Long-acting mosquito-repellent spray based on European wild red eggplant essential oil and film-forming technology and preparation method of long-acting mosquito-repellent spray

Abstract

The invention discloses a long-acting mosquito-repellent spray based on European wild red eggplant essential oil and a film-forming technology and a preparation method of the long-acting mosquito-repellent spray. The spray comprises a water phase, an oil phase, an active substance phase and an anti-corrosion system, and is characterized in that the active substance phase comprises mosquito-repelling active substances, namely paragliptin, European wild red eggplant essential oil, lemon eucalyptus oil and citronella citriodora oil, and the mosquito-repelling active substances, polyvinylpyrrolidone (PVP) serving as a film-forming agent and cyclodextrin serving as a wrapping agent are compounded and added at a low temperature (less than or equal to 40 DEG C). According to the preparation method disclosed by the invention, through a unique low-temperature adding and homogenizing process, effective inclusion of cyclodextrin on volatile essential oil and uniform film formation of PVP on the skin surface are realized, and a'wrapping-slow release-film formation-fixation 'synergistic system is jointly formed. The product effectively solves the technical problems that a traditional mosquito repelling product is short in effective time, not resistant to sweat and large in skin irritation, and a long-acting, mild and sweat-resistant efficient mosquito repelling solution is provided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of daily chemicals, in particular to a mosquito repellent composition, especially a long-acting mosquito repellent spray based on plant essential oils and synthetic mosquito repellents, using wrapping and film-forming technology, and a preparation method thereof. BACKGROUND

[0002] As daily protection products, the core technology of mosquito repellent products mainly depends on effective mosquito repellent active ingredients. The mainstream mosquito repellents on the market can be divided into two categories: synthetic insecticides and natural plant essential oils. (1) Synthetic mosquito repellents: represented by DEET and IR3535. This type of compound plays a role by interfering with the chemical receptors of mosquitoes, has significant and long-lasting mosquito repellent effect, and is the most widely used classic mosquito repellent ingredient. However, its shortcomings are also quite prominent: DEET: Although it is highly effective, it has long-term safety and irritation controversies. It has solubility to various plastics, synthetic fibers and other materials, and there are inconveniences when using it. The potential neurotoxicity and skin irritation of high-concentration products to children and sensitive skin groups have always been the focus of consumer concerns. IR3535: Compared with DEET, it has improved mildness, but it is still irritating to the eyes, and its mosquito repellent efficiency, especially the repellent effect and durability on some mosquito species, is generally considered to be slightly inferior to DEET.

[0003] (2) Natural plant essential oil mosquito repellents: represented by OLE and citronella oil. They are derived from nature, have a pleasant smell, high safety, good consumer acceptance, and meet the current "natural and green" consumer trend. However, there are obvious technical bottlenecks in their application: strong volatility, short effective duration: the effective components in essential oils (such as citronella aldehyde and menthol) are volatile, leading to rapid decay of mosquito repellent effect, requiring frequent reapplication, and poor user experience. Single efficacy, limited mosquito repellent spectrum: the mosquito repellent effect of single essential oil is limited and may only be effective against specific mosquito species. Potential irritation: untreated essential oils directly applied to the skin may cause allergic or irritating reactions.

[0004] In summary, there is a clear contradiction in the existing technology: synthetic mosquito repellents have long-lasting effects but questionable safety, while natural plant essential oils have high safety but poor durability. Therefore, there is an urgent need in the field for a new technical solution that can combine the safety and mildness of natural products with the high efficiency and durability of synthetic products, i.e. to develop a product that significantly extends the mosquito repellent time of plant essential oils and reduces their irritation through technical innovation.

