Oral patch with pH buffering and saliva stimulating functions

Abstract

This invention discloses an oral patch for regulating the oral microenvironment, aiming to resolve the contradiction between the inability of existing technologies to simultaneously achieve long-lasting saliva stimulation and maintain a healthy oral pH level. The invention employs a multi-layered composite structure, consisting of, from the oral contact side to the outer side: a sequential flavor release layer (D), a saliva stimulation and physical release layer (C), a functional core layer (B), and a backing layer (A). The functional core layer (B) comprises a pH buffering system composed of phosphate buffer pairs and prebiotics, configured to dynamically stabilize the local oral pH within the healthy range of 6.5-7.5 and provide nutrients for beneficial bacteria. The saliva stimulation and physical release layer (C) comprises a non-pH-disrupting saliva stimulation system composed of a cooling agent and sugar alcohol, explicitly excluding organic acids. Through synergy with the microscopic uneven structure of layer (C), it safely and persistently stimulates saliva secretion. The sequential flavor release layer (D) consists of at least two sublayers with different dissolution rates and different microscopic irregularities, each encapsulating microencapsulated flavorings to achieve sequential, pulsed release of flavor and texture. This invention, through a multi-mechanism of "intelligent buffering-microbial feeding" and "synergistic effects of smell, taste, and touch," fundamentally achieves a synergistic unity of long-lasting fresh breath, stable oral pH, and optimized microbial ecology.

Description

[0001] This invention belongs to the field of oral care products technology, specifically relating to a smart patch that can adhere to the oral cavity for a long time and regulate the oral microenvironment through multiple mechanisms to achieve fundamental fresh breath.

[0002] The root cause of bad breath is mainly due to an imbalance in the oral microecology: insufficient saliva secretion leads to a decline in self-cleaning ability, the oral pH value deviates from the healthy range (usually becoming acidic), and the resulting overgrowth of harmful bacteria.

[0003] Existing solutions each have significant drawbacks: Oral ulcer patches: Their original design purpose was to physically isolate the wound and provide sustained-release anti-inflammatory and analgesic medications. Their materials are typically unidirectional barriers with a single function, completely lacking the ability to continuously stimulate healthy gums, regulate pH levels, or maintain a healthy bacterial flora. They address the problem of "local lesions," not the problem of "maintaining a healthy environment."

[0004] Chewing gum and lozenges: While they can temporarily freshen breath, they lack a sustained, localized effect. Their effect is short-lived, typically lasting only 5-40 minutes, failing to provide long-term oral hygiene management. Furthermore, organic acids such as citric acid are often added to stimulate saliva production. The research progress on oral care products (Science Press, 1st edition, 2024, p. 125) points out that traditional saliva stimulation methods rely heavily on organic acids, which, with long-term use, lower oral pH, erode tooth enamel, and deteriorate the oral environment, contradicting long-term health goals. Moreover, the facial expression management required for chewing gum / lozenges and the resulting oral noises can easily lead to embarrassment in social situations such as work meetings and dates, a significant reason for their market decline.

[0005] Probiotic ulcer patches: Directly adding probiotics to oral ulcer patches often fails because the bacteria cannot colonize in an inflammatory environment or under unfavorable pH conditions. The core reason for the failure of probiotic ulcer patches is that when the pH of the inflammatory environment is <6.5, the activity of probiotics decreases by more than 60%, and they cannot effectively proliferate on the ulcer wound.

[0006] Therefore, there is an urgent need in this field for an innovative product that can release fragrance over a long period, provide sustained effects, and work synergistically across four dimensions—stimulating saliva, stabilizing pH, and optimizing the oral microbiota—to fundamentally create and maintain a healthy oral microenvironment. III. Summary of the Invention

[0007] The purpose of this invention is to provide an oral patch that can work continuously for more than 4 hours and solve the problem of halitosis from the root.

[0008] Specifically, the purpose of this invention includes: to safely, persistently and efficiently promote saliva secretion through a mechanism of 'sense-gustatory-touch synergy'.

[0009] Through the synergistic mechanism of 'intelligent buffering and microbial feeding', a healthy oral microenvironment is maintained for a long time, especially by stabilizing the local pH within a healthy range.

