Mild whitening anhydrous toothpaste and preparation method thereof

Abstract

The invention relates to mild whitening anhydrous toothpaste and a preparation method thereof, and the toothpaste comprises the following components in percentage by weight: 0.4 to 12 percent of polyvinylpyrrolidone, 0.1 to 3 percent of hydrogen peroxide, 0.1 to 3 percent of sodium phytate, 0.1 to 3 percent of sodium dihydrogen phosphate, 0.001 to 1 percent of composite plant extract, 0.001 to 0.1 percent of enzyme, 16 to 30 percent of abrasive, 0.5 to 3 percent of thickening agent, 0.5 to 3 percent of surfactant, 0.05 to 0.4 percent of sweetening agent, 0.5 to 2 percent of essence and 0.05 to 1 percent of cooling agent, and the balance of humectant. Wherein the composite plant extract is a grapefruit seed extract, a dendrobium extract and a perilla stem extract. According to the toothpaste disclosed by the invention, through stable design of an anhydrous formula system and a synergistic effect of the composite plant extract, stimulation to oral mucosa and gingiva is remarkably reduced, and efficient whitening effects of mildness, soothing and gingiva protection are realized.

Description

Technical Field

[0001] This invention relates to the technical field of toothpaste, specifically to a mild whitening waterless toothpaste and its preparation method. Background Technology

[0002] Toothpaste can be categorized into different types based on its function, such as whitening, gum care, anti-sensitivity, and anti-cavity. In the current domestic oral care market, whitening toothpaste holds a leading market share, reflecting the high demand for teeth whitening among consumers. Most whitening toothpastes on the market currently focus on removing stains and often contain highly abrasive cleaning agents and chelating agents. Peroxides are proven to have significant stain-removing and whitening effects, and their efficacy is more pronounced than that of conventional chelating agents. However, toothpastes containing peroxides are not common in the market, and these toothpastes are prone to several problems during use: 1) The manufacturing process is complex and requires high-quality raw materials; when the moisture content in the formula reaches a certain level, hydrogen peroxide decomposes, causing gas buildup; 2) Hydrogen peroxide is extremely unstable under alkaline conditions and easily decomposes, and the decomposition rate also accelerates when metal ions are present in the system, leading to decreased toothpaste effectiveness and gas buildup. In addition, when anhydrous peroxide toothpaste is used, it releases hydrogen peroxide as it comes into contact with saliva, causing the pH value in the oral cavity to rise rapidly in a short period of time, which can cause significant irritation to the oral mucosa to some extent. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a mild whitening waterless toothpaste and its preparation method.

[0004] In a first aspect, the present invention provides a mild whitening anhydrous toothpaste comprising the following components by weight percentage: 0.4-12% polyvinylpyrrolidone, 0.1-3% hydrogen peroxide, 0.1-3% sodium phytate, 0.1-3% sodium dihydrogen phosphate, 0.001-1% compound plant extract, 0.001-0.1% enzyme, 16-30% abrasive, 0.5-3% thickener, 0.5-3% surfactant, 0.05-0.4% sweetener, 0.5-2% fragrance, and 0.05-1% cooling agent, with the balance being a humectant; wherein the compound plant extract is grapefruit seed extract, dendrobium extract, and perilla stem extract.

[0005] To address the technical problem of hydrogen peroxide's extreme instability and easy decomposition under alkaline conditions, this invention lowers the pH of the toothpaste system to below 7.4 by adding sodium dihydrogen phosphate, thus blocking the pathway of accelerated decomposition of hydrogen peroxide under alkaline conditions. To address the issue of hydrogen peroxide's decomposition rate being accelerated by the presence of metal ions in the system, this invention adds sodium phytate. Sodium phytate is a chelating stabilizer for hydrogen peroxide; its polyphosphate groups can form stable chelates with trace metal ions in the system, preventing excessively rapid decomposition of hydrogen peroxide and helping to stabilize it. Therefore, it also solves the problem of formula gas instability. This invention also incorporates polyvinylpyrrolidone (PVP) as a carrier for hydrogen peroxide, making it more stable and easier to store. Furthermore, PPVP is a common thickener in anhydrous toothpaste, not only having whitening effects but also improving the stiffness of the gel system in anhydrous toothpaste systems, enhancing the paste's consistency.

