Antibacterial gingival protection oral toothpaste and preparation method thereof

Abstract

The application discloses a bacteriostatic gingival protection oral toothpaste and a preparation method thereof. The preparation method comprises the following steps: performing microporous membrane purification on essential oil, and activating Lactobacillus plantarum LN66 for standby; stirring water, a humectant and a thickening agent to form a base at a temperature of 30 DEG C to 40 DEG C; pre-mixing the purified essential oil and a flavoring essence at room temperature, and then adding the pre-mixed essential oil and flavoring essence into the activated Lactobacillus plantarum LN66 to form a compound liquid by low-speed stirring; introducing the compound liquid into the base, and then adding a rubbing agent, a foaming agent and a sweetening agent in sequence, stirring, and then performing high-pressure homogenization treatment; and performing negative pressure degassing treatment and filling and packaging. The application can effectively improve the sterilization capacity for specific pathogenic bacteria, inhibit the contact toxicity of essential oil terpenes on probiotics, ensure a high survival rate of active substances and realize targeted release under physical shearing force during tooth brushing, and realize long-acting gingival protection and bacteriostatic effect.

Description

Technical Field

[0001] This application relates to the field of oral care technology, and more specifically, to an antibacterial and gum-protecting oral toothpaste and its preparation method. Background Technology

[0002] Oral diseases are common chronic illnesses in humans, with dental caries, periodontitis, and halitosis being directly related to the abnormal growth of harmful bacteria in the oral cavity. Studies have shown that *Porphyromonas gingivalis*, *Streptococcus mutans*, and *Helicobacter pylori* are the core pathogens causing these problems, and *Helicobacter pylori* can be transmitted orally, making it an important potential cause of digestive tract-related diseases.

[0003] Traditional toothpastes primarily function through physical cleaning, typically adding only small amounts of chemical antibacterial agents to achieve their antibacterial effect. These products have relatively weak antibacterial targeting and low sterilization rates, failing to effectively inhibit the aforementioned core pathogenic bacteria. Some toothpastes using natural antibacterial ingredients suffer from limited synergy between different substances due to their single composition, making it difficult to achieve multi-dimensional oral care. Furthermore, a more significant engineering challenge lies in the lack of barrier design for active ingredients in traditional natural formulas. When antibacterial essential oils and probiotics are directly mixed in the matrix, the active ingredients of the natural essential oils can easily cause contact killing of the added probiotics. Simultaneously, during industrial manufacturing, conventional high-temperature treatments and high-speed homogenization processes generate excessive shear heat and mechanical damage, leading to rapid inactivation of the microbial cells and natural active ingredients, severely shortening the product's shelf life. Summary of the Invention

[0004] This application provides an antibacterial and gum-protecting oral toothpaste and its preparation method, which solves the technical problems of traditional toothpaste having a single antibacterial ingredient that easily leads to the inactivation of probiotics, and the production process that easily destroys the active ingredients.

[0005] This application provides a method for preparing an antibacterial and gum-protecting oral toothpaste. By weight percentage, the raw materials include 0.2% to 5% essential oil, 0.05% to 2% Lactobacillus plantarum LN66, 20% to 40% abrasive, 10% to 30% humectant, 0.5% to 3% thickener, and the balance being water, foaming agent, sweetener, and fragrance.

[0006] The preparation method includes: purifying the essential oil using a microporous membrane filter and activating the *Lactobacillus plantarum* LN66 for later use; stirring the water, the humectant, and the thickener at a temperature of 30°C to 40°C to form a base material; premixing the purified essential oil and the fragrance at room temperature, then adding the activated *Lactobacillus plantarum* LN66 and stirring at a low speed of 100 r / min to 200 r / min to form a compound solution; introducing the compound solution into the base material, then sequentially adding the abrasive, the foaming agent, and the sweetener and stirring, followed by high-pressure homogenization twice under a pressure of 20 MPa to 30 MPa; performing negative pressure degassing treatment and filling and packaging, wherein the negative pressure degassing treatment pressure is -0.08 MPa to -0.1 MPa.

