A long-lasting moisturizing lip gloss coated with microcapsules of essential oils and a preparation process thereof

Abstract

This invention belongs to the field of cosmetic technology, specifically relating to a long-lasting moisturizing lip gloss encapsulated with essential oil microcapsules and its preparation process. The long-lasting moisturizing lip gloss comprises, by weight, the following components: 15-40 parts of essential oil-moisturizing composition microcapsules, 25-50 parts of film-forming matrix, 15-30 parts of oil composition, 5-15 parts of skin-feel conditioning agent, and 0.5-2 parts of antioxidant. The essential oil-moisturizing composition microcapsules, from the inside out, comprise an essential oil core material, a moisturizing adsorption layer, an intermediate dense layer, and a surface functional modification layer, with a mass ratio of 6-10:3-5:4-6:2-4. The particle size of the essential oil-moisturizing composition microcapsules is 6-40 μm. This invention, by forming moisturizing ingredients into microcapsules, enables the gradient release of essential oils and moisturizing compositions, resulting in long-lasting moisturizing and nourishing effects.

Description

Technical Field

[0001] This invention belongs to the field of cosmetic technology, specifically relating to a long-lasting moisturizing lip gloss encapsulating essential oil microcapsules and its preparation process. Background Technology

[0002] Lip cosmetics include lipsticks, lip glosses, and lip stains, mostly composed of oils, waxes, and powders. Among them, lip stains combine the saturated color of lipsticks with the glossy texture of lip glosses, and are a type of lip makeup product. Using lip stains can achieve effects that lipsticks and lip glosses cannot, and in recent years they have occupied an important position in the cosmetics market.

[0003] Traditional lip gloss products typically use an oil-based base combined with various oils and moisturizing ingredients to achieve an immediate moisturizing effect through direct application. However, due to the extremely thin stratum corneum of the lips, the oils and moisturizing ingredients have a very limited time to remain on the lips. The moisturizing effect of ordinary lip glosses usually only lasts for 1-2 hours, which is insufficient to meet consumers' dual needs for long-lasting makeup and lasting hydration. To address these issues, existing technologies attempt to introduce microencapsulation technology into lip makeup products. For example, patent publication number CN117731576A encapsulates oils and active ingredients in microbeads, achieving slow release through microbead breakage during application, thus improving the application feel; patent publication number CN111544365A adds blueberry anthocyanin microcapsules to lip gloss to stabilize natural pigments and protect active ingredients. However, the aforementioned existing technologies still have certain shortcomings. For example, the release of microcapsules or microspheres relies on mechanical breakage during application. If the microcapsules break at the initial stage of application, the internal active ingredients are released all at once, failing to achieve a sustained-release moisturizing effect. Furthermore, moisturizing ingredients are often added directly to the matrix in free form, which easily evaporates or is mechanically removed after application, limiting the deep moisturizing effect. Although liposomes are used for encapsulation, their poor stability in oily matrices leads to leakage and poor sustained-release effect. In addition, while plant essential oils have good moisturizing and hydrating effects, their volatility, instability, and potential irritation mean that adding them directly to lip gloss accelerates evaporation and can easily irritate sensitive lips due to excessively high local concentrations. Therefore, there is an urgent need to develop a long-lasting moisturizing lip gloss that can achieve a gradient release of essential oils and moisturizing ingredients throughout the application process to meet consumer demand. Summary of the Invention

[0004] To address the aforementioned shortcomings, this invention provides a long-lasting moisturizing lip gloss encapsulated with essential oil microcapsules and its preparation process. This lip gloss enables gradient release of essential oils and moisturizing compositions, providing long-lasting moisturizing and hydrating effects.

[0005] The purpose of this invention is to provide a long-lasting moisturizing lip gloss encapsulating essential oil microcapsules, comprising the following components by weight: 15-40 parts of essential oil-moisturizing composition microcapsules, 25-50 parts of film-forming matrix, 15-30 parts of oil composition, 5-15 parts of skin feel conditioning agent, and 0.5-2 parts of antioxidant. The essential oil-moisturizing composition microcapsules consist of an essential oil core material, a moisturizing and adsorption layer, an intermediate dense layer, and a surface functional modification layer from the inside out, with a mass ratio of 6-10:3-5:4-6:2-4. The microcapsules of the essential oil-moisturizing composition have a particle size of 6-40 μm.

[0006] This invention encapsulates moisturizing ingredients into microcapsules, using long-lasting moisturizing active ingredient essential oil as the core material. Then, it sequentially encapsulates the microcapsules with a moisturizing adsorption layer, an intermediate dense layer, and a surface functional modification layer. The surface modification layer can automatically adjust the release rate after contact with the lips. The intermediate dense layer ensures that the core material of the microcapsules and the moisturizing adsorption layer are not damaged during storage and initial application, stably sealing the moisturizing ingredients. The moisturizing adsorption layer can preferentially release the moisturizer after the microcapsules are broken, achieving rapid hydration in the initial stage, and then gradually releasing the core material moisturizing ingredients, ultimately achieving the purpose of gradient release and long-lasting moisturization.

