Micro-capsule, preparation method thereof and micro-capsule cosmetic

Abstract

The invention relates to a microcapsule, a preparation method thereof and a microcapsule cosmetic, and belongs to the technical field of cosmetics. The preparation method comprises the following steps: mixing a film-forming agent, a thickening agent and water, and heating to obtain a first water phase; mixing a viscosity control agent with water to respectively obtain a second water phase A and a second water phase B; mixing the first water phase and the second water phase A to obtain a prefabricated water phase; mixing grease and active substances to obtain a first oil phase; mixing grease and a surfactant to obtain a second oil phase; performing a first stirring reaction on the prefabricated water phase, the first oil phase and the second oil phase at a first stirring speed, and synchronously adding the second water phase B during the first stirring reaction to obtain an emulsification system; adjusting the stirring speed to a second stirring speed, carrying out a second stirring reaction, standing for layering, and taking a lower layer to obtain microcapsules; wherein the second stirring speed is 1t; a first stirring speed. Through the preparation method provided by the invention, the degradation rate of active substances in the microcapsule can be effectively reduced.

Description

Technical Field

[0001] The present application relates to the field of cosmetic technology, and in particular to a microcapsule and a preparation method thereof, and microcapsule cosmetics. Background Art

[0002] Vitamin A is commonly found in animal livers, especially in saltwater fish and mammals. In the field of cosmetics, the skin is considered to be one of the main vitamin A-responsive tissues because both epidermal keratinocytes and dermal fibroblasts have retinol receptors. Vitamin A is involved in cell proliferation, differentiation and apoptosis. The vitamin A family includes retinal, retinoic acid, carotenoids, retinol, and other derivatives. Based on the effects of vitamin A on promoting the metabolism of keratinocytes and acting on fibroblasts in the dermis to promote collagen production, it is a popular active ingredient in skin care products for whitening, antioxidant and anti-aging.

[0003] Hydroxypinacolone retinoate (HPR), as a new type of retinol derivative, shows similar skin care effects as retinol, while being less irritating, and is therefore favored by the market. Despite this, many retinol and its derivatives on the market currently often ignore the characteristics of the raw materials during the encapsulation process, especially under process conditions such as heating, which will accelerate the degradation of retinol and its derivatives; in addition, traditional encapsulation processes usually require the use of some toxic reagents, such as ether, chloroform, etc., which increases safety risks. Summary of the invention

[0004] In view of the deficiencies in the prior art, the purpose of the embodiments of the present application includes providing a microcapsule and a preparation method thereof, and a microcapsule cosmetic to reduce the degradation rate of active substances while increasing the safety of the product.

[0005] In the first aspect, an embodiment of the present application provides a method for preparing microcapsules, comprising: mixing a film-forming agent, a thickener and water, heating to obtain a first aqueous phase; mixing a viscosity controller with water to obtain a second aqueous phase A and a second aqueous phase B, respectively; mixing the first aqueous phase and the second aqueous phase A to obtain a prefabricated aqueous phase; mixing fats and active substances to obtain a first oil phase; mixing fats and surfactants to obtain a second oil phase; subjecting the prefabricated aqueous phase, the first oil phase and the second oil phase to a first stirring reaction at a first stirring speed, and while conducting the first stirring reaction, simultaneously adding the second aqueous phase B to obtain an emulsified system; adjusting the stirring speed to a second stirring speed to conduct a second stirring reaction, standing to separate layers, removing the layers, and obtaining microcapsules; wherein the second stirring speed is < the first stirring speed.

[0006] In the present application, a film-forming agent, a thickener and water are first mixed and then heated to form a water phase, and then the oil and active substance are mixed to form an oil phase, and then emulsification is achieved through appropriate stirring and temperature control. Through this inverse emulsification method, an oil-in-water emulsion is formed, which can reduce the formation of bubbles in the emulsion, improve the stability of the emulsion, and prevent phase separation; it can also promote the formation of a more uniform microcapsule structure, achieve uniform encapsulation of the active substance, and effectively reduce the degradation rate of the active substance in the microcapsule. Among them, the preparation of the prefabricated aqueous phase in advance can make the components in the aqueous phase interact well, so that the active substance can be effectively wrapped in the microcapsule during the emulsification process; the prefabricated aqueous phase, the first oil phase and the second oil phase are subjected to a first stirring reaction at a first stirring speed, and the second aqueous phase B is added synchronously during the first stirring reaction. In this process, by controlling the stirring speed, on the one hand, the phases can be fully mixed to form a stable emulsified system, and on the other hand, the uniform distribution of the microcapsules can be promoted and the particle size of the microcapsules can be better controlled, so as to facilitate the preparation of microcapsules with smaller particle sizes (10 to 150 μm); then the stirring speed is reduced, and a second stirring reaction is carried out to promote stratification and sedimentation of the microcapsules, which can also maintain the structural integrity of the microcapsules to the greatest extent, reduce the risk of rupture or deformation, and improve the quality and stability of the microcapsules; after the final static stratification, the separated upper layer is the second oil phase part, which can also be recycled, which not only reduces the cost, but also reduces the waste of resources, and is more environmentally friendly. Moreover, the encapsulation process of the present application does not use toxic reagents (such as ether and chloroform) commonly used in traditional encapsulation systems.

[0007] In some embodiments of the present application, in the prefabricated aqueous phase, the mass ratio of the first aqueous phase to the second aqueous phase A is (8-18): (95-105).

[0008] By prefabricating the aqueous phase in advance, the active substances can be better encapsulated in the microcapsules, and the microcapsules can be better formed. Among them, the mass ratio of the first aqueous phase and the second aqueous phase A is limited to the range of (8-18): (95-105), which can make the components in the aqueous phase interact well, enhance the possibility of effective encapsulation of the active substances during the emulsification process, and then the active ingredients are more easily completely encapsulated in the microcapsules, reducing the loss of active ingredients. Moreover, within this ratio range, the film former and the thickener can be fully dissolved, thereby improving the strength and integrity of the microcapsule membrane, so that the morphology of the microcapsules in subsequent operations remains stable. When the oil phase is added later, the emulsification reaction can be made more efficient, thereby improving the yield and quality of the microcapsules.