[0007] Optionally, the purification of the essential oil by microporous filtration is configured to perform a two-stage series filtration process on the essential oil using a polytetrafluoroethylene hydrophilic filter membrane with a pore size of 0.22 micrometers; the activation of the Lactobacillus plantarum LN66 for later use is configured to inoculate the freeze-dried Lactobacillus plantarum LN66 into a skim milk culture medium and perform a resuscitation and activation treatment in a constant temperature incubator.

[0008] Optionally, the step of resuscitation and activation treatment in a constant temperature incubator is configured to perform a first-stage constant temperature incubation at an initial temperature of 37°C until the optical density value of the bacterial solution reaches the critical point of the logarithmic growth phase; then, a gradient cooling program is started, and the incubation temperature is reduced to 25°C at a cooling rate of 0.5°C per minute and maintained stably; in the step of adding the activated Lactobacillus plantarum LN66 and stirring at a low speed of 100 r / min to 200 r / min to form a compound solution, a double planetary mixer with a flexible silicone scraper is used to perform the stirring action.

[0009] Optionally, the raw material for preparation further comprises mesoporous silica, which is configured as a loading carrier for the essential oil and forms loading particles.

[0010] Optionally, the thickener is xanthan gum, and the preparation method further includes a surface sealing step after forming the loaded particles. The surface sealing step is configured to mix the loaded particles with a dissolved xanthan gum solution, wherein the xanthan gum adheres to the mesoporous outer surface of the loaded particles through electrostatic adsorption and physical entanglement, and forms a shear-responsive sealing shell layer with a thickness of 100 nm to 200 nm on the mesoporous outer surface.

[0011] Optionally, the process of attaching to the mesoporous outer surface of the loaded particles is defined as follows: by adjusting the pH value of the mixing system to make the molecular chains of xanthan gum extend and expose negatively charged side chain groups; by using surface modification technology to pre-carry a positive charge on the surface of the mesoporous silica, the xanthan gum molecular chains are deposited on the mesoporous outer surface; as the deposition density increases, the long polymer chains of xanthan gum undergo steric crosslinking and physical entanglement and solidify to form a dense shear-responsive sealing shell. This shear-responsive sealing shell maintains a closed and isolated structure in a static state and collapses when subjected to mechanical frictional shear force.

[0012] Optionally, during the high-pressure homogenization process, an online viscometer is used for real-time feedback control; the online viscometer is installed in the main pipeline of the homogenizing equipment, and is configured to measure the dynamic viscosity data of the homogenized system in real time and transmit the dynamic viscosity data to the controller of the homogenizing equipment, and the controller adjusts the actual driving speed of the homogenizing equipment based on the dynamic viscosity data.

[0013] Optionally, the controller performs an adaptive limiting operation, which includes establishing an adaptive rotation speed conversion model for the paste-hydrogel system based on the fluid internal friction law; the online viscometer refreshes and outputs the dynamic viscosity data at a frequency of 100Hz; the controller combines the dynamic viscosity data and the rotation speed conversion model to calculate in real time the current maximum permissible rotation speed limit without exceeding the critical yield strength of 4500Pa for the paste-hydrogel system; during the homogenization and mixing stages, the controller acquires the control signal of the intervention power output module in real time and limits the actual driving speed of the homogenizing equipment to no more than 95% of the current maximum permissible rotation speed limit.

[0014] Optionally, the negative pressure degassing process is configured as a multi-stage stepped vacuuming operation, which includes reducing the pressure to -0.05 MPa and holding it for a specified time, followed by a second pressure reduction to a target range of -0.08 MPa to -0.1 MPa.

[0015] This application also provides an antibacterial and gum-protecting oral toothpaste, which is prepared using the above-described method for preparing antibacterial and gum-protecting oral toothpaste.