[0006] The combination of polyvinylpyrrolidone loaded with hydrogen peroxide, sodium phytate, and sodium dihydrogen phosphate not only has a strong whitening and stain-removing effect, but also provides stain prevention. Commercially available oxygen toothpastes only have whitening effects and do not have stain-preventing properties. Hydrogen peroxide removes stains through oxidation, while sodium phytate and sodium dihydrogen phosphate chelate pigments to achieve whitening. Therefore, the combination of these three ingredients not only has a strong stain-removing effect but also a good stain-preventing effect.

[0007] To reduce the irritation of hydrogen peroxide to the oral cavity, this invention also incorporates a complex of plant extracts, including grapefruit seed extract, dendrobium extract, and perilla stem extract. These plant extracts all possess excellent anti-inflammatory, antibacterial, and restorative effects, reducing the irritation of hydrogen peroxide to the oral mucosa. Dendrobium extract contains polyphenols and flavonoids, exhibiting excellent antioxidant effects, scavenging free radicals, and preventing oxidative stress damage to the mucosa and tooth enamel. Grape seed extract contains naringin, limonene, quercetin, kaempferol, and hesperidin, possessing antibacterial, antiviral, antifungal, and antioxidant activities. Perilla stem extract contains various natural anti-inflammatory components that can directly inhibit pathogenic bacteria, reduce tissue inflammation, and further enhance the soothing effect. The three components of this complex of plant extracts synergistically enhance the toothpaste's antioxidant effect, scavenge free radicals, reduce oxidative stress, and provide anti-inflammatory and soothing effects, relieving stress responses in the mucosa and gums.

[0008] Preferably, the mass ratio of grapefruit seed extract, dendrobium extract and perilla extract is (0.2-0.5):1:(1.3-1.8).

[0009] Preferably, the mild whitening anhydrous toothpaste further includes at least one of tetrapotassium pyrophosphate, pentasodium tripolyphosphate, disodium dihydrogen pyrophosphate, sodium hexametaphosphate, potassium phytate, and sodium pyrophosphate decahydrate.

[0010] Preferably, the enzyme is at least one selected from glucanase, papain, glucosidase, lysozyme, superoxide dismutase, bromelain, and amylase.

[0011] Preferably, the friction agent is anhydrous calcium hydrogen phosphate and / or anhydrous calcium pyrophosphate.

[0012] Preferably, the compound plant extract accounts for 0.001-0.5% of the total mass of the mild whitening anhydrous toothpaste.

[0013] Preferably, the surfactant is at least one of sodium lauryl sulfate, sodium lauroyl sarcosinate, cocamidopropyl betaine, lauryl glucoside, sodium lauroyl glutamate, potassium cocoyl glycinate, sodium cocoyl glycinate, sodium cocoyl glutamate, decanyl glucoside, sodium methyl cocoyl taurate, sodium polyaspartate, and rhamnolipid.

[0014] Preferably, the thickener is at least one of carbomer, polyvinylpyrrolidone, and hydroxypropyl cassia gum; and the sweetener is at least one of sucralose, sodium saccharin, asparagine, and steviol glycosides.

[0015] Preferably, the moisturizer is at least one of glycerin, propylene glycol, and polyethylene glycol.