[0007] Preferably, in the above technical solution, the essential oil of the essential oil core material is two or more of the following: jojoba oil, avocado oil, rosehip oil, lavender essential oil, and sweet almond oil. Jojoba oil is a liquid wax extracted from the seeds of the desert shrub jojoba. Its molecular structure is similar to human sebum, and it is rich in vitamins and minerals. It provides long-lasting hydration, prevents dry lips, and forms a breathable film to prevent moisture loss. Avocado oil is extracted from avocado pulp and is rich in unsaturated fatty acids, vitamins A, D, and E, and lecithin. It deeply nourishes dry skin, improves skin elasticity, and enhances moisturizing and softening effects. Rosehip oil is cold-pressed from rosehip seeds and is rich in linoleic acid, vitamin C, and antioxidants. It moisturizes, reduces fine lines, promotes skin cell regeneration, and enhances skin elasticity. Lavender essential oil is extracted from lavender flowers and mainly contains linalool and linalyl acetate. It has soothing and anti-inflammatory effects. Sweet almond oil is cold-pressed from sweet almond seeds and is rich in unsaturated fatty acids and vitamin E. It provides gentle moisturizing and soothes dryness. In this technical solution, using two or more of the above essential oils as the core material of the lip gloss provides long-lasting hydration, reduces skin moisture loss, and improves lip elasticity.

[0008] Preferably, in the above technical solution, the moisturizing adsorption layer is a porous starch adsorption layer with a water-soluble moisturizing agent adsorbed on its surface; the specific surface area of ​​the porous starch is 100-200 m². 2 / g, with a particle size of 2-10μm; the water-soluble moisturizer is at least two of hyaluronic acid, collagen oligopeptides, glycerin, and ceramide; the adsorption amount of the water-soluble moisturizer is 15-25% of the mass of the porous starch. Hyaluronic acid is an acidic mucopolysaccharide with strong moisturizing properties, providing long-lasting hydration to the lips and preventing dry skin; collagen oligopeptides are small molecule peptides obtained after collagen hydrolysis, possessing hydrophilicity and skin affinity, capable of quickly penetrating the lip skin, replenishing collagen, promoting lip skin cell metabolism, and enhancing skin elasticity and firmness; glycerin is a small molecule polyol that absorbs moisture and moisturizes by forming hydrogen bonds with water molecules through hydroxyl groups, quickly replenishing moisture to the lips; ceramide is a major component of lipids in the stratum corneum of the skin, possessing hydrophilicity and lipophilicity, capable of binding with water and lipids in the stratum corneum to form a network structure to lock in moisture, repair the skin barrier, and prevent moisture loss. In this technical solution, the above-mentioned water-based moisturizer is adsorbed into porous starch, which can effectively avoid phase separation or precipitation caused by direct addition to oil-based matrix. This allows the water-based moisturizer to be released preferentially before the essential oil, replenishing water first and then locking in oil, releasing in layers to achieve long-lasting moisturizing.

[0009] Preferably, in the above technical solution, the intermediate dense layer is a composite dense membrane formed by cross-linking chitosan and sodium alginate through polyelectrolyte complexation; the molecular weight of chitosan is 50-200 kDa; the mass ratio of chitosan to sodium alginate is 1:0.8-1.2. Chitosan is a cationic polysaccharide with a positive charge, while sodium alginate is an anionic polysaccharide with a negative charge. After complexation with a polyelectrolyte, the two can form a dense ion-crosslinked membrane, which has a barrier effect on the intermediate layer of the microcapsule.

[0010] Preferably, in the above technical solution, the surface functional modification layer is formed by mesoporous silica nanoparticles wrapped around the outer surface of the intermediate dense layer. The pore size of the mesoporous silica is 2-10 nm, the thickness is 50-200 nm, and a temperature-sensitive polymer is grafted onto the surface of the mesoporous silica. The temperature-sensitive polymer is poly(N-isopropylacrylamide), with a grafting rate of 3-10%. In this technical solution, a mesoporous silica layer is formed on the outermost layer of the microcapsule. The mesoporous structure provides a high specific surface area, providing nanochannels for sustained release and also providing a framework for subsequent grafting of the temperature-sensitive polymer. The temperature-sensitive polymer grafted onto the microcapsule can be controlled according to different lip temperatures. For example, when the temperature is higher than 32°C, the poly(N-isopropylacrylamide) chains collapse, partially blocking the mesoporous channels and reducing the release rate. When the external temperature is lower than 32°C (such as in winter or after a wind), the poly(N-isopropylacrylamide) chains extend, accelerating the release.

[0011] Preferably, in the above technical solution, the film-forming matrix comprises the following components in parts by weight: 25-35 parts of phenyl polytrimethylsiloxane, 15-25 parts of cyclopentamethoxysiloxane, 15-20 parts of isododecane, 8-15 parts of VP / hexadecene copolymer, and 5-10 parts of trimethylsiloxysilicate. Phenylene polytrimethylsiloxane is a film-forming agent that can form a flexible and glossy film, enhancing color adhesion and durability; cyclopentamethoxysiloxane is a volatile silicone oil that provides a silky feel during application, carries other components for even spreading, and leaves a uniform film layer after evaporation; isododecane is a light alkane that evaporates quickly, resulting in fast makeup setting; VP / hexadecene copolymer is a film-forming enhancer that acts as a moisturizing barrier, improves dispersibility, and prevents lip gloss from accumulating in lip lines; trimethylsiloxysilicate is a high-hardness film-forming agent that can adjust the viscoelasticity and durability of the film layer; the combination of these components can quickly and stably form a film, effectively locking in moisturizing ingredients.