[0016] This application utilizes natural Murraya paniculata essential oil (preferably Murraya paniculata (Emei Mountain) essential oil) combined with activated Lactobacillus plantarum to form a compound dual antibacterial engine, effectively enhancing the bactericidal ability against specific pathogenic bacteria such as Porphyromonas gingivalis. By combining a specific mesoporous silica encapsulation method with homogeneous adaptive feedback control, it inhibits the toxicity of terpenoids in the essential oil to probiotics, overcoming the pain point of failure caused by the incompatibility between active bacteria and plant antibacterial components, ensuring a high survival rate of active ingredients in the product within its shelf life, and enabling targeted release under the physical shear force of brushing, thus achieving long-lasting gum protection and antibacterial effects. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the production system provided in an embodiment of the present invention.

[0018] Figure 2 This is a flowchart of the preparation method provided in the embodiments of the present invention.

[0019] Figure 3 This is a block diagram of the logic structure of the control system provided in an embodiment of the present invention.

[0020] Figure 4 This is a partial cross-sectional view of the loaded particles provided in an embodiment of the present invention.

[0021] Explanation of reference numerals in the attached figures:

[0022] In the diagram: 101 Reactor, 102 High-pressure homogenizer, 103 Vacuum degassing tank, 301 Online viscometer, 302 Controller, 303 Drive motor, 401 Carrier, 402 Shell. Detailed Implementation

[0023] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0024] This application provides an antibacterial and gum-protecting oral toothpaste. The toothpaste, by weight percentage, consists of a core active ingredient and conventional oral care additives, with a total weight percentage of 100%. Targeting the different microecological characteristics of various user groups, this application divides the formula into adult and children's versions.

[0025] Regarding the core components of the formula, the adult version contains: 0.5% to 5% essential oil and 0.1% to 2% *Lactobacillus plantarum* LN66. The children's version contains: 0.2% to 1% essential oil and 0.05% to 1% *Lactobacillus plantarum* LN66. Gas chromatography-mass spectrometry analysis revealed that the essential oil is rich in 37 natural active ingredients, including α-pinene, phellandrene, and limonene. After resuscitation and activation, *Lactobacillus plantarum* LN66 has a viable count ≥10-1. 9CFU / g. When combined at appropriate concentrations, both can exert biological effects in regulating the oral microecological environment.

[0026] Furthermore, the oral care excipients in the raw materials include, by total amount: 20% to 40% abrasive, 10% to 30% humectant, 0.5% to 3% thickener, 1% to 5% foaming agent, 0.01% to 0.5% sweetener, 0.1% to 1% natural fragrance, and the balance being deionized water. The abrasive is selected from one or a combination of silica and light calcium carbonate. To reduce physical abrasion to the enamel of young children's teeth, the abrasive in the children's toothpaste is specifically formulated as an all-silica system. The humectant is selected from one or a combination of glycerin and sorbitol. The thickener is selected from one or a combination of sodium carboxymethyl cellulose and xanthan gum. The foaming agent is selected from one of sodium lauryl sulfate and sodium cocoyl glycinate. The sweetener is selected from one of xylitol and steviol glycosides to achieve a sugar-free, caries-preventing formula. The natural fragrance is selected from one of peppermint oil and lemon flavoring. This specific material system configuration enables the utilization of the bioactivity of natural extracts and probiotics to achieve a mild and targeted antibacterial effect. It should be noted that the above-described excipient ratios are merely examples; those skilled in the art can achieve the basic functions of this application using similar alternative matrix materials with comparable performance.

[0027] Figure 1 This is a schematic diagram of the overall structure of the production system provided in an embodiment of the present invention. Figure 1 As shown, the basic preparation process of this application is carried out using the following physical equipment: a raw material pretreatment module, a reaction vessel 101, a high-pressure homogenizer 102, and a vacuum degassing tank 103. The various processing units are connected in a closed loop via fluid transport pipelines.

[0028] Figure 2 This is a flowchart of the preparation method provided in an embodiment of the present invention. (In conjunction with...) Figure 1 and Figure 2 The method for preparing the antibacterial and gum-protecting oral toothpaste provided in this application includes the following steps.

