Sustained-release microcapsule and preparation method thereof as well as sunscreen lotion and preparation method thereof

Abstract

The invention discloses a sustained-release microcapsule and a preparation method thereof as well as a sunscreen lotion and a preparation method thereof, and relates to the technical field of cosmetics, the sustained-release microcapsule comprises the following components in percentage by mass: 82.3%-85.5% of a microcapsule carrier and 14.5%-17.7% of an embedding material, wherein the material of the microcapsule carrier comprises a cross-linking material formed by triethoxy silane polyethylene glycol hydroxyl and dihydroxyl-terminated polysiloxane, and the embedding material comprises lycopene; the sustained-release microcapsule can effectively reduce the degradation rate of lycopene, the embedding rate is high, and the friction coefficient of the sustained-release microcapsule is low, so that the mechanical stimulation to the skin is reduced, and meanwhile, the sustained-release microcapsule has the effect of intelligently and slowly releasing lycopene.

Description

Technical Field

[0001] This invention relates to the field of cosmetic technology, and in particular to a sustained-release microcapsule and its preparation method, and a sunscreen lotion and its preparation method. Background Technology

[0002] Phytoene (8-hydrolycopene) and phytofluene (6-hydrolycopene) are both colorless precursors of lycopene in the plant biosynthetic pathway, and the three are in a progressive relationship within the biosynthetic pathway. As a fat-soluble substance, lycopene's poor solubility limits its applications; furthermore, its light / oxygen instability makes it prone to significant loss of activity when directly applied to cosmetics due to ultraviolet radiation.

[0003] To address the aforementioned issues and improve the stability of lycopene, reduce its degradation rate, and prolong its half-life, various steady-state delivery mechanisms have been developed, including emulsion systems, microencapsulation technology, nanoliposome carriers, and solid inclusion complexes. Among these, emulsion delivery systems for lycopene mainly include traditional emulsions, nanoemulsions, and Pickering emulsions. Studies have shown that lycopene nanoemulsions can enhance its antioxidant and anti-inflammatory activities, offering potential applications for inflammation treatment or ointment additives.

[0004] Microencapsulation technology refers to the technique of encapsulating lycopene into tiny particles using natural or synthetic polymers to enhance its stability against light, heat, and oxygen, and to achieve controlled release, ensuring its antioxidant activity and effectively avoiding problems such as oxidation, isomerization, and degradation. However, existing microcapsules cannot reduce the photodegradation rate of phytoene and hexahydrolycopene, have low encapsulation efficiency, poor sustained-release effect, and a high coefficient of friction, resulting in high mechanical irritation to the skin. Summary of the Invention

[0005] The purpose of this invention is to provide a sustained-release microcapsule and its preparation method, as well as a sunscreen lotion and its preparation method. The sustained-release microcapsule can effectively reduce the degradation rate of lycopene, has a high encapsulation rate, and has a low coefficient of friction, thereby reducing mechanical irritation to the skin, while also having the effect of intelligently releasing lycopene.

[0006] To achieve the above objectives, a first aspect of the present invention provides a sustained-release microcapsule, wherein the sustained-release microcapsule comprises 82.3%-85.5% of a microcapsule carrier and 14.5%-17.7% of an encapsulating material by weight percentage; wherein the material of the microcapsule carrier comprises a crosslinked material formed by triethoxysilane polyethylene glycol hydroxyl and dihydroxy-terminated polysiloxane, and the encapsulating material comprises lycopene.

[0007] Compared with the prior art, the sustained-release microcapsules provided by the present invention contain a specific amount of microcapsule carrier and encapsulating material. The material of the microcapsule carrier includes a cross-linked material formed by triethoxysilane polyethylene glycol hydroxyl and dihydroxy-terminated polysiloxane, and the encapsulating material contains lycopene. By using a specific type of microcapsule carrier, oxygen and ultraviolet light can be blocked, thereby effectively reducing the photodegradation rate of lycopene and improving the retention rate of lycopene.

[0008] In existing technologies, when dihydroxy-terminated polysiloxanes are used as carriers, the microcapsules cause strong mechanical irritation to the skin and easily lead to micro-damage to the stratum corneum. Furthermore, the microcapsules are incompatible with inorganic sunscreens, making it difficult for the inorganic sunscreens to disperse evenly in the sunscreen lotion, resulting in aggregation and phase separation. The inorganic compounds in the sunscreen lotion, after absorbing ultraviolet light, generate hydroxyl radicals that can degrade lycopene. The low porosity of dihydroxy-terminated polysiloxanes leads to low lycopene encapsulation rates. This invention modifies dihydroxy-terminated polysiloxanes with triethoxysilane polyethylene glycol hydroxyl groups. Since the terminal hydroxyl groups of the triethoxysilane polyethylene glycol hydroxyl groups do not participate in the reaction, they can remain on the outside of the carrier, thereby reducing the friction coefficient of the sustained-release microcapsules and increasing their hydrophilicity, thus eliminating the mechanical irritation to the skin. The triethoxysilane polyethylene glycol hydroxyl-modified dihydroxy-terminated polysiloxane has better porosity, which is beneficial for encapsulating lycopene, thereby increasing the lycopene loading. Furthermore, the microcapsule carrier of the present invention has an intelligent sustained-release mechanism. The triethoxysilane polyethylene glycol hydroxyl groups on the microcapsule carrier undergo a hydrophilic-hydrophobic transition under ultraviolet irradiation, that is, the triethoxysilane polyethylene glycol hydroxyl groups undergo a shrinkage reaction, which further increases the porosity of the microcapsule carrier and releases lycopene from the microcapsules. Moreover, as the temperature rises, the polymer network formed by the dihydroxyl-terminated polysiloxane expands due to heat, which increases the micropores of the microcapsule carrier, thereby accelerating the release and penetration of lycopene to achieve the effect of intelligent sustained release.

[0009] Furthermore, the dihydroxy-terminated polysiloxane includes at least one of dihydroxy-terminated polydimethylsiloxane and dihydroxy-terminated polymethylphenylsiloxane.

[0010] Furthermore, the polyethylene glycol segment in the triethoxysilane polyethylene glycol hydroxyl group has a molecular weight of 2kDa-5kDa, and the weight-average molecular weight of the dihydroxy-terminated polysiloxane is 3kDa-6kDa.

[0011] In this invention, when the molecular weight of the polyethylene glycol segment in the triethoxysilane polyethylene glycol hydroxyl group and the molecular weight of the dihydroxy-terminated polysiloxane meet the above-mentioned range, the microcapsule itself cannot pass through the gaps in the stratum corneum of the skin, thereby avoiding causing allergic reactions of the skin; while the lycopene inside the sustained-release microcapsule can be slowly released from the microcapsule, penetrate into the skin, and exert a sun protection effect.

[0012] Furthermore, the lycopene includes at least one of 8-hydrolycopene, 6-hydrolycopene, all-trans lycopene, and all-cis lycopene.

[0013] A second aspect of the present invention provides a method for preparing sustained-release microcapsules, applicable to the preparation of the aforementioned sustained-release microcapsules, comprising the following steps: The microcapsule preform was obtained by condensing the hydroxyl groups of triethoxysilane polyethylene glycol with dihydroxy-terminated polysiloxane. The microcapsule preform is mixed and dissolved with a first organosilicon solvent to obtain a mixed solution; The mixed solution is mixed with a lycopene solution and subjected to a first emulsification treatment to prepare an emulsion; A crosslinking agent is added to the emulsion for curing treatment, and an alcohol solution is added to the cured product for mixing to obtain a mixed product; The mixture was subjected to solid-liquid separation, and the resulting precipitate was dried to prepare sustained-release microcapsules.

[0014] Compared with existing technologies, this invention obtains microcapsule preforms by condensing the hydroxyl groups of triethoxysilane polyethylene glycol with dihydroxy-terminated polysiloxane. The polysiloxane ends of the microcapsule preforms are more affinity-for-silicone oil and can dissolve well in the continuous phase of silicone oil. When the two are mixed, it is easier to obtain a uniformly dispersed mixed solution. Mixing the mixed solution with lycopene solution is beneficial to forming an emulsion with better particle size. During the curing process of the emulsion, the microcapsule preforms react with crosslinking agents to form crosslinked materials, i.e., microcapsule carriers. After mixing with alcohol solution and solid-liquid separation to remove solvents such as silicone oil, the microcapsules are dried to obtain sustained-release microcapsules with good sustained-release effect and high transdermal rate. At the same time, the friction coefficient of the sustained-release microcapsules is reduced to eliminate the mechanical irritation of the skin by the sustained-release microcapsules.

[0015] Furthermore, the process of condensing the triethoxysilane polyethylene glycol hydroxyl group with the dihydroxy-terminated polysiloxane includes: After mixing the dihydroxy-terminated polysiloxane with the second organosilicon solvent, a first mixture is obtained; Triethoxysilane polyethylene glycol hydroxyl group was added to the first mixture, and the mixture was then mixed to obtain a second mixture; In the presence of a protective gas, a catalyst is added to the second mixture to carry out a condensation reaction. The resulting reaction product is washed and dried to obtain a microcapsule preform.

[0016] In this invention, when prepared using the above method, the triethoxysilane polyethylene glycol hydroxyl triethoxysilane ( First, it is produced through hydrolysis / alcoholization. ; The terminal hydroxyl groups of the dihydroxy-terminated polysiloxane condense to form –Si–O–Si– bonds, while the terminal hydroxyl groups of the triethoxysilane polyethylene glycol do not participate in the reaction and can remain on the outside of the polymer molecule. This gives the microcapsule preform better hydrophilicity, thereby giving the sustained-release microcapsules a lower coefficient of friction and higher hydrophilicity, thus eliminating the mechanical irritation of the skin by the sustained-release microcapsules.

[0017] Furthermore, the weight ratio of the microcapsule preform to the first organosilicon solvent is 1:(2-4).

[0018] Furthermore, the weight ratio of the mixed solution to the lycopene solution is (7-9):1.

[0019] Furthermore, the conditions for the first emulsification treatment include: intermittent cyclic ultrasonic treatment using an ultrasonic disruptor under conditions of ultrasonic power of 150W-300W and ice bath conditions; or, the first emulsification treatment under ice bath conditions and high shear homogenization treatment at a speed of 10000rpm-20000rpm.

[0020] Furthermore, the particle size of the emulsion is less than or equal to 5 μm.

[0021] Furthermore, the crosslinking agent is selected from at least one of vinyltriethoxysilane, vinyltrimethoxysilane, and allyltriethoxysilane.

[0022] Furthermore, the amount of crosslinking agent added is 0.08%-0.2% of the weight of the emulsion.

[0023] Furthermore, the curing treatment conditions include: being carried out under ultraviolet light irradiation and the action of a thermally activated catalyst.

