A sunscreen composition, method of making and use thereof

Abstract

The present application relates to the technical field of cosmetic preparation, in particular to a sunscreen composition and a preparation method thereof.The sunscreen composition has moderate hardness, is not easy to break, does not ooze out at high temperature, and is convenient to carry and use.Through the synergistic effect of microsphere particles, free sunscreen agents, sunscreen enhancers and other components, the composition has high SPF and PFA values, realizes full-band protection of UVA, UVB, HEV and IRA, improves skin barrier function, enhances water-locking and moisturizing capacity, reduces skin damage caused by ultraviolet rays, and prevents photoaging.

Description

Technical Field

[0001] This invention relates to the field of cosmetic preparation technology, specifically to a sunscreen composition and its preparation method. Background Technology

[0002] As people pay increasing attention to skin health, sun protection has become an important part of daily skin care. Long-term exposure to UVA and UVB rays can cause serious damage to the skin, such as sunburn, tanning, accelerated aging, and even increasing the risk of skin cancer. In recent years, with in-depth research, it has been found that HEV (blue light) and IRA (near-infrared light) can also have adverse effects on the skin, such as causing pigmentation and damaging skin cell structure.

[0003] Currently, various sunscreen products exist on the market. For example, CN102302417A discloses a sunscreen lotion that primarily achieves protection against UVA and UVB by adding specific organic and inorganic sunscreen agents. However, this product is significantly insufficient in protecting against HEV and IRA, failing to meet the needs of modern consumers for full-spectrum protection. Additionally, CN110251406A discloses a sunscreen spray, which, while offering some advantages in ease of use, is prone to nozzle clogging and uneven spraying in high-temperature environments, and its effect on improving skin barrier function is poor.

[0004] Furthermore, many sunscreen products suffer from inconvenient packaging or restrictions on carrying them on public transportation. For example, traditional bottled sunscreens are bulky and inconvenient to carry during travel or outdoor activities, while some sunscreen sprays, due to their pressurized can design, may be restricted when using public transportation such as airplanes. Additionally, the texture of existing sunscreen products needs improvement; some products leave a greasy, heavy feeling or cause skin irritation after application, affecting the consumer experience.

[0005] In conclusion, developing a sunscreen product that provides full-spectrum protection, has a pleasant feel on the skin, is easy to carry, and enhances the skin barrier function is of significant practical importance. Summary of the Invention

[0006] The purpose of this invention is to provide a sunscreen composition that is easy to carry and use, and can provide effective protection against UVA, UVB, HEV and IRA across the entire spectrum, solving the technical problems of existing sunscreen products such as being greasy and heavy, having an unpleasant skin feel, and not being effective in improving the skin barrier function.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A sunscreen composition comprising, by weight percentage: 20%-40% oils, 5%-20% waxes, 5%-20% emollients, 1%-3% preservatives, 4%-10% vitamin E, 3%-8% skin conditioning agents, 5%-15% sunscreen agents, 1%-4% sunscreen enhancers, and 0.5%-2% fragrance; wherein the sunscreen agent comprises microspheres and free sunscreen agents, and the microspheres are loaded with sunscreen ingredients.

[0009] As a preferred embodiment, the oil is one or more of olive oil, jojoba oil, and meadowfoam seed oil; the emollient is one or more of glycerin and propylene glycol.

[0010] As a preferred embodiment, the wax is one or more of beeswax, carnauba wax, and candelilla wax; the preservative is one or more of phenoxyethanol and methylparaben; and the skin conditioning agent is bisabolol.

[0011] Furthermore, the free sunscreen agent is selected from organic sunscreen agents and / or inorganic sunscreen agents. Specifically, the organic sunscreen agent is one or more of ethylhexyl methoxycinnamate and octocrylene, and the inorganic sunscreen agent is one or more of nano-titanium dioxide and nano-zinc oxide.

[0012] To further improve the sun protection performance of the composition, the weight ratio of organic sunscreen to inorganic sunscreen in the free sunscreen is preferably 1:0.5-2.

[0013] Furthermore, the sun protection enhancer is one or more of marigold extract, calendula extract, kale extract, and blueberry extract.

[0014] The sunscreen enhancer of this invention contains a specific chemical structure that can absorb the energy of HEV and IRA. For example, carotenoids with conjugated double bond systems have absorption peaks in the blue and near-infrared light regions. The conjugated double bonds in their molecules can absorb photon energy through electronic transitions, converting light energy into other forms of energy such as heat energy, thereby reducing the dose of harmful light reaching the skin.