[0016] In a second aspect, the present invention provides a method for preparing the mild whitening anhydrous toothpaste of the first aspect, comprising the following steps: S1. Disperse the thickener evenly in the humectant, homogenize or stir until the colloid is free of fish eyes, and obtain the first dispersion. S2. Add the premixed sodium phytate, sodium dihydrogen phosphate, sweetener, compound plant extract, enzyme and abrasive to the first dispersion and stir evenly to obtain the second dispersion. S3. Add the premixed polyvinylpyrrolidone and hydrogen peroxide to the second dispersion and stir until homogeneous to obtain the third dispersion. S4. Add the fragrance, cooling agent, surfactant and fragrance to the third dispersion, stir and disperse evenly under vacuum conditions, and degas to obtain the mild whitening anhydrous toothpaste.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention utilizes a combination of sodium dihydrogen phosphate, sodium phytate, and polyvinylpyrrolidone to stabilize hydrogen peroxide, control its release rate, and regulate the system's pH, reducing strong irritation at the source while achieving powerful oxidative stain removal and chelation stain prevention, ensuring both whitening and stain prevention effects. Furthermore, a complex of plant extracts, including grapefruit seed extract, dendrobium extract, and perilla extract, specifically eliminates residual irritation, repairs the mucosa, and inhibits bacteria and protects gums, addressing the pain points of traditional hydrogen peroxide-containing whitening toothpastes, such as severe irritation and gum discomfort. Enzymes and abrasives assist in gentle cleaning, avoiding physical abrasion caused by high-hardness abrasives, further enhancing overall gentleness. Therefore, this toothpaste, while retaining the strong whitening effect of hydrogen peroxide and the stain prevention effect of sodium phytate and sodium dihydrogen phosphate, significantly reduces irritation to the oral mucosa and gums through a stable anhydrous formula system and the synergistic effect of the complex plant extracts, achieving a gentle, soothing, and highly effective whitening effect that protects gums. Detailed Implementation

[0018] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0019] The sources of the raw materials used in the following examples and comparative examples are as follows: Unless otherwise specified, all other materials and reagents used in the examples are commercially available.

[0020] Grapefruit seed extract: manufactured by Shaanxi Xintianyu Biotechnology Co., Ltd. Dendrobium extract: manufactured by Shaanxi Xintianyu Biotechnology Co., Ltd. Perilla stem extract: manufactured by Shaanxi Xintianyu Biotechnology Co., Ltd.; Unless otherwise specified, all other materials, reagents, etc. used in the examples and comparative examples are commercially available.

[0021] Example 1 A mild whitening anhydrous toothpaste comprises the following components by weight percentage: 6% polyvinylpyrrolidone, 1.8% hydrogen peroxide, 1.5% sodium phytate, 2.2% sodium dihydrogen phosphate, 0.01% compound plant extract, 1% pentasodium tripolyphosphate, 0.04% enzyme, 20% abrasive, 1% thickener, 2% surfactant, 0.1% sweetener, 1% fragrance, and 0.3% cooling agent, with the balance being a humectant; wherein the compound plant extract has a mass ratio of 0.3: The formula contains grapefruit seed extract, dendrobium extract, and perilla stem extract in a 1:1.5 ratio; the enzyme is glucanase and papain in a 1:1 mass ratio; the abrasive is anhydrous calcium pyrophosphate; the thickener is polyvinylpyrrolidone; the surfactant is sodium lauryl sulfate and cocamidopropyl betaine in a 3:1 mass ratio; the sweetener is sucralose; the cooling agent is menthol; and the humectant is propylene glycol and polyethylene glycol in a 2.1525:1 mass ratio. The preparation method of the mild whitening anhydrous toothpaste includes the following steps: S1. Disperse the thickener evenly in the humectant, homogenize or stir until the colloid is free of fish eyes, and obtain the first dispersion. S2. Add the premixed sodium phytate, sodium dihydrogen phosphate, pentasodium tripolyphosphate, sweetener, compound plant extract, enzyme and abrasive to the first dispersion and stir until uniform to obtain the second dispersion. S3. Add the premixed polyvinylpyrrolidone and hydrogen peroxide to the second dispersion and stir until homogeneous to obtain the third dispersion. S4. Add the fragrance, cooling agent, surfactant and fragrance to the third dispersion, stir and disperse evenly under vacuum conditions, and degas to obtain the mild whitening anhydrous toothpaste.