[0029] Step S201: Purify the essential oil using a microporous membrane filter and activate Lactobacillus plantarum LN66 for later use.

[0030] Specifically, this step involves using a 0.22-micron pore size polytetrafluoroethylene hydrophilic filter membrane to perform a two-stage cascade filtration process on the crudely extracted essential oils to remove large molecular impurities. The filtered filtrate is stored at 4°C in the dark. Simultaneously, freeze-dried *Lactobacillus plantarum* LN66 is inoculated into sterile skim milk medium and revived and activated in a constant-temperature incubator. This activation step involves a dynamic thermodynamic control process. A first-stage isothermal incubation is performed at an initial temperature of 37°C until the optical density of the bacterial solution reaches the critical point of the logarithmic growth phase, as detected by a spectrophotometer. Subsequently, a gradient cooling program is initiated, gradually lowering the incubation temperature to 25°C at a rate of 0.5°C per minute and maintaining stability. By employing this gradient cooling and activation method, the expression buffer period of microbial heat shock proteins can be utilized to effectively reduce the physical damage to the bacterial cell membrane caused by temperature mutations, thereby improving the survival rate of the bacteria.

[0031] Step S202: At a temperature of 30°C to 40°C, water, humectant and thickener are stirred to form a base material.

[0032] Add the prescribed amount of humectant and deionized water to reactor 101. Heat the reactor using a jacketed water bath to maintain a constant temperature between 30°C and 40°C. Turn on the stirring motor and stir at 300 rpm to 500 rpm for 10 to 15 minutes until the system becomes clear. Then, slowly sieve in the thickener powder that has passed through an 80-mesh sieve. Continue stirring for 20 to 30 minutes until the thickener particles have completely absorbed water, swelled, and dissolved, forming a homogeneous excipient base. This base is then kept at 35°C for later use.

[0033] In step S203, the purified essential oil and natural fragrance are premixed at room temperature, and then activated Lactobacillus plantarum LN66 is added and stirred at a low speed of 100 r / min to 200 r / min to form a compound solution.

[0034] This stage employs a dual planetary mixer with a flexible silicone scraper for stirring. Purified essential oils and natural fragrances are briefly mixed at room temperature for 5 minutes to form an essential oil premix; then, the previously activated probiotic culture, which has undergone gradient cooling, is added. By strictly controlling the low-speed stirring boundary of 100 rpm to 200 rpm and maintaining mixing for 5 minutes, physical tearing and damage to the bacterial cells due to excessive fluid shear force is avoided.

[0035] Step S204: The compound solution is introduced into the base material, and the friction agent, foaming agent and sweetener are added in sequence and stirred. Then, high-pressure homogenization is performed twice under a pressure of 20MPa to 30MPa.

[0036] The compound solution was slowly injected into the auxiliary base material in reactor 101 and stirred for 15 minutes at 300 rpm under a constant temperature of 35°C. Then, the abrasive, foaming agent, and sweetener were added sequentially, and stirring continued for 20 minutes to achieve preliminary mixing. The preliminarily mixed coarse paste was pumped into a high-pressure homogenizer 102. During the homogenization stage, the operating pressure range was set to 20 MPa to 30 MPa. The coarse paste underwent high-speed shearing and cavitation effects as it passed through the homogenizer's slit. The homogenization operation was repeated twice, each time lasting 5 minutes.

[0037] Step S205 involves negative pressure degassing and filling / packaging.

[0038] The homogenized, fine paste is then fed into a vacuum degassing tank 103. This process is configured as a multi-stage, stepped vacuum operation. The pressure inside the tank is reduced to -0.05 MPa and maintained for approximately 5 minutes to forcibly extract large air bubbles from the paste. A second depressurization operation is then performed, further reducing the ambient pressure to the target range of -0.08 MPa to -0.1 MPa. Degassing continues at this high vacuum and 30°C for 10 to 15 minutes to completely remove gases from the micropores. By employing this stepped negative pressure degassing process, the gradually decreasing pressure gradient prevents structural stratification caused by sudden boiling, maintaining the physical homogeneity of the finished product. The degassed paste is then filled and sealed using fully automated equipment.

