Safe sunscreen microcapsule coating composition, microcapsule coating method, cosmetic and application

Abstract

The invention provides a safe sunscreen microcapsule coating composition, a sunscreen microcapsule coating method, cosmetics and application, and belongs to the technical field of cosmetics. The sunscreen microcapsule coating composition comprises a coating medium, an auxiliary coating agent and a structuring agent, the coating medium is lecithin; the auxiliary coating agent is prepared from at least one of polyglycerol-10 stearate, polyglycerol-10 oleate, polyglycerol-10 palmitate, polyglycerol-10 myristate, polyglycerol-10 distearate and sucrose palmitate; the auxiliary coating agent is prepared from at least one of polyglycerol-10 stearate, polyglycerol-10 oleate, polyglycerol-10 palmitate, polyglycerol-10 myristate and polyglycerol-10 distearate; the structuring agent comprises a cellulose substance and potassium ascorbyl phosphate tocopheryl ester. The sunscreen microcapsule coating composition disclosed by the invention can be used for better coating the sunscreen agent and reducing the residue of the sunscreen agent on the skin, and is good in stability at the same time.

Description

Technical Field

[0001] This invention provides a safe sunscreen microcapsule encapsulation composition, a sunscreen microcapsule encapsulation method, a cosmetic product, and its application, belonging to the field of cosmetic technology. Background Technology

[0002] Encapsulation technology for sunscreens, as an optimization solution to improve the safety and skin feel of sunscreen products, currently offers various technical approaches, such as silicone-based encapsulation, liposome encapsulation, microemulsion encapsulation, and polymer encapsulation. These methods can prevent sunscreens from being directly exposed to the skin, change particle size, adjust the skin feel, and alter the film formation and retention patterns on the surface. This results in a uniform and dense sunscreen film on the skin's surface, while preventing penetration, thus achieving better sun protection performance, safety, and user experience.

[0003] Although there are different types of sunscreen encapsulation technologies and solutions available today, they still have various drawbacks in terms of application. For example, silicone-based encapsulation ingredients, while offering good skin feel and encapsulation stability, have limited sunscreen encapsulation capacity, resulting in high costs and poor compatibility in practical applications.

[0004] For example, liposome encapsulation has a low encapsulation amount, and the compatibility and stability of the formulation are limited. Overall, current technologies are basically unable to meet the comprehensive product requirements in terms of stability, compatibility, safety, and skin feel.

[0005] Chinese patent CN117695169A discloses a liposome containing a strong electrolyte skincare ingredient, composed of the following components by weight percentage: 0.1-10% potassium ascorbate phosphate, 1-10% lecithin or hydrogenated lecithin, 0.1-10% skincare ingredient, 20-60% cosolvent, and the balance being deionized water. This invention solves the technical problem of poor transdermal absorption of skincare ingredients, and the resulting liposomes are convenient to use, have good stability, and provide good transdermal absorption of the strong electrolyte skincare ingredient. However, this invention promotes the absorption of skincare ingredients and does not act as a barrier against sunscreens.

[0006] Chinese patent CN120225161A discloses a core-shell microcapsule comprising a core and a shell. The core contains at least one active ingredient, and the shell constitutes the wall surrounding the core and accounts for at least 20% of the total mass of the microcapsule. The shell of the microcapsule contains at least one crosslinked polymer, preferably obtained through interfacial polymerization. The size of the microcapsule is preferably less than 1 μm. The active ingredient can be a sunscreen. The shell contains at least one anionic surfactant and / or at least one nonionic surfactant. The anionic surfactant can be hydrogenated lecithin, and the nonionic surfactant can be sucrose palmitate. However, experiments have shown that even with only sucrose palmitate and lecithin, the sunscreen can still penetrate the skin in large quantities, leaving residues. Summary of the Invention

[0007] The purpose of this invention is to provide:

[0008] A safe sunscreen microencapsulation composition, microencapsulation method, cosmetic and application thereof, and related technologies thereof, to solve technical problems such as better encapsulation of sunscreen agents and reduction of sunscreen agent residue on the skin, or combinations thereof.