[0005] Although the wrapping technology and film-forming technology are mature technologies in their respective fields, their "transfer" from the field of cosmetics to the field of mosquito repellents is not a conventional technical means in this field, and there are technical barriers and inherent biases: First, the technical objectives differ. The primary purpose of encapsulation and film-forming technologies in cosmetics is moisturizing, sun protection, and makeup setting, focusing on sensory experience and ingredient stability. In contrast, the core objective of mosquito repellent products is to form an effective "chemical barrier" on the skin surface and maintain its concentration for a long time to repel mosquitoes. The requirements for active ingredient release kinetics and film performance are drastically different. Second, the compatibility of the formulation system is unknown. Mosquito repellent formulations typically contain high concentrations of ethanol or non-polar solvents (used to dissolve synthetic mosquito repellents and essential oils), which are incompatible with many cosmetic encapsulation systems (often water-based), potentially leading to encapsulation rupture and uneven film formation. Constructing a formulation system that can stabilize the encapsulation, effectively form a film, and is compatible with picaridin and the complex oil phases of various essential oils requires creative effort. Third, the effects are difficult to predict. Can the "film" formed after cosmetic film formation effectively fix the mosquito repellent active ingredients and regulate their release rate? How will external factors such as sweat and friction affect the integrity of this "mosquito repellent film"? These are all questions that those skilled in the art cannot directly glean technical insights from cosmetic applications.

[0006] Those skilled in the art have been dedicated to solving the problem of balancing the long-lasting effect and mildness of mosquito repellents, but existing attempts have limitations: (1) Simply reducing the concentration of synthetic mosquito repellents will directly lead to a shorter product expiration time and cannot achieve long-lasting effect. (2) Simply combining plant essential oils with synthetic mosquito repellents fails to solve the inherent problems of essential oil volatility and irritation, and may exacerbate the risk of skin allergies due to complex formulations. (3) Although the use of conventional sustained-release technology (such as simple microcapsules) may slightly extend the effective time, it often cannot effectively cope with actual usage scenarios such as sweat washing and clothing friction, the long-lasting effect is not significant, and the improvement on skin irritation is limited.

[0007] Therefore, the market urgently needs a completely new technological approach and formulation architecture that can fundamentally overcome the aforementioned limitations. This solution must not only significantly extend the effective mosquito-repelling time to over 8 hours, but also fundamentally reduce the irritation caused by direct skin contact through efficient encapsulation and slow release of active substances, thereby achieving a balance between the seemingly contradictory attributes of "long-lasting" and "mild." Currently, no technological solutions that can systematically solve this problem have been reported.

[0008] In summary, existing technologies have failed to effectively resolve the inherent contradiction between the long-lasting effect, sweat resistance, and gentleness of mosquito repellents. Therefore, the technical problem this invention aims to solve is to provide a novel mosquito repellent spray that simultaneously overcomes the following challenges: (1) Extending the effective time: Significantly inhibiting the rapid evaporation of active ingredients such as plant essential oils, extending the effective mosquito repellent time to over 8 hours, comparable to highly effective synthetic mosquito repellents. (2) Enhancing sweat resistance: Imparting good water resistance and rub resistance to maintain the integrity of the mosquito repellent effect even after sweating or slight friction. (3) Reducing skin irritation: Reducing direct contact between active ingredients and skin through technical means, making the product gentle on the skin and suitable for sensitive skin. Summary of the Invention

[0009] The purpose of this invention is to provide a long-lasting, mild mosquito repellent spray and its preparation method.

[0010] Technical solution: (1) After the magnesium aluminum silicate is hydrated, cool it to 75°C, then pre-wet xanthan gum (0.05%) with glycerin (1%) → add it to the main pot and homogenize at 6000 rpm for 3 minutes (avoid excessive shear). (2) Mix all oil phases (B4-B11) → heat to 75°C, then slowly pour the oil phase (75°C) into the water phase (75°C) → mix at medium speed and homogenize at 10000 rpm for 1 minute (short-term high shear avoids damaging the thixotropic structure), and finally turn on the cooling. Water → Stir and cool to 40℃ (3) Add active material to low temperature phase (≤40℃), then add preservative group and stir to dissolve, use reserved water (15.7%) to dissolve pH, then perform viscosity test, the target value is 300-500cP (Brookfeld RV, No. 3 rotor / 20rpm), if too high: add ≤1% water; if too low: add 0.1% pre-dispersed magnesium aluminum silicate slurry, finally perform vacuum (-0.8bar / 5min) → 200 mesh filter.