[0009] In some embodiments of the present application, during the first stirring reaction, the second aqueous phase B is added simultaneously, wherein the ratio of the mass of the second aqueous phase B to the mass of the first aqueous phase in the prefabricated aqueous phase is 1:(3-13).

[0010] By adding the second aqueous phase B simultaneously during the stirring process, the rapid mixing of the components can be promoted to form a uniform emulsified system, thereby improving the stability and uniformity of the microcapsules. In addition, the mass ratio of the second aqueous phase B to the mass ratio of the first aqueous phase in the prefabricated aqueous phase is 1:(3-13). A higher proportion of the first aqueous phase can provide sufficient film-forming agents and thickeners to improve the strength and integrity of the microcapsule membrane. By adjusting the amount of the second aqueous phase B added, the particle size and morphology of the microcapsules can be controlled within a certain range to meet the needs of different products.

[0011] In some embodiments of the present application, in the first stirring reaction, the first stirring speed is 215-225 r / min, and the stirring time is 10-20 min; and / or, in the second stirring reaction, the second stirring speed is 95-105 r / min, and the stirring time is 25-35 min.

[0012] Through the first stirring reaction (215-225r / min), the liquid can be mixed quickly, the interaction between the oil and water phases can be enhanced, and smaller droplets can be formed, thereby improving the uniformity and stability of the emulsification; it can also effectively disperse the active ingredients in the oil phase, so that they are evenly distributed in the microcapsules, reducing the loss of active ingredients; limiting the stirring time of the first stirring reaction to 10-20 minutes is conducive to the full progress of the emulsification process. Further, by reducing the stirring speed to carry out the second stirring reaction, the microcapsule membrane will not be excessively affected by shear force during the formation process, thereby maintaining its structural integrity; limiting the stirring time of the second stirring reaction to 25-35 minutes, the microcapsules can be fully settled and stratified, the cross-linking degree of the microcapsule membrane is enhanced, and its stability during storage and use is improved.

[0013] In some embodiments of the present application, the film-forming agent includes xanthan gum. Xanthan gum can form a tough film structure on the surface of the microcapsule, effectively protecting the internal active ingredients and preventing them from being oxidized or degraded. In addition, xanthan gum has good biocompatibility and safety.

[0014] In some embodiments of the present application, the thickener includes sodium alginate. Sodium alginate can significantly increase the viscosity of the aqueous phase, prevent phase separation during the emulsification process, and improve the uniformity of the microcapsules. In addition, the gel formed by sodium alginate in water can enhance the strength of the microcapsule membrane and further improve the stability of the microcapsules.

[0015] In some embodiments of the present application, the viscosity control agent includes calcium chloride.

[0016] By adding calcium chloride, the rheology of the emulsified system can be optimized, the viscosity can be balanced, and the emulsification process can be promoted smoothly. At the same time, calcium chloride can also react with sodium alginate to form a cross-linked structure, further enhancing the strength and stability of the microcapsule membrane.

[0017] In some embodiments of the present application, the mass percentage of the film-forming agent in the first aqueous phase is 0.1-3%.

[0018] Setting the mass percentage of the film-forming agent within the range of 0.1% to 3% can effectively form a strong film structure, optimize the stability of the microcapsule, and reduce irritation.

[0019] In some embodiments of the present application, the mass percentage of the thickener in the first aqueous phase is 0.2-1%.

[0020] Setting the mass percentage of the thickener within the range of 0.2% to 1% can effectively thicken the aqueous phase, optimize the structural stability of the microcapsules, and reduce irritation.

[0021] In some embodiments of the present application, the mass percentage of the viscosity control agent in the second aqueous phase is 0.15-0.5%.

[0022] Setting the mass percentage of the viscosity controller within the range of 0.15% to 0.5% can effectively adjust the viscosity of the water phase, enhance the emulsification stability, improve the film-forming properties, and reduce the risk of bubble generation.

[0023] In some embodiments of the present application, the oil includes one or more of caprylic acid, capric acid, succinic acid triglyceride, white meadowfoam seed oil, isononyl isononanoate, triethylhexanoin, squalane, mineral oil, decyl cocoate and ethylhexyl palmitate.

[0024] These oils are all skin-friendly ingredients with good compatibility and strong moisturizing ability. Heating the above oils in microcapsules can improve the application feel and smoothness of microcapsule products, as well as enhance the skin compatibility and moisturizing properties of microcapsule products, while enhancing the stability of the microcapsule formula.

[0025] In some embodiments of the present application, the active substance includes one or more of Centella asiatica extract, hydroxypinacolone retinoic acid ester, Lithospermum officinale extract, oil-soluble recombinant collagen, ascorbyl palmitate, sea buckthorn extract and plant oils and fats.

[0026] The interaction of these raw materials can achieve multiple skin care effects, such as moisturizing, repairing, anti-aging and anti-oxidation, meeting consumers' demand for high-efficiency skin care products.

[0027] In some embodiments of the present application, the HLB value of the surfactant is greater than 14.

[0028] Selecting liquid surfactants with an HLB value greater than 14 can significantly enhance emulsification ability and improve product stability.

[0029] In some embodiments of the present application, the surfactant includes one or more of Tween 20, Tween 60 and Tween 80.

[0030] The above-mentioned surfactants can provide good emulsification properties and mildness, and can also enhance the stability of the product.

[0031] In some embodiments of the present application, the mass percentage of the active substance in the first oil phase is 10-95%.

[0032] In some embodiments of the present application, in the second oil phase, the mass percentage of the surfactant is 0.2-4.8%.

[0033] Setting the mass percentage of surfactant within the range of 0.2 to 4.8% can effectively optimize the emulsification effect and improve the stability, mildness and safety of the formula.

[0034] In a second aspect, an embodiment of the present application provides a microcapsule prepared by the above preparation method.