[0009] Terminology Explanation: Unless otherwise defined, all technical terms used herein have the same meanings as commonly understood by one of ordinary skill in the art to which the subject matter pertains. Unless otherwise stated, all patents, patent inventions, and publications cited throughout this document are incorporated herein by reference in their entirety. Where multiple definitions exist for terms, the definitions provided in this chapter shall prevail.

[0010] It should be understood that the above brief description and the following detailed description are exemplary and for illustrative purposes only, and do not limit the subject matter of the invention in any way. In this invention, the singular is used in conjunction with the plural unless otherwise specifically stated. It should also be noted that, unless otherwise stated, the use of “or” or “or” means “and / or”. Furthermore, the use of the term “comprising” and other forms such as “including,” “containing,” and “contains” are not limiting.

[0011] The definitions of standard chemical terms can be found in the reference "Cosmetic Safety Technical Specifications (2015 Edition)".

[0012] Unless specifically defined herein, the use of all commercially available products herein employs standard techniques. For example, it may be carried out using the manufacturer's instructions for use with the kit, or in accordance with methods known in the art or the description of this invention. The techniques and methods described herein can generally be implemented according to conventional methods well known in the art, based on the descriptions in the various summary and more specific documents cited and discussed in this specification.

[0013] In a first aspect, the present invention provides: a safe sunscreen microcapsule encapsulation composition, comprising: an encapsulation medium, a co-encapsulation agent, and a structural agent; wherein the encapsulation medium is lecithin; the co-encapsulation agent comprises at least one selected from polyglycerol-10 stearate, polyglycerol-10 oleate, polyglycerol-10 palmitate, polyglycerol-10 myristate, polyglycerol-10 distearate, and sucrose palmitate; and the structural agent comprises a cellulose-based substance and potassium ascorbate phosphate tocopheryl ester.

[0014] Furthermore, the mass ratio of the coating medium, the co-coating agent, and the structural agent is (1-4):(1-8):(1-5).

[0015] Preferably, the mass ratio of the coating medium, the co-coating agent, and the structural agent is 1:8:2, 4:1:4.1, 3:4:3.5, 2:5:2.3, 2.5:3:3.6, or any combination thereof.

[0016] Furthermore, the mass ratio of the cellulose material to potassium ascorbate phosphate is (1-4):(0.1-1).

[0017] Furthermore, the mass ratio of the cellulose material to potassium ascorbate phosphate is within the range of 1:1, 4:0.1, 3:0.5, 2:0.3, 3:0.6, or any combination thereof.

[0018] Furthermore, lecithin includes at least one of soybean lecithin, egg yolk lecithin, and hydrogenated lecithin.

[0019] Furthermore, the cellulose-based material includes at least one of hydroxyethyl cellulose, hydroxypropyl methyl cellulose, sodium carboxymethyl cellulose, hydroxypropyl cellulose, ethyl cellulose, cellulose, and microcrystalline cellulose.

[0020] Further, by weight, the sunscreen microcapsule encapsulation composition comprises: 1-4 parts encapsulation medium, 1-8 parts encapsulation aid and 1-5 parts structuring agent.

[0021] Secondly, the present invention provides a microencapsulation method, comprising the following steps: (1) Mix the substance to be coated with the coating medium and the coating agent evenly and disperse them evenly to obtain a dispersion; (2) Add a structural agent to the dispersion and complete the coating by high pressure microjets.

[0022] Furthermore, the mass ratio of the substance to be coated, the coating medium, the co-coating agent and the structural agent is (0.1-50):(1-4):(1-8):(1-5).

[0023] Preferably, the mass ratio of the substance to be coated, the coating medium, the co-coating agent and the structural agent is 20:1:8:2, 20:4:1:4.1, 50:3:4:3.5, 20:2:5:2.3, 20:2.5:3:3.6 or any combination thereof.

[0024] Thirdly, the present invention provides the application of a safe sunscreen microencapsulation composition in cosmetics.

[0025] Furthermore, the cosmetic product is a cosmetic product containing sun protection.