[0024] Furthermore, the temperature of the alcohol solution is between -30°C and -15°C.

[0025] Furthermore, the solid-liquid separation process includes centrifugal separation.

[0026] Further, the preparation step of the lycopene solution includes: mixing lycopene with ethyl acetate to prepare a lycopene solution, wherein the mass ratio of lycopene to ethyl acetate is (0.3-0.8):1.

[0027] In this invention, ethyl acetate is used as a solvent to prepare a lycopene solution. When the amounts of lycopene and ethyl acetate meet the aforementioned range, lycopene is more readily soluble in ethyl acetate. Furthermore, due to the low boiling point and high volatility of ethyl acetate, it is easily and completely removed during the subsequent drying process. In addition, the lycopene solution prepared by mixing lycopene and ethyl acetate, combined with a mixture of the microcapsule preform and the first organosilicon solvent, undergoes a first emulsification treatment to form an emulsion, which further facilitates the encapsulation of lycopene, thereby further improving the sustained-release effect and transdermal penetration rate of the sustained-release microcapsules.

[0028] A third aspect of the present invention provides a sunscreen lotion, wherein, by weight percentage, it comprises the following components: 1.5%-4.5% sustained-release microcapsules, 12%-22% sunscreen agent, 1.4%-3.4% emulsifier, 12.7%-23.4% auxiliary ingredients, and an appropriate amount of water; The sustained-release microcapsules are the sustained-release microcapsules described in the first aspect above.

[0029] Compared with existing technologies, the sunscreen provided by this invention contains specific types of sustained-release microcapsules. These microcapsule carriers can block the oxidative catalytic reaction between lycopene and other components, thereby improving the stability of the sunscreen while maintaining the effectiveness and activity of lycopene. Furthermore, the specific amount of sustained-release microcapsules synergistically with sunscreen agents and emulsifiers gives the sunscreen excellent UVB-UVA absorption and antioxidant capabilities. Moreover, the sustained-release microcapsules exhibit good dispersion stability in this system, preventing crystallization and aggregation, making the sunscreen easy to apply, evenly covering the skin, and eliminating localized sunspots.

[0030] Furthermore, the sunscreen agent is selected from chemical sunscreen agents and / or physical sunscreen agents.

[0031] Furthermore, the emulsifier is selected from at least one of polyglycerol-6 distearate, inulin lauryl carbamate, polyglycerol-3 diisostearate, and cetearyl alcohol olive oil ester.

[0032] Furthermore, the auxiliary ingredients include fillers, emollients, antioxidants, thickeners, humectants, and chelating agents.

[0033] Furthermore, the filler is silylated silica and / or boron nitride.

[0034] Furthermore, the emollient is selected from at least one of cyclopentylsiloxane (D5), cyclohexylsiloxane (D6), and isododecane.

[0035] Furthermore, the antioxidant is selected from at least one of tocopherol, coenzyme Q10, rosemary extract, and green tea polyphenols.

[0036] Furthermore, the thickener is selected from at least one of aluminum hydroxide, silicon dioxide, triethoxyoctylsilane, stearyl alcohol, cetyl alcohol, and synthetic beeswax.

[0037] Furthermore, the moisturizer is selected from at least one of 1,2-pentanediol, caprylyl glycol, glycerin, and dipropylene glycol.

[0038] Furthermore, the chelating agent is selected from at least one of disodium ethylenediaminetetraacetate, phytic acid, and gluconic acid.

[0039] Furthermore, based on the mass percentage of the sunscreen, the content of the filler is 0.6%-1%, the content of the emollient is 7%-11%, the content of the antioxidant is 0.35%-0.65%, the content of the thickener is 1.5%-2.8%, the content of the moisturizer is 3.2%-7.8%, and the content of the chelating agent is 0.08%-0.12%.

[0040] A fourth aspect of the present invention provides a method for preparing a sunscreen lotion, applicable to the aforementioned sunscreen lotion, comprising the following steps: The oil phase is obtained by mixing some emulsifiers, sunscreens, and some auxiliary ingredients. The remaining emulsifier, remaining auxiliary ingredients, and water are mixed to obtain an aqueous phase; The aqueous phase is added to the oil phase, and after a second emulsification treatment, sustained-release microcapsules are added to the system. After mixing and defoaming, the sunscreen emulsion is obtained.

[0041] In this invention, a portion of the emulsifier, sunscreen agent, and auxiliary ingredients are mixed to obtain an oil phase, and the remaining emulsifier, remaining auxiliary ingredients, and water are mixed to obtain an aqueous phase. By mixing in stages, the emulsifier can be evenly distributed in the oil and aqueous phases, improving the subsequent emulsification efficiency. After emulsification, sustained-release microcapsules are added to the system, which further facilitates the even dispersion of the sustained-release microcapsules in the system, thereby improving the stability of the sunscreen, making the sunscreen easy to apply, able to evenly cover the skin, and eliminate localized sun spots.

[0042] Furthermore, the sunscreen agent is selected from chemical sunscreen agents and / or physical sunscreen agents.

[0043] Furthermore, the auxiliary ingredients include fillers, emollients, antioxidants, thickeners, humectants, and chelating agents.

[0044] Furthermore, the process of mixing a portion of the emulsifier, sunscreen, and auxiliary ingredients includes: mixing a portion of the emulsifier, a portion of the thickener, and the chemical sunscreen at 70℃-80℃, then adding the physical sunscreen, the remaining thickener, and the emollient, performing a first stirring, then cooling to 55℃-65℃, adding the filler and a portion of the antioxidant, and performing a second stirring to obtain the oil phase; The process of mixing the remaining emulsifier, remaining auxiliary ingredients and water includes: mixing a portion of the humectant and chelating agent with water at 75℃-85℃, adding the remaining humectant and remaining emulsifier and stirring for the third time, cooling to 40℃-50℃, adding the remaining antioxidant, and mixing to obtain an aqueous phase.

[0045] Further, after the second emulsification process, the temperature is lowered to 30℃-40℃, and slow-release microcapsules are added to the system. The mixture is then stirred at 200rpm-400rpm to obtain the sunscreen emulsion.

[0046] Furthermore, the second emulsification process is followed by homogenization at 6000rpm-10000rpm.

[0047] Furthermore, the first stirring is performed at a speed of 8000rpm-10000rpm.

[0048] Furthermore, the second stirring is performed at a speed of 200 rpm to 400 rpm.

[0049] Furthermore, the third stirring is performed at a speed of 3000rpm-5000rpm. Detailed Implementation

[0050] To make the technical problems, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature.

[0052] In a first aspect, embodiments of the present invention provide a sustained-release microcapsule, wherein, based on the mass percentage of the sustained-release microcapsule, it comprises 82.3%-85.5% of a microcapsule carrier and 14.5%-17.7% of an encapsulating material; wherein, the material of the microcapsule carrier comprises: a crosslinked material formed by triethoxysilane polyethylene glycol hydroxyl and dihydroxy-terminated polysiloxane, and the encapsulating material comprises lycopene.

[0053] Using the above technical solution, the sustained-release microcapsules contain a specific amount of microcapsule carrier and encapsulating material. The material of the microcapsule carrier includes a cross-linked material formed by triethoxysilane polyethylene glycol hydroxyl and dihydroxy-terminated polysiloxane, and the encapsulating material contains lycopene. By using a specific type of microcapsule carrier, oxygen and ultraviolet light can be blocked, thereby effectively reducing the photodegradation rate of lycopene and improving the retention rate of lycopene.

[0054] In existing technologies, when dihydroxy-terminated polysiloxanes are used as carriers, the microcapsules cause strong mechanical irritation to the skin and easily lead to micro-damage to the stratum corneum. Furthermore, the microcapsules are incompatible with inorganic sunscreens, making it difficult for the inorganic sunscreens to disperse evenly in the sunscreen lotion, easily resulting in aggregation and phase separation. The low porosity of dihydroxy-terminated polysiloxanes also leads to low lycopene encapsulation rates. This invention modifies dihydroxy-terminated polysiloxanes with triethoxysilane polyethylene glycol hydroxyl groups. Since the terminal hydroxyl groups of the triethoxysilane polyethylene glycol hydroxyl groups do not participate in the reaction, they can remain on the outside of the carrier, thereby reducing the friction coefficient of the sustained-release microcapsules and increasing their hydrophilicity, thus eliminating the mechanical irritation to the skin. The triethoxysilane polyethylene glycol hydroxyl-modified dihydroxy-terminated polysiloxane has better porosity, which is beneficial for encapsulating lycopene, thereby increasing the lycopene loading. Furthermore, the microcapsule carrier of the present invention possesses an intelligent sustained-release mechanism. Under ultraviolet irradiation, the triethoxysilane polyethylene glycol hydroxyl groups on the microcapsule carrier undergo a hydrophilic-hydrophobic transition, i.e., the triethoxysilane polyethylene glycol hydroxyl groups undergo a contraction reaction, further increasing the porosity of the microcapsule carrier and releasing lycopene from the microcapsules. Moreover, as the temperature rises, the polymer network formed by the dihydroxyl-terminated polysiloxane expands thermally, increasing the micropores of the microcapsule carrier, thereby accelerating the release and penetration of lycopene to achieve the intelligent sustained-release effect. The sustained-release microcapsules of the present invention can be applied to skincare or cosmetic products.

[0055] In this invention, the mass percentage of the microcapsule carrier and the encapsulated material in the sustained-release microcapsules is calculated based on the amount of raw materials added during the preparation process. The sustained-release microcapsules may contain trace amounts of residual silicone oil and solvent from the lycopene solution, but since the residual content is extremely low, the silicone oil and solvent from the lycopene solution in the sustained-release microcapsules can be ignored.

[0056] For example, the content of the capsule carrier, based on the mass percentage of the sustained-release microcapsules, can be 82.3%, 82.5%, 83%, 83.5%, 84%, 84.5%, 85%, or 85.5%, or any range consisting of any two points; the content of the encapsulant can be 14.5%, 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, or 17.7%, or any range consisting of any two points.

[0057] Preferably, the sustained-release microcapsules comprise 83%-85% microcapsule carrier and 15%-17% encapsulating material by weight percentage.

[0058] In some embodiments, the dihydroxy-terminated polysiloxane includes at least one of dihydroxy-terminated polydimethylsiloxane and dihydroxy-terminated polymethylphenylsiloxane.

[0059] In some embodiments, the polyethylene glycol segment in the triethoxysilane polyethylene glycol hydroxyl group has a molecular weight of 2kDa-5kDa, and the weight-average molecular weight of the dihydroxy-terminated polysiloxane is 3kDa-6kDa.