[0035] In a second aspect, an embodiment of the present application provides a microcapsule cosmetic comprising the above-mentioned microcapsule. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0037] Figure 1 This is a naked eye observation picture of the microcapsule prepared in Example 7 of the present application;

[0038] Figure 2 This is a microscopic observation picture of the microcapsule prepared in Example 7 of the present application;

[0039] Figure 3 This is a naked eye observation picture of the microcapsule prepared in Example 9 of the present application;

[0040] Figure 4 This is a microscopic observation picture of the microcapsule prepared in Example 9 of the present application;

[0041] Figure 5 This is a naked eye observation picture of the microcapsule prepared in Example 1 of the present application;

[0042] Figure 6 This is a microscopic observation picture of the microcapsule prepared in Example 1 of the present application;

[0043] Figure 7This is a naked eye observation picture of the microcapsule prepared in Example 6 of the present application;

[0044] Figure 8 This is a microscopic observation picture of the microcapsule prepared in Example 6 of the present application;

[0045] Fig. 9 This is a graph showing the degradability test results of the microcapsules prepared in Example 6 of the present application. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to the conventional conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0047] The following is a detailed description of a microcapsule and a preparation method thereof, and a microcapsule cosmetic according to an embodiment of the present application.

[0048] The present invention provides a microcapsule, and the preparation method thereof comprises the following steps:

[0049] (1) Preparation of the first aqueous phase

[0050] The film-forming agent, thickener and water are mixed, stirred and heated to 85° C. to dissolve the raw materials uniformly to obtain a first aqueous phase.

[0051] Among them, the film-forming agent includes xanthan gum; the thickener includes sodium alginate.

[0052] In the first water phase, the mass percentage of the film former is 0.1-3%; the mass percentage of the thickener is 0.2-1%.

[0053] A film-forming agent concentration of 0.1% to 3% can effectively form a tough film structure. A good film structure can effectively isolate the external environment, prevent the invasion of moisture and oxygen, and thus protect the internal active ingredients. Moreover, within this concentration range, it can reduce irritation to the skin. It can also form a good interaction with other ingredients such as thickeners and viscosity controllers to enhance the stability of the entire system.

[0054] A thickener concentration of 0.2% to 1% can effectively increase the viscosity of the water phase, which can help stabilize the emulsified system, avoid stratification of the oil and water phases, and improve the uniformity of the microcapsules; by forming a more uniform network structure in the microcapsule membrane, it can effectively improve the mechanical strength of the membrane and reduce the risk of damage during storage and use. Moreover, within this concentration range, the irritation to the skin can be reduced.

[0055] In the embodiment of the present application, the first aqueous phase also includes a moisturizer and a preservative. By way of example, the moisturizer includes but is not limited to glycerin and 1,3-butylene glycol; the preservative includes but is not limited to phenoxyethanol.

[0056] The mass percentage of the moisturizer in the first aqueous phase is 4-8%, and the mass percentage of the preservative in the first aqueous phase is 0.1-1%. As an example, the mass percentage of the moisturizer in the first aqueous phase includes but is not limited to 4%, 5%, 6%, 7%, and 8%; the mass percentage of the preservative in the first aqueous phase is 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, and 1%.

[0057] In the embodiment of the present application, the first aqueous phase also includes active substances. As an example, the active substances include but are not limited to Centella asiatica extract and Lithospermum officinale extract.

[0058] (2) Preparation of the second aqueous phase

[0059] The viscosity control agent is mixed with water to obtain a second aqueous phase A and a second aqueous phase B, respectively.

[0060] Wherein, the viscosity control agent includes calcium chloride.

[0061] In the second aqueous phase, the mass percentage of the viscosity control agent is 0.15-0.5%.

[0062] A viscosity controller concentration of 0.15% to 0.5% can effectively adjust the viscosity of the water phase. By adjusting the viscosity of the water phase, the separation rate between the oil and water phases can be reduced, phase separation and precipitation can be prevented, and the uniformity and stability of the microcapsules can be improved; at the same time, it can also help form a tougher membrane structure, enhance the protection ability of the microcapsules, and effectively encapsulate the internal active ingredients.

[0063] (3) Preparation of prefabricated aqueous phase

[0064] The first aqueous phase prepared in step (1) and the second aqueous phase A prepared in step (2) are mixed to obtain a prefabricated aqueous phase.

[0065] In the prefabricated aqueous phase, the mass ratio of the first aqueous phase to the second aqueous phase A is (8-18): (95-105) 0. As an example, the mass ratio of the first aqueous phase to the second aqueous phase A includes but is not limited to 8:95, 8:96, 8:97, 8:98, 8:99, 8:100, 8:101, 8:102, 8:103, 8:104, 8:105, 10:95, 11:96, 11:97, 11:98, 11:99, 11:100, 11:101, 11:102, 11:103, 11:104, 11:105, 13:95, 13:96, 13:97, 13:98, 13:99. 9. 13:100, 13:101, 13:102, 13:103, 13:104, 13:105, 15:95, 15:96, 15:97, 15:98, 15:99, 15:100, 15:101, 15:102, 15:103, 15:104, 15:105, 18:95, 18:96, 18:97, 18:98, 18:99, 18:100, 18:101, 18:102, 18:103, 18:104, 18:105.

[0066] (4) Preparation of the first oil phase

[0067] The oil and active ingredients are mixed to obtain the first oil phase.

[0068] Among them, the oils include but are not limited to one or more of caprylic acid, capric acid, succinic acid triglyceride, white meadowfoam seed oil, isononyl isononanoate, triethylhexanoin, squalane, mineral oil, decyl cocoate and ethylhexyl palmitate.

[0069] In the embodiments of the present application, the active substances include but are not limited to one or more of Centella asiatica extract, hydroxypinacolone retinoic acid ester, Lithospermum officinale extract, oil-soluble recombinant collagen, ascorbyl palmitate, sea buckthorn extract and plant oils and fats.