[0039] Furthermore, based on the above embodiments, in order to solve the problem of contact toxicity of high-concentration antibacterial essential oils to live bacteria during storage, this application has made in-depth extensions in the microstructure of the formulation and the preparation control algorithm.

[0040] Specifically, mesoporous silica was introduced into the raw materials. The mass percentage of this mesoporous silica was set at 5% of the total formulation. Its physical properties were limited to a specific surface area of ​​600 m² / g. 2 / g to 800m 2 The material has a density between 5 nm and 10 nm, and an average pore size between 5 nm and 10 nm. It serves as a carrier for essential oils. Simultaneously, the thickener in the formulation is specifically designated as a 1.5% xanthan gum aqueous solution.

[0041] Figure 4 This is a partial cross-sectional view of the loaded particles provided in an embodiment of the present invention. For example... Figure 4As shown, this extended scheme adds a pre-assembly step of microparticle assembly after steps S201 and S202. Essential oil and mesoporous silica are placed in a vacuum negative pressure adsorption vessel and maintained at -0.08 MPa for 30 minutes. This negative pressure condition forces out trapped air from the internal pores of the mesopores, allowing the essential oil to be drawn in by capillary force and fill the internal mesopores of the carrier 401. Subsequently, a surface sealing step is performed. The particles loaded with essential oil are mixed with a dissolved xanthan gum solution. During this process, the pH of the mixture is adjusted to encourage the xanthan gum molecular chains to extend, exposing negatively charged side chain groups. Simultaneously, surface modification techniques such as silane coupling agents are used to pre-charge the outer surface of the mesoporous silica with a positive charge. The electrostatic attraction of opposite charges guides a large amount of xanthan gum molecular chains to deposit on the outer surface of the mesopores; as the deposition density increases, strong steric crosslinking and physical entanglement occur between the long polymer chains of xanthan gum. After drying and curing, a dense shell 402 is formed on the outer surface of the mesopores. The thickness of this shell 402 is precisely controlled between 100 nm and 200 nm. This shell 402 is defined as a shear-responsive sealing shell. During its static shelf life, it maintains a closed and isolated structure; however, when subjected to mechanical frictional shear forces during brushing, it undergoes physical structural breakdown, releasing the internal essential oils. It should be noted that the thickness and ratio of the sealing material are merely examples; those skilled in the art can achieve similar hydrogel coating effects using polysaccharide materials with equivalent film-forming properties, such as sodium alginate.

[0042] After applying the above-mentioned physically loaded particles, the order of raw material integration is changed to: first, probiotics are inoculated into the matrix excipients, and finally the loaded particles are mixed in, establishing a dual physical isolation barrier at both the macroscopic and microscopic levels.

[0043] In conventional high-pressure homogenization processes, the high-speed fluid shear forces generated by the stator and rotor can easily exceed the critical physical tolerance limit of the xanthan gum shell, causing the essential oil to be released prematurely during the production stage, resulting in the large-scale death of probiotics. To prevent this secondary defect, this application configures a corresponding feedback algorithm on the hardware electrical control link.

[0044] Figure 3 This is a block diagram of the logic structure of the control system provided in an embodiment of the present invention. Figure 3 As shown, the system includes an online viscometer 301, a controller 302, and a frequency converter drive motor 303 for driving the equipment. The online viscometer 301 is installed in the main feed pipe of the high-pressure homogenizer 102, and its probe has a measurement range covering 0 to 50 Pa·s. The online viscometer 301 is configured to measure the dynamic viscosity data of the homogenized mixture in real time and transmit it to the controller 302 via a data link.