[0060] Using the above technical solution, when the molecular weight of the polyethylene glycol segment in the triethoxysilane polyethylene glycol hydroxyl group and the molecular weight of the dihydroxy-terminated polysiloxane meet the above range, the microcapsule itself cannot pass through the gaps in the stratum corneum of the skin, thereby avoiding causing allergic reactions to the skin; while the lycopene inside the sustained-release microcapsule can be slowly released from the microcapsule, penetrate into the skin, and exert a sun protection effect.

[0061] For example, the molecular weight of the polyethylene glycol segment in the triethoxysilane polyethylene glycol hydroxyl group can be 2kDa, 3kDa, 4kDa, or 5kDa, or any range consisting of any two values; the weight-average molecular weight of the dihydroxy-terminated polysiloxane can be 3kDa, 4kDa, 5kDa, or 6kDa, or any range consisting of any two values.

[0062] Preferably, the polyethylene glycol segment in the triethoxysilane polyethylene glycol hydroxyl group has a molecular weight of 3kDa-5kDa, and the weight-average molecular weight of the dihydroxy-terminated polysiloxane is 4kDa-6kDa.

[0063] In some embodiments, the lycopene includes at least one of 8-hydrolycopene, 6-hydrolycopene, all-trans lycopene, and all-cis lycopene.

[0064] Using the above technical solution, when the sustained-release microcapsules contain the above-mentioned types of lycopene, they can have stronger UVB-UVA absorption capacity and antioxidant capacity.

[0065] Preferably, the lycopene is phytoene and / or hexahydrolycopene. More preferably, the lycopene is phytoene and hexahydrolycopene, and the mass ratio of phytoene to hexahydrolycopene is 1:(0.8-1.5).

[0066] In some embodiments, the average particle size of the sustained-release microcapsules is 3-5 μm.

[0067] By adopting the above technical solution, when the average particle size of the sustained-release microcapsules meets the above range, the transdermal permeability of lycopene can be improved, and the product containing sustained-release microcapsules can have stronger UVB-UVA absorption capacity and antioxidant capacity.

[0068] Preferably, the average particle size of the sustained-release microcapsules is 3.2-4.4 μm.

[0069] A second aspect of the present invention provides a method for preparing sustained-release microcapsules, applicable to the preparation of the aforementioned sustained-release microcapsules, comprising the following steps: The microcapsule preform was obtained by condensing the hydroxyl groups of triethoxysilane polyethylene glycol with dihydroxy-terminated polysiloxane. The microcapsule preform is mixed and dissolved with a first organosilicon solvent to obtain a mixed solution; The mixed solution is mixed with a lycopene solution and subjected to a first emulsification treatment to prepare an emulsion; A crosslinking agent is added to the emulsion for curing treatment, and an alcohol solution is added to the cured product for mixing to obtain a mixed product; The mixture was subjected to solid-liquid separation, and the resulting precipitate was dried to prepare sustained-release microcapsules.

[0070] Using the above technical solution, a microcapsule preform is obtained by condensing the hydroxyl groups of triethoxysilane polyethylene glycol with dihydroxy-terminated polysiloxane. The polysiloxane end of the microcapsule preform is more affinity for silicone oil and can dissolve well in the continuous silicone oil phase. When the two are mixed, it is easier to obtain a uniformly dispersed mixed solution. Then, the mixed solution is mixed with lycopene solution, which is conducive to forming an emulsion with better particle size. During the curing process of the emulsion, the microcapsule preform reacts with the crosslinking agent to form a crosslinking material, i.e., a microcapsule carrier. After mixing with alcohol solution and solid-liquid separation to remove solvents such as silicone oil, the microcapsule is dried to obtain sustained-release microcapsules with good sustained-release effect and high transdermal rate. At the same time, the friction coefficient of the sustained-release microcapsules is reduced to eliminate the mechanical irritation of the skin by the sustained-release microcapsules.

[0071] In some embodiments, the process of condensing the triethoxysilane polyethylene glycol hydroxyl group with the dihydroxy-terminated polysiloxane includes: After mixing the dihydroxy-terminated polysiloxane with the second organosilicon solvent, a first mixture is obtained; Triethoxysilane polyethylene glycol hydroxyl group was added to the first mixture, and the mixture was then mixed to obtain a second mixture; In the presence of a protective gas, a catalyst is added to the second mixture to carry out a condensation reaction. The resulting reaction product is washed and dried to obtain a microcapsule preform.

[0072] When preparing microcapsule preforms using the above technical solution, the triethoxysilane polyethylene glycol hydroxyl triethoxysilane ( First, it is produced through hydrolysis / alcoholization. ; The terminal hydroxyl groups of the dihydroxy-terminated polysiloxane condense to form –Si–O–Si– bonds, while the terminal hydroxyl groups of the triethoxysilane polyethylene glycol do not participate in the reaction and can remain on the outside of the polymer molecule. This gives the microcapsule preform better hydrophilicity, thereby giving the sustained-release microcapsules a lower coefficient of friction and higher hydrophilicity, thus eliminating the mechanical irritation of the skin by the sustained-release microcapsules.

[0073] In the preparation of the microcapsule preform, the second organosilicon solvent is cyclopentasiloxane and / or cyclohexylsiloxane.

[0074] In the preparation of the microcapsule preform, the weight ratio of the dihydroxy-terminated polysiloxane to the second organosilicon solvent is 1:(1.5-3).

[0075] Using the above technical solution, when a specific type of second organosilicon solvent is used, and / or the weight ratio of dihydroxy-terminated polysiloxane to the second organosilicon solvent meets the above range, the silicone oil can better dissolve the dihydroxy-terminated polysiloxane to form a homogeneous mixture, which is beneficial to the subsequent condensation reaction.

[0076] Preferably, the second organosilicon solvent is cyclopentadioxane.

[0077] In the preparation of the microcapsule preform, there are no special limitations on the mixing conditions of the dihydroxy-terminated polysiloxane and the second organosilicon solvent, as long as the dihydroxy-terminated polysiloxane is fully dispersed in the silicone oil. Preferably, the mixing conditions of the dihydroxy-terminated polysiloxane and the second organosilicon solvent include: a mixing temperature of 55℃-65℃, a mixing rate of 300rpm-800rpm, and a mixing time of 20min-30min.

[0078] In the preparation of the microcapsule preform, the weight ratio of the first mixture to the triethoxysilane polyethylene glycol hydroxyl group is 1:(1.5-3).

[0079] In the preparation of the microcapsule preform, 25-100 ppm of catalyst is added to the second mixture to carry out a condensation reaction.

[0080] In the preparation of the microcapsule preform, the catalyst is selected from at least one of tetrabutyl titanate, tetraisopropyl titanate, and tetraethyl titanate.

[0081] In the preparation of the microcapsule preform, the conditions for the condensation reaction include: a condensation reaction temperature of 85℃-95℃, a stirring rate of 500rpm-800rpm, and a reaction time of 80min-100min.

[0082] When the above technical solution is adopted, and at least one of the following conditions is met, such as the weight ratio of the first mixture to the triethoxysilane polyethylene glycol hydroxyl group, the amount of catalyst, the type of catalyst, and the condensation reaction conditions, it is more conducive to the condensation reaction between the triethoxysilane polyethylene glycol hydroxyl group and the dihydroxyl-terminated polysiloxane. This allows the terminal hydroxyl groups of the triethoxysilane polyethylene glycol hydroxyl group to remain on the outside of the polymer molecule, resulting in better hydrophilicity of the microcapsule preform. Consequently, the sustained-release microcapsules have a lower coefficient of friction and higher hydrophilicity, thereby eliminating the mechanical irritation of the skin by the sustained-release microcapsules.

[0083] In the preparation of the microcapsule preform, there are no special limitations on the mixing conditions of the first mixture and the triethoxysilane polyethylene glycol hydroxyl group. Those skilled in the art can adjust the conditions according to the actual situation to ensure that the triethoxysilane polyethylene glycol hydroxyl group is uniformly dispersed in the second mixture.

[0084] In the preparation of microcapsule preforms, there are no specific restrictions on the type of protective gas; for example, the protective gas can be nitrogen.

[0085] In the preparation of the microcapsule preform, the washing and drying process of the reaction product includes: cooling the reaction product to 20-30°C, adding the reaction product to ethanol at -30°C to -15°C, centrifuging, washing, and then drying the resulting solid product. Preferably, the volume ratio of ethanol to the reaction product is (4-6):1. This invention does not specifically limit the number of centrifugation and washing cycles; for example, it can be three times. This invention does not specifically limit the conditions for centrifugation and washing; those skilled in the art can adjust them according to actual conditions. Preferably, the centrifugation speed is 2500-3500 rpm, and the time is 5-15 min. Preferably, the solvent used for washing is ethanol.

[0086] In some embodiments, the weight ratio of the microcapsule preform to the first organosilicon solvent is 1:(2-4).

[0087] In some embodiments, the first organosilicon solvent is cyclopentasiloxane and / or cyclohexylsiloxane.

[0088] Using the above technical solution, when the weight ratio of the microcapsule preform to the first organosilicon solvent and / or the type of the first organosilicon solvent meets the above-mentioned limitations, the first organosilicon solvent, due to its low viscosity and moderate volatility, effectively dissolves and dilutes the microcapsule preform through physical interaction (a chemical reaction without chemical bonding), forming a homogeneous and easily operable mixed solution. This creates better fluid conditions for the subsequent first emulsification step. The volatility and low surface tension of the first organosilicon solvent help form a stable polymer layer at the emulsion droplet interface, which is more conducive to encapsulating lycopene, thereby further improving the sustained-release effect and transdermal penetration rate of the sustained-release microcapsules.

[0089] In some embodiments, the mixing conditions for dissolving the microcapsule preform in the first organosilicon solvent include: a temperature of 55°C-65°C, a rotation speed of 450 rpm-550 rpm, and a time of 20 min-30 min.

[0090] In some embodiments, the weight ratio of the mixed solution to the lycopene solution is (7-9):1.

[0091] In some embodiments, the conditions for the first emulsification treatment include: intermittent cyclic ultrasonic treatment using an ultrasonic disruptor under conditions of ultrasonic power of 150W-300W and ice bath conditions; or, the first emulsification treatment is performed under conditions of ice bath conditions and high shear homogenization at a rotation speed of 10000rpm-20000rpm.

[0092] By adopting the above technical solution, when the weight ratio of the mixed solution to the lycopene solution and / or the conditions of the first emulsification treatment meet the above range, it is beneficial to obtain an emulsion with a suitable particle size, thereby obtaining sustained-release microcapsules with better sustained-release effect.

[0093] In some embodiments, the mixing of the mixed solution with the lycopene solution and the first emulsification process can be carried out under light-protected conditions.

