A dual-phase mouthwash and preparation method thereof

Abstract

The present invention relates to the field of oral care and discloses a biphasic mouthwash and a preparation method thereof. The biphasic mouthwash comprises the following components in mass percentage: oil phase: 8-16% isopropyl myristate, 2.5-8% caprylic capric glyceride; aqueous phase: 0.02-0.1% cetylpyridinium chloride, 0.04-0.2% PEG-40 hydrogenated castor oil, 0.12-2.0% propylene glycol, 10-25% sorbitol, 0.1-10% glycerol, a pH regulator, and water. The biphasic mouthwash of the present invention has the following characteristics: (1) the aqueous phase and the oil phase are kept separated during storage, and a temporary emulsion is formed after being shaken during use, with an ideal emulsification duration, so that consumers have a refreshing mouthfeel when rinsing their mouths; (2) after emulsification and standing, the water-oil phase can be smoothly restored to the initial clear and transparent state, with a clear interface between the two phases, no emulsified layer, and good appearance; and (3) it has excellent low-temperature antifreeze properties.

Description

Technical Field

[0001] The present invention relates to the field of oral care, and in particular to a dual-phase mouthwash and a preparation method thereof. Background Art

[0002] With increasing awareness of oral health, consumers are increasingly favoring oral care products, in addition to effective and scientific toothbrushing. Mouthwash, a key oral hygiene product, not only freshens breath like mouth sprays and gum, but also contains a variety of antibacterial, anti-inflammatory, and anti-caries ingredients, which can help prevent tooth decay and periodontal problems. Some medicated mouthwashes can even treat oral diseases. Currently available mouthwashes contain antibacterial and anti-inflammatory substances, which can help control plaque and maintain oral health. For example, chlorhexidine mouthwash kills bacteria neutralized in saliva and adsorbed on tooth surfaces, making it suitable for periodontal patients. Mouthwashes with essential oils as their primary active ingredient have broad-spectrum antibacterial properties and are suitable for daily use. Some mouthwashes can also be used to gargle with stomatitis and cheilitis, helping to prevent infection and promote wound healing. Therefore, mouthwash not only removes food debris and soft plaque from the mouth but also softens plaque. Combined with effective and scientific toothbrushing, it can significantly enhance plaque control.

[0003] Traditional mouthwashes are typically homogeneous and transparent. They require the solubilization of an oil phase into an aqueous phase to create a single system. This creates limitations in formulation design, restricting the application of some oil-phase ingredients. Dual-phase mouthwashes are a new product emerging on the market. They consist of an aqueous phase and an oil phase. The aqueous phase includes water-soluble ingredients, humectants, and water. The oil phase includes oil-soluble functional ingredients and an oil-phase solvent. The aqueous and oil phases are separated into separate layers, requiring thorough mixing before use. Compared to traditional mouthwashes, dual-phase mouthwashes offer a more diverse and aesthetically pleasing appearance, making them easier to differentiate from the conventional mouthwash market. Furthermore, the appropriate proportion of the oil phase provides a lubricating effect, enhancing the comfort of rinsing. Because dual-phase mouthwashes do not require solubilization, they can optionally incorporate more oil-phase functional ingredients, increasing the product's added value.

[0004] For example, Chinese patent CN 109260102 A provides a multiphase oral care composition in which the aqueous and oil phases are separated by layers. This avoids the micelles formed by solubilizers in traditional mouthwashes, which weaken the antibacterial effect of oil-soluble active ingredients. This composition offers minimal side effects while maintaining a significant bactericidal effect. Chinese patent CN 107106473 A provides a biphasic mouthwash containing coconut oil in its hydrophobic phase, which can be used to alleviate dry mouth symptoms.