[0015] As a preferred embodiment, the sunscreen composition of the present invention comprises the following components by weight percentage: 35%-40% oils, 14%-18% waxes, 16%-20% emollients, 1%-2% preservatives, 6%-8% vitamin E, 3%-5% skin conditioning agents, 9%-13% sunscreen agents, 2%-3% sunscreen enhancers, and 1%-2% fragrance.

[0016] As a preferred embodiment, the sunscreen composition of the present invention comprises the following components by weight percentage:

[0017] Phase A: Oils 35%-40%, emollients 16%-20%, microspheres 2%-6%;

[0018] Phase B: Wax 14%-18%, Preservatives 1%-2%;

[0019] Phase C: 4%-8% free sunscreen, 6%-8% vitamin E;

[0020] Phase D: 3%-5% skin conditioning agents, 2%-3% sun protection enhancers, and 1%-2% fragrance.

[0021] The preparation method of the sunscreen composition of the present invention includes the following steps: adding phase A raw material to an emulsifying pot, heating to 40-50°C, and homogenizing at a speed of 500-1000 rpm for 5-10 minutes to make it evenly mixed; adding phase B raw material and stirring for 15-20 minutes until completely dissolved; cooling to 30-40°C, adding phase C raw material and stirring for 10-15 minutes; cooling to below 30°C, adding phase D raw material and stirring for 5-10 minutes; cooling to room temperature, and after checking for any abnormalities, discharging and filling.

[0022] The method for preparing microspheres includes the following steps:

[0023] An appropriate amount of polylactic acid was added to ethyl acetate and stirred at room temperature to disperse it evenly. Ethylhexyl methoxycinnamate, a sunscreen agent, was slowly added to the polymer solution and stirred until evenly dispersed to obtain an oil phase. An appropriate amount of sodium dodecyl sulfate was dissolved in deionized water and stirred until evenly dispersed to obtain an aqueous phase. The oil phase was slowly added dropwise to the aqueous phase, and emulsification was carried out under high-speed stirring to form an emulsion. The organic solvent was removed by rotary evaporation to obtain a microsphere suspension. After centrifugation, the suspension was washed with deionized water and vacuum dried to obtain microspheres loaded with the sunscreen agent.

[0024] The above preparation method can yield microspheres loaded with sunscreen agents with uniform particle size, stable loading rate, and good photoprotective properties. These microspheres are suitable for the preparation of sunscreen compositions and can effectively improve the performance and stability of sunscreen products.

[0025] The sunscreen composition of the present invention can be used to prepare cosmetics. It has the characteristics of moderate softness and hardness, not easy to break, and no oil production at high temperatures. Therefore, it is particularly suitable for preparing stick-shaped cosmetics.

[0026] The beneficial effects of this invention are as follows: The sunscreen composition of this invention has a moderately soft and firm consistency, is not easily broken, does not produce oil at high temperatures, and is convenient to carry and use. Through the synergistic effect of components such as microspheres, free sunscreen agents, and sun protection enhancers, the composition can achieve high SPF and PFA values, providing full-band protection against UVA, UVB, HEV, and IRA, improving skin barrier function, enhancing water retention and moisturizing ability, reducing skin damage caused by ultraviolet rays, and preventing photoaging. The preparation method of the composition of this invention is simple to operate, mild, and highly efficient, suitable for large-scale production, with low production costs, which is conducive to the promotion and application of the product. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The specific embodiments described below further illustrate the present invention.

[0028] According to the specific substances and weight percentages of each component shown in Table 1, the preparation method of the sunscreen compositions in Examples 1-5 includes the following steps: Add the raw material of phase A to the emulsification pot, heat to 45°C, and homogenize at 700 rpm for 10 minutes to make it evenly mixed; add the raw material of phase B and stir for 15 minutes until completely dissolved; cool down to 35°C, add the raw material of phase C and stir for 15 minutes; cool down to below 30°C, add the raw material of phase D and stir for 8 minutes; cool down to room temperature, check for any abnormalities, and then discharge and fill the product.