[0026] Fourthly, the present invention provides: a cosmetic product, which uses the aforementioned sunscreen microcapsule encapsulation composition and is encapsulated by a microcapsule encapsulation method.

[0027] Furthermore, the cosmetic product is a cosmetic product containing sun protection.

[0028] Furthermore, the cosmetic with the sun protection effect also includes solvents, preservatives, sunscreens, and cosmetic-acceptable additives.

[0029] Furthermore, the sunscreen agent includes chemical sunscreen agents and physical sunscreen agents.

[0030] Preferably, the chemical sunscreen agent comprises at least one of the following: ethylhexyl methoxycinnamate, butyl methoxydibenzoylmethane, octocrylene, benzophenone-3, benzophenone-4, ethylhexyl salicylate, diethylaminohydroxybenzoylhexyl benzoate, bis-ethylhexyloxyphenol methoxyphenyl triazine, p-methoxycinnamate, cresoltrazolium trisiloxane, polysiloxane-15, terephthalimide dicamphor sulfonic acid, ethylhexyl triazine ketone, diethylhexylbutyrylaminotriazine ketone, phenylbenzimidazole sulfonic acid, methylene bis-benzotriazolyl tetramethylbutylphenol, and homosalate.

[0031] Preferably, the physical sunscreen agent includes zinc oxide and titanium dioxide.

[0032] Furthermore, the sunscreen microcapsule encapsulation composition and microcapsule encapsulation method of the present invention are applicable to the types of sunscreens described in the "Cosmetic Safety Technical Specifications".

[0033] Furthermore, the microcapsules in the cosmetic have a particle size of 100-1000 nm.

[0034] Preferably, the microcapsules in the cosmetic have a particle size of 200-500 nm.

[0035] The beneficial effects of this invention are as follows: This invention achieves high-content coating of sunscreen agents through a high-pressure microfluidic process. In the composition of this invention, lecithin forms a preliminary multi-layer bilayer coating effect, effectively coating the sunscreen agent. The particle size of the coating is controlled by combining the coating agent and lecithin, while simultaneously improving the structural stability of the phospholipid coating.

[0036] Potassium ascorbate tocopheryl phosphate inserts a negative charge into the phospholipid bilayer, enhancing the mutual repulsion between the bilayers and improving the long-term stability of the structure. Simultaneously, the combination of lecithin and potassium ascorbate tocopheryl phosphate can regulate the outer charge structure of the coating, creating a better mutual repulsion effect with the negative charge on the skin surface and preventing the penetration of sunscreen agents.

[0037] Cellulose substances in the structural agent can form a three-dimensional network structure. The modified three-dimensional network structure is effectively compatible with the particle size after coating, further improving the structural stability and surface rigidity of the outer coating layer, while effectively reducing the long-term agglomeration of the granules. Attached Figure Description

[0038] Figure 1 The particle size distribution diagrams are for application examples 1-4 of the present invention.

[0039] Figure 2 The figure shows the results of the stability experiment. Detailed Implementation

[0040] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following content is merely an exemplary description of the scope of protection claimed by the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, and such changes should also fall within the scope of protection claimed by the present invention.

[0041] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all instruments, devices, equipment, reagents, products, etc., used in the embodiments of the present invention are obtained through conventional commercial means.

[0042] I. A safe sunscreen microencapsulation composition Examples 1-5 of this invention are safe sunscreen microencapsulation compositions, and Comparative Examples 1-7 are comparative experiments of Example 3. Their formulations are shown in Tables 1, 2 and 3.

[0043] Table 1 (parts by weight)

[0044] Table 2

[0045] Table 3

[0046] Note: The types of raw materials used in Comparative Examples 1-7 are the same as those in Example 3; Example: Replace potassium ascorbate phosphate with vitamin C and vitamin E in a 1:1 mass ratio.

[0047] II. A microencapsulation method Taking sunscreen microencapsulation as an example, the sunscreen includes: sunscreen agent, oil, polyol, sunscreen microencapsulation composition, preservative and water. The composition and mass percentage are shown in Table 4.