[0094] Preferably, the conditions for the first emulsification treatment include: intermittent cyclic ultrasonic treatment using an ultrasonic disruptor under conditions of ultrasonic power of 150W-300W and ice bath conditions, wherein the intermittent cyclic ultrasonic treatment includes: turning on the ultrasonic for 3s-7s, then turning off the ultrasonic for 3s-7s, repeating 8-15 times; or, the first emulsification treatment is carried out under ice bath conditions and high shear homogenization at a speed of 10000rpm-20000rpm for a time of 3min-8min.

[0095] In some embodiments, the particle size of the emulsion is less than or equal to 5 μm.

[0096] In some embodiments, the crosslinking agent is selected from at least one of vinyltriethoxysilane, vinyltrimethoxysilane, and allyltriethoxysilane.

[0097] In some embodiments, the amount of crosslinking agent added is 0.08%-0.2% of the weight of the emulsion.

[0098] In some embodiments, the curing process is carried out under ultraviolet light irradiation and with the action of a thermally activated catalyst.

[0099] Preferably, the curing conditions include: using ultraviolet light irradiation and 20-80ppm thermally activated catalyst, stirring the reaction at 75℃-85℃ and 300rpm-500rpm for 1h-2h.

[0100] In some embodiments, the thermally activated catalyst is selected from platinum catalysts (i.e., Karstedt catalysts).

[0101] When the type of crosslinking agent, the amount of crosslinking agent added, the curing conditions, or the type of thermally activated catalyst meet the above ranges, it is more conducive to improving the sustained-release effect and transdermal rate of sustained-release microcapsules, while reducing the friction coefficient of sustained-release microcapsules to eliminate the mechanical irritation of the skin by sustained-release microcapsules.

[0102] In some embodiments, the temperature of the alcohol solution is -30°C to -15°C.

[0103] In some embodiments, the volume ratio of the cured product to the alcohol solution is 1:(15-25).

[0104] In this invention, there are no special limitations on the mixing conditions of the cured product and the alcohol solution. Those skilled in the art can adjust the mixing time according to the actual situation. For example, the mixing time can be 1 min to 3 min.

[0105] In some embodiments, the solid-liquid separation process includes centrifugal separation.

[0106] Preferably, the solid-liquid separation process includes: first centrifuging at a high speed of 2500-4000 rpm for 3-8 minutes, and then centrifuging at a low speed of 1000-2000 rpm at least twice, with each low-speed centrifugation lasting 7-15 minutes.

[0107] In some embodiments, the conditions for drying the precipitate include vacuum drying at 35°C-45°C for 5-7 hours.

[0108] In some embodiments, the preparation steps of the lycopene solution include: Lycopene and ethyl acetate are mixed to prepare a lycopene solution, wherein the mass ratio of lycopene to ethyl acetate is (0.3-0.8):1.

[0109] Using the above technical solution, a lycopene solution is prepared by using ethyl acetate as a solvent. When the amounts of lycopene and ethyl acetate meet the above-mentioned range, lycopene is more easily soluble in ethyl acetate. Furthermore, due to the low boiling point and high volatility of ethyl acetate, it is easily and completely removed during the subsequent drying process. In addition, the lycopene solution prepared by mixing lycopene and ethyl acetate, combined with a mixture of microcapsule preform and a first organosilicon solvent, undergoes a first emulsification treatment to form an emulsion, which further facilitates the encapsulation of lycopene, thereby further improving the sustained-release effect and transdermal penetration rate of the sustained-release microcapsules.

[0110] In some embodiments, the lycopene solution is prepared under light-protected conditions.

[0111] It should be noted that in this application, "first organosilicon solvent" and "second organosilicon solvent" are actually both selected from organosilicon solvents. The terms "first" and "second" are only used to distinguish different steps and have no other special meaning.

[0112] A third aspect of the present invention provides a sunscreen lotion, wherein, by weight percentage, it comprises the following components: 1.5%-4.5% sustained-release microcapsules, 12%-22% sunscreen agent, 1.4%-3.4% emulsifier, 12.7%-23.4% auxiliary ingredients, and an appropriate amount of water; The sustained-release microcapsules are the sustained-release microcapsules described in the first aspect above.

[0113] Using the above technical solution, the sunscreen lotion contains specific types of sustained-release microcapsules. The capsule shell can block the oxidative catalytic reaction between lycopene and other components, thereby improving the stability of the sunscreen lotion while maintaining the effectiveness and activity of lycopene. Furthermore, the specific amount of sustained-release microcapsules, in synergy with sunscreen agents and emulsifiers, gives the sunscreen lotion excellent UVB-UVA absorption and antioxidant capabilities. Moreover, the sustained-release microcapsules exhibit good dispersion stability in this system, preventing crystallization and aggregation, making the sunscreen lotion easy to apply, evenly covering the skin, and eliminating localized sunspots.

[0114] For example, by weight percentage of the sunscreen lotion, the content of the sustained-release microcapsules may be 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, or 4.5%, or a range consisting of any two of the aforementioned values; the content of the sunscreen agent may be 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, or 22%, or a range consisting of any two of the aforementioned values; the content of the emulsifier may be 1.4%, 1.7%, 2%, 2.5%, 3%, or 3.4%, or a range consisting of any two of the aforementioned values; and the content of the auxiliary ingredients may be 12.7%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, or 23.37%, or a range consisting of any two of the aforementioned values.

[0115] In some embodiments, the sunscreen agent is selected from chemical sunscreen agents and / or physical sunscreen agents.

[0116] In some embodiments, the chemical sunscreen agent is selected from at least one of ethylhexyl methoxycinnamate, ethylhexyl triazine, ethylhexyl salicylate, and octocrylene; the physical sunscreen agent is zinc oxide and / or titanium dioxide.

[0117] By employing the above-mentioned technical solutions and using the above-mentioned types of sunscreens, the damage of ultraviolet rays to the skin can be effectively reduced.

[0118] Preferably, the sunscreen agent comprises chemical sunscreen agents and physical sunscreen agents.

[0119] By adopting the above technical solution, when sunscreen contains both chemical and physical sunscreens, it can synergistically protect against multiple wavelengths of ultraviolet rays, achieving a better sun protection effect.

[0120] More preferably, the content of the chemical sunscreen agent is 8%-14% and the content of the physical sunscreen agent is 4%-8% by weight of the sunscreen lotion. For example, the content of the chemical sunscreen agent may be 8%, 9%, 10%, 11%, 12%, 13% or 14% by weight of the sunscreen lotion, or a range consisting of any two of the aforementioned values; the content of the physical sunscreen agent may be 4%, 5%, 6%, 7% or 8%, or a range consisting of any two of the aforementioned values.

[0121] In some embodiments, the average particle size of the physical sunscreen agent is less than or equal to 5 μm.

[0122] In some embodiments, the emulsifier is selected from at least one of polyglycerol-6 distearate, inulin lauryl carbamate, polyglycerol-3 diisostearate, and cetearyl alcohol olive oil ester.

[0123] Preferably, the emulsifier is polyglycerol-6 distearate and / or inulin lauryl carbamate. More preferably, the emulsifier is polyglycerol-6 distearate and inulin lauryl carbamate.

[0124] In some embodiments, the auxiliary ingredients include fillers, emollients, antioxidants, thickeners, humectants, and chelating agents.

[0125] In some embodiments, the filler is silylated silica and / or boron nitride.

[0126] In some embodiments, the emollient is selected from at least one of cyclopentylsiloxane (D5), cyclohexylsiloxane (D6), and isododecane.

[0127] In some embodiments, the antioxidant is selected from at least one of tocopherol, coenzyme Q10, rosemary extract and green tea polyphenols.

[0128] In some embodiments, the thickener is selected from at least one of aluminum hydroxide, silica, triethoxyoctylsilane, stearyl alcohol, cetyl alcohol, and synthetic beeswax.

[0129] In some embodiments, the moisturizer is selected from at least one of 1,2-pentanediol, caprylyl glycol, glycerin, and dipropylene glycol.

[0130] In some embodiments, the chelating agent is selected from at least one of disodium ethylenediaminetetraacetate, phytic acid, and gluconic acid.

[0131] By employing the above technical solution and selecting specific types of fillers, emollients, antioxidants, thickeners, humectants, and chelating agents, the resulting sunscreen lotion exhibits better stability, can maintain the effectiveness and activity of lycopene for a longer period of time, and is easy to apply, can evenly cover the skin, eliminate localized sun spots, and achieve better sun protection.

[0132] In some embodiments, the content of the filler is 0.6%-1% by weight of the sunscreen, the content of the emollient is 7%-11%, the content of the antioxidant is 0.35%-0.65%, the content of the thickener is 1.5%-2.8%, the content of the moisturizer is 3.2%-7.8%, and the content of the chelating agent is 0.08%-0.12%.

[0133] By employing the above technical solutions, when specific types and amounts of fillers, emollients, antioxidants, thickeners, humectants, and chelating agents are selected, the stability of sunscreen lotion can be further improved, and the effectiveness and activity of lycopene can be maintained. Moreover, the sunscreen lotion is easy to apply, can evenly cover the skin, eliminate local sun spots, and thus further improve the sun protection effect.

[0134] For example, based on the mass percentage of the sunscreen, the filler content may be 0.6%, 0.7%, 0.8%, 0.9%, or 1%, or a range consisting of any two of the aforementioned values; the emollient content may be 7%, 8%, 9%, 10%, or 11%, or a range consisting of any two of the aforementioned values; the antioxidant content may be 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, 0.6%, or 0.65%, or a range consisting of any two of the aforementioned values. The range formed by two point values; the content of the thickener can be 1.5%, 2%, 2.5% or 2.8%, the content of the humectant can be 3.2%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5% or 7.8%, or the range formed by any two point values ​​mentioned above; the content of the chelating agent can be 0.08%, 0.09%, 0.1%, 0.11% or 0.12%, or the range formed by any two point values ​​mentioned above.

[0135] A fourth aspect of the present invention provides a method for preparing a sunscreen lotion, applicable to the aforementioned sunscreen lotion, comprising the following steps: The oil phase is obtained by mixing some emulsifiers, sunscreens, and some auxiliary ingredients. The remaining emulsifier, remaining auxiliary ingredients, and water are mixed to obtain an aqueous phase; The aqueous phase is added to the oil phase, and after a second emulsification treatment, sustained-release microcapsules are added to the system. After mixing and defoaming, the sunscreen emulsion is obtained.

[0136] Using the above technical solution, a portion of the emulsifier, sunscreen agent, and auxiliary ingredients are mixed to obtain an oil phase, and the remaining emulsifier, remaining auxiliary ingredients, and water are mixed to obtain an aqueous phase. By using a stepwise mixing method, the emulsifier can be evenly distributed in the oil and aqueous phases, improving the subsequent emulsification efficiency. After emulsification, slow-release microcapsules are added to the system, which further facilitates the even dispersion of the slow-release microcapsules in the system, thereby improving the stability of the sunscreen, making the sunscreen easy to apply, able to evenly cover the skin, and eliminate local sun spots.