[0012] Preferably, in the above technical solution, the oil composition contains at least one component identical to the essential oil in the core layer; the skin-feeling agent is one or more of silica, mica, and polymethylsilsesquioxane; and the antioxidant is tocopherol. In this technical solution, the oil composition provides moisturizing and occlusive effects. The addition of the same component as the essential oil in the core layer aims to ensure rapid fusion of the core oil and base oil after microcapsule rupture, preventing separation and providing comprehensive moisturization. The addition of the skin-feeling agent improves application smoothness and shine. The added antioxidant prevents oxidation, rancidity, and discoloration during storage, extending shelf life and providing antioxidant protection.

[0013] This invention also provides a process for preparing a long-lasting moisturizing lip gloss encapsulating essential oil microcapsules, comprising the following steps: (1) Mix the plant essential oils evenly, add half of the antioxidant, and stir evenly at 40-50℃ to obtain the essential oil core material oil phase; use low temperature to promote the mutual solubility of different essential oils and antioxidants, and avoid high temperature to destroy heat-sensitive components; (2) The porous starch and water-soluble humectant are thoroughly mixed and stirred at room temperature for 2-4 hours for adsorption. The mixture is then filtered and dried under vacuum to obtain a porous starch adsorption carrier loaded with water-soluble humectant. Furthermore, the porous starch adsorption carrier loaded with water-soluble humectant has a water content of less than 5% and better fluidity. (3) After the oil phase of the essential oil core material obtained in step (1) is mixed with the porous starch adsorbent carrier loaded with water-soluble moisturizer obtained in step (2) at high speed, it is added dropwise to the chitosan aqueous solution, emulsified and homogenized for 5-10 min to form a primary emulsion, and then sodium alginate aqueous solution is slowly added dropwise, the temperature is controlled at 35-45℃, and the reaction is stirred for 1-3 h to form an intermediate dense layer. Then the curing agent is added, and the mixture is stirred and cured at 25-35℃ for 2-4 h to obtain the initial microcapsules. (4) The initial microcapsules obtained in step (3) are dispersed in an ethanol solution, and tetraethyl orthosilicate and ammonia are added to carry out a sol-gel reaction to form a mesoporous silica coating layer. Then, temperature-sensitive monomers and ammonium persulfate are added, and the polymerization reaction is carried out at 60-70℃ for 3-6 hours to obtain microcapsules of essential oil-moisturizing composition with surface function modification. (5) Mix the components of the film-forming matrix and heat and stir in a water bath at 70-80℃ until completely dissolved and homogeneous, and set aside; mix the oil composition at 50-60℃ and set aside; grind the skin-feeling conditioner and set aside; mix the above components at 50-60℃ according to the ratio and homogenize for 2-8 minutes to obtain a mixture; (6) Cool the mixture from step (5) to 40-45°C, add the essential oil-moisturizing composition microcapsules obtained in step (4) and the remaining antioxidant, stir evenly, defoam, fill and obtain the long-lasting moisturizing lip gloss product.

[0014] Preferably, in step (3) of the above technical solution, the homogenization speed is 8000-12000 r / min; the mass concentration of chitosan in the chitosan aqueous solution is 2-3%, and the mass concentration of sodium alginate in the sodium alginate aqueous solution is 2.5-3.5%; the curing agent is glutaraldehyde, and the amount added is 1-2% of the total mass of the system.

[0015] Preferably, in step (5) of the above technical solution, the film-forming matrix further includes a colorant, the amount of which is 0.1-2% of the total mass of the film-forming matrix; the mixing and homogenization speed is 1000-2000 r / min; in step (6), the essential oil-moisturizing composition microcapsules are centrifuged, washed and redispersed in an oily suspension medium before mixing, and the content of the microcapsules is 20-35%. Specifically, the oily suspension medium is isododecane or silicone oil.

[0016] Advantages compared to existing technologies: This invention uses long-lasting moisturizing active ingredient essential oil as the core material, then sequentially coats it with a moisturizing adsorption layer, an intermediate dense layer, and a surface functional modification layer to form multi-layered microcapsules. This allows for release at different stages and rates. The surface modification layer regulates the release, automatically adjusting the release rate based on temperature after the microcapsules come into contact with the lips. The intermediate dense layer stabilizes and seals the moisturizing ingredients, ensuring that the core material of the microcapsules and the moisturizing adsorption layer are not damaged during storage and initial application, preventing premature leakage of the essential oil. The moisturizing adsorption layer provides initial moisturizing, preferentially releasing the moisturizer after the microcapsules are broken, achieving rapid initial hydration, followed by gradual release of the core material moisturizing ingredients and rapid water retention, ultimately achieving gradient release and long-lasting moisturization.