[0048] The sunscreen microcapsule encapsulation compositions are respectively Examples 1-5 and Comparative Examples 1-7, and the sunscreens obtained after encapsulation are referred to as Application Examples 1-5 and Application Comparative Examples 1-7.

[0049] Includes the following steps: (1) Heat the sunscreen, oil, coating medium and co-coating agent to 55°C and mix them evenly to obtain mixture A; (2) Mixture A is stirred with water and polyol, heated to 60°C and mixed evenly to obtain mixture B; (3) Mixture B was subjected to high-pressure homogenization (homogenization pressure 80MPa, homogenization times 3 times, homogenization temperature 50℃) to obtain a dispersion; (4) Add a structural agent to the dispersion and coat it with a high-pressure microjet (pressure 50MPa, number of times 2, temperature 60℃). Add a preservative and mix evenly to obtain the final product.

[0050] The sunscreens used in Application Examples 1-5 are shown in Table 4, and the sunscreens used in Comparative Examples 1-7 are the same as those used in Application Example 3.

[0051] Table 4

[0052] Note: The percentage content in Table 4 is the mass percentage content of the substance in the application examples.

[0053] The preservatives used in Application Examples 1-5 and Application Comparative Examples 1-7 were phenoxyethanol and ethylhexylglycerin in a mass ratio of 9:1.

[0054] Application Comparative Example 8 The difference from Application Example 3 is that the structural agent is added in step (1).

[0055] Application Examples 1-5 and Comparative Examples 1-8 of this invention are not the final sunscreen products, but rather one of the raw material components in the preparation of sunscreen products. The preparation of sunscreen products also includes one or more components selected from emulsifiers, thickeners, emollients, film-forming agents, fragrances, and preservatives. Application Examples 1-5 and Comparative Examples 1-8 were added according to the requirements of sunscreen products and the content specified in the "Cosmetic Safety Technical Specifications".

[0056] III. Detection Examples 1. Skin permeability (1) Using isolated pig abdominal skin, the experiment was conducted according to the method described in GB / T 27818-2011 In vitro test method for skin absorption of chemicals.

[0057] Experimental Methods: Before the experiment, the integrity of the skin barrier was checked using a moisture evaporation rate meter. A TK-24BL transdermal diffusion cell was used, with isolated porcine abdominal skin fixed between the drug delivery and receiving cells. The effective permeation area of ​​the diffusion cell was 2.80 cm². 2 The stratum corneum faces the supply chamber, while the dermis side contacts the receiving solution to remove air bubbles. The receiving solution is physiological saline.

[0058] Eight hours later, the pig skin was removed, pulped, centrifuged, and the supernatant was used to detect the amount of sunscreen residue in the skin by LC-MS / MS.

[0059] Experimental Groups: The experimental group consisted of 13 groups, with samples representing Application Examples 1-5 and Comparative Examples 1-8, respectively. The coating amount was 2 mg / cm³. 2 .

[0060] Reference Groups: The reference groups are divided into Reference Group 1 to Reference Group 5. The samples were prepared using the same methods as Application Examples 1-5, except that they did not contain the corresponding sunscreen microcapsule-encapsulated compositions. Reference Group 3 was used for Comparative Examples 1-8. The coating amount of the reference groups was consistent with that of the corresponding application examples, where the amount of sunscreen applied to the skin was the same.

[0061] The experimental results are shown in Table 5.

[0062] Table 5 (Unit: μg / g)

[0063] Application examples 1-5 of the present invention have a good coating effect on various sunscreens, reducing sunscreen residue on the skin by 38%-59%.

[0064] Comparative Example 1 changed the dosage relationship of the sunscreen microcapsule coating composition. Comparative Examples 2-5 and Comparative Example 7 adjusted the composition of the sunscreen microcapsule coating composition. Comparative Example 6 changed the dosage relationship of the structural agent. Comparative Example 8 adjusted the order of addition of the structural agent. The skin residue of the sunscreen agent was increased compared with Comparative Example 3, and the reduction rate was only 11%-26%.