[0022] Example 2 A mild whitening anhydrous toothpaste comprises the following components by weight percentage: 0.4% polyvinylpyrrolidone, 0.1% hydrogen peroxide, 0.1% sodium phytate, 0.1% sodium dihydrogen phosphate, 0.05% tetrapotassium pyrophosphate, 0.001% compound plant extract, 0.01% enzyme, 16% abrasive, 2.2% thickener, 2% surfactant, 0.05% sweetener, 1% fragrance, and 0.5% cooling agent, with the balance being a humectant; wherein the compound plant extract is present in a mass ratio of 0.2:1. The extract comprises grapefruit seed extract, dendrobium extract, and perilla stem extract in a mass ratio of 1.3; the enzymes are papain, superoxide dismutase, and bromelain in a mass ratio of 1:1:1; the abrasive is anhydrous calcium pyrophosphate; the thickener is carbomer and polyvinylpyrrolidone in a mass ratio of 5:1; the surfactant is sodium lauryl sulfate; the sweetener is sucralose; the cooling agent is menthol; and the humectant is propylene glycol, glycerin, and polyethylene glycol in a mass ratio of 1.85445:1:1. The preparation method of the mild whitening anhydrous toothpaste includes the following steps: S1. Disperse the thickener evenly in the humectant, homogenize or stir until the colloid is free of fish eyes, and obtain the first dispersion. S2. Add the premixed sodium phytate, sodium dihydrogen phosphate, tetrapotassium pyrophosphate, sweetener, compound plant extract, enzyme and abrasive to the first dispersion and stir until uniform to obtain the second dispersion. S3. Add the premixed polyvinylpyrrolidone and hydrogen peroxide to the second dispersion and stir until homogeneous to obtain the third dispersion. S4. Add the fragrance, cooling agent, surfactant and fragrance to the third dispersion, stir and disperse evenly under vacuum conditions, and degas to obtain the mild whitening anhydrous toothpaste.

[0023] Example 3 A mild whitening anhydrous toothpaste comprises the following components by weight percentage: 12% polyvinylpyrrolidone, 3% hydrogen peroxide, 3% sodium phytate, 3% sodium dihydrogen phosphate, 1% compound plant extract, 0.1% enzyme, 22% abrasive, 0.5% thickener, 3% surfactant, 0.4% sweetener, 1.5% fragrance, and 0.1% cooling agent, with the balance being a humectant; wherein the compound plant extract is grapefruit seed extract, dendrobium extract, and perilla stem extract in a mass ratio of 0.5:1:1.8; the enzyme is lysozyme; the abrasive is anhydrous calcium pyrophosphate; the thickener is hydroxypropyl cassia gum; the surfactant is sodium lauroyl glutamate and potassium cocoyl glycinate in a mass ratio of 2:1; the sweetener is sodium saccharin; the cooling agent is menthol; and the humectant is glycerin and polyethylene glycol in a mass ratio of 1.52:1. The preparation method of the mild whitening anhydrous toothpaste includes the following steps: S1. Disperse the thickener evenly in the humectant, homogenize or stir until the colloid is free of fish eyes, and obtain the first dispersion. S2. Add the premixed sodium phytate, sodium dihydrogen phosphate, tetrapotassium pyrophosphate, sweetener, compound plant extract, enzyme and abrasive to the first dispersion and stir until uniform to obtain the second dispersion. S3. Add the premixed polyvinylpyrrolidone and hydrogen peroxide to the second dispersion and stir until homogeneous to obtain the third dispersion. S4. Add the fragrance, cooling agent, surfactant and fragrance to the third dispersion, stir and disperse evenly under vacuum conditions, and degas to obtain the mild whitening anhydrous toothpaste.

[0024] Example 4 The only difference between Example 4 and Example 1 is that the amount of compound plant extract added remains the same, and the mass ratio of grapefruit seed extract, dendrobium extract and perilla stem extract is 1:0.3:1.5.

[0025] Example 5 The only difference between Example 5 and Example 1 is that the amount of compound plant extract added remains the same, and the mass ratio of grapefruit seed extract, dendrobium extract and perilla stem extract is 0.3:1.5:1.

[0026] Comparative Example 1 The only difference between Comparative Example 1 and Example 1 is that Comparative Example 1 does not add compound plant extracts, but uses an equal amount of moisturizer to make up for the missing amount.

[0027] Comparative Example 2 The only difference between Comparative Example 2 and Example 1 is that the amount of compound plant extract added remains the same, grapefruit seed extract is not added, and dendrobium extract and perilla stem extract with a mass ratio of 1:1.5 are used to make up the missing amount.