[0010] Resolving inherent technical contradictions: By constructing a synergistic system of 'non-pH-interference salivary stimulation system' and 'intelligent buffering system', the inherent contradiction of 'stimulating saliva' and 'maintaining a healthy pH' in traditional technologies can be completely resolved.

[0011] To achieve the above objectives, the present invention adopts the following technical solution: A smart responsive oral patch for regulating the oral microenvironment, characterized by a multi-layered composite structure comprising, from the oral contact side to the outer side: a sequential flavor release layer (layer D), a salivary stimulation and physical release layer (layer C), a functional core layer (layer B), and a backing layer (layer A); specifically including:

[0012] Material and Structure: Made from safe bioadhesive polymers, such as HPMC (50-70%) and carbomer (30-50%) dissolved in purified water. Its adhesion surface to the gums or teeth can be designed with micro-indentations or specific rough textures.

[0013] Function: Provides safe, gentle, and long-lasting adhesion to tooth or gum surfaces, ensuring the patch remains in place for 4-6 hours. The microstructure of this layer helps increase the adhesive surface area and stability.

[0014] Composition and Structure: Contains a "pH buffer-prebiotic complex system". The surface of this layer can also be prepared with a unique micro-uneven structure (e.g., square grid).

[0015] Function and Mechanism: pH Buffering System: Composed of food-grade phosphate buffer pairs (such as disodium hydrogen phosphate / sodium dihydrogen phosphate), accounting for 0.5-2 wt% of the total mass. These phosphate buffer pairs coexist in the functional layer in a specific molar ratio and are stable. When dissolved in saliva, they rapidly establish a dynamic equilibrium (H₂PO₄⁻ ⇌ H⁺ + HPO₄²⁻). This equilibrium system is the core of its 'smart sponge' function: when the environment is acidic (increased H⁺), the equilibrium shifts to the left, and HPO₄²⁻ combines with H⁺; when the environment is alkaline (increased OH⁻), the equilibrium shifts to the right, and H₂PO₄⁻ dissociates to release H⁺, thereby dynamically stabilizing the pH of the microenvironment around the patch within a healthy range of 6.8-7.5.

[0016] Prebiotics: such as fructooligosaccharides (FOS), which account for 1-5 wt% of the total mass of the functional core layer. Their function is to provide specific nutrition for beneficial bacteria inherent in the oral cavity (such as Streptococcus salivarius), actively promote their reproduction, and thus competitively inhibit harmful bacteria.

[0017] Structural and functional enhancement: The concave and convex structure of this layer is exposed after the C layer dissolves, which can continue to provide different physical stimulation than the preceding layer and release the internal functional components into the oral environment more efficiently.

[0018] Structure: This layer is designed with a safe and rounded micro-protrusion structure (such as hexagon), with a protrusion height of 10-50μm.

[0019] Principle and Function: Through in-depth research, the inventors discovered that when the oral mucosa is subjected to continuous and varying physical contact stimulation, it promotes a significant increase in the secretion rate and volume of salivary glands via a neural reflex arc. This is an inherent physiological protective mechanism of the human body. Traditional oral ulcer patches aim to minimize this stimulation, while this invention takes the opposite approach, actively and controllably utilizing this physiological mechanism.

[0020] Ingredients: Non-pH-interfering salivary stimulation system containing a high-intensity cooling agent (such as WS-23, 0.1-1wt%) and non-cariogenic sugar alcohols (such as xylitol 1-5wt% / erythritol 1-3wt%).

[0021] Key Inventive Step: A key choice of this invention is that the non-pH-disrupting salivary stimulation system explicitly does not contain (or excludes) organic acids such as citric acid and malic acid that significantly reduce oral pH.

[0022] Structure: This is the outermost layer (in direct contact with saliva), composed of at least two sublayers (e.g., layers D1 and D2). These sublayers achieve sequential disintegration using film-forming materials with different dissolution rates (e.g., hydroxypropyl methylcellulose of varying viscosities). The core innovation lies in the fact that these sublayers not only have different dissolution rates, but their surfaces in contact with saliva are also pre-shaped with distinct microscopic irregularities (e.g., layer D1 has spherical protrusions, and layer D2 has mountain-shaped protrusions). Furthermore, the irregularity of each sublayer is completely different from the irregularity of its adjacent layers (including layer C).