[0070] Among them, Centella asiatica extract has good repair and anti-inflammatory effects, promotes wound healing, and improves skin barrier function. Lithospermum officinale extract is rich in natural antioxidant ingredients, which helps soothe the skin and improve uneven skin tone and dullness. Hydroxypinacolone retinoic acid ester can promote collagen synthesis, reduce fine lines and wrinkles, and improve skin elasticity. Oil-soluble recombinant collagen can help improve the firmness and smoothness of the skin and enhance the structural support of the skin. Ascorbyl palmitate has a significant antioxidant effect, which can resist free radical damage to the skin and promote skin brightness and uniformity. Sea buckthorn extract is rich in vitamins C, E and various antioxidant ingredients, which protect the skin from environmental stress and aging.

[0071] In the first oil phase, the mass percentage of the active substance is 10-95%. As an example, the mass percentage of the active substance includes but is not limited to 10%, 14%, 18%, 20%, 24%, 28%, 30%, 35%, 37%, 40%, 45%, 50%, 55%, 60%, 62%, 66%, 70%, 78%, 80%, 85%, 90%, 95%. It should be noted that the mass percentage of the active substance can be adjusted according to the matrix of the active substance, which is not limited in this application.

[0072] (5) Preparation of the second oil phase

[0073] The oil and surfactant are mixed to obtain the second oil phase.

[0074] Among them, the oils include but are not limited to one or more of caprylic acid, capric acid, succinic acid triglyceride, white meadowfoam seed oil, isononyl isononanoate, triethylhexanoin, squalane, mineral oil, decyl cocoate and ethylhexyl palmitate.

[0075] The surfactant is a liquid surfactant with an HLB value greater than 14. As an example, the surfactant includes, but is not limited to, one or more of Tween 20, Tween 60 and Tween 80.

[0076] Surfactants with HLB values ​​greater than 14 have very high hydrophilicity, which enables them to effectively mix with water, making them suitable for use in oil-in-water (W / O) or water-in-oil (O / W) emulsion systems to enhance the stability of the emulsion. Moreover, surfactants with high HLB values ​​generally have stronger emulsifying abilities, and can effectively mix the oil phase and the water phase to form smaller, more uniform droplets, thereby improving the stability and uniformity of the emulsified product. In addition, surfactants with high HLB values ​​are generally mild and less likely to irritate the skin. They can also improve the fluidity and spreadability of the emulsion, as well as enhance the expansibility and permeability of the product on the skin surface, allowing the active ingredients to penetrate the skin more effectively.

[0077] In the second oil phase, the mass percentage of the surfactant is 0.2-4.8%. As an example, the mass percentage of surfactant includes, but is not limited to, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, 2.1%, 2.2%, 2.3%, 2.4%, 2.5%, 2.6%, 2.7%, 2.8%, 2.9%, 3%, 3.1%, 3.2%, 3.3%, 3.4%, 3.5%, 3.6%, 3.7%, 3.8%, 3.9%, 4%, 4.1%, 4.2%, 4.3%, 4.4%, 4.5%, 4.6%, 4.7%, 4.8%.

[0078] A surfactant concentration of 0.2 to 4.8% can effectively promote the emulsification of the oil-water phase. By reducing the surface tension, the surfactant can form a stable emulsion film and enhance the uniformity of the product during storage and use. Moreover, the surfactant concentration within this concentration range can also reduce irritation to the skin.

[0079] (6) Preparation of emulsified system

[0080] The prefabricated water phase, the first oil phase and the second oil phase prepared above are subjected to a first stirring reaction at a first stirring speed. During the first stirring reaction, the second water phase B is added simultaneously to obtain an emulsified system.

[0081] Wherein, the first stirring speed is 215-225 r / min, and the stirring time is 10-20 min. As an example, the first stirring speed includes but is not limited to 215 r / min, 216 r / min, 217 r / min, 218 r / min, 219 r / min, 220 r / min, 221 r / min, 222 r / min, 223 r / min, 224 r / min, 225 r / min; the stirring time includes but is not limited to 10 min, 11 min, 12 min, 13 min, 14 min, 15 min, 16 min, 17 min, 18 min, 19 min, 20 min.

[0082] In the embodiment of the present application, the mass ratio of the second aqueous phase B to the mass ratio of the first aqueous phase in the prefabricated aqueous phase is 1:(3-13). As an example, the mass ratio of the second aqueous phase B to the mass ratio of the first aqueous phase in the prefabricated aqueous phase includes but is not limited to 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, 1:11, 1:12, 1:13.

[0083] (7) Sedimentation and stratification to obtain microcapsules

[0084] The stirring speed is adjusted to a second stirring speed for a second stirring reaction, the layers are allowed to stand for stratification, and the lower layer is taken to obtain microcapsules; wherein the second stirring speed is less than the first stirring speed.

[0085] In the embodiment of the present application, the second stirring speed is 95-105 r / min, and the stirring time is 25-35 min. As an example, the second stirring speed includes but is not limited to 95 r / min, 96 r / min, 97 r / min, 98 r / min, 99 r / min, 100 r / min, 101 r / min, 102 r / min, 103 r / min, 104 r / min, 105 r / min; the stirring time includes but is not limited to 25 min, 26 min, 27 min, 28 min, 29 min, 30 min, 31 min, 32 min, 33 min, 34 min, 35 min.

[0086] In the preparation method, first, the first step of the preparation process is to mix the film former, thickener and water, and heat them to form a first aqueous phase. This process not only allows the film former and thickener to be fully dissolved, but also enhances the structural strength of the microcapsule membrane and improves the overall stability of the microcapsule. The role of the film former is to form a tough membrane structure, while the thickener increases the viscosity of the system and prevents phase separation that may occur during the emulsification process.

[0087] Next, the viscosity controller is mixed with water to obtain the second aqueous phase A and the second aqueous phase B. The design of this step allows the viscosity of the aqueous phase to be precisely adjusted to optimize the emulsification effect. By flexibly adjusting the properties of the aqueous phase, the uniformity of the emulsification can be effectively improved, making the emulsification system stable under different process conditions.

[0088] Subsequently, the first aqueous phase is mixed with the second aqueous phase A to obtain a prefabricated aqueous phase. At this time, the oil and the active substance are mixed to form the first oil phase, so that the active substance in the oil phase can be effectively protected. By mixing the active substance with the oil, the risk of its degradation in the aqueous phase environment can be effectively reduced, thereby maintaining the stability and effectiveness of the active substance.