[0045] The controller 302 is programmed with adaptive limiting operations. Since the toothpaste system is a typical non-Newtonian fluid, its dynamic viscosity exhibits shear-thinning rheological characteristics with changing shear rate. This operation includes an adaptive rotational speed conversion model based on Newton's law of internal friction in fluid dynamics. Specifically, the system performs calculations without exceeding the critical yield strength of the hydrogel; in this model, the maximum fluid shear stress at the stator-rotor gap of the homogenizing device is... Constrained by the following mathematical equations:

[0046]

[0047] in, This represents the actual shear stress of the fluid; The instantaneous dynamic viscosity of the mixture system is collected in real time by the online viscometer 301; D represents the outer diameter constant of the homogenizer rotor, which is specifically taken as 0.12m in this embodiment; N max This indicates the upper limit of the speed command issued by the controller to the frequency converter; This represents the radial working clearance constant between the stator and rotor of the homogenizer, and in this embodiment, it is specifically taken as [value missing]. m; The critical shear yield strength of the xanthan gum coating is indicated by the rheometer test. The failure threshold of the 1.5% xanthan gum sealing layer is calibrated to a constant of 4500 Pa.

[0048] After algebraic rearrangement and simplification, the controller 302 executes the following dynamic speed limit calculation formula in each control cycle:

[0049]

[0050] The online viscometer 301 continuously outputs dynamic viscosity data at a high refresh rate of 100Hz. Controller 302 will filter the... Substituting the value into the above calculation formula, the maximum allowable rotational speed N that does not exceed the critical yield strength of 4500 Pa for the hydrogel system under the current fluid properties is calculated in real time. max Throughout the homogenization and mixing phase, the controller 302 acquires the control signal from the intervention power output module in real time and outputs a limiting command to the drive motor 303, limiting the actual driving speed of the high-pressure homogenizer 102 to no more than 95% of the theoretically calculated maximum allowable speed limit.

[0051] By adopting a scheme that combines fluid dynamic constraints with hardware isolation structure, and using real-time feedback of non-Newtonian fluid viscosity to suppress the mechanical kinetic energy of the equipment, the homogenization of the paste material is ensured while all mesoporous loaded particles pass through the homogenizer intact without rupture or leakage.

[0052] To illustrate the specific application of this application, two specific embodiments are listed below.

[0053] Example 1:

[0054] By weight percentage, the formula comprises: 2% Murraya paniculata (Emei Mountain) essential oil, 1% Lactobacillus plantarum LN66, 30% silica, 20% a mixture of glycerin and sorbitol in equal proportions, 1.5% sodium carboxymethyl cellulose, 3% sodium lauryl sulfate, 0.2% xylitol, 0.3% peppermint oil, and deionized water to 100%. It is prepared using the aforementioned production process described in this application, wherein the high-pressure homogenization treatment pressure is 25 MPa, and the vacuum degassing pressure is -0.09 MPa. Performance testing shows that this adult toothpaste achieves a 99.99% sterilization rate against Helicobacter pylori, a 99.98% sterilization rate against Porphyromonas gingivalis, and a 99.96% sterilization rate against Streptococcus mutans. It also demonstrates an effectiveness rate of over 95% in improving halitosis. The paste is uniform without layering and exhibits good foaming properties.

[0055] Example 2:

[0056] By weight percentage, the formula comprises: 0.5% Murraya paniculata (Emei Mountain) essential oil, 0.1% Lactobacillus plantarum LN66, 25% silica, 15% glycerin, 1% xanthan gum, 2% sodium cocoyl glycinate, 0.05% steviol glycosides, 0.2% lemon flavoring, and deionized water to 100%. It is prepared using the aforementioned production process described in this application, wherein the high-pressure homogenization pressure is 20 MPa and the vacuum degassing pressure is -0.08 MPa. Performance testing shows that this children's toothpaste achieves a 99.96% sterilization rate against Streptococcus mutans, exhibits no enamel abrasion, has a mild taste, and meets the requirements for children's oral care.

[0057] To verify the beneficial effects of the application extension scheme of this application, a control experiment was performed.

[0058] Comparative example: Using a conventional mixing process, essential oils and lactobacilli were directly mixed in the liquid phase at low speed.

[0059] Example: The complete process of this application includes mesoporous microparticle encapsulation, isolated feeding sequence, and homogeneous dynamic shear speed feedback control mechanism.