[0011] Beneficial effects: (1) Long-lasting mosquito repellency: Due to the encapsulation effect of cyclodextrin and the film-forming fixation effect of PVP, the active ingredients are released slowly, significantly extending the effective mosquito repellency time to 8-12 hours, according to experimental data. (2) Reduced irritation: The encapsulation technology reduces the direct contact between plant essential oils and the skin, making the product gentler and suitable for children and sensitive skin. (3) Sweat resistance: The film formed by PVP has a certain degree of water resistance and is not easily washed away by sweat. (4) Good stability: The low-temperature process and encapsulation technology protect the active ingredients, resulting in a long product shelf life. Detailed Implementation

[0012] “Accurately weigh each component according to the formula shown in Table 1.” “Preparation process: (1) Add the aqueous phase components (1-5) to the main vessel, heat to 75-80℃, stir until completely dissolved, and homogenize for 5 minutes. (2) Mix the oil phase components (6-12) in another container, heat to 75-80℃, and stir until clear and transparent. (3) Slowly add the oil phase to the aqueous phase, emulsify at high speed for 5-10 minutes, and then turn on the stirring to cool. (4) When the temperature drops to 40℃, add the pre-mixed C phase (active material phase, 13-15, 24, 25), and stir for 15 minutes until uniform. (5) Continue to cool to 35℃, add the D phase (16-18) and E phase (19-22), and stir to homogenize. (6) Adjust the pH to 5.5-6.5 with citric acid aqueous solution (23, 24). (7) Fill and fill with nitrogen (propellant) to obtain the product.”

Claims

1. A long-lasting mosquito repellent spray based on European wild red tomato essential oil and film-forming technology, and its preparation method, characterized in that, Includes the following steps: (1) After the magnesium aluminum silicate is hydrated, cool it to 75°C, then pre-wet xanthan gum (0.05%) with glycerin (1%) → add it to the mixing bowl and homogenize at 6000 rpm for 3 minutes (avoid excessive shearing). (2) Mix all oil phases (B4-B11) and heat to 75°C. Then slowly pour the oil phase (75°C) into the water phase (75°C) and mix at medium speed. Homogenize at 10,000 rpm for 1 minute (short-term high shear to avoid damaging the thixotropic structure). Finally, turn on the cooling water and stir to cool down to 40°C. (3) Add C active material at low temperature (≤40℃), then add preservative group and stir to dissolve, dissolve pH with reserved water (15.7%), then conduct viscosity test, the target value is 300-500cP (BrookfeldRV, No.3 rotor / 20rpm), if too high: add ≤1% water; if too low: add 0.1% pre-dispersed magnesium aluminum silicate slurry, and finally perform vacuum degassing (-0.8bar / 5min) → filter with 200 mesh filter.

2. The preparation method according to claim 1, characterized in that, The active phase comprises the following components by mass percentage: picaridin 10-20%, dipropylene glycol 5-8%, solanum oil 3-8%, cyclodextrin 2-5%, and PVP 1-3%.

3. A long-lasting mosquito repellent spray prepared using the method described in any one of claims 1-2, characterized in that, The product contains the following components by weight percentage: water 48%, xanthan gum 0.5%, magnesium aluminum silicate 0.7%, glycerin 2%, disodium EDTA 0.1%, polysorbate-80 4%, PEG-40 hydrogenated castor oil 2%, cyclopentasiloxane 0.8%, eucalyptus oil 1%, lemongrass oil 1%, solanum oil 5%, tocopherol (vitamin E) 0.5%, isobutyl hydroxyethylpiperidine carboxylate (picaridin) 15%, dipropylene glycol 6%, 1,2-pentanediol 2%, allantoin 0.3%, menthol 0.1%, ethylhexylglycerin 0.3%, phenoxyethanol 0.8%, chlorophenoxyethanol 0.3%, capryloyl hydroxamic acid 0.15%, p-hydroxyacetophenone 0.2%, water 8.5%, PvP-30 1.5%, and cyclodextrin 3%.

4. The mosquito repellent spray according to claim 3, characterized in that, The European wild tomato essential oil, lemon eucalyptus oil, and lemon citronella oil are blended in a mass ratio of (4-6):(0.5-2):(0.5-2) to form a synergistic mosquito repellent system.

5. The mosquito repellent spray according to claim 3, characterized in that, The film-forming agent is polyvinylpyrrolidone, and the encapsulating agent is cyclodextrin.

6. The use of a mosquito repellent spray as described in any one of claims 3-5 in the preparation of mosquito repellent products, particularly long-lasting, sweat-resistant mosquito repellent products.

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