[0017] This invention first prepares an essential oil core material oil phase and a porous starch adsorbent carrier loaded with a water-soluble moisturizer. The two are then mixed and coated with a chitosan and trehalose polyelectrolyte complex to form a dense membrane, forming initial microcapsules. Finally, mesoporous silica and temperature-sensitive monomers are grafted onto the surface of the microcapsules to form microcapsules with a multi-layered structure. At the same time, it is combined with a high-efficiency film-forming matrix, an oil composition, and a skin-feeling conditioner. The resulting lip gloss has a long shelf life, good spreadability and film-forming properties, strong water-locking ability, and long-lasting moisturizing effect, effectively overcoming the defects of existing lip glosses such as poor moisturizing effect and short duration. Detailed Implementation

[0018] The above-described technical features of the present invention and the technical features specifically described below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. However, the present invention is not limited to these embodiments, nor are these embodiments limited in any way.

[0019] Unless otherwise specified, the experimental methods used in the following examples are conventional methods. Unless otherwise specified, the formulations involved in the following examples are all commercially available products that can be purchased from the market.

[0020] The present invention will be further described in detail below with reference to embodiments: Example 1 A long-lasting moisturizing lip gloss encapsulating essential oil microcapsules, comprising the following components by weight: 30 parts essential oil-moisturizing composition microcapsules, 35 parts film-forming matrix, 20 parts oil composition, 10 parts skin feel conditioning agent, and 1 part antioxidant; The essential oil-moisturizing composition microcapsules consist of an essential oil core material, a moisturizing and adsorption layer, an intermediate dense layer, and a surface functional modification layer, with a mass ratio of 8:4:4:3. The essential oil core material is a mixture of jojoba oil and rosehip oil in a 1:1 mass ratio; The film-forming matrix comprises the following components by weight percentage: 30 parts of phenyl polytrimethylsiloxane, 20 parts of cyclopentadimethylsiloxane, 18 parts of isododecane, 12 parts of VP / hexadecene copolymer and 8 parts of trimethylsiloxysilicate. The oil composition is a mixture of jojoba oil and triglycerides in a mass ratio of 3:1; The skin-feel conditioning agent is a mixture of silica and mica in a mass ratio of 1:2; The antioxidant is tocopherol.

[0021] The manufacturing process of this long-lasting moisturizing lip gloss includes the following steps: (1) Mix the plant essential oils in the formula evenly, add half of the tocopherol, stir evenly at 45°C to obtain the essential oil core material oil phase; (2) Add the specified amount of porous starch (specific surface area of ​​100-200 m²) to the formula. 2 / g, with a particle size of 2-10μm) and a water-soluble moisturizer (hyaluronic acid and collagen oligopeptide in a mass ratio of 2:1, the total amount being 20% ​​of the porous starch) were thoroughly mixed, stirred and adsorbed at room temperature for 3h, filtered, and vacuum dried until the water content was less than 5%, to obtain a porous starch adsorbent carrier loaded with water-soluble moisturizer. (3) After the oil phase of the essential oil core material is mixed with the porous starch adsorbent carrier loaded with water-soluble moisturizer at high speed, it is added dropwise to a 2.5% chitosan aqueous solution (the molecular weight of chitosan is 100kDa). The mixture is emulsified and homogenized at 10000r / min for 6min to form a primary emulsion. Then, a 3% sodium alginate aqueous solution is slowly added dropwise, and the mass ratio of chitosan to sodium alginate is controlled at 1:1. The temperature is 40℃, and the mixture is stirred and reacted for 2h to form an intermediate dense layer. Then, 0.5% glutaraldehyde is added, and the mixture is stirred and solidified at 30℃ for 3h to obtain the initial microcapsules. (4) The initial microcapsules were dispersed in 90% ethanol solution, and an appropriate amount of tetraethyl orthosilicate and ammonia were added to carry out sol-gel reaction to form a 100nm thick mesoporous silica (particle size 2-10nm) coating layer. Then N-isopropylacrylamide monomer and ammonium persulfate were added, and the polymerization reaction was carried out at 65℃ for 4h to obtain essential oil-moisturizing composition microcapsules (particle size 6-40μm) with a polyN-isopropylacrylamide grafting rate of 8%. After centrifugation and washing, they were dispersed in isododecane or silicone oil to form a suspension with a microcapsule content of 30%. (5) Mix all components of the film-forming matrix according to the formula and heat and stir in a 75°C water bath until completely dissolved and homogeneous, set aside; mix the oil composition according to the formula at 55°C until homogeneous, set aside; grind the skin-feeling conditioner to D... 50 Less than 15μm is reserved; the above components are mixed and homogenized at 1500r / min for 5min at 55℃ according to the ratio to obtain a mixed solution; (6) Cool the mixture to 42°C, add the essential oil-moisturizing composition microcapsule suspension and the remaining tocopherol, stir evenly, defoam, fill and obtain the long-lasting moisturizing lip gloss product.

[0022] Example 2 A long-lasting moisturizing lip gloss encapsulating essential oil microcapsules, comprising the following components by weight: 15 parts essential oil-moisturizing composition microcapsules, 25 parts film-forming matrix, 15 parts oil composition, 5 parts skin feel conditioning agent, and 0.5 parts antioxidant. The essential oil-moisturizing composition microcapsules consist of an essential oil core material, a moisturizing and adsorption layer, an intermediate dense layer, and a surface functional modification layer, with a mass ratio of 6:3:4:2. The essential oil core material is a mixture of jojoba oil and lavender essential oil in a 1:1 mass ratio; The film-forming matrix comprises the following components by weight percentage: 25 parts phenyl polytrimethylsiloxane, 15 parts cyclopentadimethylsiloxane, 15 parts isododecane, 8 parts VP / hexadecene copolymer, and 5 parts trimethylsiloxysilicate. The oil composition is a mixture of jojoba oil and avocado oil in a mass ratio of 2:1; The skin-feeling conditioner is a mixture of polymethylsilsesquioxane and mica in a mass ratio of 1:2; The antioxidant is tocopherol.