[0028] Comparative Example 3 The only difference between Comparative Example 3 and Example 1 is that the amount of compound plant extract added remains the same, no Dendrobium extract is added, and grapefruit seed extract and perilla stem extract with a mass ratio of 0.3:1 are used to make up for the missing amount.

[0029] Comparative Example 4 The only difference between Comparative Example 4 and Example 1 is that the amount of compound plant extract added remains the same, and the missing amount is made up by grapefruit seed extract and dendrobium extract with a mass ratio of 0.3:1 instead of perilla stem extract.

[0030] Comparative Example 5 The only difference between Comparative Example 5 and Example 1 is that sodium phytate is not added to the toothpaste, and sodium dihydrogen phosphate is used to make up for the missing amount.

[0031] Comparative Example 6 The only difference between Comparative Example 6 and Example 1 is that sodium dihydrogen phosphate is not added to the toothpaste, and sodium phytate is used to make up for the missing amount.

[0032] Test Example 1: DPPH Free Radical Scavenging Test The DPPH free radical scavenging was detected, and the quantitative antioxidant capacity of the toothpastes in Examples 1-5 and Comparative Examples 1-4 was evaluated. The higher the DPPH free radical scavenging rate, the better the antioxidant effect of the toothpaste.

[0033] 1) Prepare DPPH solution: Weigh 2.5 mg of DPPH, dissolve it in an appropriate amount of anhydrous ethanol, sonicate it in the dark until fully dissolved, and then dilute it to 50.0 ml with anhydrous ethanol to prepare a DPPH solution of 50.0 ug / mL. This solution should be prepared and used immediately.

[0034] 2) Prepare sample solution: Weigh 5g of toothpaste from Examples 1-5 and Comparative Examples 1-4, dilute to 50ml in a volumetric flask with distilled water, sonicate for 30min until completely dissolved, centrifuge for 20min, and take the supernatant for later use.

[0035] 3) Grouping: Examples 1-5 and Comparative Examples 1-9 were divided into 14 groups. Three volumetric flasks were taken from each group and numbered 1#, 2#, and 3# respectively. The following components were added to each volumetric flask: 5 mL of the sample solution prepared from toothpaste of Examples 1-5 and Comparative Examples 1-4 was added to test tube 1, DPPH solution was added to test tube 2, and distilled water was added to test tube 3 as a control group. After thorough mixing, the mixture was reacted at room temperature in the dark for 30 min. The sample was zeroed with distilled water and the absorbance of the three test tubes in group 1 was measured with a UV spectrophotometer at a wavelength of 517 nm.

[0036] 4) The formula for calculating DPPH removal rate is as follows: Where A1 is the absorbance of the mixture in test tube #1; A2 is the absorbance of the mixture in test tube #2; and A3 is the absorbance of the solution in test tube #3. Specific test results are shown in Table 1. The DPPH clearance rate is positively correlated with the antioxidant properties of toothpaste: a higher clearance rate indicates a higher content or stronger activity of antioxidant active substances in the toothpaste formula, theoretically resulting in a stronger ability to protect the oral mucosa from oxidation, inhibit lipid peroxidation, and reduce inflammatory responses.

[0037] Table 1. DPPH free radical scavenging test of each group of toothpastes Group / Performance DPPH removal rate / % Example 1 62.93 Example 2 61.07 Example 3 65.14 Example 4 57.96 Example 5 58.43 Comparative Example 1 48.89 Comparative Example 2 51.34 Comparative Example 3 50.52 Comparative Example 4 54.90 As shown in Table 1, and combining the data from Examples 1 and 4-5, the antioxidant properties of the toothpaste in Examples 4-5 are slightly lower than those in Example 1. This indicates that when the mass ratio of grapefruit seed extract, dendrobium extract, and perilla stem extract is in the range of (0.2-0.5):1:(1.3-1.8), the antioxidant properties of the toothpaste are at a relatively good level.

[0038] Based on the data from Example 1 and Comparative Examples 1-4, it can be seen that the antioxidant performance of Comparative Example 1 is the lowest among all groups. This indicates that the compound plant extract is an important factor affecting the antioxidant effect of toothpaste. Comparative Examples 2-4 lack one of the compound plant extracts, resulting in a significant decrease in the antioxidant performance of the toothpaste. This may indicate that grapefruit seed extract, dendrobium extract, and perilla stem extract synergistically improve the antioxidant performance of toothpaste.