[0005] However, the biphasic mouthwashes in the prior art, including those in the above patents and those available on the market, generally have the following defects:

[0006] (1) The mouthfeel is rather sticky and not refreshing when used. Specifically, after the water phase and the oil phase are shaken and emulsified, the time it takes for the product to return to the two-phase state is too short. As a result, when consumers take the product, the oil phase accounts for too high a proportion (the oil phase has a low density and is easy to float), resulting in a sticky mouthfeel, which seriously affects the user experience.

[0007] (2) The appearance is poor. Specifically, after the water phase and the oil phase are shaken and emulsified, the product cannot be restored to a clear two-phase state with a clear interface for a long time. There will be an emulsion layer at the interface or a large number of cloud points in the liquid.

[0008] (3) Poor low-temperature frost resistance. Specifically, below 0°C, the oil phase will freeze and flocs will precipitate in the water phase. Summary of the Invention

[0009] To solve the above technical problems, the present invention provides a biphasic mouthwash and a preparation method thereof. The biphasic mouthwash of the present invention has the following characteristics: (1) it maintains a water phase and an oil phase separation state during storage, and forms a temporary emulsion after being shaken during use, with an ideal emulsification duration, so that consumers can have a refreshing mouthfeel when rinsing their mouths; (2) after emulsification and standing, it can smoothly return to the initial clear and transparent state of the water and oil phases, with a clear interface between the two phases, no emulsified layer, and good appearance; and (3) it has excellent low-temperature resistance.

[0010] The specific technical solutions of the present invention are:

[0011] In a first aspect, the present invention provides a dual-phase mouthwash comprising the following components in percentage by weight:

[0012] Oil phase: Isopropyl myristate 8-16%, Caprylic / capric glyceride 2.5-8.0%;

[0013] Aqueous phase: Cetylpyridinium chloride 0.02-0.1%, PEG-40 hydrogenated castor oil 0.04-0.2%, propylene glycol 0.12-2.0%, sorbitol 10-25%, glycerin 0.1-10%, pH adjuster, water.

[0014] The two-phase mouthwash of the present invention maintains a state of separation between the water phase and the oil phase during storage, and can form a temporary emulsion after being shaken during use, with an ideal emulsification duration, so that consumers have a refreshing mouthfeel when rinsing their mouths; after emulsification and standing, the two phases can spontaneously separate and smoothly return to the initial clear and transparent state of the water and oil phases without forming an emulsion, with a clear interface between the two phases and no emulsified layer, and a good appearance; the mouthwash has excellent low-temperature antifreeze properties, and the mouthwash product can remain clear and transparent at low temperatures (-2°C) for one month without freezing.

[0015] In response to the problem that existing two-phase mouthwashes have a greasy mouthfeel and poor appearance after emulsification: the present invention adds cetylpyridinium chloride as a surfactant in the aqueous phase. In existing conventional oral care products, cetylpyridinium chloride is often used as an antibacterial agent. The present invention accidentally discovered during research that: on the one hand, after adding cetylpyridinium chloride to the aqueous phase of the two-phase mouthwash, the surface tension of the aqueous phase can be changed, so that the water and oil phases can be quickly emulsified and mixed when shaken, and a longer emulsification time can be maintained, thereby reducing the greasy feeling of the mouthwash and improving the consumer experience (if the emulsification time is short, the oil phase is more likely to float due to its lower density, resulting in a larger proportion of the oil phase during sampling); on the other hand, by selecting cetylpyridinium chloride as a surfactant, the emulsified mouthwash can smoothly return to the initial clear and transparent state of the water and oil phases after standing, with a clear interface between the two phases, no emulsion layer and cloud point, and a good appearance. If other commonly used surfactants are used, the liquid will be turbid after re-stratification and an emulsion layer will be present at the interface between the two phases.

[0016] It should be emphasized that cetylpyridinium chloride needs to be at a specific concentration to better achieve the above-mentioned technical effects. If the concentration is too low, the duration of the water-oil mixture to form an emulsion will be too short, resulting in the mouthwash having a greasy taste and not refreshing enough, and a poor user experience; if the concentration is too high, it will easily lead to an unclear interface between the two phases after the water and oil are re-stratified, and there will be a thin white emulsion layer, which will affect the appearance of the product.