[0089] During the emulsification process, the prefabricated water phase, the first oil phase and the second oil phase are emulsified at the first stirring speed, and the second water phase B is added simultaneously. This process utilizes different stirring speeds to promote uniform distribution of microcapsules and good particle size control. The setting of the first stirring speed helps to fully mix the phases and form a stable emulsified system.

[0090] Next, the stirring speed is adjusted to the second stirring speed for the second stirring reaction. The stirring speed in this stage is lower than the first stirring speed, which can promote the sedimentation and stratification of the microcapsules. By reducing the stirring speed, the structural integrity of the microcapsules can be maintained to the greatest extent, the risk of rupture or deformation can be reduced, and the quality and stability of the microcapsules can be improved.

[0091] Finally, the lower layer is removed after standing for stratification to obtain microcapsules. In this process, standing allows the microcapsules to settle effectively, facilitating efficient recovery, reducing the complexity of the operation and improving production efficiency.

[0092] The features and performance of the present application are further described in detail below in conjunction with the embodiments.

[0093] Example 1

[0094] This embodiment provides a microcapsule, and the preparation method thereof comprises the following steps:

[0095] (1) Preparation of the first aqueous phase

[0096] Mix 0.2 g xanthan gum, 1 g sodium alginate, 6 g glycerol, 5 g 1,3-butylene glycol, 0.6 g phenoxyethanol, 0.8 g Centella asiatica extract and water (the total reaction system is 100 g, and water is used as a finishing medium), stir and heat to 85°C to evenly dissolve the above raw materials to obtain a first aqueous phase.

[0097] (2) Preparation of the second aqueous phase

[0098] Mix 0.2 g of calcium chloride with water (the total reaction system is 100 g, and water is used as a filling medium) to obtain a second aqueous phase. To facilitate subsequent preparation, the second aqueous phase is divided into two parts of different masses, namely, a second aqueous phase A and a second aqueous phase B. That is to say, the second aqueous phase A and the second aqueous phase B are the same substance, but with different masses.

[0099] (3) Preparation of prefabricated aqueous phase

[0100] The first aqueous phase prepared in step (1) and the second aqueous phase A prepared in step (2) are uniformly mixed in a mass ratio of 13:100 to obtain a prefabricated aqueous phase.

[0101] (4) Preparation of the first oil phase

[0102] 3.55 g of caprylic / capric / succinic triglyceride, 1.25 g of hydroxypinacolone retinoic acid ester and 0.2 g of lithospermum officinale extract were mixed to obtain a first oil phase.

[0103] It should be noted here that caprylic / capric / succinic triglyceride is a common raw material name in the cosmetics industry, and the manufacturer it was purchased from is: German oleo chemicals.

[0104] (5) Preparation of the second oil phase

[0105] Meadowfoam seed oil (total reaction system is 100 g, and meadowfoam seed oil is used as a finishing medium) and 2.4 g of Tween 20 are mixed to obtain a second oil phase.

[0106] (6) Preparation of emulsified system

[0107] The prefabricated water phase, the first oil phase and the second oil phase prepared above were subjected to a first stirring reaction at 220 r / min for 15 min. During the first stirring reaction, the second water phase B with 8 times the mass of the first water phase in the prefabricated water phase was simultaneously added to obtain an emulsified system.

[0108] (7) Sedimentation and stratification to obtain microcapsules

[0109] The stirring speed was adjusted to 99 r / min for the second stirring reaction. After stirring for 30 min, the stirrer was turned off, and the mixture was allowed to stand for 1 h. The layers were recovered and the lower layer was removed to obtain microcapsules.

[0110] The preparation methods and raw material ratios of the remaining embodiments and comparative examples are basically the same as those of Example 1, except that some raw material ratios or parameter steps are different. Please see Table 1 for the different parameters.

[0111] Table 1

[0112]

[0113]

[0114] Comparative Example 1

[0115] This comparative example is basically the same as Example 1, except that the aqueous phase is not prefabricated in advance.

[0116] This comparative example provides a microcapsule, and its preparation method comprises the following steps:

[0117] (1) Preparation of the first aqueous phase

[0118] Mix 0.2 g xanthan gum, 1 g sodium alginate, 6 g glycerol, 5 g 1,3-butylene glycol, 0.6 g phenoxyethanol, 0.8 g Centella asiatica extract and water (the total reaction system is 100 g, and water is used as a finishing medium), stir and heat to 85°C to evenly dissolve the above raw materials to obtain a first aqueous phase.

[0119] (2) Preparation of the second aqueous phase

[0120] 0.2 g of calcium chloride was mixed with water (the total reaction system was 100 g, and water was used as a supplementary medium) to obtain a second aqueous phase.

[0121] (3) Preparation of the first oil phase

[0122] 3.55 g of caprylic / capric / succinic triglyceride, 1.25 g of hydroxypinacolone retinoic acid ester and 0.2 g of lithospermum officinale extract were mixed to obtain a first oil phase.

[0123] It should be noted here that caprylic / capric / succinic triglyceride is a common raw material name in the cosmetics industry, and the manufacturer it was purchased from is: German oleo chemicals.

[0124] (4) Preparation of the second oil phase

[0125] Meadowfoam seed oil (total reaction system is 100 g, and meadowfoam seed oil is used as a finishing medium) and 2.4 g of Tween 20 are mixed to obtain a second oil phase.

[0126] (5) Preparation of emulsified system

[0127] The first aqueous phase, the first oil phase and the second oil phase prepared above were subjected to a first stirring reaction at 220 r / min for 15 min. During the first stirring reaction, a second aqueous phase having a mass 8 times that of the first aqueous phase was simultaneously added to obtain an emulsified system.

[0128] (6) Sedimentation and stratification to obtain microcapsules

[0129] The stirring speed was adjusted to 99 r / min for the second stirring reaction. After stirring for 30 min, the stirrer was turned off, and the mixture was allowed to stand for 1 h. The layers were recovered and the lower layer was removed to obtain microcapsules.

[0130] Comparative Example 2

[0131] This comparative example is basically the same as Example 1, except that there is no second oil phase.

