, washing, and drying, quaternized modified chitosan with a degree of substitution of 0.3 was obtained. Step 2: Weigh 8g sodium carboxymethyl cellulose, 8g hyaluronic acid, 6g polyvinyl alcohol, 9g quaternized modified chitosan, and 3g polyγ-glutamic acid by weight percentage, add them to 59.5g deionized water, and stir at 300r / min for 60 minutes under 50℃ water bath conditions until completely dissolved to obtain a mixed substrate solution. Step 3: Add 2g of pectin and 2g of propylene glycol to the mixed substrate solution in sequence. Stir at 200r / min for 30 minutes under a 50℃ water bath. After mixing evenly, cool to room temperature. Step 4: Add 2g of tetracaine, 0.5g of borax, and 0.5g of menthol to the cooled solution at the same time, and stir at 200r / min for 40 minutes until tetracaine and menthol are evenly dispersed and borax is completely reacted to obtain the hydrogel precursor solution. Step 5: Pour the hydrogel precursor solution into a circular mold and place it in a constant temperature environment of 25°C for 24 hours to form a hydrogel preform; Step 6: Remove the hydrogel preform from the mold, cut it to the preset circular size (diameter 2.0cm), and sterilize it by ultraviolet irradiation for 60 minutes at an intensity of 200μW / cm². After sterilization, the oral hydrogel topical anesthetic patch is obtained.
[0029] The oral hydrogel topical anesthetic patch prepared in this embodiment, after testing, showed that the swelling degree of the novel composite hydrogel substrate was 120%, the adhesion time in the oral saliva environment was 45 minutes, and the sustained release time of the anesthetic drug was 35 minutes. After being applied to the buccal mucosa, it adhered tightly without any detachment due to saliva seepage, and the drug did not diffuse. The anesthetic effect was mild and long-lasting, and the menthol provided a cooling sensation, improving patient comfort. At the same time, it could inhibit the growth of oral bacteria and reduce mucosal irritation. Compared with conventional hydrogel topical anesthetic patches, the adhesion firmness and drug release uniformity were significantly improved, demonstrating the synergistic effect and inventiveness of the novel composite substrate of this invention.
[0030] Example 3 An oral hydrogel topical anesthetic patch comprises a novel composite hydrogel substrate, an anesthetic drug, and an antibacterial component. The novel composite hydrogel substrate is composed of the following components by weight percentage: sodium carboxymethyl cellulose 15%, hyaluronic acid 4%, polyvinyl alcohol 12%, quaternized modified chitosan 4%, polyγ-glutamic acid 7%, sodium alginate (adhesion regulator) 6%, glycerin (humectant) 5%, glutaraldehyde (crosslinking agent) 2%, and the balance being deionized water. The anesthetic drug is lidocaine, which has a mass fraction of 8% in the oral hydrogel topical anesthetic patch. The antibacterial component is honeysuckle extract, which has a mass fraction of 1%. The degree of substitution of the quaternized modified chitosan is 0.6, and the molecular weight of the polyγ-glutamic acid is 50,000 Da. The oral hydrogel topical anesthetic patch has a thickness of 1.0 mm and is made into an irregular shape to fit the gingival area around the molars.
[0031] The preparation method of the above-mentioned oral hydrogel topical numbing patch includes the following steps: Step 1: Preparation of quaternized modified chitosan: Chitosan was dissolved in a 3% acetic acid solution, 3-chloro-2-hydroxypropyltrimethylammonium chloride was added, and the mixture was reacted in an 80°C water bath for 4 hours. The pH was adjusted to 7.5, and after precipitation, washing, and drying, quaternized modified chitosan with a degree of substitution of 0.6 was obtained. Step 2: Weigh 15g sodium carboxymethyl cellulose, 4g hyaluronic acid, 12g polyvinyl alcohol, 4g quaternized modified chitosan, and 7g polyγ-glutamic acid by weight percentage, add them to 45g deionized water, and stir at 500r / min for 30 minutes under 70℃ water bath conditions until completely dissolved to obtain a mixed substrate solution. Step 3: Add 6g sodium alginate and 5g glycerol to the mixed substrate solution in sequence. Stir at 300r / min for 15 minutes under 70℃ water bath conditions. After mixing evenly, cool to room temperature. Step 4: Add 8g lidocaine, 2g glutaraldehyde, and 1g honeysuckle extract to the cooled solution at the same time, and stir at 300r / min for 20 minutes until lidocaine and honeysuckle extract are evenly dispersed and glutaraldehyde is completely reacted to obtain the hydrogel precursor solution. Step 5: Pour the hydrogel precursor solution into an irregularly shaped mold (fitting the gingiva around the molars), place it in a constant temperature environment of 35℃ and let it stand for 12 hours to form a hydrogel preform; Step 6: Remove the hydrogel preform from the mold, fine-tune its size, and sterilize it by ultraviolet irradiation for 30 minutes at an intensity of 300 μW / cm². After sterilization, the oral hydrogel topical anesthetic patch is obtained.