[0023] The manufacturing process of this long-lasting moisturizing lip gloss includes the following steps: (1) Mix the plant essential oils in the formula evenly, add half of the tocopherol, stir evenly at 40°C to obtain the essential oil core material oil phase; (2) Add the specified amount of porous starch (specific surface area of ​​100-200 m²) to the formula. 2 / g, with a particle size of 2-10μm) and a water-soluble moisturizer (hyaluronic acid and ceramide in a mass ratio of 2:1, the total amount being 25% of the porous starch) are thoroughly mixed, stirred and adsorbed at room temperature for 2h, filtered, and vacuum dried until the water content is less than 5%, to obtain a porous starch adsorbent carrier loaded with water-soluble moisturizer. (3) After the oil phase of the essential oil core material is mixed with the porous starch adsorbent carrier loaded with water-soluble moisturizer at high speed, it is added dropwise to a 2% chitosan aqueous solution (the molecular weight of chitosan is 100kDa). The mixture is emulsified and homogenized at 8000r / min for 10min to form a primary emulsion. Then, a 2.5% sodium alginate aqueous solution is slowly added dropwise, and the mass ratio of chitosan to sodium alginate is controlled at 1:1. The temperature is 35℃, and the mixture is stirred and reacted for 3h to form an intermediate dense layer. Then, 0.1% glutaraldehyde is added, and the mixture is stirred and solidified at 25℃ for 4h to obtain the initial microcapsules. (4) The initial microcapsules were dispersed in 90% ethanol solution, and an appropriate amount of tetraethyl orthosilicate and ammonia were added to carry out sol-gel reaction to form a 50 nm thick mesoporous silica (particle size 2-10 nm) coating layer. Then, N-isopropylacrylamide monomer and ammonium persulfate were added, and the polymerization reaction was carried out at 60 °C for 6 h to obtain essential oil-moisturizing composition microcapsules (particle size 6-40 μm) with a poly(N-isopropylacrylamide) grafting rate of 5%. After centrifugation and washing, they were dispersed in isododecane or silicone oil to form a suspension with a microcapsule content of 35%. (5) Mix the components of the film-forming matrix according to the formula and heat and stir in a 70°C water bath until completely dissolved and homogeneous, set aside; mix the oil composition evenly at 50°C, set aside; grind the skin-feeling conditioner to D... 50 Use samples smaller than 15μm; mix the above components at 50℃ and 1000r / min for 8min to obtain a mixed solution; (6) Cool the mixture to 40°C, add the essential oil-moisturizing composition microcapsule suspension and the remaining tocopherol, stir evenly, defoam, fill and obtain the long-lasting moisturizing lip gloss product.

[0024] Example 3 A long-lasting moisturizing lip gloss encapsulating essential oil microcapsules, comprising the following components by weight: 40 parts essential oil-moisturizing composition microcapsules, 50 parts film-forming matrix, 25 parts oil composition, 15 parts skin feel conditioning agent, and 2 parts antioxidant. The essential oil-moisturizing composition microcapsules consist of an essential oil core layer, a moisturizing and adsorption layer, an intermediate dense layer, and a surface functional modification layer, with a mass ratio of 10:4:5:3. The essential oils in the core layer are a mixture of avocado oil, rosehip oil, and sweet almond oil in a mass ratio of 1:1:1. The film-forming matrix comprises the following components by weight percentage: 35 parts phenyl polytrimethylsiloxane, 25 parts cyclopentadimethylsiloxane, 20 parts isododecane, 15 parts VP / hexadecene copolymer, 10 parts trimethylsiloxysilicate, and 2 parts colorant. The oil composition is a mixture of avocado oil and rosehip oil in a mass ratio of 1:1; The skin-feel conditioning agent is a mixture of silica and mica in a mass ratio of 1:2; The antioxidant is tocopherol.