[0065] 2. Particle size distribution Dynamic light scattering (DLS) was used to detect the microcapsule particle size distribution in application examples 1-4 of the present invention.

[0066] Dynamic light scattering (DLS), also known as photon correlation spectroscopy (PCS), is based on the correlation between the Brownian motion of particles and the intensity fluctuations of scattered light. It calculates the particle diffusion coefficient using the Stokes-Einstein equation, thereby obtaining the equivalent spherical particle size and distribution. It is suitable for particle size analysis of colloidal / nanoparticles from 1 nm to 1000 nm (equivalent spherical particle size for non-spherical particles) and is a commonly used method for particle size characterization in nanomaterials, cosmetic raw materials, and biomedicine. This method follows a general operating procedure and can be adjusted appropriately according to sample properties and instrument model.

[0067] (1) Experimental principle Particles undergo random Brownian motion in the dispersion medium. The smaller the particle, the faster the Brownian motion rate, and the higher the fluctuation frequency of the scattered light intensity; conversely, the larger the particle, the lower the fluctuation frequency. The instrument calculates the particle diffusion coefficient (D) by detecting the time correlation function of the scattered light, and then uses the Stokes-Einstein equation: D=3πηdkT (where k is the Boltzmann constant, T is the absolute temperature, η is the viscosity of the dispersion medium, and d is the equivalent spherical particle size) to convert the particle size. At the same time, the particle size distribution curve is obtained by fitting the particle size distribution curve using algorithms (such as CONTIN, NNLS), and the polydispersity index (PDI) is used to evaluate the particle dispersibility.

[0068] (2) Test reagents and instruments Core Instruments Dynamic light scattering instrument: equipped with laser light source (633 nm), temperature control module (accuracy ±0.1℃), and multi-angle detection unit (90°); Matching cuvettes: Disposable polystyrene cuvettes (convenient and free from cross-contamination), which must be free of particles and have good light transmittance; Sample pretreatment equipment: ultrasonic cleaner (to disperse the sample), high-speed centrifuge (to remove large particulate impurities), 0.22μm filter membrane and filter (to filter the dispersion medium), pipette (100μL-5 mL), electronic analytical balance (accuracy 0.01 mg).

[0069] reagents Dispersion medium: Select a medium that is insoluble and non-reactive with the sample and can disperse the sample well, based on the properties of the sample. Commonly used media include deionized water, anhydrous ethanol, methanol, isopropanol, and buffer solution (PBS). The medium must be particle-free and should be vacuum filtered through a 0.22μm filter membrane before use to remove background particles. Sample: Must be dry and free of large particle agglomerates; (3) Preparation before the experiment Instrument warm-up: Turn on the DLS instrument and warm up for more than 30 minutes to allow the laser source, temperature control module and detector to reach a stable state. At the same time, set the test temperature (25℃). Dispersion medium preparation: Filter the selected dispersion medium using a suitable filter membrane, pack it into a clean sample vial, and seal it for later use; Cuvette preparation: Disposable cuvettes can be used directly; reusable quartz cuvettes should be rinsed with acetone for 10 minutes, rinsed with ultrapure water 3 times, and dried with nitrogen to avoid residual impurities. Blank verification: Take the filtered pure dispersion medium, add it to a cuvette and perform a blank test. Confirm that the average particle size of the blank is much smaller than that of the sample to be tested, and that the scattered light intensity signal is low (without obvious background particle interference). Otherwise, filter the dispersion medium again.