[0039] Test Example 2: Oral Mucosal Irritation Test of Toothpaste in Each Group (Refer to YY / T0127.13-2018 "Biological Evaluation of Oral Medical Devices - Part 13: Oral Mucosal Irritation Test") Experimental animals: Forty-four adult, healthy rats weighing 50±5g were selected, with half males and half females.

[0040] Test substances: toothpastes from Examples 1-5 and Comparative Examples 1-6, with 4 rats selected for each group for testing.

[0041] Experimental Method: Animals were anesthetized before the experiment. The oral cavity and surrounding tissues were cleaned with disinfectant. The left cheek pouch was designated as the test area, and the right cheek pouch as the control area. The test substance was applied to the test area at 8:00 AM and 10:00 PM daily, with a dosage of 0.5 mg / cm² each time. 2 After 3 minutes of application, the oral cavity was rinsed. This process was repeated for 7 days. Distilled water was administered to the control area using the same method. The cheek pouches were examined before and after each application, and observed 24 hours after the last application. Animals were euthanized painlessly, and the buccal pouches were examined for irritation, damage, congestion, swelling, erosion, and ulceration of the buccal mucosa. The buccal pouches on the experimental side and the control side of the same animal were compared, and the condition of the buccal pouches was recorded for each measurement. Clinical manifestations of the oral mucosa were scored according to Table 2. The scores of each animal in each period were added together and then divided by the total number of animals observed to obtain the average score per animal. The experimental results are shown in Table 3. The lower the score of the oral mucosal irritation score, the less irritating and safer the toothpaste is.

[0042] Table 2 Oral Mucosal Response Scoring System reaction integral No erythema 0 Very slight erythema (barely visible) 1 Clear erythema 2 moderate erythema 3 Severe erythema (purplish-red) to eschar formation 4 Table 3. Oral mucosal scores of rats after toothpaste application in each group. Group / Performance Average rating Example 1 0.14 Example 2 0.06 Example 3 0.28 Example 4 0.30 Example 5 0.24 Comparative Example 1 1.22 Comparative Example 2 0.81 Comparative Example 3 1.10 Comparative Example 4 0.93 Comparative Example 5 0.23 Comparative Example 6 0.10 As shown in Table 3, and combining the data from Examples 1 and 4-5, the toothpaste from Examples 4-5 is slightly more irritating than that from Example 1. This indicates that when the mass ratio of grapefruit seed extract, dendrobium extract, and perilla stem extract is in the range of (0.2-0.5):1:(1.3-1.8), the toothpaste is less irritating to the mucous membrane.

[0043] Based on the data from Example 1 and Comparative Examples 1-4, it can be seen that the irritation of Comparative Example 1 is higher than that of Example 1 and Comparative Examples 2-4. This indicates that the compound plant extract is an important factor in reducing the irritation of toothpaste. However, Comparative Examples 2-4 lack one of the compound plant extracts, which reduces the synergistic effect of the composition in terms of anti-oxidation, anti-inflammation and repair, resulting in an increase in the mucosal irritation score of the toothpaste.

[0044] Based on the data from Example 1 and Comparative Examples 5-6, it can be seen that the toothpaste of Comparative Example 5 is more irritating than that of Example 1, while the toothpaste of Example 6 is slightly less irritating than that of Example 1. This may be because: the toothpaste of Comparative Example 5 does not contain sodium dihydrogen phosphate, thus losing its pH buffering capacity, which may increase the alkalinity of the paste. Hydrogen peroxide is unstable under alkaline conditions, leading to a decrease in hydrogen peroxide content. Moreover, the increased alkalinity of the paste also increases irritation. At the same time, because hydrogen peroxide is unstable, it easily decomposes and produces gas, causing the paste to bloat, affecting the stability and whitening effect of the paste. Therefore, the addition of sodium dihydrogen phosphate lowers the pH value to neutral or below (approximately below 7.5), which helps stabilize the paste. On the other hand, the toothpaste of Comparative Example 6 does not contain sodium phytate, thus losing its metal ion chelating ability. The decomposition of hydrogen peroxide during storage and use is accelerated, leading to a decrease in hydrogen peroxide content. Although the irritation of the paste decreases, the paste bloats. Sodium phytate is a chelating stabilizer for hydrogen peroxide. Its polyphosphate groups can form stable chelates with trace metal ions in the system. Therefore, adding sodium phytate to toothpaste can prevent hydrogen peroxide from decomposing too quickly and help stabilize it.