[0137] In some embodiments, during the mixing of a portion of the emulsifier, sunscreen, and auxiliary ingredients, the mixing temperature is 55°C-80°C, and the mixing time is 5 min-15 min. It should be understood that the emulsifier includes at least one of polyglycerol-6 distearate, polyglycerol-3 diisostearate, and cetearyl alcohol olive oil ester, and the auxiliary ingredients include at least one of thickeners, emollients, fillers, and antioxidants.

[0138] In some embodiments, during the mixing of the remaining emulsifier, remaining auxiliary ingredients, and water, the mixing temperature is 40°C-85°C, and the mixing time is 3 min-10 min. It should be understood that the remaining emulsifier includes inulin lauryl carbamate, and the remaining auxiliary ingredients include at least one of humectants, chelating agents, and antioxidants.

[0139] In some embodiments, the sunscreen agent is selected from chemical sunscreen agents and / or physical sunscreen agents.

[0140] In some embodiments, when the aqueous phase is added to the oil phase, the temperature of the aqueous phase is 38°C-42°C, and the temperature of the oil phase is 55°C-65°C.

[0141] In some embodiments, the second emulsification process is performed as a homogenization process at 6000 rpm to 10000 rpm.

[0142] In some embodiments, the auxiliary ingredients include fillers, emollients, antioxidants, thickeners, humectants, and chelating agents.

[0143] In some embodiments, the process of mixing a portion of the emulsifier, sunscreen agent, and auxiliary ingredients includes: mixing a portion of the emulsifier, a portion of the thickener, and the chemical sunscreen agent at 70°C-80°C, then adding the physical sunscreen agent, the remaining thickener, and the emollient, performing a first stirring, then cooling to 55°C-65°C, adding the filler and a portion of the antioxidant, and performing a second stirring to obtain the oil phase; The process of mixing the remaining emulsifier, remaining auxiliary ingredients and water includes: mixing a portion of the humectant and chelating agent with water at 75℃-85℃, adding the remaining humectant and remaining emulsifier and stirring for the third time, cooling to 40℃-50℃, adding the remaining antioxidant, and mixing to obtain an aqueous phase.

[0144] In some embodiments, the mass ratio of a portion of the emulsifier to the remaining emulsifier is (1-5):(1-5), the portion of the emulsifier includes at least one of polyglycerol-6 distearate, polyglycerol-3 diisostearate and cetearyl oleate, and the remaining emulsifier includes inulin lauryl carbamate.

[0145] In some embodiments, the mass ratio of partial thickener to residual thickener is (1-5):(1-5), wherein the partial thickener includes at least one of stearyl alcohol, cetyl alcohol and synthetic beeswax; and the residual thickener includes at least one of aluminum hydroxide, silica and triethoxyoctylsilane.

[0146] In some embodiments, the mass ratio of a partial antioxidant to a residual antioxidant is (1-5):(1-5), wherein the partial antioxidant includes at least one of tocopherol and coenzyme Q10; and the residual antioxidant includes at least one of rosemary extract and green tea polyphenols.

[0147] In some embodiments, the mass ratio of a portion of the humectant to the remaining humectant is (1-5):(1-5), wherein the portion of the humectant includes at least one of 1,2-pentanediol, caprylyl glycol, glycerin, and dipropylene glycol; and the remaining humectant includes at least one of 1,2-pentanediol, caprylyl glycol, glycerin, and dipropylene glycol.

[0148] In some embodiments, after the second emulsification treatment, the temperature is lowered to 30°C-40°C, and slow-release microcapsules are added to the system. The mixture is then mixed at a speed of 200 rpm-400 rpm to obtain a sunscreen emulsion.

[0149] By using the above technical solution, when the oil phase and water phase are prepared using the above method and then cooled to 30℃-40℃ before adding the sustained-release microcapsules, not only can the various components in the sunscreen be evenly dispersed, but the sustained-release microcapsules can also be further avoided from being damaged, thereby improving the stability and sun protection effect of the sunscreen.

[0150] In some embodiments, the first stirring is performed at a speed of 8000 rpm to 10000 rpm.

[0151] In some embodiments, the first stirring time is 3 min to 8 min.

[0152] In some embodiments, the second stirring is performed at a speed of 200 rpm to 400 rpm.

[0153] In some embodiments, the second stirring time is 5 min to 15 min.

[0154] In some embodiments, the third stirring is performed at a speed of 3000 rpm to 5000 rpm.

[0155] In some embodiments, the third stirring time is 3-8 minutes.

[0156] To better illustrate the technical solution of the present invention, the following specific embodiments are also provided.

[0157] In the examples and comparative examples, the average particle size of zinc oxide was 50 nm. The average particle size of titanium dioxide was 30 nm. Specific Implementation

[0158] Raw materials not specifically described in the examples and comparative examples were all obtained commercially.

[0159] Example 1 A sunscreen lotion, the composition of each raw material in which the sunscreen lotion is shown in Table 1. The sustained-release microcapsules in the sunscreen lotion (by mass percentage) comprise 83.5% microcapsule carrier and 16.5% encapsulating material; the microcapsule carrier is a cross-linked material formed by triethoxysilane polyethylene glycol hydroxyl and dihydroxy-terminated polydimethylsiloxane (dihydroxy PDMS), wherein the polyethylene glycol segment of the triethoxysilane polyethylene glycol hydroxyl (Xi'an Kaixin Biotechnology Co., Ltd., PEG segment molecular weight 4 kDa) has a molecular weight of 4 kDa, and the weight-average molecular weight of the dihydroxy-terminated polysiloxane (Merck, Mw 5.6 kDa) is 5.6 kDa; the encapsulating material consists of phytoene and hexahydrolycopene (mass ratio 1:1.2); the average particle size of the sustained-release microcapsules is 4 μm.

[0160] The preparation process of sustained-release microcapsules in sunscreen lotion is as follows: (1) Mix dihydroxy-terminated polydimethylsiloxane (dihydroxy PDMS) with cyclopentadiene siloxane D5 (the mass ratio of dihydroxy PDMS to D5 is 1:2), and stir at 500 rpm for 30 min in a 60°C water bath to fully disperse it and obtain the first mixture.

[0161] (2) Triethoxysilane polyethylene glycol hydroxyl (silane PEG hydroxyl) was added to the first mixture (the mass ratio of the first mixture to the silane PEG hydroxyl was 1:2). Under nitrogen protection, 50 ppm of tetrabutyl titanate catalyst was added to carry out the condensation reaction in a water bath at 90°C, and the reaction was stirred at 800 rpm for 90 min.

[0162] (3) After the condensation reaction is completed, wait for the reaction solution to cool to 25°C, pour the mixed reaction solution into cold ethanol (-20°C) (the volume ratio of ethanol to reaction solution is 5:1), centrifuge (3000 rpm, 10 min), discard the supernatant, repeat the ethanol washing 3 times, and vacuum dry to obtain the microcapsule preform. (4) Mix the above microcapsule preform with cyclopentasiloxane D5 (the weight ratio of microcapsule preform to D5 is 1:3), and stir at 60°C (500 rpm, 30 min) to obtain a mixed solution; (5) Under light-protected conditions, phytoene, hexahydrolycopene and ethyl acetate were prepared to form a lycopene solution (the mass ratio of phytoene, hexahydrolycopene and ethyl acetate was 0.3:0.36:1); lycopene solution was added to the mixed solution obtained in step (4) (the weight ratio of the mixed solution to the lycopene solution was 8:1), and the obtained mixed solution was subjected to intermittent cyclic ultrasonic operation under ice bath conditions using an ultrasonic disruptor (ultrasonic power was 200W, ultrasonic was turned on for 5s, then turned off for 5s, and the cycle was repeated 10 times) to obtain an emulsion (average particle size was 4.5 μm); (6) Add 0.1% by mass of crosslinking agent (vinyltriethoxysilane) and 30ppm of thermally activated catalyst (Karstedt catalyst: Shanghai McLean Biochemical Technology Co., Ltd.) to the emulsion obtained in step (5), and stir at 80°C (400rpm) for 1.5h. (7) Add a pre-cooled (-20℃) ethanol solution (HPLC grade) to the cured product in step (6) (the volume ratio of the cured product to the ethanol solution is 1:20), and vortex mix for 1 min to obtain a mixed product; (8) The mixed product obtained in step (7) is first centrifuged at a high speed of 3000 rpm for 5 min, and then centrifuged twice at a low speed of 1500 rpm for 10 min each time. The precipitate is then vacuum dried (40℃, 6 h) to obtain sustained-release microcapsules.

[0163] The preparation process of sunscreen lotion is as follows: Oil phase preparation: Stearyl alcohol (thickener), polyglycerol-6 distearate (emulsifier), ethylhexyl methoxycinnamate (chemical sunscreen), and ethylhexyl triazine ketone (chemical sunscreen) were mixed at 75°C for 8 min; then zinc oxide (physical sunscreen), aluminum hydroxide (thickener), and cyclopentasiloxane (emollient) were added and homogenized (8000 rpm, 5 min); then the mixture was cooled to 60°C, silyl silica (filler) and tocopherol (antioxidant) were added, and stirred until homogeneous (300 rpm, 10 min) to obtain the oil phase; Aqueous phase preparation: Glycerin (humectant), EDTA-disodium (chelating agent) and water were mixed at 80°C for 4 min; then 1,2-pentanediol (humectant) and inulin lauryl amino acid ester (emulsifier) ​​were added and homogenized completely (5000 rpm, 3 min). When the mixture was cooled to 40°C, rosemary extract (antioxidant) was added and mixed well to obtain the aqueous phase. Emulsification stage: The aqueous phase (40℃) is slowly added to the oil phase (60℃), and the mixture is completely emulsified and dispersed using a homogenizer (6000 rpm, 4 min). Add sustained-release microcapsules: When the emulsified system is cooled to 30°C, slowly add the sustained-release microcapsules and stir at low speed until homogeneous (300 rpm, 10 min); obtain the sunscreen emulsion after vacuum defoaming.

[0164] Table 1 Example 2 A sunscreen lotion differs from Example 1 in that the type of sustained-release microcapsules is different. The sustained-release microcapsules in Example 2 (by weight percentage) comprise 82.3% microcapsule carrier and 17.7% encapsulant. The microcapsule carrier is a cross-linked material formed by triethoxysilane polyethylene glycol hydroxyl and dihydroxy-terminated polydimethylsiloxane (dihydroxy PDMS). The polyethylene glycol segment in the triethoxysilane polyethylene glycol hydroxyl (Xi'an Kaixin Biotechnology Co., Ltd., PEG segment molecular weight 3kDa) has a molecular weight of 3kDa, and the weight-average molecular weight of the dihydroxy-terminated polysiloxane (Merck, Mw 4kDa) is 4kDa. The encapsulant is phytoene. The average particle size of the sustained-release microcapsules is 4μm. The content of sustained-release microcapsules in the sunscreen lotion, as well as the content and type of other components, are the same as in Example 1.