[0132] This comparative example provides a microcapsule, and its preparation method comprises the following steps:

[0133] (1) Preparation of the first aqueous phase

[0134] Mix 0.2 g xanthan gum, 1 g sodium alginate, 6 g glycerol, 5 g 1,3-butylene glycol, 0.6 g phenoxyethanol, 0.8 g Centella asiatica extract and water (the total reaction system is 100 g, and water is used as a finishing medium), stir and heat to 85°C to evenly dissolve the above raw materials to obtain a first aqueous phase.

[0135] (2) Preparation of the second aqueous phase

[0136] Mix 0.2 g of calcium chloride with water (the total reaction system is 100 g, and water is used as a filling medium) to obtain a second aqueous phase. To facilitate subsequent preparation, the second aqueous phase is divided into two parts of different masses, namely, a second aqueous phase A and a second aqueous phase B. That is to say, the second aqueous phase A and the second aqueous phase B are the same substance, but with different masses.

[0137] (3) Preparation of prefabricated aqueous phase

[0138] The first aqueous phase prepared in step (1) and the second aqueous phase A prepared in step (2) are uniformly mixed in a mass ratio of 13:100 to obtain a prefabricated aqueous phase.

[0139] (4) Preparation of the first oil phase

[0140] 3.55 g of caprylic / capric / succinic triglyceride, 1.25 g of hydroxypinacolone retinoic acid ester and 0.2 g of lithospermum officinale extract were mixed to obtain a first oil phase.

[0141] It should be noted here that caprylic / capric / succinic triglyceride is a common raw material name in the cosmetics industry, and the manufacturer it was purchased from is: German oleo chemicals.

[0142] (5) Preparation of emulsified system

[0143] The prefabricated water phase and the first oil phase prepared above were subjected to a first stirring reaction at 220 r / min for 15 min. During the first stirring reaction, a second water phase B having a mass 8 times that of the first water phase in the prefabricated water phase was simultaneously added to obtain an emulsified system.

[0144] (6) Sedimentation and stratification to obtain microcapsules

[0145] The stirring speed was adjusted to 99 r / min for the second stirring reaction. After stirring for 30 min, the stirrer was turned off, and the mixture was allowed to stand for 1 h. The layers were recovered and the lower layer was removed to obtain microcapsules.

[0146] Comparative Example 3

[0147] This comparative example is basically the same as Example 1, except that the stirring speed is not reduced and the second stirring reaction is continued.

[0148] This comparative example provides a microcapsule, and its preparation method comprises the following steps:

[0149] (1) Preparation of the first aqueous phase

[0150] Mix 0.2 g xanthan gum, 1 g sodium alginate, 6 g glycerol, 5 g 1,3-butylene glycol, 0.6 g phenoxyethanol, 0.8 g Centella asiatica extract and water (the total reaction system is 100 g, and water is used as a finishing medium), stir and heat to 85°C to evenly dissolve the above raw materials to obtain a first aqueous phase.

[0151] (2) Preparation of the second aqueous phase

[0152] Mix 0.2 g of calcium chloride with water (the total reaction system is 100 g, and water is used as a filling medium) to obtain a second aqueous phase. To facilitate subsequent preparation, the second aqueous phase is divided into two parts of different masses, namely, a second aqueous phase A and a second aqueous phase B. That is to say, the second aqueous phase A and the second aqueous phase B are the same substance, but with different masses.

[0153] (3) Preparation of prefabricated aqueous phase

[0154] The first aqueous phase prepared in step (1) and the second aqueous phase A prepared in step (2) are uniformly mixed in a mass ratio of 13:100 to obtain a prefabricated aqueous phase.

[0155] (4) Preparation of the first oil phase

[0156] 3.55 g of caprylic / capric / succinic triglyceride, 1.25 g of hydroxypinacolone retinoic acid ester and 0.2 g of lithospermum officinale extract were mixed to obtain a first oil phase.

[0157] It should be noted here that caprylic / capric / succinic triglyceride is a common raw material name in the cosmetics industry, and the manufacturer it was purchased from is: German oleo chemicals.

[0158] (5) Preparation of the second oil phase

[0159] Meadowfoam seed oil (total reaction system is 100 g, and meadowfoam seed oil is used as a finishing medium) and 2.4 g of Tween 20 are mixed to obtain a second oil phase.

[0160] (6) Preparation of emulsified system

[0161] The prefabricated water phase, the first oil phase and the second oil phase prepared above were subjected to a first stirring reaction at 220 r / min for 15 min. During the first stirring reaction, the second water phase B with 8 times the mass of the first water phase in the prefabricated water phase was simultaneously added to obtain an emulsified system.

[0162] (7) Sedimentation and stratification to obtain microcapsules

[0163] The stirring speed was maintained at 220 r / min, and the stirring was continued for 30 min. Then the stirrer was turned off, and the mixture was allowed to stand for 1 h. The layers were recovered and the lower layer was removed to obtain microcapsules.

[0164] Test Example 1

[0165] This test example is to observe the preparation and molding of the microcapsules prepared in Examples 1-10 and Comparative Examples 1-3, wherein the preparation conditions include sedimentation rate, yield, whether the active substance is completely encapsulated, whether there is rupture, floating oil, coagulation, wall adhesion, etc.

[0166] The definition criteria are as follows:

[0167] Good forming: The particles are round and well packed under the microscope.

[0168] Poor molding: The particles are not full or round, or appear to be agglomerated, and the particle core is not well coated with grease under a microscope.

[0169] Unformed: Particles cannot be formed into spherical shape.

[0170] Rupture: Oil floating appears, and the core of the particles is not well coated with grease under the microscope.

[0171] Agglomeration: The membrane shell of the outer phase of the oil core gathers into agglomerates (refer to Figure 1 , Figure 2 )

[0172] Wall adhesion: After the membrane shell of the oil core phase gathers into a mass, the floccules / lumps stick to the cup wall (refer to Figure 1 )

[0173] Floating oil: Oil on the surface of the matrix can be seen with the naked eye floating up due to its specific gravity.