[0017] Aiming at the problem of poor low-temperature frost resistance of existing two-phase mouthwashes: Although the present invention uses cetylpyridinium chloride to improve the mouthfeel, we found that the property of cetylpyridinium chloride that is easy to precipitate at low temperatures will further reduce the product's frost resistance. To this end, in the aqueous phase formula, the present invention adds PEG-40 hydrogenated castor oil and propylene glycol to solubilize cetylpyridinium chloride, making it difficult for cetylpyridinium chloride to precipitate at low temperatures. We found that PEG-40 hydrogenated castor oil, as a non-ionic surfactant, does not exist in an ionic state in the solution and has high stability. The solubilization of PEG-40 hydrogenated castor oil is mainly to form micelles in water, thereby encapsulating cetylpyridinium chloride, increasing its solubility at low temperatures and making it difficult to precipitate. Propylene glycol acts as a cosolvent to promote the solubilization effect and lower the freezing point of PEG-40 hydrogenated castor oil. At the same time, in the oil phase formula, the present invention compounds isopropyl myristate, which has a higher freezing point and good taste, with caprylic capric glyceride, which has a low freezing point, to lower the freezing point of the oil phase and improve the product's frost resistance.

[0018] Preferably, the mass ratio of isopropyl myristate to caprylic / capric glyceride is ≤4:1.

[0019] The reason why the present invention controls the ratio of isopropyl myristate to caprylic capric glyceride within the above-mentioned range is that we have found that if the proportion of isopropyl myristate in the oil phase is too high, the freezing point of the oil phase will be high, and it will be easy to freeze at low temperatures, affecting the user experience; conversely, if the proportion of caprylic capric glyceride in the oil phase is too high, although it has no obvious effect on the product properties, the cost of caprylic capric glyceride is relatively high. Therefore, it is necessary to reduce the amount of caprylic capric glyceride added as much as possible while meeting the performance requirements.

[0020] Preferably, the mass ratio of the PEG-40 hydrogenated castor oil to cetylpyridinium chloride is ≥2:1; the mass ratio of the PEG-40 hydrogenated castor oil to propylene glycol is 1:3 to 1:10.

[0021] The present invention finds that, the ratio of PEG-40 hydrogenated castor oil and cetylpyridinium chloride needs to be controlled within a specific range so that PEG-40 hydrogenated castor oil can better play its solubilizing effect.If PEG-40 hydrogenated castor oil ratio is too low, solubilizing effect is poor, and cetylpyridinium chloride will still be separated out at low temperature;If ratio is too high, it is found that white emulsion layer is easily present at water-oil interface, affecting product appearance.Similarly, the ratio of PEG-40 hydrogenated castor oil and propylene glycol also needs to be controlled within a specific range, if ratio is too high, the PEG-40 hydrogenated castor oil of higher concentration is due to the solubilizing effect of lacking cosolvent, and viscosity is higher, and solubilizing ability declines;Similarly, because PEG-40 hydrogenated castor oil and cosolvent need to just play good solubilizing effect under specific ratio, therefore if ratio is too low (cosolvent addition is too high), the solubilizing efficiency of PEG-40 hydrogenated castor oil can be caused to decline, i.e., the solubilizing agent dosage required for cetylpyridinium chloride of solubilizing equal mass becomes large.

[0022] Preferably, the mass ratio of the water phase to the oil phase is 4-7:1.

[0023] To balance product appearance and mouthfeel, an appropriate ratio of the water phase to the oil phase is essential. In terms of mouthfeel, the lower the oil phase, the more refreshing the mouthwash, and the less noticeable greasiness afterward. However, if the oil phase ratio is too low, the product's appearance will be compromised, undermining the distinctive characteristics of a dual-phase mouthwash. Furthermore, if the oil phase ratio is too low, the product will be depleted before the water phase during use. Through comprehensive considerations, the present invention finds that the above ratio is more suitable.