[0060] The results of the bioactivity test after 6 months of storage at room temperature are shown in Table 1.

[0061] Table 1 Performance Test Comparison Table

[0062]

[0063] As can be seen from the data in Table 1, the probiotics in the comparative example suffered a drastic decline, with the live bacteria survival rate falling below 0.01%. In contrast, after applying the solution in this embodiment, *Lactobacillus plantarum* LN66 showed high survival during the 18-month equivalent shelf-life assessment, with a survival rate of 90.9%. Furthermore, the *Murraya paniculata* (Emei Mountain) essential oil, due to its sealed protection, exhibited significantly reduced volatility and a high retention rate of 98.1%. Moreover, while ensuring that the microparticles did not break down, the adaptive homogenization operation through intelligent rate-limiting calculation still resulted in a fine particle size distribution in the product, indicating that the process adjustment did not sacrifice the fineness of the paste.

[0064] In summary, this application combines natural Murraya paniculata (Emei Mountain) essential oil extract with specific components of Lactobacillus plantarum, along with a physical coating structure of mesoporous silica and xanthan gum shells, and a dynamic speed closed-loop control method based on an online viscometer 301 and the critical yield strength equation. This prevents the toxicity of high-concentration terpenes to probiotics and improves the retention rate of natural essential oils, ensuring that the product releases medication through brushing shear force only after entering the oral cavity. This system balances potent bactericidal activity, microecological regulation, and long-term storage stability, solving the technical pain points of mutual incompatibility and easy inactivation of multi-effect antibacterial toothpaste ingredients, demonstrating comprehensive system-level advantages.

Claims

1. A method for preparing an antibacterial and gum-protecting oral toothpaste, characterized in that, The raw materials, by weight percentage, comprise 0.2% to 5% essential oil, 0.05% to 2% Lactobacillus plantarum LN66, 20% to 40% abrasive, 10% to 30% humectant, and 0.5% to 3% thickener, with the remainder being water, foaming agent, sweetener, and fragrance. The raw materials also include mesoporous silica, and the thickener comprises xanthan gum. The preparation method includes purifying the essential oil using a microporous membrane filter and activating the Lactobacillus plantarum LN66 for later use; stirring the water, humectant, and thickener at 30°C to 40°C to form a base; premixing the purified essential oil and fragrance at room temperature, followed by adding the activated Lactobacillus plantarum LN66 and stirring at a low speed of 100 r / min to 200 r / min to form a compound solution. The compound solution is introduced into the base material, and the abrasive, foaming agent and sweetener are added sequentially and stirred. The purified essential oil is mixed with the mesoporous silica, allowing the essential oil to be absorbed and fill the internal mesopores to form loaded particles. The loaded particles are mixed with the dissolved xanthan gum solution for surface sealing, and the surface of the mesopores of the loaded particles is solidified to form a shear-responsive sealing shell. The activated Lactobacillus plantarum LN66 is inoculated into a matrix excipient formed by water, the humectant and conventional oral care excipients, and finally the loaded particles with the sealing shell are mixed in to obtain a mixture. Subsequently, high-pressure homogenization is performed twice under a pressure of 20 MPa to 30 MPa. Negative pressure degassing treatment and filling and packaging are performed, and the negative pressure degassing treatment pressure is -0.08 MPa to -0.1 MPa.

2. The method for preparing the antibacterial and gingival-protecting oral toothpaste as described in claim 1, characterized in that, The essential oil is Murraya paniculata essential oil; preferably, the essential oil is Murraya paniculata (Emei) essential oil extracted from the Emei production area.

3. The method for preparing the antibacterial and gingival-protecting oral toothpaste as described in claim 1, characterized in that, The purification of the essential oil by microporous filtration membrane is configured to perform two-stage cascade filtration of the essential oil using a polytetrafluoroethylene hydrophilic filter membrane with a pore size of 0.22 micrometers; the activation of the Lactobacillus plantarum LN66 for later use is configured to inoculate the freeze-dried Lactobacillus plantarum LN66 into skim milk culture medium and perform revival and activation treatment in a constant temperature incubator.