[0165] The preparation method of the above-mentioned sustained-release microcapsules is the same as that in Example 1, with the amount of raw materials added adjusted accordingly to prepare the sustained-release microcapsules of Example 2. The specific differences are as follows: In step (4) of the preparation method of sustained-release microcapsules in Example 2, the weight ratio of microcapsule preform to cyclopentasiloxane D5 is 1:2.5; in step (5), the mass ratio of phytoene to ethyl acetate is 0.35:1; and the weight ratio of mixed solution to lycopene solution is 8.5:1.

[0166] The preparation method of the sunscreen lotion is the same as in Example 1.

[0167] Example 3 A sunscreen lotion differs from Example 1 in that the type of sustained-release microcapsules is different. The sustained-release microcapsules in Example 2 (by weight percentage) comprise 85.5% microcapsule carrier and 14.5% encapsulant. The microcapsule carrier is a cross-linked material formed by triethoxysilane polyethylene glycol hydroxyl and dihydroxy-terminated polydimethylsiloxane (dihydroxy PDMS). The polyethylene glycol segment in the triethoxysilane polyethylene glycol hydroxyl (Xi'an Kaixin Biotechnology Co., Ltd., PEG segment molecular weight 5kDa) has a molecular weight of 5kDa, and the weight-average molecular weight of the dihydroxy-terminated polysiloxane (Merck, Mw 4.5kDa) is 4.5kDa. The encapsulant is all-trans lycopene. The average particle size of the sustained-release microcapsules is 4μm. The content of sustained-release microcapsules in the sunscreen lotion, as well as the content and type of other components, are the same as in Example 1.

[0168] The preparation method of the above-mentioned sustained-release microcapsules is the same as that in Example 1, with the amount of raw materials added adjusted accordingly to prepare the sustained-release microcapsules of Example 3. The specific differences are as follows: In step (4) of the preparation method of sustained-release microcapsules in Example 3, the weight ratio of microcapsule preform to cyclopentadioxane D5 is 1:3.5; in step (5), the mass ratio of all-trans lycopene to ethyl acetate is 0.4:1; and the weight ratio of mixed solution to lycopene solution is 9:1.

[0169] The preparation method of the sunscreen lotion is the same as in Example 1.

[0170] Example 4 A sunscreen lotion differs from Example 1 in that the type of sustained-release microcapsules is different. The sustained-release microcapsules in Example 2 (by mass percentage) comprise 83.5% microcapsule carrier and 16.5% encapsulant. The microcapsule carrier is a cross-linked material formed by triethoxysilane polyethylene glycol hydroxyl and dihydroxyl-terminated polymethylphenylsiloxane. The polyethylene glycol segment in the triethoxysilane polyethylene glycol hydroxyl (Xi'an Kaixin Biotechnology Co., Ltd., PEG segment molecular weight 4kDa) has a molecular weight of 4kDa, and the weight-average molecular weight of the dihydroxyl-terminated polymethylphenylsiloxane (Merck, Mw 4kDa) is 4kDa. The encapsulant consists of phytoene and hexahydrolycopene (mass ratio 1:0.8). The average particle size of the sustained-release microcapsules is 4μm. The content of sustained-release microcapsules in the sunscreen lotion, as well as the content and type of other components, are the same as in Example 1.

[0171] The preparation process of the sustained-release microcapsules in the sunscreen lotion is the same as in Example 1, with the specific difference being in the following steps: (3) After the condensation reaction is completed, wait for the reaction solution to cool to 30°C, pour the mixed reaction solution into cold ethanol at -15°C (the volume ratio of ethanol to reaction solution is 4:1), centrifuge (3500 rpm, 10 min), discard the supernatant, repeat the ethanol washing 3 times, and vacuum dry to obtain the microcapsule preform. (5) Under light-protected conditions, phytoene, hexahydrolycopene and ethyl acetate were prepared to form a lycopene solution (the mass ratio of phytoene, hexahydrolycopene and ethyl acetate was 0.3:0.24:1); lycopene solution was added to the mixed solution obtained in step (4) (the weight ratio of the mixed solution to the lycopene solution was 8:1), and the obtained mixed solution was subjected to intermittent cyclic ultrasonic operation (ultrasonic power was 300W) under ice bath conditions, with the ultrasonic being turned on for 7s and then turned off for 7s, and the cycle was repeated 10 times) to obtain an emulsion (average particle size was 3μm); (6) Add 0.1% by mass of crosslinking agent (vinyltriethoxysilane) and 30ppm of thermally activated catalyst (Karstedt catalyst: Shanghai McLean Biochemical Technology Co., Ltd.) to the emulsion obtained in step (5), and stir at 75°C (500rpm) for 2h.

[0172] Example 5 A sunscreen lotion, the composition of which is shown in Table 2. The type of sustained-release microcapsules in the sunscreen lotion is the same as that in Example 1.

[0173] The preparation method of the sustained-release microcapsules is the same as that in Example 1.

[0174] The preparation process of sunscreen lotion is as follows: Oil phase preparation: Stearyl alcohol (thickener), polyglycerol-6 distearate (emulsifier), ethylhexyl methoxycinnamate (chemical sunscreen), and ethylhexyl triazine ketone (chemical sunscreen) were mixed at 75°C for 7 min; then zinc oxide (physical sunscreen), aluminum hydroxide (thickener), and cyclopentasiloxane (emollient) were added and homogenized (8000 rpm, 3 min); then the mixture was cooled to 55°C, silyl alkyl silica (filler) and tocopherol (antioxidant) were added, and stirred until homogeneous (200 rpm, 5 min) to obtain the oil phase; Aqueous phase preparation: Glycerin (humectant), EDTA-disodium (chelating agent) and water were mixed at 75°C for 5 min; then 1,2-pentanediol (humectant) and inulin lauryl amino acid ester (emulsifier) ​​were added and homogenized completely (3000 rpm, 3 min). When the mixture was cooled to 40°C, rosemary extract (antioxidant) was added and mixed well to obtain the aqueous phase. Emulsification stage: The aqueous phase (40℃) is slowly added to the oil phase (60℃), and the mixture is completely emulsified and dispersed using a homogenizer (6000 rpm, 4 min). Add sustained-release microcapsules: When the emulsified system is cooled to 30°C, slowly add the sustained-release microcapsules and stir at low speed until homogeneous (200 rpm, 10 min); obtain the sunscreen emulsion after vacuum defoaming.

[0175] Table 2 Example 6 A sunscreen lotion, the composition of which is shown in Table 3. The type of sustained-release microcapsules in the sunscreen lotion is the same as that in Example 1.

[0176] The preparation method of the sustained-release microcapsules is the same as that in Example 1.

[0177] The preparation process of sunscreen lotion is as follows: Oil phase preparation: Stearyl alcohol (thickener), polyglycerol-6 distearate (emulsifier), ethylhexyl methoxycinnamate (chemical sunscreen), and ethylhexyl triazine ketone (chemical sunscreen) were mixed at 75°C for 9 min; then zinc oxide (physical sunscreen), aluminum hydroxide (thickener), and cyclopentasiloxane (emollient) were added and homogenized (10000 rpm, 8 min); then the mixture was cooled to 65°C, silyl alkyl silica (filler) and tocopherol (antioxidant) were added, and stirred until homogeneous (400 rpm, 15 min) to obtain the oil phase; Aqueous phase preparation: Glycerin (humectant), disodium EDTA (chelating agent) and water were mixed at 85°C for 5 min; then 1,2-pentanediol (humectant) and inulin lauryl amino acid ester (emulsifier) ​​were added and homogenized completely (5000 rpm, 3 min). When the mixture was cooled to 50°C, rosemary extract (antioxidant) was added and mixed well to obtain the aqueous phase. Emulsification stage: The aqueous phase (40℃) is slowly added to the oil phase (60℃), and the mixture is completely emulsified and dispersed using a homogenizer (10000 rpm, 4 min). Add sustained-release microcapsules: When the emulsified system is cooled to 40°C, slowly add the sustained-release microcapsules and stir at low speed until homogeneous (400 rpm, 10 min); obtain the sunscreen emulsion after vacuum defoaming.

[0178] Table 3 Example 7 A sunscreen lotion, the composition of which is shown in Table 4. The type of sustained-release microcapsules in the sunscreen lotion is the same as that in Example 1.

[0179] The preparation method of the sustained-release microcapsules is the same as that in Example 1.

[0180] The preparation process of sunscreen lotion is as follows: Oil phase preparation: Stearyl alcohol (thickener), polyglycerol-3 diisostearate (emulsifier), ethylhexyl salicylate (chemical sunscreen), and octocrylene (chemical sunscreen) were mixed at 75°C for 8 min; then titanium dioxide (physical sunscreen), aluminum hydroxide (thickener), and cyclopentasiloxane (emollient) were added and homogenized (9000 rpm, 6 min); then the mixture was cooled to 60°C, silyl silica (filler) and tocopherol (antioxidant) were added, and stirred until homogeneous (300 rpm, 10 min) to obtain the oil phase; Aqueous phase preparation: Glycerin (humectant), EDTA-disodium (chelating agent) and water were mixed at 80°C for 4 min; then 1,2-pentanediol (humectant) and inulin lauryl amino acid ester (emulsifier) ​​were added and homogenized completely (5000 rpm, 3 min). When the mixture was cooled to 40°C, rosemary extract (antioxidant) was added and mixed well to obtain the aqueous phase. Emulsification stage: The aqueous phase (40℃) is slowly added to the oil phase (60℃), and the mixture is completely emulsified and dispersed using a homogenizer (8000 rpm, 4 min). Add sustained-release microcapsules: When the emulsified system is cooled to 35°C, slowly add the sustained-release microcapsules and stir at low speed until homogeneous (300 rpm, 10 min); obtain the sunscreen emulsion after vacuum defoaming.

[0181] Table 4 Example 8 A sunscreen lotion, the composition of which is shown in Table 5. The type of sustained-release microcapsules in the sunscreen lotion is the same as that in Example 1.

[0182] The preparation method of the sustained-release microcapsules is the same as that in Example 1.