[0024] Preferably, the pH regulator is sodium citrate dihydrate and / or citric acid monohydrate.

[0025] Preferably, the amount of the pH regulator is based on the pH of the aqueous phase being 6-7.

[0026] Preferably, the components of the oil phase further include one or more of essences, oil-soluble pigments, and oil-soluble functional ingredients.

[0027] Preferably, the mass percentage of the flavor in the biphasic mouthwash is 0.3-2.0%; the mass percentage of the oil-soluble pigment in the biphasic mouthwash is 0-0.001%, excluding 0; and the mass percentage of the oil-soluble functional ingredient in the biphasic mouthwash is 0-1.0%.

[0028] Preferably, the components of the aqueous phase further include one or more of preservatives, sweeteners, water-soluble pigments, and water-soluble functional ingredients.

[0029] Preferably, the sweetener is sucralose, and the preservative is sodium benzoate; the mass percentage of the sweetener in the biphasic mouthwash is 0.001-0.01%; the mass percentage of the water-soluble pigment in the biphasic mouthwash is 0-0.001%, excluding 0; and the mass percentage of the water-soluble functional ingredient in the biphasic mouthwash is 0-5.0%.

[0030] In a second aspect, the present invention provides a method for preparing the above-mentioned dual-phase mouthwash, comprising the following steps:

[0031] (1) Preparation of aqueous phase:

[0032] (1.1) Add pH adjuster, sweetener, and preservative to water and stir to dissolve;

[0033] (1.2) Add sorbitol and glycerol to the solution obtained in step (1.1) and stir evenly;

[0034] (1.3) Dissolve the water-soluble pigment in water, add it to the solution obtained in step (1.2) and stir evenly;

[0035] (1.4) Mix cetylpyridinium chloride, propylene glycol, and PEG-40 hydrogenated castor oil and heat to 40-50° C. until the mixture becomes clear and transparent, then add the solution obtained in step (1.3) to obtain an aqueous phase;

[0036] (2) Preparation of oil phase:

[0037] (2.1) Dissolve the oil-soluble pigment with a portion of isopropyl myristate;

[0038] (2.2) Add the solution obtained in step (2.1), caprylic / capric glyceride, and flavor to the remaining isopropyl myristate and stir evenly to obtain an oil phase;

[0039] (3) Fill the water phase and the oil phase in sequence to obtain a biphasic mouthwash.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] (1) The present invention adds a specific amount of cetylpyridinium chloride as a surfactant to the water phase of the two-phase mouthwash, thereby maintaining the separation of the water phase and the oil phase during storage. When used, a temporary emulsion can be formed after shaking and has an ideal emulsification duration, so that consumers can have a refreshing mouthfeel when rinsing their mouths. After the emulsification is allowed to stand, the two phases can spontaneously separate and smoothly return to the initial clear and transparent state of the water and oil phases without forming an emulsion. The interface between the two phases is clear, there is no emulsified layer, and the appearance is good.

[0042] (2) The present invention solubilizes cetylpyridinium chloride by adding specific amounts and proportions of PEG-40 hydrogenated castor oil and propylene glycol to the water phase formula of the biphasic mouthwash, thereby preventing cetylpyridinium chloride from precipitating at low temperatures. Furthermore, isopropyl myristate, which has a high freezing point and good taste, is compounded with caprylic / capric glyceride, which has a low freezing point, in a specific proportion in the oil phase formula, thereby lowering the freezing point of the oil phase and improving the product's antifreeze properties. The biphasic mouthwash of the present invention has excellent low-temperature antifreeze properties, and the mouthwash product can remain clear and transparent at low temperatures (-2°C) for one month without freezing. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 The following are photos of the stratification of the two-phase mouthwashes of each formula in Table 1 after shaking;