4. The method for preparing the antibacterial and gingival-protecting oral toothpaste as described in claim 3, characterized in that, The step of resuscitation and activation treatment in the constant temperature incubator is configured to carry out the first stage of constant temperature incubation at an initial temperature of 37°C until the optical density value of the bacterial solution reaches the critical point of the logarithmic growth phase; then, a gradient cooling program is started, and the incubation temperature is reduced to 25°C at a cooling rate of 0.5°C per minute and maintained stably; in the step of adding the activated Lactobacillus plantarum LN66 and stirring at a low speed of 100r / min to 200r / min to form a compound solution, a double planetary mixer with a flexible silicone scraper is used to perform the stirring action.

5. The method for preparing the antibacterial and gingival-protecting oral toothpaste as described in claim 1, characterized in that, The raw materials for preparation also include mesoporous silica, which is configured as a carrier for the essential oil and forms loading particles.

6. The method for preparing the antibacterial and gingival-protecting oral toothpaste as described in claim 5, characterized in that, The thickener is xanthan gum. The preparation method further includes a surface sealing step after the loading particles are formed. The surface sealing step is configured to mix the loading particles with the dissolved xanthan gum solution. The xanthan gum is attached to the mesoporous outer surface of the loading particles by electrostatic adsorption and physical entanglement, and a shear-responsive sealing shell with a thickness of 100 nm to 200 nm is formed on the mesoporous outer surface.

7. The method for preparing the antibacterial and gingival-protecting oral toothpaste as described in claim 6, characterized in that, The process of attaching to the mesoporous outer surface of the loaded particles is defined as follows: by adjusting the pH value of the mixing system to make the molecular chains of xanthan gum extend and expose negatively charged side chain groups; and by using surface modification technology to pre-carry a positive charge on the surface of the mesoporous silica, the xanthan gum molecular chains are guided to deposit on the mesoporous outer surface. As the deposition density increases, the long polymer chains of xanthan gum undergo steric crosslinking and physical entanglement, and solidify to form a dense shear-responsive sealing shell. This shear-responsive sealing shell maintains a closed and isolated structure in a static state, and collapses when subjected to mechanical frictional shear forces.

8. The method for preparing the antibacterial and gingival-protecting oral toothpaste as described in claim 1, characterized in that, During the high-pressure homogenization process, an online viscometer is used for real-time feedback control. The online viscometer is installed in the main pipeline of the high-pressure homogenizer to measure the dynamic viscosity data of the homogenized system in real time and transmit the dynamic viscosity data to the controller of the high-pressure homogenizer. Based on the dynamic viscosity data, the actual driving speed of the high-pressure homogenizer is adjusted.

9. The method for preparing the antibacterial and gingival-protecting oral toothpaste as described in claim 8, characterized in that, Perform an adaptive limiting operation, which includes establishing an adaptive rotation speed conversion model for the paste hydrogel system based on the fluid internal friction law; refreshing and outputting the dynamic viscosity data at a frequency of 100Hz; and combining the dynamic viscosity data with the rotation speed conversion model to calculate the current maximum allowable rotation speed limit value in real time without exceeding the critical yield strength of 4500Pa for the paste hydrogel system. During the homogenization and mixing stage, the control signal of the intervention power output module is acquired in real time, and the actual driving speed of the high-pressure homogenizer is limited to not exceeding 95% of the current maximum allowable speed limit.

10. The method for preparing the antibacterial and gingival-protecting oral toothpaste as described in claim 1, characterized in that, The negative pressure degassing process is configured as a multi-stage stepped vacuuming operation, which includes reducing the pressure to -0.05 MPa and holding it for a specified time, followed by a second pressure reduction to the target range of -0.08 MPa to -0.1 MPa.

11. An antibacterial and gum-protecting oral toothpaste, characterized in that, The toothpaste is prepared using the method described in any one of claims 1 to 10 for antibacterial and gingival-protecting oral toothpaste.

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