[0025] The manufacturing process of this long-lasting moisturizing lip gloss includes the following steps: (1) Mix the plant essential oils in the formula evenly, add half of the tocopherol, stir evenly at 50°C to obtain the essential oil core material oil phase; (2) Add the specified amount of porous starch (specific surface area of ​​100-200 m²) to the formula. 2 / g, with a particle size of 2-10μm) and a water-soluble moisturizer (collagen oligopeptide, glycerol, and ceramide in a mass ratio of 1:2:1, the total amount being 15% of the porous starch) were thoroughly mixed, stirred and adsorbed at room temperature for 2h, filtered, and vacuum dried until the water content was less than 5%, to obtain a porous starch adsorbent carrier loaded with water-soluble moisturizer. (3) After the oil phase of the essential oil core material is mixed with the porous starch adsorbent carrier loaded with water-soluble moisturizer at high speed, it is added dropwise to a 3% chitosan aqueous solution (the molecular weight of chitosan is 100kDa). The mixture is emulsified and homogenized at 12000r / min for 5min to form a primary emulsion. Then, a 3% sodium alginate aqueous solution is slowly added dropwise, and the mass ratio of chitosan to sodium alginate is controlled at 1:1.2. The temperature is 45℃, and the mixture is stirred and reacted for 1h to form an intermediate dense layer. Then, 2% glutaraldehyde is added, and the mixture is stirred and solidified at 35℃ for 2h to obtain the initial microcapsules. (4) The initial microcapsules were dispersed in 90% ethanol solution, and an appropriate amount of tetraethyl orthosilicate and ammonia were added to carry out sol-gel reaction to form a 200 nm thick mesoporous silica (particle size 2-10 nm) coating layer. Then, N-isopropylacrylamide monomer and ammonium persulfate were added, and the polymerization reaction was carried out at 70 °C for 3 h to obtain essential oil-moisturizing composition microcapsules (particle size 6-40 μm) with a poly(N-isopropylacrylamide) grafting rate of 10%. After centrifugation and washing, they were dispersed in isododecane or silicone oil to form a suspension with a microcapsule content of 20%. (5) Mix the components of the film-forming matrix according to the formula and heat and stir in an 80°C water bath until completely dissolved and homogeneous, set aside; mix the oil composition evenly at 60°C, set aside; grind the skin-feeling conditioner to D... 50 Use samples smaller than 15μm; mix and homogenize the above components at 2000r / min for 2 min at 60℃ according to the specified ratio to obtain a mixed solution; (6) Cool the mixture to 45°C, add the essential oil-moisturizing composition microcapsule suspension and the remaining tocopherol, stir evenly, defoam, fill and obtain the long-lasting moisturizing lip gloss product.

[0026] Comparative Example 1 A long-lasting moisturizing lip gloss encapsulating essential oil microcapsules differs from Example 1 in that the essential oil-moisturizing composition microcapsules do not have a surface functional modification layer, and the preparation process does not include step (4); otherwise, it is the same as Example 1.

[0027] Comparative Example 2 A long-lasting moisturizing lip gloss encapsulating essential oil microcapsules differs from Example 1 in that the preparation of the moisturizing adsorption layer (2) and (3) is combined as follows: the essential oil core material oil phase is mixed with a water-soluble moisturizer (hyaluronic acid and collagen oligopeptide in a mass ratio of 2:1) at high speed, and then added dropwise to a 2.5% chitosan aqueous solution (chitosan molecular weight is 100kDa). The mixture is emulsified and homogenized at 10,000 r / min for 6 min to form an initial emulsion. Then, a 3% sodium alginate aqueous solution is slowly added dropwise, controlling the mass ratio of chitosan to sodium alginate to be 1:1. The temperature is maintained at 40°C, and the mixture is stirred for 2 h to form an intermediate dense layer. Then, 0.5% glutaraldehyde is added, and the mixture is stirred and solidified at 30°C for 3 h to obtain the initial microcapsules. The rest is the same as in Example 1.

[0028] Comparative Example 3 A long-lasting moisturizing lip gloss encapsulating essential oil microcapsules differs from Example 1 in that the oil composition is a mixture of avocado oil and triglycerides in a mass ratio of 3:1; otherwise, it is the same as Example 1.

[0029] Comparative Example 4 A long-lasting moisturizing lip gloss, differing from Example 1 in that, by weight, it comprises the following components: 20 parts essential oil, 10 parts moisturizing composition, 35 parts film-forming matrix, 20 parts oil composition, 10 parts skin-feeling conditioner, and 1 part antioxidant; the preparation process is as follows: (1) Mix the plant essential oil and moisturizing composition in the formula evenly, add half of the tocopherol, and stir evenly at 45°C to obtain the essential oil-moisturizing mixture; (2) Mix all components of the film-forming matrix according to the formula and heat and stir in a 75°C water bath until completely dissolved and homogeneous, set aside; mix the oil composition according to the formula at 55°C until homogeneous, set aside; grind the skin-feeling conditioner to D 50 Less than 15μm is reserved; the above components are mixed and homogenized at 1500r / min for 5min at 55℃ according to the ratio to obtain a mixed solution; (3) Cool the mixture to 42°C, add the essential oil-moisturizing mixture and the remaining tocopherol, stir evenly, defoam, and fill to obtain the long-lasting moisturizing lip gloss. Other steps are the same as in Example 1.

[0030] Test case 1. Evaluation of release rate The lip gloss samples prepared in Examples 1-3 and Comparative Examples 1-4 were subjected to in vitro release tests under simulated artificial lip environment (37℃, pH 6.8). The cumulative release rate of the active ingredients of the essential oil was measured within 48 hours, and the results are shown in Table 1. The cumulative release rate is calculated as: (initial essential oil amount - essential oil amount at test) * 100% / initial essential oil amount.