[0183] The preparation process of sunscreen lotion is as follows: Oil phase preparation: Stearyl alcohol (thickener), polyglycerol-6 distearate (emulsifier), ethylhexyl methoxycinnamate (chemical sunscreen), and ethylhexyl triazine ketone (chemical sunscreen) were mixed at 75°C for 8 min; then zinc oxide (physical sunscreen), aluminum hydroxide (thickener), and cyclopentasiloxane (emollient) were added and homogenized (8000 rpm, 5 min); then the mixture was cooled to 60°C, silyl alkyl silica (filler) and tocopherol (antioxidant) were added, and stirred until homogeneous (350 rpm, 13 min) to obtain the oil phase; Aqueous phase preparation: Glycerin (humectant), EDTA-disodium (chelating agent) and water were mixed at 80°C for 4.5 min; then 1,2-pentanediol (humectant) and inulin lauryl amino acid ester (emulsifier) ​​were added and homogenized completely (4500 rpm, 4 min). When the mixture was cooled to 40°C, rosemary extract (antioxidant) was added and mixed well to obtain the aqueous phase. Emulsification stage: The aqueous phase (40℃) is slowly added to the oil phase (60℃), and the mixture is completely emulsified and dispersed using a homogenizer (6500 rpm, 4 min). Add sustained-release microcapsules: When the emulsified system is cooled to 30°C, slowly add the sustained-release microcapsules and stir at low speed until homogeneous (300 rpm, 10 min); obtain the sunscreen emulsion after vacuum defoaming.

[0184] Table 5 Comparative Example 1 The difference between the sunscreen in Comparative Example 1 and Example 1 lies in the type of sustained-release microcapsules. Specifically, the microcapsule carrier material is a cross-linked material formed from dihydroxy-terminated polydimethylsiloxane (dihydroxyPDMS). The content of sustained-release microcapsules in the sunscreen, as well as the content and types of other components, are the same as in Example 1.

[0185] The sustained-release microcapsules were prepared according to the preparation method of the sustained-release microcapsules in Example 1. The difference is that the preparation method of the sustained-release microcapsules in Comparative Example 1 does not perform steps (1)-(3), and the microcapsule preform in step (4) is replaced with dihydroxy-terminated polydimethylsiloxane. The subsequent steps are the same as in Example 1.

[0186] The preparation process of the sunscreen lotion is the same as in Example 1.

[0187] Comparative Example 2 The sunscreen in Comparative Example 2 differs from that in Example 1 in that the type of sustained-release microcapsules is different. Specifically, the microcapsule carrier is a cross-linked material formed by dodecyltriethoxysilane and dihydroxy-terminated polydimethylsiloxane (dihydroxyPDMS). The content of sustained-release microcapsules in the sunscreen, as well as the content and type of other components, are the same as in Example 1.

[0188] The sustained-release microcapsules were prepared according to the method of Example 1, but the following steps differed from the sustained-release microcapsule preparation method of Example 1: (2) Add dodecyltriethoxysilane to the first mixture (the mass ratio of the first mixture to the PEG hydroxyl group of silane is 1:2). Under nitrogen protection, add 50 ppm of the catalyst tetrabutyl titanate in a water bath at 90°C to carry out the condensation reaction, and stir at 800 rpm for 90 min.

[0189] (3) After the condensation reaction is completed, wait for the reaction solution to cool to 25°C, pour the mixed reaction solution into cold ethanol (-20°C) (the volume ratio of ethanol to reaction solution is 5:1), centrifuge (3000 rpm, 10 min), discard the supernatant, repeat the ethanol washing 3 times, and vacuum dry to obtain the microcapsule preform. The subsequent steps for the sustained-release microcapsules are the same as in Example 1.

[0190] The preparation process of the sunscreen lotion is the same as in Example 1.

[0191] Comparative Example 3 A sunscreen lotion differs from Example 1 in that the type of sustained-release microcapsules is different. The sustained-release microcapsules in Comparative Example 3 (by weight percentage) comprise 75% microcapsule carriers and 25% encapsulating agents. The content of sustained-release microcapsules in the sunscreen lotion, as well as the content and type of other components, are the same as in Example 1.

[0192] Comparative Example 4 The difference between the sunscreen lotion of Comparative Example 4 and Example 1 is that the type of sustained-release microcapsules is different. Specifically, the material of the microcapsule carrier is whey protein isolate-xylooligosaccharide conjugate. The content of sustained-release microcapsules in the sunscreen lotion, as well as the content and type of other components, are the same as in Example 1.

[0193] The sustained-release microcapsules were prepared according to the preparation method of sustained-release microcapsules in Example 1. The difference is that the preparation method of sustained-release microcapsules in Comparative Example 4 does not perform steps (1)-(3), and the microcapsule preform in step (4) is replaced with whey protein isolate-xylooligosaccharide conjugate. The subsequent steps are the same as in Example 1.

[0194] The preparation process of the sunscreen lotion is the same as in Example 1.

[0195] Test Example 1 - Sunscreen SPF The sunscreens from Examples 1-8 and Comparative Examples 1-4 were used as test samples, and a 2 mg / cm² sample was evenly applied to a quartz glass plate. 2 One test sample was applied to each quartz glass plate and allowed to dry naturally in the dark for 15 minutes. Then, ultraviolet light was applied from 10 mm above the glass plate. At 0 h, 2 h, and 4 h after ultraviolet light irradiation, five locations on the quartz glass plate were randomly measured using an ultraviolet transmission analyzer within the range of 280-400 nm to obtain the SPF of the sunscreen. The average value of the five measurements was rounded to the nearest integer and expressed as the SPF of the sunscreen for that time period. Specific test results are shown in Table 6.

[0196] Table 6 As shown in Table 6, when the sunscreens in Examples 1-8 contain sustained-release microcapsules, and the type of microcapsule carrier and the ratio between the microcapsule carrier and the encapsulated material meet the requirements of this invention, the SPF values ​​of the sunscreens in Examples 1-8 all show a trend of "significantly increasing from the initial value and maintaining it," indicating that the sustained-release microcapsules in the sunscreens continuously release lycopene under ultraviolet light and temperature triggering, achieving an intelligent sustained-release effect. The sunscreens in Comparative Examples 1-4 have lower SPF values, and the SPF values ​​do not show a significant increasing trend over time, indicating that the sustained-release microcapsules in the sunscreens in Comparative Examples 1-4 cannot achieve a sustained-release effect.

[0197] Test Example 2 - Allergy Test The sunscreens from Examples 1-8 and Comparative Examples 1-4 were tested. Thirty subjects were selected, including 15 males and 15 females, aged between 18 and 50 years old, meeting the inclusion criteria. Using qualified patch testing equipment, 0.1g of each of the sunscreens prepared in Examples 1-8 and Comparative Examples 1-4 was placed in the patch testing device using a closed patch test method. A hypoallergenic adhesive tape was applied to the back of each subject. The test substance was removed after 0.5 hours, and skin reactions were observed at 0.5 hours and 24 hours after removal. The corresponding number of subjects was recorded according to the skin reaction grading standards in the 2015 edition of the "Cosmetic Safety Technical Specifications". Grade 0 is a negative reaction; Grade 1 is a suspicious reaction, with only slight erythema; Grade 2 is a weak positive reaction (erythema reaction): erythema, infiltration, edema, and papules may be present; Grade 3 is a strong positive reaction (herpes reaction): erythema, infiltration, edema, papules, and vesicles; the reaction may extend beyond the tested area; Grade 4 is an extremely strong positive reaction (confluent herpes reaction): obvious erythema, severe infiltration, edema, confluent herpes, and the reaction may extend beyond the test area; The specific test results are shown in Table 7.

[0198] Table 7 As shown in Table 7, the sunscreens of Examples 1-8 did not cause (Grade 0) or caused mild, reversible suspicious reactions (Grade 1) in 30 subjects; while the sunscreens of Comparative Examples 1-4 had a significantly higher positive rate in subjects than those of Examples 1-8, and a small number of weak positive reactions (Grade 2) and strong positive reactions (Grade 3) appeared. This indicates that the skin safety of the sustained-release microcapsules and sunscreens provided by the present invention is higher than that of the sustained-release microcapsules and sunscreens in the comparative examples.

[0199] Test Example 3 - Sunscreen Film-Forming Speed ​​and Sensory Evaluation The sunscreens from Examples 1-8 and Comparative Examples 1-4 were tested to evaluate their film-forming speed, irritation, spreadability, lightness, and durability, as detailed below: 120 volunteers aged 18-50 were selected and randomly divided into 12 groups of 10 people each, referred to as Example 1 to Example 8 and Comparative Example 1 to Comparative Example 4.

[0200] Film-forming speed test: After cleaning the inner skin of volunteers' arms to ensure no skincare product residue, each group of volunteers used sunscreens corresponding to Examples 1-8 and Comparative Examples 1-4, respectively, at a rate of 0.25 g / cm³. 2 Apply the sunscreen evenly; start timing immediately after application, and lightly touch the applied area with your fingertip every 5 seconds. Record the time when the feel changes from sticky and moist to dry and non-sticky, and calculate the average time for each group as the film-forming time. The test results are shown in Table 8.

[0201] Irritation, spreadability, lightness and longevity: Each group of volunteers used the sunscreen lotion of Examples 1-8 and Comparative Examples 1-4 respectively, applying the sunscreen lotion 2-3 times a day, with an interval of no less than 2 hours between each application; after two weeks of the trial, the volunteers rated the irritation, spreadability, lightness and longevity of the sunscreen lotion according to the following scoring system, and the scoring results are shown in Table 8; Stimulation rating system: 1 point - extremely strong stimulation, 2 points - strong stimulation, 3 points - moderate stimulation, 4 points - mild stimulation, 5 points - no stimulation; Expansion scoring system: 1 point: Difficult to spread, with obvious white streaks or lumps; 2 points: Requires multiple applications; uneven application in some areas. 3 points: It can be basically pushed open, but a little massage is needed; 4 points: Spreads easily and provides even coverage; 5 stars: Spreads easily with a single swipe, leaving no residue or white marks; Freshness rating system: 1 point: The stickiness is intense, severely affecting the skin feel; 2 points: It has a noticeable stickiness; 3 points: Slightly sticky; 4 points: virtually no stickiness; 5 stars: Completely refreshing and non-sticky; Persistence rating system: 1 point: Obvious oiliness or mottled appearance after 2 hours; 2 points: Obvious oiliness or mottled appearance after 4 hours; 3 points: Obvious oiliness or mottled appearance after 6 hours; 4 points: Obvious oiliness or mottled appearance after 8 hours; 5 points: Obvious oiliness or mottled appearance after 10 hours.

[0202] Table 8 As shown in Table 8, compared with the sunscreens of Comparative Examples 1-4, the sunscreens of Examples 1-8 of the present invention contain specific types of sustained-release microcapsules, which makes the sunscreens more spreadable and longer-lasting; they feel more refreshing on the skin when used, are less irritating to the skin, and have relatively good film-forming properties.

[0203] Test Example 4 The photodegradation rate of lycopene in sunscreens of Examples 1-8 and Comparative Examples 1-4 was tested.