[0023] Ingredients and Functions: Each sublayer encapsulates a different microencapsulated flavoring (such as orchid, jasmine, white tea, etc.). For example, layer D1 (fast-release layer) releases a "fresh mint" flavor within 0-30 minutes, while layer D2 (slow-release layer) releases an "elegant white tea" flavor within 30-120 minutes. The microcapsules achieve "pulsating" and "sequential" release through saliva flushing and friction between the tongue and the uneven structure. The released aroma molecules, through the olfactory pathway, together with the sweetness and coolness perceived through the gustatory pathway and the physical stimulation of the uneven structure perceived through the tactile pathway, collectively create a multi-directional, three-dimensional stimulation of the salivary glands.

[0024] Synergistic Stimulation Mechanism: Once the outermost D2 layer dissolves completely, the spherical, uneven structure of the D1 layer, which was originally filled with its material, is fully exposed, providing the user with a completely new tactile experience. As the D1 layer dissolves, the hexagonal, uneven structure of the C layer itself becomes visible. Furthermore, as the C layer dissolves, the square grid structure of the underlying B layer is also exposed. This progressively evolving, continuously changing programmed synergistic refreshing mechanism of "olfaction-gustatory-tactile sensation" thoroughly and programmatically blocks sensory adaptation from multiple sensory dimensions, thereby maximizing the effect of saliva stimulation.

[0025] Compared with the prior art, the present invention has the following outstanding substantive features and significant progress: Problem innovation: It completely shifts the product positioning from "treating local lesions" or "temporarily masking odor" to "actively managing and maintaining the micro-ecological environment of a healthy oral cavity", solving a completely new and more fundamental technical problem.

[0026] System Synergy and Long-Lasting Synergistic Effects: This invention is not simply a collection of components. 'Mechanical stimulation (tactile),' 'flavor stimulation (gustatory),' and 'aroma stimulation (olfactory)' work synergistically through different physiological pathways to ensure the persistence and intensity of saliva secretion; while the 'pH buffering system' creates a necessary environment for prebiotics to thrive, and the two work together to achieve targeted microbial regulation. These subsystems are interconnected and mutually reinforcing, jointly achieving a simultaneous and long-lasting enhancement of the effects of 'saliva secretion, pH stability, and microbial balance.' This comprehensive effect cannot be achieved by a single system or simply by combining existing technologies.

[0027] Experimental data support: In the in vitro co-culture model with the control group (containing 0.5% citric acid, without pH buffer system), the number of beneficial bacteria (Salinomyces streptococci) in the present invention group increased by about 3 times compared with the blank control group (p<0.01), and the number of Fusobacterium nucleatum decreased by 40% (p<0.05) (t-test performed using SPSS 26.0) (culture conditions: 37℃, anaerobic environment, 24 hours).

[0028] Technological Breakthrough: The "non-pH-interference saliva stimulation system" was creatively proposed, successfully resolving the conflicting goals of "stimulating saliva" and "maintaining a neutral and healthy pH" in traditional solutions.

[0029] This invention achieves a programmed synergistic refresh of olfaction, taste, and touch: By designing a sequential flavor layer (D layer) and a physical release layer (C layer) with different microscopic irregularities, the invention sequentially presents a variety of different physical sensations during use, synchronized with the release of different flavors and aromas. This design of combined 'olfaction-taste-touch' staged changes produces a synergistic stimulation effect far exceeding that of single or dual sensory changes, ensuring that the salivation rate remains at a peak level throughout the entire treatment cycle.

[0030] Ultimate User Experience: Through all the technologies mentioned above, a long-lasting, elegant, unembarrassing, and enjoyable user experience is provided, effectively combating sensory fatigue and greatly enhancing user stickiness.

[0031] Preparation of the backing layer (Layer A): Hydroxypropyl methylcellulose (HPMC) and polycarboxymethyl cellulose are dissolved in purified water, cast into a film, and dried to form the backing layer.