[0174] Fast sedimentation: After standing, the microcapsule particles can be observed to settle immediately with the naked eye.

[0175] Slow sedimentation: After standing, the sedimentation of microcapsule particles was observed 2 hours later.

[0176] Bead yield: the total mass of the microcapsules finally obtained / the total mass of the raw materials x 100% = bead yield. A bead yield greater than 60% is a high bead yield, and a yield less than 30% is a low bead yield.

[0177] Please see Table 2 for details of the detection results of the microcapsules prepared in the above Examples 1-10 and Comparative Examples 1-3.

[0178] Table 2

[0179]

[0180]

[0181] As can be seen from Table 2, in Examples 5 and 7-10, particles agglomerated or ruptured and failed to be completely encapsulated, while the microcapsules prepared in Examples 1-4 and Example 6 of the present application were well formed, and the microcapsules prepared in Example 6 had a larger particle size (>150 μm).

[0182] By comparing Example 1 and Example 2, it can be seen that the content of surfactant affects the speed of sedimentation. The higher the content of Tween 20, the slower the sedimentation rate. However, when the content of Tween 20 is lower than 0.2% (such as Example 7, the content of Tween 20 is 0.1%), agglomeration and wall adhesion will occur. Therefore, when the content of surfactant is between 0.2-4.8%, a more ideal sedimentation rate and beading rate can be achieved. Similarly, by comparing the preparation conditions of Examples 1 and 11, it can be found that the concentration of sodium alginate is also a factor affecting the sedimentation rate. The sedimentation rate of the 1% sodium alginate aqueous phase matrix is ​​faster than that of the 0.55% matrix, and the beading rate is higher. In addition, it can be seen from Example 8 that when the content of sodium alginate is lower than 0.2%, agglomeration and easy rupture will occur. In addition, under an optical electron microscope, the particle size of the microcapsules prepared in Example 11 was observed to be concentrated at <50 μm; while the particle size of the microcapsules prepared in Example 1 was observed to be between 50 and 150 μm; this result shows that the concentration of sodium alginate will affect the particle size of the microcapsules under this process.

[0183] Figure 1 This is a naked eye observation picture of the microcapsule obtained in Example 7; Figure 2 This is a microscopic observation picture of the microcapsule prepared in Example 7; Figure 3 This is a naked eye observation picture of the microcapsule prepared in Example 9; Figure 4 This is a microscopic observation picture of the microcapsule prepared in Example 9; Figure 5 This is a naked eye observation picture of the microcapsule prepared in Example 1; Figure 6 This is a microscopic observation picture of the microcapsule prepared in Example 1; Figure 7 This is a macroscopic observation picture of the microcapsule obtained in Example 6; Figure 8 This is a microscopic observation picture of the microcapsule obtained in Example 6; please refer to Figure 1-Figure 8 .

[0184] from Figure 1 and Figure 2 It can be seen that in Example 7, when the surfactant is less than 0.2%, coagulation and wall adhesion occur, and similar situations also occur in Examples 8 and 10 (not shown); in Example 9, when the oil content is as high as 50g, floating oil will appear, and microscopic observation shows that the molding is also poor (such as Figure 3 and Figure 4 ).from Figure 5 and Figure 6 It can be seen that the particle size of the microcapsules prepared in Example 1 is 10 to 150 μm; Figure 7 and Figure 8 It can be seen that the microcapsules prepared in Example 6 are well formed, and the particle size of the microcapsules prepared in Example 6 is relatively large (>150 μm).

[0185] Test Example 2

[0186] This test example tests the stability of the microcapsules prepared in Examples 1-10 and Comparative Examples 1-3 at high temperature, low temperature and room temperature. The treatment parameters are as follows: room temperature (25°C, 3 months), high temperature (45°C, 3 months), low temperature (-18°C, 3 months).

[0187] Stability definition standard: A product is considered stable if its form and appearance remain the same as before testing.

[0188] Please see Table 3 for the above test results.

[0189] Table 3

[0190]

[0191]

[0192] As shown in Table 3, Examples 7-10 have different degrees of coagulation or oil floating problems at room temperature, indicating that the content of Tween 20, sodium alginate, calcium ions, and encapsulated oil will affect the stability of the system. At the same time, it can be seen from Comparative Examples 1 and 2 that the process operation has a greater impact on the system. Among them, Comparative Example 1 has a low consistency due to the lack of pre-fabricated water phase in the early stage, which leads to the incomplete encapsulation of the active substance into the microcapsule; after removing the second oil phase in Comparative Example 2, only an unstable gel body suspending the oil is formed, and no microcapsule can be obtained; in Comparative Example 3, the second stirring reaction is carried out without reducing the stirring speed, which will break the particles still in the reaction, resulting in poor microcapsule formation and oil floating on the surface.

[0193] Test Example 3

[0194] In this test example, the microcapsules prepared in Examples 1, 5, 6, and 11 were filtered, washed, and dried, and then added into the following essences and cream bases for testing. The ratio of the essences and cream bases is shown in Table 4.

[0195] Table 4

[0196]

[0197]

[0198] 1. The preparation method of the essence is as follows:

[0199] S11. The raw materials of phase A1 are mixed and heated to 80°C, kept warm for 20 min, and set aside;

[0200] S12. Homogenize phase A1 (8000 r / min) for 2 min;

[0201] S13. Add phase A2 to the material in step S12, stir and cool to below 45°C, and add phase C;

[0202] S14. Continue stirring and cool to 38°C, then discharge and cool to room temperature.

[0203] 2. Preparation method of cream:

[0204] S21. The raw materials of phase A1 are mixed and heated to 80°C, kept warm for 20 min, and set aside;

[0205] S22. Mix the raw materials of phase B, heat to 80 ° C, keep warm for 20 min, stir until dissolved, and set aside;

[0206] S23. Homogenize phase A1 (8000 r / min) for 1 min, then slowly add phase B into phase A1 and homogenize (8000 r / min) for 1 min;

[0207] S24. Add phase A2 to the material in step S23, stir and cool to below 45°C, and add phase C;

[0208] S25. Continue stirring and cool to 38°C, then discharge the material and cool to room temperature.