[0070] (4) Sample preparation DLS has extremely high requirements for sample concentration and dispersibility. Excessive concentration will result in multiple scattering (leading to overly high results), while insufficient concentration will result in weak scattered light signals (unstable data). Aggregates will lead to a wide particle size distribution and an overly high PDI, necessitating strict control of the preparation process. Determine sample concentration: Dilute liquid samples to 1 mg / mL; Weighing and Dispersion: Accurately weigh the solid sample to be tested using an electronic balance, add it to a clean centrifuge tube, add the filtered dispersion medium according to the calculated concentration, and pipette 20 times to initially disperse it; 3. Ultrasonic dispersion: Place the centrifuge tubes in an ultrasonic cleaner (50 W) or an ultrasonic cell disruptor (200 W, gentle mode) and sonicate for 10 min; 4. Removal of large particles: After sonication, if the sample has obvious large particles / agglomerates, centrifuge at low speed (3000 r / min, 10 min) and filter, and take the supernatant / filtrate as the sample to be tested (to avoid filtering out the target particles through the filter membrane). 5. Remove air bubbles: If there are air bubbles after sample preparation, let it stand for 5 minutes, or gently tap the side wall of the cuvette to let the air bubbles escape (air bubbles will produce strong scattering, which will seriously interfere with the data).

[0071] Experimental results are as follows Figure 1 .

[0072] The particle size distribution range of the present invention is 100-1000nm, preferably 200-500nm.

[0073] 3. Stability test Experimental sample: Application Example 3.

[0074] The experiment includes: ① Experiment 1: Six thermal shock stability tests were conducted at -10℃ and 48℃, with one cycle every 24 hours and a humidity of 50%.

[0075] ② Experiment 2: A one-month low-temperature stability test was conducted at -10℃ (50% humidity). ③ Experiment 3: A high-temperature stability test was conducted at 48℃ for one month (50% humidity). ④ Experiment 4: Load the sample into two centrifuge tubes and centrifuge at 5000 rpm for 30 minutes to test the stability.

[0076] Experimental results are as follows Figure 2 In the third application embodiment of the present invention, the state is stable under alternating hot and cold, high temperature, low temperature and centrifugal conditions.

[0077] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, and is not intended to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions made by those skilled in the art to the technical solution of the present invention do not depart from the essence and scope of the technical solution of the present invention.

Claims

1. A safe sunscreen microencapsulation composition, characterized in that, include: Coating media, co-coating agents, and structuring agents; The coating medium is lecithin; The coating agent comprises at least one of the following: polyglycerol-10 stearate, polyglycerol-10 oleate, polyglycerol-10 palmitate, polyglycerol-10 myristate, polyglycerol-10 distearate, and sucrose palmitate; The structural agents include cellulose-based substances and potassium ascorbate phosphate tocopherol ester.

2. The sunscreen microcapsule coating composition according to claim 1, characterized in that, The mass ratio of the coating medium, the co-coating agent and the structural agent is (1-4):(1-8):(1-5).

3. The sunscreen microcapsule encapsulation composition according to claim 1, characterized in that, The mass ratio of the cellulose material to potassium ascorbate phosphate is (1-4):(0.1-1).

4. The sunscreen microcapsule coating composition according to claim 1, characterized in that, The lecithin includes at least one of soybean lecithin, egg yolk lecithin, and hydrogenated lecithin.

5. The sunscreen microcapsule coating composition according to claim 1, characterized in that, The cellulose-based substances include at least one of the following: hydroxyethyl cellulose, hydroxypropyl methyl cellulose, sodium carboxymethyl cellulose, hydroxypropyl cellulose, ethyl cellulose, cellulose, and microcrystalline cellulose.

6. A microencapsulation method, characterized in that, Includes the following steps: (1) Mix the substance to be coated with the coating medium and the coating agent evenly and disperse them evenly to obtain a dispersion; (2) Add a structural agent to the dispersion and complete the coating by high pressure microjets.

7. The microencapsulation method according to claim 6, characterized in that, The mass ratio of the substance to be coated, the coating medium, the co-coating agent and the structural agent is (0.1-50):(1-4):(1-8):(1-5).

8. The use of the sunscreen microencapsulation composition according to any one of claims 1-5 in cosmetics.

9. A cosmetic product, characterized in that, It includes the sunscreen microcapsule encapsulation composition according to any one of claims 1-5 and / or obtained by encapsulation by the microcapsule encapsulation method according to any one of claims 6-7.

10. The cosmetic product according to claim 9, characterized in that, The microcapsules in the cosmetic product have a particle size of 100-1000 nm.

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