[0032] Preparation of functional core layer (B layer) slurry: Xylitol, WS-23 cooling agent, disodium hydrogen phosphate, sodium dihydrogen phosphate, and fructooligosaccharides (FOS) are uniformly dispersed in an ethanol solution of polyvinylpyrrolidone (PVP) to form a homogeneous slurry.

[0033] Coating and molding: The above slurry is coated onto the backing layer. While the slurry is not completely dry, it is embossed using a mold with microscopic hexagonal protrusions to form a textured structure of the "saliva stimulation and physical release layer (C layer)".

[0034] Cutting and Packaging: After drying, cut it into circular patches with a diameter of 3-8mm and a thickness of 100-150μm, and package them in aluminum foil.

[0035] The backing layer (layer A), the functional core layer (layer B), and the saliva stimulation and physical release layer (layer C) with hexagonal concave-convex features were prepared according to the method of Example 1.

[0036] Preparation of sequential flavor release layer (D layer): D1 layer slurry and molding: Low viscosity HPMC with fast disintegration rate is mixed with "mint" flavor microcapsules in solvent, coated on C layer, and embossed on the surface using a mold with spherical protrusions, and then dried.

[0037] D2 Layer Slurry and Molding: High-viscosity HPMC with a slow disintegration rate is mixed with "white tea" flavored microcapsules in a solvent, coated on the D1 layer, and embossed on the surface using a mold with mountain-shaped protrusions, and then dried.

[0038] Cutting and packaging.

[0039] Test conditions: The patch was placed in simulated saliva with an initial pH of 6.0 at a constant temperature of 37℃ (the ingredients are based on the standard formula in "Oral Biochemistry") to simulate the oral environment.

[0040] The comparative sample (containing 0.5% citric acid, without a pH buffer system) rapidly (within 5 minutes) lowered the local pH to below 5.0 after use, and the aroma and cooling sensation largely disappeared after 15 minutes.

[0041] In Example 2 of this invention, the pH was raised and stabilized within the range of 7.0 ± 0.2 within 5 minutes, and the cooling sensation and aroma lasted for more than 4 hours. Through tactile simulation testing, it can be confirmed that the surface morphology underwent the expected phased changes as it dissolved.

[0042] Conclusion: This comparative experiment demonstrates that the present invention, through a specific combination of components and structures, not only successfully resolves the contradiction between 'stimulating saliva' and 'maintaining a healthy pH', but also achieves a significant improvement in the durability of the effect through a synergistic mechanism.

[0043] A double-blind test was conducted on 20 healthy volunteers, evaluating factors including pH stability, saliva production, aroma persistence, and perceived changes in tactile sensation. Results showed that the oral patch prepared in Example 2 of this invention could raise the local pH from 6.2 to around 7.0 within 5 minutes of application and maintain this level for over 4-6 hours. Its cooling sensation, aroma, and progressively changing tactile sensation were continuously perceptible, and it had a comfortable taste without any acidic or uncomfortable feeling.

[0044] An oral patch for regulating the oral microenvironment, characterized in that, from the oral contact side to the outer side, it comprises, in sequence: a sequential flavor release layer (layer D), a salivary stimulation and physical release layer (layer C), a functional core layer (layer B), and a backing layer (layer A); wherein the functional core layer (layer B) comprises: a) an intelligent buffering system consisting of food-grade phosphate buffer pairs configured to dynamically stabilize the local oral pH within the range of 6.5 to 7.5; b) prebiotics; wherein the salivary stimulation and physical release layer (layer C) comprises a non-pH-disrupting salivary stimulation system containing a cooling agent and sugar alcohol, and does not contain organic acids.

[0045] The oral patch as described in claim 1 is characterized in that the saliva contact surface of the saliva stimulation and physical release layer (C layer) has a micro-uneven structure.

[0046] The oral patch as described in claim 2 is characterized in that the micro-uneven structure is an irregular, rounded geometric shape with a protrusion height of 10-50 μm, which is used to provide continuously changing physical stimulation to maintain the persistence of saliva secretion.

[0047] The oral patch as claimed in claim 1, wherein the sequential flavor release layer (D layer) comprises microencapsulated flavoring.