[0209] 3. Skin feel and stability test results

[0210] Skin feel test: The microcapsules prepared in Examples 1, 5, 6, and 11 were added to the corresponding essences and creams to prepare products, and then 0.15 g of each product was sampled on the back of the hand of the subject, smeared in circles until the material was absorbed, and a skin feel evaluation questionnaire was filled out.

[0211] Stability test: The microcapsules prepared in Examples 1, 5, 6, and 11 were made into corresponding essences and creams, and then 3 parallel samples of each product were taken and placed at: room temperature (25°C, 3 months), high temperature (45°C, 3 months), and low temperature (-18°C, 3 months). Stability definition standard: The product is called stable if its shape and appearance remain the same as before the test.

[0212] Please see Table 5 for the above skin feel and stability tests.

[0213] Table 5

[0214]

[0215] The essence and cream have high viscosity, and the viscosity of the essence and cream in the control group are 32000 and 46850 mPa·s respectively. A common problem encountered in the microbead encapsulation system is the consistency of the matrix, which is easy to break at high viscosity (viscosity>30000 mPa·s), while the examples show good stability in the aforementioned high-viscosity essence and cream, and no stirring cracking and phenomenon are found.

[0216] As can be seen from Table 5, the skin feel of Examples 11 and 1 has little change, indicating that 0.55-1% sodium alginate has little effect on the skin feel. By comparing Examples 1 and 5, it can be found that the higher the calcium ion concentration, the higher the hardness of the microcapsule particles. At a calcium ion concentration of 0.6%, a granular feel can be felt, so the calcium ion concentration under this process system should not be greater than 0.5%. At the same time, by comparing Example 6, it can be seen that the microcapsules containing 30% oil content significantly improve the moisturizing feeling of the essence and cream.

[0217] Test Example 4

[0218] This test example will test the degradation of the microcapsules prepared in Example 6. Generally, it is a room temperature degradation test, and raising the temperature is regarded as an accelerated degradation treatment. The microcapsules are placed in a constant temperature incubator for accelerated degradation treatment at 50°C, and separated by HPLC high-performance liquid chromatography, detected by ultraviolet detector, qualitatively determined by retention time, quantitatively determined by peak area, and the content of encapsulated and non-encapsulated hydroxypinacolone retinoic acid ester after a certain period of time is calculated by the standard curve method, thereby calculating the comparative degradation curve. Mobile phase A-methanol, mobile phase B trichloroacetic acid aqueous solution, flow rate 0.8mL / min, detection wavelength 325nm, injection volume 10μl.

[0219] Degradability test results Fig. 9 As shown, from Fig. 9 It can be seen that after 2 months (50°C), the degradation rate of the unwrapped retinol derivative (HPR) exceeded half, while the degradation rate was significantly reduced after wrapping. The above test results show that the microcapsule preparation process provided by the present application can effectively delay the degradation of HPR.

[0220] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

Claims

1. A method for preparing microcapsules, characterized in that: include: Mixing a film former, a thickener and water, and heating to obtain a first aqueous phase; Mixing a viscosity control agent with water to obtain a second aqueous phase A and a second aqueous phase B respectively; mixing the first aqueous phase and the second aqueous phase A to obtain a prefabricated aqueous phase; Mixing the oil and the active substance to obtain a first oil phase; Mixing the oil and surfactant to obtain a second oil phase; The prefabricated water phase, the first oil phase and the second oil phase are subjected to a first stirring reaction at a first stirring speed, and the second water phase B is added simultaneously during the first stirring reaction to obtain an emulsified system; adjusting the stirring speed to a second stirring speed to carry out a second stirring reaction, standing to separate layers, and removing the lower layer to obtain the microcapsule; Wherein, the second stirring speed is less than the first stirring speed.

2. The preparation method according to claim 1, characterized in that: In the prefabricated aqueous phase, the mass ratio of the first aqueous phase to the second aqueous phase A is (8-18):(95-105).

3. The preparation method according to claim 1, characterized in that: While the first stirring reaction is being carried out, the second aqueous phase B is added simultaneously, wherein the ratio of the mass of the second aqueous phase B to the mass of the first aqueous phase in the prefabricated aqueous phase is 1:(3-13).

4. The preparation method according to claim 1, characterized in that: In the first stirring reaction, the first stirring speed is 215-225 r / min, and the stirring time is 10-20 min; And / or, in the second stirring reaction, the second stirring speed is 95-105 r / min, and the stirring time is 25-35 min.

5. The preparation method according to any one of claims 1 to 4, characterized in that: The film-forming agent includes xanthan gum; Optionally, the thickener comprises sodium alginate; Optionally, the viscosity control agent comprises calcium chloride.

6. The preparation method according to claim 5, characterized in that: In the first aqueous phase, the mass percentage of the film-forming agent is 0.1 to 3%; Optionally, in the first aqueous phase, the mass percentage of the thickener is 0.2 to 1%; Optionally, in the second aqueous phase, the mass percentage of the viscosity control agent is 0.15-0.5%.

7. The preparation method according to any one of claims 1 to 4, characterized in that: The oil comprises one or more of caprylic acid, capric acid, succinic acid triglyceride, white meadowfoam seed oil, isononyl isononanoate, triethylhexanoin, squalane, mineral oil, decyl cocoate and ethylhexyl palmitate; Optionally, the active substance includes one or more of Centella asiatica extract, hydroxypinacolone retinoic acid ester, Lithospermum officinale extract, oil-soluble recombinant collagen, ascorbyl palmitate, sea buckthorn extract and plant oil; Optionally, the HLB value of the surfactant is greater than 14; Optionally, the surfactant includes one or more of Tween 20, Tween 60 and Tween 80.

8. The preparation method according to claim 7, characterized in that: In the first oil phase, the mass percentage of the active substance is 10 to 95%; Optionally, in the second oil phase, the mass percentage of the surfactant is 0.2-4.8%.

9. A microcapsule, characterized in that Prepared by the preparation method described in any one of claims 1 to 8.

10. A microcapsule cosmetic, characterized in that: The microcapsule according to claim 9.

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