[0032] The oral hydrogel topical anesthetic patch prepared in this embodiment, after testing, showed that the swelling degree of the novel composite hydrogel substrate was 240%, the adhesion time in the oral saliva environment was 55 minutes, and the sustained release time of the anesthetic drug was 60 minutes. After being applied to the gingival area around the molars, it could adapt to the uneven gingival surface, firmly fix it, and resist the risk of dislodgement caused by chewing movements, with no drug diffusion. The anesthetic drug concentration was uniform, and the anesthetic effect was strong, making it suitable for moderate topical anesthesia before molar extraction. Honeysuckle extract could effectively inhibit oral bacteria and reduce the risk of infection. Compared with conventional hydrogel topical anesthetic patches, its adhesion, drug sustained release time, and anesthetic effect were all significantly improved.
[0033] Comparative Example 1 Compared with Example 3, the difference is that the quaternized modified chitosan is replaced with an equal amount of polyγ-glutamic acid.
[0034] The oral hydrogel topical anesthetic patch prepared in this comparative example, after testing, showed that the swelling degree of the novel composite hydrogel substrate was 100%, the adhesion time in the oral saliva environment was 42 minutes, and the sustained release time of the anesthetic drug was 25 minutes. After being applied to the gingival area around the molars, it could basically adapt to the uneven gingival surface, firmly fix it, and resist the risk of falling off due to chewing movements; however, the anesthetic effect was poor.
[0035] Comparative Example 2 Compared with Example 3, the difference is that polyγ-glutamic acid is replaced with an equal amount of quaternized modified chitosan.
[0036] The oral hydrogel topical anesthetic patch prepared in this comparative example, after testing, showed that the swelling degree of the novel composite hydrogel substrate was 110%, the adhesion time in the oral saliva environment was 39 minutes, and the sustained release time of the anesthetic drug was 32 minutes. After being applied to the gingival area around the molars, it could basically adapt to the uneven gingival surface, firmly fix it, and resist the risk of falling off due to chewing movements; however, the anesthetic effect was poor.
[0037] Comparative Example 3 Compared with Example 3, the difference is that hyaluronic acid is replaced with an equal amount of polyvinyl alcohol.
[0038] The oral hydrogel topical anesthetic patch prepared in this embodiment, after testing, showed that the swelling degree of the novel composite hydrogel substrate was 150%, the adhesion time in the oral saliva environment was 15 minutes, and the sustained release time of the anesthetic drug was 47 minutes. However, after being applied to the gingival area around the molars, it could not adapt to the uneven gingival surface, was not firmly fixed, could not counteract the risk of falling off due to chewing movements, and the drug diffused.
[0039] Comparative Example 4 Compared with Example 3, the difference is that polyvinyl alcohol is replaced with an equal amount of hyaluronic acid.
[0040] The oral hydrogel topical anesthetic patch prepared in this embodiment, after testing, showed that the swelling degree of the novel composite hydrogel substrate was 1350%, the adhesion time in the oral saliva environment was 14 minutes, and the sustained release time of the anesthetic drug was 36 minutes. However, after being applied to the gingival area around the molars, it could not adapt to the uneven gingival surface, was not firmly fixed, could not counteract the risk of falling off due to chewing movements, and the drug diffused.
[0041] Comparative Example 5 Compared with Example 3, the difference is that polyvinyl alcohol is replaced with an equal amount of quaternized modified chitosan.
[0042] The oral hydrogel topical anesthetic patch prepared in this embodiment, after testing, showed that the swelling degree of the novel composite hydrogel substrate was 128%, the adhesion time in the oral saliva environment was 21 minutes, and the sustained release time of the anesthetic drug was 45 minutes. However, after being applied to the gingival area around the molars, it could not adapt to the uneven gingival surface, was not firmly fixed, could not counteract the risk of falling off due to chewing movements, and the drug diffused.
[0043] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.