[0204] 1. Test Objective The stability of lycopene encapsulated in sustained-release microcapsules under ultraviolet radiation after being combined with inorganic sunscreens was quantitatively evaluated to demonstrate the protective effect of sustained-release microcapsules on lycopene.

[0205] 2. Experimental Design Samples: Sunscreen lotion samples from Examples 1-8 and Comparative Examples 1-4 were used. A positive control was also set up: the same mass of free (unencapsulated) lycopene was directly mixed with the basic sunscreen lotion system of this application.

[0206] Irradiation conditions: The above samples were evenly coated onto a quartz plate and placed in a UV aging chamber, where they were irradiated with a constant intensity UVA / UVB light source (500 W / m²). Sampling time points: Samples were taken at 0h, 2h, 4h, and 8h after irradiation.

[0207] Detection method: The residual rate of lycopene in the sample at each time point was accurately determined by high performance liquid chromatography. The test results are shown in Table 9.

[0208] Table 9 As shown in Table 9, the microcapsule carriers of Examples 1-8, comprising cross-linked materials formed by triethoxysilane polyethylene glycol hydroxyl and dihydroxy-terminated polysiloxane, significantly reduced the photodegradation rate of lycopene and maintained good activity even after 8 hours. This indicates that the microcapsule carriers of the present invention have a better protective effect on lycopene than the microcapsules and free state (positive control group) of Comparative Examples 1-4. This demonstrates that the microcapsule carriers of the sustained-release microcapsules of the present invention can effectively isolate ultraviolet rays and free radicals that may be generated by sunscreens, achieving both protective and sustained-release effects on lycopene.

[0209] Test Example 5 The water absorption rate of the sustained-release microcapsules in the sunscreens of Examples 1-4 and Comparative Examples 1-4 was tested: Test objective: To determine the hygroscopicity of sustained-release microcapsule powder in order to characterize its hydrophilic properties.

[0210] Experimental procedure: The sustained-release microcapsule powders of Examples 1-4 and Comparative Examples 1-4 were vacuum dried at 40°C to constant weight. The dried powder was placed in a constant temperature and humidity chamber (temperature 25℃, relative humidity 75%); it was removed after 24h and 48h respectively, and the mass of each sustained-release microcapsule powder was quickly weighed. ); Calculate the water absorption rate: .

[0211] The test results are shown in Table 10.

[0212] Table 10 As shown in Table 10, the sustained-release microcapsules of Examples 1-4 of the present invention have higher water absorption rates at 24h and 48h than those of Comparative Examples 1-3, indicating that the sustained-release microcapsules of the present invention have better hydrophilicity. Their application in sunscreen lotion improves its spreadability and refreshing feel. In contrast, the sustained-release microcapsules of Comparative Examples 1-3 have low hydrophilicity, resulting in a greasy feel and poor spreadability in the sunscreen lotion. The sustained-release microcapsules of Comparative Example 4 are too hydrophilic, making their release behavior uncontrollable, failing to protect lycopene, and affecting the film-forming properties of the sunscreen lotion.

[0213] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0214] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A sustained-release microcapsule, characterized in that, The sustained-release microcapsules comprise 82.3%-85.5% of a microcapsule carrier and 14.5%-17.7% of an encapsulant by weight; wherein the microcapsule carrier is made of a crosslinked material formed by triethoxysilane polyethylene glycol hydroxyl and dihydroxy-terminated polysiloxane, and the encapsulant contains lycopene.

2. The sustained-release microcapsules according to claim 1, characterized in that, The dihydroxy-terminated polysiloxane comprises at least one of dihydroxy-terminated polydimethylsiloxane and dihydroxy-terminated polymethylphenylsiloxane; and / or, The polyethylene glycol segment in the triethoxysilane polyethylene glycol hydroxyl group has a molecular weight of 2kDa-5kDa, and the weight-average molecular weight of the dihydroxy-terminated polysiloxane is 3kDa-6kDa; and / or, The lycopene includes at least one of 8-hydrolycopene, 6-hydrolycopene, all-trans lycopene, and all-cis lycopene.

3. A method for preparing sustained-release microcapsules, applied to the preparation of the sustained-release microcapsules according to claim 1 or 2, characterized in that, Includes the following steps: The microcapsule preform was obtained by condensing the hydroxyl groups of triethoxysilane polyethylene glycol with dihydroxy-terminated polysiloxane. The microcapsule preform is mixed and dissolved with a first organosilicon solvent to obtain a mixed solution; The mixed solution is mixed with a lycopene solution and subjected to a first emulsification treatment to prepare an emulsion; A crosslinking agent is added to the emulsion for curing treatment, and an alcohol solution is added to the cured product for mixing to obtain a mixed product; The mixture was subjected to solid-liquid separation, and the resulting precipitate was dried to prepare sustained-release microcapsules.

4. The method for preparing sustained-release microcapsules according to claim 3, characterized in that, The process of condensing the triethoxysilane polyethylene glycol hydroxyl group with the dihydroxy-terminated polysiloxane includes: After mixing the dihydroxy-terminated polysiloxane with the second organosilicon solvent, a first mixture is obtained; Triethoxysilane polyethylene glycol hydroxyl group was added to the first mixture, and the mixture was then mixed to obtain a second mixture; In the presence of a protective gas, a catalyst is added to the second mixture to carry out a condensation reaction. The resulting reaction product is washed and dried to obtain a microcapsule preform.

5. The method for preparing sustained-release microcapsules according to claim 3 or 4, wherein the weight ratio of the microcapsule preform to the first organosilicon solvent is 1:(2-4); and / or, The weight ratio of the mixed solution to the lycopene solution is (7-9):1; and / or, The conditions for the first emulsification treatment include: Intermittent cyclic ultrasonic treatment is performed using an ultrasonic disruptor under conditions of ultrasonic power of 150W-300W and ice bath conditions; or, the conditions for the first emulsification treatment include: high shear homogenization treatment under ice bath conditions and at a rotation speed of 10000rpm-20000rpm.

6. The method for preparing sustained-release microcapsules according to claim 3 or 4, characterized in that, The particle size of the emulsion is less than or equal to 5 μm; and / or, The crosslinking agent is selected from at least one of vinyltriethoxysilane, vinyltrimethoxysilane, and allyltriethoxysilane; and / or, The amount of crosslinking agent added is 0.08%-0.2% of the weight of the emulsion; And / or, The curing treatment conditions include: under ultraviolet light irradiation and with the action of a thermally activated catalyst; and / or, The temperature of the alcohol solution is -30°C to -15°C; and / or, The solid-liquid separation process includes centrifugal separation.

7. The method for preparing sustained-release microcapsules according to claim 3 or 4, characterized in that, The preparation steps of the lycopene solution include: Lycopene and ethyl acetate are mixed to prepare a lycopene solution, wherein the mass ratio of lycopene to ethyl acetate is (0.3-0.8):

1.

8. A sunscreen lotion, characterized in that, By weight percentage, it comprises the following components: sustained-release microcapsules 1.5%-4.5%, sunscreen agent 12%-22%, emulsifier 1.4%-3.4%, auxiliary ingredients 12.7%-23.4%, and appropriate amount of water; The sustained-release microcapsules are those described in claim 1 or 2.

9. The sunscreen lotion according to claim 8, characterized in that, The sunscreen agent is selected from chemical sunscreens and / or physical sunscreens; and / or, The emulsifier is selected from at least one of polyglycerol-6 distearate, inulin lauryl carbamate, polyglycerol-3 diisostearate, and cetearyl alcohol olive oil ester; and / or, The auxiliary ingredients include at least one of fillers, emollients, antioxidants, thickeners, humectants, and chelating agents.

10. The sunscreen lotion according to claim 9, characterized in that, The filler is silylated silica and / or boron nitride; and / or, The emollient is selected from at least one of cyclopentylsiloxane (D5), cyclohexylsiloxane (D6), and isododecane; and / or, The antioxidant is selected from at least one of tocopherol, coenzyme Q10, rosemary extract, and green tea polyphenols; and / or, The thickener is selected from at least one of aluminum hydroxide, silica, triethoxyoctylsilane, stearyl alcohol, cetyl alcohol, and synthetic beeswax; and / or, The moisturizer is selected from at least one of 1,2-pentanediol, caprylyl glycol, glycerin, and dipropylene glycol; and / or, The chelating agent is selected from at least one of disodium ethylenediaminetetraacetate, phytic acid, and gluconic acid.

11. The sunscreen lotion according to claim 10, characterized in that, Based on the mass percentage of the sunscreen lotion, the content of the filler is 0.6%-1%, the content of the emollient is 7%-11%, the content of the antioxidant is 0.35%-0.65%, the content of the thickener is 1.5%-2.8%, the content of the moisturizer is 3.2%-7.8%, and the content of the chelating agent is 0.08%-0.12%.

12. A method for preparing a sunscreen lotion, applicable to any one of the sunscreen lotions described in claims 8-11, characterized in that, Includes the following steps: The oil phase is obtained by mixing some emulsifiers, sunscreens, and some auxiliary ingredients. The remaining emulsifier, remaining auxiliary ingredients, and water are mixed to obtain an aqueous phase; The aqueous phase is added to the oil phase, and after a second emulsification treatment, sustained-release microcapsules are added to the system. After mixing and defoaming, the sunscreen emulsion is obtained.

13. The method for preparing the sunscreen lotion according to claim 12, characterized in that, The sunscreen agent is selected from chemical sunscreen agents and / or physical sunscreen agents; The auxiliary ingredients include fillers, emollients, antioxidants, thickeners, humectants, and chelating agents; And / or, The process of mixing some emulsifiers, sunscreens, and some auxiliary ingredients includes: mixing some emulsifiers, some thickeners, and chemical sunscreens at 70℃-80℃, adding physical sunscreens, the remaining thickeners, and emollients, performing a first stirring, then cooling to 55℃-65℃, adding fillers and some antioxidants, and performing a second stirring to obtain an oil phase; The process of mixing the remaining emulsifier, remaining auxiliary ingredients, and water includes: mixing a portion of the humectant and chelating agent with water at 75℃-85℃, adding the remaining humectant and remaining emulsifier, stirring for a third time, cooling to 40℃-50℃, adding the remaining antioxidant, and mixing to obtain an aqueous phase; and / or, After the second emulsification process, the temperature is lowered to 30℃-40℃, and slow-release microcapsules are added to the system. The mixture is then stirred at 200rpm-400rpm to obtain the sunscreen emulsion; and / or, The second emulsification process involves homogenization at 6000 rpm to 10000 rpm.

14. The method for preparing the sunscreen lotion according to claim 13, characterized in that, The first stirring is performed at a speed of 8000 rpm to 10000 rpm; and / or, The second stirring is performed at a speed of 200 rpm-400 rpm; and / or, The third stirring is performed at a speed of 3000rpm-5000rpm.

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