[0045] Test Example 3: Whitening Test of Each Toothpaste Group This test is an in vitro model verification experiment of the whitening efficacy of toothpaste. Hydroxyapatite (HAP) tablets stained with red tea were brushed with the test toothpaste paste using a brushing device at a force of 150g ± 5g and a speed of 80 rpm / min for a total of 1000 brushing cycles. The L*a*b* values ​​were then measured using a spectrophotometer to directly calculate the WI value (whiteness value). A higher WI value indicates a stronger ability to remove extrinsic stains and a better whitening effect. The specific experimental procedure is as follows: 1) Prepare HAP discs in advance, with two discs forming a group, and divide into 11 experimental groups (Examples 1-5 and Comparative Examples 1-6). Coat the HAP discs with 1% mucin supernatant and incubate overnight at 37°C. 2) Place all the HAP discs in a concentrated stain solution (such as black tea; Lipton black tea was used in this experiment) and shake at 37°C for 1 hour. 3) Immerse all the HAP discs in deionized water and rinse thoroughly three times; 4) Air dry all the HAP discs overnight; 5) After air drying overnight, the L*a*b* values ​​of all HAP disks were measured and recorded using a spectrophotometer, and the WI whiteness value after HAP coloring was calculated. 6) Use a spectrophotometer to measure the L*a*b* value again, and directly calculate the WI whiteness value after HAP coloring and brushing.

[0046] The formula for calculating the WI whiteness value is as follows: ; This formula defines the whiteness of a perfectly reflective diffuser as 100, compares the whiteness of the sample with the whiteness of the perfectly reflective diffuser, and evaluates the whiteness of the sample by calculating the color difference.

[0047] In the formula, L is the lightness index (representing the depth of color) of the sample in the Lab system, a and b are the chromaticity indices of the sample in the Lab system (a represents the red-green direction of the color, and b represents the yellow-blue direction of the color), K1 is a constant, which is generally taken as 1; ap and bP are the whiteness indices of ideal white in the Lab system. Since the toothpastes in each group do not have fluorescence, ap = 0.00 and bP = 0.00.

[0048] 7) Finally, the whitening effect is represented by the degree of improvement in whiteness value before and after the whitening process. The calculation formula is as follows: Calculation formula: Whiteness value % = (WI(staining after brushing) - WI(staining without brushing)) / WI(staining without brushing). Data is shown in Table 4. The higher the whiteness value, the better the whitening effect of the toothpaste.

[0049] Table 4. Whiteness values ​​of each group of toothpaste Group / Performance Whiteness value / % Example 1 41.25 Example 2 36.48 Example 3 42.60 Example 4 40.89 Example 5 40.37 Comparative Example 1 39.22 Comparative Example 2 39.40 Comparative Example 3 39.85 Comparative Example 4 39.61 Comparative Example 5 37.53 Comparative Example 6 38.18 Based on the data from Examples 1, 4-5 and Comparative Examples 1-4 in Table 4, it can be seen that the addition of the compound plant extract not only does not affect the whitening effect of the toothpaste, but also promotes it.

[0050] Based on the data from Example 1 and Comparative Examples 5-6, it can be seen that the whitening effect of the toothpaste in Comparative Examples 5-6 is significantly lower than that in Example 1. This means that the absence of either sodium dihydrogen phosphate or sodium phytate reduces the whitening effect of the toothpaste. This indicates that when sodium phytate and sodium dihydrogen phosphate are added simultaneously in anhydrous toothpaste systems, they work synergistically. Sodium dihydrogen phosphate can regulate the pH of the system to below 7.4, while sodium phytate can chelate trace metal ions in the system to stabilize the activity of hydrogen peroxide and ensure its efficient oxidative stain removal ability. Furthermore, the dual chelation effect can assist in loosening tooth stains, and sodium phytate can help achieve the best long-lasting whitening effect.