Claims
1. A hydrogel topical anesthetic patch for oral cavity, characterized in that, The hydrogel topical anesthetic patch comprises a composite hydrogel substrate and an anesthetic drug loaded on the composite hydrogel substrate; the composite hydrogel comprises, by mass percentage: 8%-15% sodium carboxymethyl cellulose, 4%-8% hyaluronic acid, 6%-12% polyvinyl alcohol, 4%-9% quaternized modified chitosan, 3%-7% polyγ-glutamic acid, 2%-6% adhesion modifier, 2%-5% humectant, 0.5%-2% crosslinking agent, and an appropriate amount of water; the anesthetic drug is lidocaine or tetracaine, and its mass fraction in the oral hydrogel topical anesthetic patch is 2%-8%.
2. The oral hydrogel topical anesthetic patch according to claim 1, characterized in that, The degree of substitution of the quaternized modified chitosan is 0.3-0.6, and it is prepared by reacting chitosan with 3-chloro-2-hydroxypropyltrimethylammonium chloride; the molecular weight of the polyγ-glutamic acid is 10000-50000 Da.
3. The oral hydrogel topical anesthetic patch according to claim 1, characterized in that, The adhesion regulator includes sodium alginate or pectin; the humectant includes glycerin or propylene glycol; and the crosslinking agent includes glutaraldehyde or borax.
4. The oral hydrogel topical anesthetic patch according to claim 1, characterized in that, The thickness of the oral hydrogel topical anesthetic patch is 0.3-1.0 mm; The composite hydrogel substrate has a swelling degree of 80%-250%, maintains morphological stability in the oral saliva environment, has an adhesion time of not less than 40 minutes, and has a sustained release time of 30-60 minutes for the anesthetic drug.
5. The oral hydrogel topical anesthetic patch according to claim 1, characterized in that, It also includes an antibacterial component at a mass ratio of 0.1%-1%, which includes honeysuckle extract or menthol.
6. A method for preparing an oral hydrogel topical numbing patch as described in any one of claims 1-5, characterized in that, Includes the following steps: Quaternized modified chitosan was prepared, and sodium carboxymethyl cellulose, hyaluronic acid, polyvinyl alcohol, quaternized modified chitosan and polyγ-glutamic acid were weighed by weight percentage, added to deionized water, and stirred in a water bath at 50-70℃ until completely dissolved to obtain a mixed substrate solution. Add an adhesion regulator and a humectant to the obtained mixed substrate solution in sequence, stir under a water bath at 50-70°C, mix evenly, and then cool to room temperature to obtain a cooled solution. The anesthetic drug and cross-linking agent were added sequentially to the cooled solution and stirred until the anesthetic drug was evenly dispersed and the cross-linking agent was completely reacted, thus obtaining the hydrogel precursor solution. The hydrogel precursor solution is poured into a mold of a pre-designed shape and left to stand at room temperature to form a hydrogel preform. The obtained hydrogel preform is removed from the mold and cut to the preset size according to the needs of the target anesthesia site in the oral cavity. After sterilization, the oral hydrogel topical anesthetic patch can be obtained.
7. The method for preparing the oral hydrogel topical numbing patch according to claim 6, characterized in that, The method for preparing quaternized modified chitosan is as follows: dissolve chitosan in an acetic acid solution with a mass fraction of 1%-3%, add 3-chloro-2-hydroxypropyltrimethylammonium chloride, react in a water bath at 60-80℃ for 4-6 hours, adjust the pH to 7.0-7.5, take the precipitate, wash and dry it to obtain quaternized modified chitosan.
8. The method for preparing the oral hydrogel topical numbing patch according to claim 6, characterized in that, In the step of stirring until completely dissolved under a water bath at 50-70℃, stir at 300-500 rpm for 30-60 minutes; and / or, In the step of stirring under a water bath at 50-70℃, the stirring speed is 200-300 rpm; and / or, The anesthetic drug and cross-linking agent were added to the cooled solution in sequence, and the stirring was carried out at a stirring speed of 200 rpm-300 rpm.
9. The method for preparing the oral hydrogel topical numbing patch according to claim 6, characterized in that, In the step of adding anesthetic drugs and cross-linking agents to the cooled solution in sequence, antibacterial components were also added at the same time.
10. The preparation method according to claim 6, characterized in that, The process of allowing the material to stand at room temperature for molding involves standing at 25-35℃ for 12-24 hours; the aseptic treatment involves sterilization by ultraviolet irradiation for 30-60 minutes at an intensity of 200-300 μW / cm². 2 .