A composition containing menthyl glycol and its use in mosquito repellent microemulsions

Abstract

The application discloses a composition containing menthone glycerol acetal and application of the composition in mosquito-repelling microemulsion, and the composition contains, in mass parts, 2-9 parts of menthone glycerol acetal, 4-10 parts of a surfactant and 2-5 parts of a co-surfactant. Compared with a common stable menthone glycerol acetal high-content surfactant water agent system, the composition has the advantages of clear and transparent appearance, non-sticky and oily use feeling and mild components, and has low manufacturing cost, low irritation, good skin feeling and excellent practical value.

Description

Technical Field

[0001] This invention relates to the field of A01N31 / 06, and more particularly to a composition containing menthol and its application in mosquito repellent microemulsions. Background Technology

[0002] Mosquitoes feed on human blood, and mosquito bites can cause discomfort such as redness, swelling, and itching. More seriously, mosquitoes are intermediate hosts for many serious infectious diseases. Therefore, daily mosquito repellent is essential. Menthol is an effective mosquito-repellent ingredient extracted from plants; however, it is a crystalline precipitate and will precipitate out when left to stand.

[0003] CN112807259A discloses a safe and non-toxic mosquito repellent composition comprising the following components in parts by weight: 91.04–99.33 parts of a fluid property modifier; 2.6–3.6 parts of a first mosquito repellent; 0.4–0.8 parts of an antibacterial, anti-inflammatory, and soothing agent; 0.06–0.07 parts of a pH adjuster; and 0.7–1.4 parts of a second mosquito repellent. It utilizes multiple plant extracts with mosquito-repellent effects to synergistically achieve the mosquito-repellent effect. However, the mosquito-repellent components, especially menthol, are present in extremely low amounts, resulting in poor mosquito-repellent efficacy.

[0004] CN112263513A discloses a water-based mosquito repellent and its preparation method. The raw materials include: montmorillonite glycol, hydrogenated castor oil, octyl / decyl glucoside, 95% alcohol, caprylyl glycol, decanol, deionized water, etc. The resulting water-based mosquito repellent is a water-based, colorless, and transparent product with a clear appearance. However, it contains many alcohols, especially alcohol, which has a high content and is somewhat irritating. Summary of the Invention

[0005] To address the aforementioned problems, this invention discloses a composition containing menthol, wherein the raw materials for preparation, by weight, include: 2-9 parts menthol, 4-10 parts surfactant, and 2-5 parts co-surfactant.

[0006] In one embodiment, the surfactant is an ionic surfactant and / or a nonionic surfactant.

[0007] Preferably, the surfactant is a nonionic surfactant.

[0008] More preferably, the nonionic surfactant is castor oil.

[0009] More preferably, the castor oil is hydrogenated castor oil.

[0010] More preferably, the hydrogenated castor oil is PEG-40 hydrogenated castor oil.

[0011] In one embodiment, the active head of the co-surfactant contains one or more of hydroxyl, carboxyl, phosphorus, sulfide, and chlorine groups.

[0012] Preferably, the active head of the co-surfactant contains a hydroxyl group.

[0013] More preferably, the co-surfactant contains more than 20 C.

[0014] More preferably, the co-surfactant is polyglycerol-3 diisostearate.

[0015] Mongan glycol is an effective mosquito repellent ingredient extracted from plants. As the raw material is alcohol-soluble, existing technologies require the addition of a large amount of alcohol solvents. The amount of mongan glycol added must also be strictly controlled. Otherwise, its stability test will be difficult to pass, and it is very easy to precipitate, affecting its use. Furthermore, the use of alcohol or solubilizers for solubilization can introduce irritation risks when the amount of alcohol or solubilizer added is high. Through extensive experiments, the inventors discovered that by adding surfactants and co-surfactants, especially PEG-40 hydrogenated castor oil as the surfactant and polyglycerol-3 diisostearate as the co-surfactant, the resulting product passed stability tests in environments ranging from -18℃ to 48℃. After being stored for one to three months, it remained transparent without any abnormalities, and its appearance was very clear, exhibiting a bluish-green transparent appearance. The inventors believe the possible reason is that the hydrophilic groups of the nonionic surfactant selected in this invention extend from the surface of the oil droplet into the aqueous phase in a wavy pattern, forming spherical bodies. Due to the difference in dielectric constant between the interior and the surrounding area, the interior of the formed spheres is nonpolar while the exterior is polar, thus encapsulating menthol. Furthermore, the active head of the co-surfactant selected in this invention contains hydroxyl groups, which further stabilizes the hydrophilic properties of menthol and reduces the polarity of water.

[0016] Preferably, the mass of the menthol is: (mass of surfactant + mass of co-surfactant) = 8:(8-11).

[0017] More preferably, the mass ratio of the menthol is (surfactant mass + co-surfactant mass) = 8:10.5.

[0018] Preferably, the mass ratio of the surfactant to the co-surfactant is (1-3):1, the product has a very clear appearance with a bluish-green transparent appearance, and is non-sticky and non-greasy to use, with a milder composition.

[0019] More preferably, the mass ratio of the surfactant to the co-surfactant is 2:1.

[0020] The second aspect of the present invention discloses the application of the composition in mosquito repellent microemulsions.

[0021] The raw materials for preparing the mosquito repellent microemulsion, by weight, include: 8-21 parts of the composition, 4.5-18 parts of humectant, 0.5-2 parts of preservative, and 60-70 parts of water.

[0022] The mass fractions of the raw materials used to prepare the composition are consistent with the mass fractions of the raw materials used to prepare the mosquito-repellent microemulsion containing the composition.

[0023] In one embodiment, the moisturizer is selected from one or more of polyols, natural moisturizing factors, and amino acids.

[0024] Preferably, the humectant is a polyol.