[0044] Figure 2 The following are photos of the stratification of the two-phase mouthwashes with each formula in Table 2 after shaking;

[0045] Figure 3 The following are photos of the stratification of the two-phase mouthwashes of each formula in Table 3 after shaking;

[0046] Figure 4 The following are photos of the stratification of the two-phase mouthwashes with each formula in Table 4 after shaking;

[0047] Figure 5 These are photos of the appearance of the dual-phase mouthwashes with the respective formulas in Table 5 according to the specific embodiments of the present invention. DETAILED DESCRIPTION

[0048] The present invention will be further described below with reference to the embodiments.

[0049] Overall embodiment

[0050] A two-phase mouthwash comprising the following components in percentage by weight:

[0051] Oil phase: Isopropyl myristate 8-16%, Caprylic / capric glyceride 2.5-8%;

[0052] Aqueous phase: cetylpyridinium chloride 0.02-0.1%, PEG-40 hydrogenated castor oil 0.04-0.2%, propylene glycol 0.12-2.0%, sorbitol 10-25%, glycerin 0.1-10%, pH adjuster (based on adjusting the pH of the aqueous phase to 6-7), water.

[0053] Preferably, in the above formula, the following conditions are also required to be met: the mass ratio of isopropyl myristate to caprylic capric glyceride is ≤4:1; the mass ratio of PEG-40 hydrogenated castor oil to cetylpyridinium chloride is ≥2:1; the mass ratio of PEG-40 hydrogenated castor oil to propylene glycol is 1:3 to 1:10; and the mass ratio of the aqueous phase to the oil phase is 4-7:1.

[0054] Preferably, the pH adjuster is sodium citrate dihydrate and / or citric acid monohydrate; the oil phase also includes one or more of a flavor, an oil-soluble pigment, and an oil-soluble functional ingredient; the flavor comprises 0.3-2.0% by weight of the biphasic mouthwash; the oil-soluble pigment comprises 0-0.001% by weight of the biphasic mouthwash, excluding zero; and the oil-soluble functional ingredient comprises 0-1.0% by weight of the biphasic mouthwash. The aqueous phase also includes a preservative (preferably sodium benzoate), a sweetener (preferably sucralose), and one or more of a water-soluble pigment and a water-soluble functional ingredient; the preservative comprises 0-0.5% by weight of the biphasic mouthwash, excluding zero; the sweetener comprises 0.001-0.01% by weight of the biphasic mouthwash; the water-soluble pigment comprises 0-0.001% by weight of the biphasic mouthwash, excluding zero; and the water-soluble functional ingredient comprises 0-5.0% by weight of the biphasic mouthwash.

[0055] A method for preparing a biphasic mouthwash comprises the following steps:

[0056] (1) Preparation of aqueous phase:

[0057] (1.1) Add pH adjuster, sweetener, and preservative to water and stir to dissolve;

[0058] (1.2) Add sorbitol and glycerol to the solution obtained in step (1.1) and stir evenly;

[0059] (1.3) Dissolve the water-soluble pigment in water, add it to the solution obtained in step (1.2) and stir evenly;

[0060] (1.4) Mix cetylpyridinium chloride, propylene glycol, and PEG-40 hydrogenated castor oil and heat to 40-50° C. until the mixture becomes clear and transparent, then add the solution obtained in step (1.3) to obtain an aqueous phase;

[0061] (2) Preparation of oil phase:

[0062] (2.1) Dissolve the oil-soluble pigment with a portion of isopropyl myristate;

[0063] (2.2) Add the solution obtained in step (2.1), caprylic / capric glyceride, and flavor to the remaining isopropyl myristate and stir evenly to obtain an oil phase;

[0064] (3) Fill the water phase and the oil phase in sequence to obtain a biphasic mouthwash.