[0031] Table 1 Release rate (%)

[0032] As can be seen from the results in Table 1, the lip gloss prepared by the method of the present invention still releases stably after 48 hours, with an essential oil release rate of less than 70%, and the entire process shows a gentle S-shaped trend, exhibiting typical controlled release characteristics and long-lasting effects. In contrast, in Comparative Example 1, although the microcapsules were relatively stable after 48 hours due to the lack of a final functional modification layer, the release was rapid in the early stages and lacked graded regulation capabilities. In Comparative Example 2, because the moisturizing ingredients were directly mixed with the essential oil without prior adsorption by porous starch, water and oil separated and were released simultaneously, resulting in a worse sustained-release effect than in Example 1. In Comparative Example 3, the base oil of the lip gloss did not contain any components identical to the essential oil components. Although this had little impact on the release of the essential oil, the potential separation when the components were combined with the essential oil could affect the overall moisturizing effect. In Comparative Example 4, the plant essential oil was directly mixed with other components to make the lip gloss, and the essential oil release rate reached 65.2% in the first 4 hours, and the release was basically completed by 24 hours, resulting in a poor sustained-release effect.

[0033] 2. Evaluation of moisturizing effect Thirty-five subjects (14 males and 21 females), aged 20-40 years, were selected and randomly divided into 7 groups, with 2 males and 3 females in each group. Before the experiment, there was no significant difference in the stratum corneum moisture content between the test and control sides. The lip glosses prepared in Examples 1-3 and Comparative Examples 1-4 (3 mg / cm³) were evenly applied to the test sides. 2 The control side was not treated with any product. Subjects remained in the same stable experimental environment throughout the trial, and their lips were kept away from food and water. Epidermal moisture content was measured on both the test and control sides before product application and at 2, 4, 8, and 12 hours after application. The lip stratum corneum moisture content was determined using a capacitance method. The difference in moisture content at each time point was calculated as: (Test side moisture content - Control side moisture content), and the average value was taken. The results are shown in Table 2.

[0034] Table 2. Difference in moisture content (%)

[0035] As can be seen from the results in Table 2, the lip gloss prepared by the method of the present invention has a significant moisturizing effect on the lip skin after use. Furthermore, the difference in moisture content between the two sides of the lip epidermis increases over time, indicating that the lip gloss prepared by the present invention has a good moisturizing effect. In Comparative Example 1, because its microcapsules lack a final functional modification layer, the moisturizing ingredients are released quickly in the early stages, resulting in a good moisturizing effect, although the duration is slightly worse than in Example 1. In Comparative Example 2, because the moisturizing ingredients are directly mixed with the essential oil without the use of porous starch for adsorption, although the release is slow in the early stages, the sustained-release effect is slightly worse due to the simultaneous release of the moisturizing ingredients and the essential oil. In Comparative Example 3, the base oil of the lip gloss does not contain any components identical to the essential oil components, so the initial effect is not significant, but it is slightly affected later due to fusion issues. In Comparative Example 4, the essential oil and moisturizing ingredients are not encapsulated, resulting in a faster release of the effective moisturizing ingredients and a better initial moisturizing effect. However, the difference in moisture content decreases over time, indicating poor duration.

[0036] 3. Sensory evaluation by the subjects After using the lip glosses prepared in Examples 1-3 and Comparative Examples 1-4 for one week, the subjects rated the samples for their spreadability, smoothness, moisturizing lasting effect, lip hydration, and lack of irritation after use. The average scores were taken, and the results are shown in Table 3. The scores were categorized as follows: Good (4.5-5 points), Fair (3.5-4.5 points), Average (2.5-3.5 points), Poor (1.5-2.5 points), and Very Poor (0-1.5 points). The extreme values ​​were assigned to the "Good" group.

[0037] Table 3 Usage Evaluation

[0038] As can be seen from the results in Table 3, the lip gloss prepared by the method of the present invention has good spreadability and smoothness, is easy to apply, is non-irritating, moisturizing and comfortable after application, and has long-lasting moisturizing effect. Comparative Examples 1-2 are slightly less durable than Example 1; Comparative Example 3, due to the absence of essential oil components in its base oil, has slightly less spreadability than Example 1; Comparative Example 4, which did not encapsulate the essential oil, has significantly less moisturizing durability than Example 1.

[0039] In summary, this invention, by forming essential oils and moisturizing ingredients into microcapsules, achieves gradient release, greatly prolonging the moisturizing effect of the lip gloss. At the same time, combined with film-forming matrix, oil composition, skin feel conditioning agent, etc., the resulting lip gloss has good spreadability, strong water-locking ability, and long-lasting moisturizing and hydrating effect.

[0040] Finally, it should be emphasized that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A long-lasting moisturizing lip gloss encapsulating essential oil microcapsules, characterized in that, By weight, it includes the following components: The composition consists of 15-40 parts of essential oil-moisturizing microcapsules, 25-50 parts of film-forming matrix, 15-30 parts of oil composition, 5-15 parts of skin feel conditioner, and 0.5-2 parts of antioxidant. The essential oil-moisturizing composition microcapsules consist of an essential oil core material, a moisturizing and adsorption layer, an intermediate dense layer, and a surface functional modification layer from the inside out, with a mass ratio of 6-10:3-5:4-6:2-4. The microcapsules of the essential oil-moisturizing composition have a particle size of 6-40 μm.

2. The long-lasting moisturizing lip gloss with encapsulated essential oil microcapsules according to claim 1, characterized in that, The essential oil core material contains two or more of the following: jojoba oil, avocado oil, rosehip oil, lavender essential oil, and sweet almond oil.