[0048] The oral patch as described in claim 1 or 4 is characterized in that the sequential flavor release layer (D layer) comprises at least two sublayers that dissolve at different time periods to sequentially release different flavors of fragrance.

[0049] The oral patch as claimed in claim 5 is characterized in that at least two sublayers of the sequential flavor release layer (D layer) have different microscopic irregularities on their surfaces that come into contact with saliva.

[0050] The oral patch as described in claim 6 is characterized in that the surface of the saliva stimulation and physical release layer (C layer) also has a micro-uneven structure, and the uneven structure is different from the uneven structure of the adjacent D layer sublayer.

[0051] The oral patch as described in claim 1 is characterized in that the surface of the functional core layer (B layer) also has a micro-uneven structure.

[0052] The oral patch as described in claim 1 is characterized in that the adhesive surface of the backing layer (layer A) has a microscopic recessed or rough textured structure.

[0053] The oral patch as described in claim 1, wherein the phosphate buffer pair is a mixture of disodium hydrogen phosphate and sodium dihydrogen phosphate.

[0054] The oral patch as described in claim 1 is characterized in that the prebiotic is fructooligosaccharide (FOS).

[0055] The oral patch as described in claim 1 is characterized in that the cooling agent is selected from one or more of WS-23, menthol, and peppermint extract.

[0056] The oral patch according to claim 1, wherein the sugar alcohol is xylitol and / or erythritol.

[0057] The oral patch provided by this invention can be used not only for daily breath freshening, but also for auxiliary care of patients with dry mouth, oral environment maintenance for people wearing braces or dentures, and for quickly improving oral health before specific social occasions. Attached Figure Description Figure 1 This is a schematic diagram of the overall structure after explosion.

Claims

1. Claims An oral patch for regulating the oral microenvironment, characterized in that, From the oral contact side to the outside, the layers are as follows: a sequential flavor release layer (layer D), a salivary stimulation and physical release layer (layer C), a functional core layer (layer B), and a backing layer (layer A); wherein the functional core layer (layer B) comprises: a) an intelligent buffering system consisting of food-grade phosphate buffer pairs configured to dynamically stabilize the local oral pH within the range of 6.5 to 7.5; b) prebiotics; the salivary stimulation and physical release layer (layer C) comprises a non-pH-disrupting salivary stimulation system containing a cooling agent and sugar alcohol, and does not contain organic acids.

2. The oral patch as described in claim 1, characterized in that, The saliva contact surface of the saliva stimulation and physical release layer (C layer) has a microscopic uneven structure.

3. The oral patch as described in claim 2, characterized in that, The micro-uneven structure has an irregular, rounded geometric shape with a protrusion height of 10-50 μm, which is used to provide continuously changing physical stimulation to maintain the persistence of saliva secretion.

4. The oral patch as described in claim 1, characterized in that, The sequential flavor release layer (D layer) contains microencapsulated flavorings.

5. The oral patch as described in claim 1 or 4, characterized in that, The sequential flavor release layer (D layer) comprises at least two sublayers that dissolve at different time periods to sequentially release flavorings of different flavors.

6. The oral patch as described in claim 5, characterized in that, The sequential flavor release layer (D layer) has at least two sublayers, each of which has a different microscopic texture on the surface that comes into contact with saliva.

7. The oral patch as described in claim 6, characterized in that, The surface of the saliva stimulation and physical release layer (C layer) also has a micro-uneven structure, and this uneven structure is different from the uneven structure of the adjacent D layer sublayer.

8. The oral patch as described in claim 1, characterized in that, The surface of the functional core layer (B layer) also has a microscopic uneven structure.

9. The oral patch as described in claim 1, characterized in that, The adhesive surface of the backing layer (layer A) has a micro-depression or rough texture structure.

10. The oral patch as described in claim 1, characterized in that, The phosphate buffer pair is a mixture of disodium hydrogen phosphate and sodium dihydrogen phosphate.

11. The oral patch as described in claim 1, characterized in that, The prebiotic is fructooligosaccharide (FOS).

12. The oral patch as described in claim 1, characterized in that, The cooling agent is selected from one or more of WS-23, menthol, and peppermint extract.

13. The oral patch as described in claim 1, characterized in that, The sugar alcohol is xylitol and / or erythritol.

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