[0065] Specific Examples and Comparative Examples

[0066] The technical solution of the present invention is further described below through specific examples and comparative examples. The preparation methods of the dual-phase mouthwash in the following examples and comparative examples are as follows:

[0067] Preparation of the aqueous phase: Add a pH adjuster, a sweetener, and a preservative into water and stir to dissolve; add sorbitol and glycerin to the resulting solution and stir evenly; dissolve a water-soluble pigment in water and add the resulting solution and stir evenly; mix a solid surfactant, propylene glycol, and PEG-40 hydrogenated castor oil and heat to 45°C until the mixture becomes clear and transparent, then add the resulting solution to obtain an aqueous phase (a liquid surfactant can be directly added to water and stirred evenly).

[0068] Preparation of the oil phase: dissolve the oil-soluble pigment in part of the oil phase solvent A; add the resulting solution, oil phase solvent B and essence to the remaining oil phase solvent A, stir evenly, and obtain the oil phase.

[0069] The water phase and the oil phase are filled in sequence to obtain a biphasic mouthwash.

[0070] (1) Mouthwash trial experience: The mouthwash was tested by a 40-person sensory evaluation panel and the taste and user experience of the mouthwash were evaluated through a questionnaire.

[0071] Table 1: Effects of different types of surfactants on the performance of dual-phase mouthwash

[0072]

[0073]

[0074] Mouthwash taste test: Conduct a retention test on a double-layer mouthwash. Require 40 subjects to rate the mouthwash taste after trying it for more than three times and provide feedback on their feelings and opinions about the product. Figure 1 Photos show:

[0075] In Example 1, after adding a surfactant combination of cetylpyridinium chloride, PEG-40 hydrogenated castor oil, and propylene glycol to the aqueous phase, only four people reported that the liquid was slightly greasy. After shaking, the water-oil separation rate was appropriate, the interface was clear, and the liquid was clear and transparent without an emulsion layer or cloud point. No one reported that the separation was too fast or that the liquid adhered to the wall.

[0076] No surfactant was added to Comparative Example 1. Even after shaking, the water and oil phases could not be temporarily emulsified and would quickly separate. 14 out of 40 subjects reported that it was greasy, and the water and oil phases separated too quickly after shaking, with the oil phase sticking to the wall severely, affecting the user experience.

[0077] Comparative Example 2 adds cocamidopropyl betaine (zwitterionic surfactant) as a surfactant. Cocamidopropyl betaine is relatively stable to acid and alkali and produces a lot of foam. After adding it to the aqueous phase, it is easy to form fine foam when shaken, and it is difficult to defoam, which affects the appearance of the product.

[0078] Comparative Example 3 added sodium lauroyl sarcosinate (anionic surfactant) as a surfactant. Sodium lauroyl sarcosinate has excellent foaming properties and produces fine, long-lasting foam. However, when added to the aqueous phase, shaking easily forms fine foam that is difficult to defoam, affecting the product appearance.

[0079] In Comparative Example 4, benzalkonium chloride (cationic surfactant) was added as a surfactant. After adding it to the aqueous phase, it was shaken to produce a large amount of foam. After standing, an emulsion layer existed at the interface between the two phases.

[0080] From the above comparison, it can be seen that Example 1 adds cetylpyridinium chloride and PEG-40 hydrogenated castor oil as low-foaming surfactants, which can quickly emulsify the oil phase while having an ideal two-phase recovery time, and during the recovery process, no large amount of foam will remain and accumulate in the water-oil layer to affect the product appearance.

[0081] Table 2: Effects of different contents of cetylpyridinium chloride on the performance of biphasic mouthwash

[0082]

[0083]

[0084] According to the data in Table 2 and Figure 2 Photos show:

[0085] In Examples 1-3, 0.05%, 0.03% and 0.08% of cetylpyridinium chloride were added, respectively. Within this addition amount range, the emulsion formed after the water-oil mixture can be stable for a long enough time to be distributed to the user. After the sample is allowed to stand, the water and oil are re-separated and the water-oil phase returns to a clear and transparent state, with a clear interface, no emulsification layer and no cloud point.