3. The long-lasting moisturizing lip gloss with encapsulated essential oil microcapsules according to claim 1, characterized in that, The moisturizing adsorption layer is a porous starch adsorption layer with water-soluble moisturizing agents adsorbed on its surface; the specific surface area of ​​the porous starch is 100-200 m². 2 / g, with a particle size of 2-10μm; the water-soluble moisturizer is at least two of hyaluronic acid, collagen oligopeptide, glycerin, and ceramide; the adsorption amount of the water-soluble moisturizer is 15-25% of the mass of the porous starch.

4. The long-lasting moisturizing lip gloss with encapsulated essential oil microcapsules according to claim 1, characterized in that, The intermediate dense layer is a composite dense membrane formed by cross-linking chitosan and sodium alginate through polyelectrolyte complexation; the molecular weight of chitosan is 50-200 kDa; the mass ratio of chitosan to sodium alginate is 1:0.8-1.

2.

5. A long-lasting moisturizing lip gloss with microcapsules of essential oil as described in claim 1, characterized in that, The surface functional modification layer is formed by mesoporous silica nanoparticles wrapped around the outer surface of the intermediate dense layer. The pore size of the mesoporous silica is 2-10 nm and the thickness is 50-200 nm. The surface of the mesoporous silica is also grafted with a temperature-sensitive polymer. The temperature-sensitive polymer is poly(N-isopropylacrylamide) with a grafting rate of 3-10%.

6. The long-lasting moisturizing lip gloss with encapsulated essential oil microcapsules according to claim 1, characterized in that, The film-forming matrix comprises the following components in parts by weight: 25-35 parts of phenyl polytrimethylsiloxane, 15-25 parts of cyclopentadimethylsiloxane, 15-20 parts of isododecane, 8-15 parts of VP / hexadecene copolymer, and 5-10 parts of trimethylsiloxysilicate.

7. A long-lasting moisturizing lip gloss with microcapsules of essential oil as described in claim 1, characterized in that, The oil composition contains at least one component that is the same as the essential oil in the core layer; the skin-feeling agent is one or more of silica, mica, and polymethylsilsesquioxane; and the antioxidant is tocopherol.

8. The preparation process of a long-lasting moisturizing lip gloss encapsulating essential oil microcapsules as described in any one of claims 1-7, characterized in that, Includes the following steps: (1) Mix the plant essential oils evenly, add half of the antioxidant, and stir evenly at 40-50℃ to obtain the essential oil core material oil phase; (2) The porous starch and water-soluble humectant were thoroughly mixed and stirred at room temperature for 2-4 hours for adsorption. The mixture was then filtered and dried under vacuum to obtain a porous starch adsorbent carrier loaded with water-soluble humectant. (3) After the oil phase of the essential oil core material obtained in step (1) is mixed with the porous starch adsorbent carrier loaded with water-soluble moisturizer obtained in step (2) at high speed, it is added dropwise to the chitosan aqueous solution, emulsified and homogenized for 5-10 min to form a primary emulsion, and then sodium alginate aqueous solution is slowly added dropwise, the temperature is controlled at 35-45℃, and the reaction is stirred for 1-3 h to form an intermediate dense layer. Then the curing agent is added, and the mixture is stirred and cured at 25-35℃ for 2-4 h to obtain the initial microcapsules. (4) The initial microcapsules obtained in step (3) are dispersed in an ethanol solution, and tetraethyl orthosilicate and ammonia are added to carry out a sol-gel reaction to form a mesoporous silica coating layer. Then, temperature-sensitive monomers and ammonium persulfate are added, and the polymerization reaction is carried out at 60-70℃ for 3-6 hours to obtain microcapsules of essential oil-moisturizing composition with surface function modification. (5) Mix the components of the film-forming matrix and heat and stir in a water bath at 70-80℃ until completely dissolved and homogeneous, and set aside; mix the oil composition at 50-60℃ and set aside; grind the skin-feeling conditioner and set aside; mix the above components at 50-60℃ according to the ratio and homogenize for 2-8 minutes to obtain a mixture; (6) Cool the mixture from step (5) to 40-45°C, add the essential oil-moisturizing composition microcapsules obtained in step (4) and the remaining antioxidant, stir evenly, defoam, fill and obtain the long-lasting moisturizing lip gloss product.

9. The preparation process of a long-lasting moisturizing lip gloss encapsulating essential oil microcapsules according to claim 8, characterized in that, In step (3), the homogenization speed is 8000-12000 r / min; the mass concentration of chitosan in the chitosan aqueous solution is 2-3%, and the mass concentration of sodium alginate in the sodium alginate aqueous solution is 2.5-3.5%; the curing agent is glutaraldehyde, and the amount added is 1-2% of the total mass of the system.

10. The preparation process of a long-lasting moisturizing lip gloss encapsulating essential oil microcapsules according to claim 8, characterized in that, In step (5), the film-forming matrix also includes a colorant, the amount of which is 0.1-2% of the total mass of the film-forming matrix; the mixing and homogenization speed is 1000-2000 r / min; in step (6), the essential oil-moisturizing composition microcapsules are centrifuged, washed and redispersed in an oily suspension medium before mixing, and the content of the microcapsules is 20-35%.

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