[0051] In summary, the toothpaste of the present invention retains the strong whitening effect of hydrogen peroxide and the stain-resistant effects of sodium phytate and sodium dihydrogen phosphate, while significantly reducing irritation to the oral mucosa and gums through the stable design of the anhydrous formula system and the synergistic effect of the compound plant extracts, achieving a gentle, soothing, and gum-protecting high-efficiency whitening effect.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A mild whitening anhydrous toothpaste, characterized in that, The product comprises the following components by weight percentage: 0.4-12% polyvinylpyrrolidone, 0.1-3% hydrogen peroxide, 0.1-3% sodium phytate, 0.1-3% sodium dihydrogen phosphate, 0.001-1% compound plant extract, 0.001-0.1% enzyme, 16-30% abrasive, 0.5-3% thickener, 0.5-3% surfactant, 0.05-0.4% sweetener, 0.5-2% fragrance, and 0.05-1% cooling agent, with the balance being a humectant; wherein the compound plant extract is grapefruit seed extract, dendrobium extract, and perilla stem extract.

2. The mild whitening anhydrous toothpaste as described in claim 1, characterized in that, The mass ratio of grapefruit seed extract, dendrobium extract and perilla extract is (0.2-0.5):1:(1.3-1.8).

3. The mild whitening anhydrous toothpaste as described in claim 1, characterized in that, The mild whitening anhydrous toothpaste also includes at least one of tetrapotassium pyrophosphate, pentasodium tripolyphosphate, disodium dihydrogen pyrophosphate, sodium hexametaphosphate, potassium phytate, and sodium pyrophosphate decahydrate.

4. The mild whitening anhydrous toothpaste as described in claim 1, characterized in that, The enzyme is at least one of glucanase, papain, glucosidase, lysozyme, superoxide dismutase, bromelain, and amylase.

5. The mild whitening anhydrous toothpaste as described in claim 1, characterized in that, The friction agent is anhydrous calcium hydrogen phosphate and / or anhydrous calcium pyrophosphate.

6. The mild whitening anhydrous toothpaste as described in claim 1, characterized in that, The compound plant extract accounts for 0.001-0.5% of the total mass of the mild whitening anhydrous toothpaste.

7. The mild whitening anhydrous toothpaste as described in claim 1, characterized in that, The surfactant is at least one of sodium lauryl sulfate, sodium lauroyl sarcosinate, cocamidopropyl betaine, lauryl glucoside, sodium lauroyl glutamate, potassium cocoyl glycinate, sodium cocoyl glycinate, sodium cocoyl glutamate, decanyl glucoside, sodium methyl cocoyl taurate, sodium polyaspartate, and rhamnolipid.

8. The mild whitening anhydrous toothpaste as described in claim 1, characterized in that, The thickener is at least one of carbomer, polyvinylpyrrolidone, and hydroxypropyl cassia gum; the sweetener is at least one of sucralose, sodium saccharin, asparagine, and steviol glycosides.

9. The mild whitening anhydrous toothpaste as described in claim 1, characterized in that, The moisturizer is at least one of glycerin, propylene glycol, and polyethylene glycol.

10. The method for preparing the mild whitening anhydrous toothpaste according to any one of claims 1-9, characterized in that, Includes the following steps: S1. Disperse the thickener evenly in the humectant, homogenize or stir until the colloid is free of fish eyes, and obtain the first dispersion. S2. Add the premixed sodium phytate, sodium dihydrogen phosphate, sweetener, compound plant extract, enzyme and abrasive to the first dispersion and stir evenly to obtain the second dispersion. S3. Add the premixed polyvinylpyrrolidone and hydrogen peroxide to the second dispersion and stir until homogeneous to obtain the third dispersion. S4. Add the fragrance, cooling agent, surfactant and fragrance to the third dispersion, stir and disperse evenly under vacuum conditions, and degas to obtain the mild whitening anhydrous toothpaste.