[0086] In Comparative Example 5, the amount of cetylpyridinium chloride added is 0.01%. At this amount, the duration of the water-oil mixture to form an emulsion is too short, resulting in a high proportion of oil phase in the mouthwash taken by the user (the oil phase has a light density and quickly floats to the upper layer), resulting in a greasy taste that is not refreshing enough and a poor user experience.

[0087] In Comparative Example 6, the addition amount of cetylpyridinium chloride is 0.12%. At this addition amount, the interface between the water and oil phases is unclear after re-separation, and a thin white emulsion layer exists, which affects the appearance of the product.

[0088] From the above comparison, it can be seen that cetylpyridinium chloride has a better effect at a concentration of 0.03-0.08%.

[0089] (2) Low temperature frost resistance test: Place the test sample in a -2℃ constant temperature box for one month and observe the sample condition regularly.

[0090] Table 3: Effect of low temperature antifreeze properties of biphasic mouthwash

[0091]

[0092]

[0093] According to the data in Table 3 and Figure 3 Photos show:

[0094] In Comparative Example 7, compared with Examples 1 and 4, the addition amount of PEG-40 hydrogenated castor oil is higher. The sample does not precipitate flocculent precipitation at low temperature, but a white emulsion layer is formed at the water-oil interface.

[0095] Comparative Example 8 was compared with Examples 1 and 4, except that PEG-40 hydrogenated castor oil and propylene glycol were not added to solubilize cetylpyridinium chloride. The results showed that flocculent precipitates formed within 4 hours at low temperature.

[0096] In Comparative Example 9, compared with Example 1, the ratio of propylene glycol to PEG-40 hydrogenated castor oil was too small, resulting in poor solubilization ability of PEG-40 hydrogenated castor oil. Flocculent matter precipitated in the aqueous phase of the sample within one week.

[0097] In Comparative Example 10, compared with Example 1, the ratio of propylene glycol to PEG-40 hydrogenated castor oil was too high, resulting in poor solubilization efficiency of PEG-40 hydrogenated castor oil. Flocculent matter precipitated in the aqueous phase of the sample within one week.

[0098] Table 4: Effects of different ratios of caprylic capric glyceride and isopropyl myristate on low temperature resistance

[0099]

[0100]

[0101] According to the data in Table 4 and Figure 4 Photos show:

[0102] Compared with Examples 1, 5 and 6, Comparative Example 11 has a higher ratio of isopropyl myristate:caprylic capric glyceride and a higher freezing point of the oil phase, which freezes at -2°C within a week.

[0103] In Comparative Example 12, compared with Examples 1, 5, and 6, no caprylic / capric glyceride was added, and the oil phase consisted only of isopropyl myristate having a higher freezing point, and the oil phase froze within 1 day.

[0104] (3) The influence of the ratio of water phase and oil phase on appearance.

[0105] Table 5: Effect of water-oil ratio on biphasic mouthwash

[0106]

[0107] From Table 5 and Figure 5 Photos show:

[0108] Compared with Example 1 and Comparative Example 13, the oil phase ratio is higher. Example 1 is more refreshing when rinsing, the mouth feels moisturized after rinsing, and the product appearance is more coordinated. Comparative Example 10 has an uncoordinated overall appearance due to the low oil phase ratio. During use, the oil phase is easily consumed earlier than the water phase due to the low proportion.

[0109] Compared to Example 1 and Comparative Example 14, the oil phase ratio in Comparative Example 14 is too high, resulting in a slightly greasy feeling both during and after rinsing. A high oil phase ratio can create a strong greasy feeling, affecting the user experience. A suitable oil phase ratio can provide a moisturizing feeling after rinsing, likely due to the lubricating effect of the oil phase solution. A low oil phase ratio can result in an unbalanced product appearance, lacking the aesthetic appeal of a double-layer mouthwash.