[0025] More preferably, the humectant is a small molecule polyol with a C content of less than 10.

[0026] More preferably, the humectant is a mixture of 1,3-butanediol and isopentanediol in a mass ratio of (3-8):1.

[0027] In one embodiment, the preservative is a chemical preservative and / or a natural preservative.

[0028] Preferably, the preservative is a chemical preservative.

[0029] More preferably, the chemical preservative is an organic preservative.

[0030] More preferably, the organic preservative is an alcohol. For example, a mixture of phenoxyethanol and 1,2-hexanediol in a mass ratio of 1:(1-3).

[0031] The mosquito-repellent microemulsion is prepared by mixing the raw materials in sequence.

[0032] In one embodiment, the surfactant, co-surfactant, humectant, and methyl glycol are first mixed and heated and stirred until clear and transparent to obtain solution 1.

[0033] Preferably, the heating temperature is 50-55°C.

[0034] In one embodiment, the preservative and water are mixed, heated, and stirred to obtain solution 2.

[0035] Preferably, the heating temperature is 50-55°C.

[0036] After obtaining solution 1 and solution 2, solution 2 is slowly added to solution 1 to obtain a homogeneous solution, which is the mosquito repellent microemulsion.

[0037] Beneficial effects

[0038] 1. When the mass ratio of the menthol is (surfactant mass + co-surfactant mass) = 8:(8-11) and the mass ratio of the surfactant to co-surfactant mass = (1-3):1, the resulting product can pass the stability test in an environment of -18℃ to 48℃. After being stored for one to three months, it remains transparent without any abnormalities, and the product has a very clear appearance with a bluish transparent appearance.

[0039] 2. The prepared product is easy and convenient to use; simply spray and spread it evenly.

[0040] 3. Compared to common alcohol-soluble products, this formula is water-based, less irritating, and mild.

[0041] 4. Compared to common stable menthol-based surfactant aqueous systems with high content, it has a clear and transparent appearance, a non-sticky and non-greasy feel, and a gentler composition.

[0042] 5. This invention has low manufacturing cost, low irritation, good skin feel, and excellent practical value. Attached Figure Description

[0043] Figure 1 The stability test results of the mosquito repellent microemulsion prepared by the composition in Example 1 are shown in the figure from left to right as 48℃, 40℃, 25℃, 4℃, and -18℃.

[0044] Figure 2 Image of the mosquito-repellent microemulsion prepared from the composition in Example 6.

[0045] Figure 3 Photograph of the mosquito-repellent microemulsion prepared by the composition in Example 6 after standing.

[0046] Figure 4 Particle size distribution test results of the mosquito repellent microemulsion prepared by the composition in Example 1. Detailed Implementation

[0047] Examples 1-6 disclose a composition containing menthol.

[0048] The composition containing menthol is used in mosquito repellent microemulsions.

[0049] Examples 1-6 also disclose a method for preparing a mosquito-repellent microemulsion containing the composition, and the raw materials and mass fractions are shown in Table 1.

[0050] Table 1

[0051]

[0052] The montmorillonite glycol was purchased from Guangdong Baifang Fragrance Chemicals Co., Ltd.

[0053] The PEG-40 hydrogenated castor oil was purchased from BASF (China) Co., Ltd.

[0054] The polyglycerol-3 diisostearate was purchased from GATTEFORSE SAS.

[0055] The polyglycerol-4 isostearate was purchased from Evonik Operations GmbH.

[0056] Preparation method: Mix methyl methacrylate, PEG-40 hydrogenated castor oil, polyglycerol-3 diisostearate (or polyglycerol-4 isostearate), 1,3-butanediol, and isopentanediol, and heat to 52°C until clear and transparent to obtain solution 1; heat water, phenoxyethanol, and 1,2-hexanediol to 52°C to obtain solution 2; add solution 2 to solution 1 with stirring to obtain a homogeneous solution.

[0057] Performance testing

[0058] Stability testing: The stability of the mosquito-repellent microemulsions prepared from the compositions of Examples 1-6 was tested at five different temperatures. Stability was observed for one month at -18°C (freezing) and 48°C (high temperature), and for three months at 4°C (low temperature), room temperature (25°C), and 40°C. The results are shown in Table 2 below.

[0059] Table 2

[0060]

[0061] In Example 6, when polyglycerol-3 diisostearate was replaced with polyglycerol-4 isostearate in the composition, the system failed to form a transparent bluish microemulsion, such as... Figure 2 Let it stand and the oil will come out. Figure 3 The system cannot be stable.

[0062] The particle size of the mosquito-repellent microemulsion obtained in Example 1 was tested, and the results are as follows: Figure 4 The main particle size peaks are at 52nm and 395nm, proving that it is a nanoemulsion.

Claims

1. A menthadiol-containing composition characterized in that, The preparation raw materials include 2-9 parts of monobenzenediol, 4-10 parts of surfactant, 2-5 parts of co-surfactant by mass fraction; The mass ratio of the monobenzenediol to the total mass of the surfactant and the co-surfactant is 8:10.5; The mass ratio of the surfactant to the co-surfactant is 2:1; The surfactant is PEG-40 hydrogenated castor oil; The co-surfactant is polyglyceryl-3 diisostearate.

2. Use of a composition containing menthols according to claim 1, characterized in that, The application is applied to the preparation of mosquito repellent microemulsion products.

3. Use according to claim 2, characterized in that, The preparation raw materials of the mosquito repellent microemulsion include 8-21 parts of composition, 4.5-18 parts of humectant, 0.5-2 parts of preservative and 60-70 parts of water by mass fraction.

4. Use according to claim 3, characterized in that, The preparation method of the mosquito repellent microemulsion is that the preparation raw materials are sequentially mixed to obtain the mosquito repellent microemulsion.

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