[0110] Unless otherwise specified, the raw materials and equipment used in the present invention are commonly used in the art; the methods used in the present invention are conventional methods in the art unless otherwise specified.

[0111] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A dual-phase mouthwash, characterized in that The following components are included in mass percentage: Oil phase: Isopropyl myristate 8-16%, Caprylic / capric glyceride 2.5-8.0%; Aqueous phase: Cetylpyridinium chloride 0.02-0.1%, PEG-40 hydrogenated castor oil 0.04-0.2%, propylene glycol 0.12-2.0%, sorbitol 10-25%, glycerin 0.1-10%, pH adjuster, water; The mass ratio of isopropyl myristate to caprylic / capric glyceride is ≤4:1; The mass ratio of the PEG-40 hydrogenated castor oil to cetylpyridinium chloride is ≥2:1; The mass ratio of the PEG-40 hydrogenated castor oil to propylene glycol is 1:3 to 1:10; The mass ratio of the water phase to the oil phase is 4-7:

1.

2. The dual-phase mouthwash according to claim 1, wherein: The pH regulator is sodium citrate dihydrate and / or citric acid monohydrate.

3. The dual-phase mouthwash according to claim 1 or 2, characterized in that: The amount of the pH regulator used is based on the pH of the aqueous phase being 6-7.

4. The dual-phase mouthwash according to claim 1, wherein: The components of the oil phase also include one or more of essence, oil-soluble pigment, and oil-soluble functional ingredients.

5. The dual-phase mouthwash according to claim 4, wherein: The mass percentage of the essence in the dual-phase mouthwash is 0.3-2.0%.

6. The dual-phase mouthwash according to claim 4, wherein: The mass percentage of the oil-soluble pigment in the dual-phase mouthwash is 0-0.001%, excluding 0.

7. The dual-phase mouthwash according to claim 4, wherein: The mass percentage of the oil-soluble functional ingredient in the dual-phase mouthwash is 0-1.0%.

8. The dual-phase mouthwash according to claim 4, wherein: The components of the water phase also include one or more of preservatives, sweeteners, water-soluble pigments, and water-soluble functional ingredients.

9. The dual-phase mouthwash according to claim 8, wherein: The mass percentage of the preservative in the dual-phase mouthwash is 0-0.5%, excluding 0.

10. The dual-phase mouthwash according to claim 8, wherein: The mass percentage of the sweetener in the dual-phase mouthwash is 0.001-0.01%.

11. The dual-phase mouthwash according to claim 8, wherein: The mass percentage of the water-soluble pigment in the dual-phase mouthwash is 0-0.001%, excluding 0.

12. The dual-phase mouthwash according to claim 8, wherein: The mass percentage of the water-soluble functional ingredient in the biphasic mouthwash is 0-5.0%.

13. A method for preparing the dual-phase mouthwash according to claim 8, characterized in that The following steps are involved: (1) Preparation of aqueous phase (1.1) Add pH adjuster, sweetener, and preservative to water and stir to dissolve; (1.2) Add sorbitol and glycerol to the solution obtained in step (1.1) and stir evenly; (1.3) Dissolve the water-soluble pigment in water and add it to the solution obtained in step (1.2) and stir evenly; (1.4) Mix cetylpyridinium chloride, propylene glycol, and PEG-40 hydrogenated castor oil and heat to 40-50°C until the mixture becomes clear. Then, add the solution obtained in step (1.3) to obtain an aqueous phase. (2) Preparation of oil phase (2.1) Dissolve the oil-soluble pigment with a portion of isopropyl myristate; (2.2) Add the solution obtained in step (2.1), caprylic / capric glyceride, and flavor to the remaining isopropyl myristate and stir evenly to obtain an oil phase; (3) Fill the water phase and oil phase in sequence to obtain a biphasic mouthwash.

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