[0029] The method for preparing microspheres includes the following steps:

[0030] An appropriate amount of polylactic acid was added to ethyl acetate and stirred at room temperature to disperse it evenly. Ethylhexyl methoxycinnamate, a sunscreen agent, was slowly added to the polymer solution and stirred until evenly dispersed to obtain an oil phase. An appropriate amount of sodium dodecyl sulfate was dissolved in deionized water and stirred until evenly dispersed to obtain an aqueous phase. The oil phase was slowly added dropwise to the aqueous phase, and emulsification was carried out under high-speed stirring to form an emulsion. The organic solvent was removed by rotary evaporation to obtain a microsphere suspension. After centrifugation, the suspension was washed with deionized water and vacuum dried to obtain microspheres loaded with the sunscreen agent.

[0031] The sunscreen composition prepared by the above method is a paste with a moderately soft and hard texture, which is not easily broken and does not produce oil at high temperatures of 30-40℃.

[0032] Table 1

[0033]

[0034] Sunscreen performance test

[0035] The SPF (Sun Protection Factor) test method involves applying a certain amount of test sample to the subject's skin. Using a xenon arc lamp, ultraviolet light in the 290nm-320nm range is applied to the skin area with the sample and adjacent untreated skin areas. The minimum irradiation time (MED) required for erythema to appear on the skin is observed after irradiation. The SPF value is calculated by dividing the MED required for erythema on protected skin to the MED required for erythema on unprotected skin. A total of 50 subjects were tested and divided into 5 groups. The final SPF value was the average of the SPF values ​​from all groups.

[0036] The PFA (Protection Factor of UVA) test method involves applying a certain amount of test sample to the subject's skin. Using a xenon arc lamp, ultraviolet light in the 320nm-400nm range is applied to the skin area with the sample and adjacent untreated skin areas. After irradiation, the minimum irradiation time required to produce slight darkening (i.e., minimum sustained darkening dose, MPPD) is observed on the skin. The PFA value is obtained by calculating the ratio of the MPPD required to cause darkening in the protected skin to the MPPD required to cause darkening in the unprotected skin. A total of 50 subjects were tested and divided into 5 groups. The final PFA value was the average of the PFA values ​​from each group.

[0037] In addition, the absorbance of the sunscreen compositions of Examples 1-5 in different wavelength bands of UVA, UVB, HEV and IRA was determined by spectrophotometry, and the test results are shown in Table 2.

[0038] Table 2

[0039]

[0040] As can be seen from the test data in Table 2, the sunscreen compositions of Examples 1-5 have high SPF and PFA values, and exhibit excellent absorption performance in the UVA, UVB, HEV, and IRA bands, indicating that the sunscreen compositions of the present invention have excellent all-band protection capabilities.

[0041] Existing sunscreen ingredients are mainly divided into organic and inorganic sunscreens. Organic sunscreens primarily work by absorbing the energy of ultraviolet (UV) rays and releasing it as heat or harmless visible light, thus preventing UV damage to the skin. Generally, organic sunscreens offer relatively narrower wavelength protection. For example, ethylhexyl methoxycinnamate absorbs UVB rays (290-320nm), while octocrylene primarily protects against UVA rays (320-340nm). Inorganic sunscreens, on the other hand, mainly work by reflecting and scattering UV rays, providing broader wavelength protection against both UVA and UVB. Combining organic and inorganic sunscreens in specific ratios can achieve an even wider range of protection, and the synergistic effect of multiple sunscreens results in a higher level of protection. Example 2 contains only organic sunscreen agents, and Example 3 contains only inorganic sunscreen agents. It can be seen that Example 3 has a slightly better overall sun protection effect than Example 2, and Example 3 has a greater advantage in UVA protection. Examples 1 and 4 contain both organic and inorganic sunscreen agents, and their overall sun protection effect and protection effect across different wavelengths are superior to Examples 2 and 3. Example 5 also contains both organic and inorganic sunscreen agents, but the amount of organic sunscreen agent is greater than that of inorganic sunscreen agent. This ratio may prevent the free sunscreen agents from having a significant synergistic effect, resulting in a significant decrease in the sun protection performance of Example 5, with lower protection capabilities across different wavelengths than the sunscreen compositions of Examples 2 and 3.

[0042] Table 3

[0043]

[0044] Comparative Examples 1-6 were prepared according to the specific substances and weight percentages of each component shown in Table 3, using the same preparation method as above. The sun protection properties of the compositions of Comparative Examples 1-6 were tested using the same method described above, and the results are listed in Table 4.

[0045] Table 4

[0046]

[0047] Comparative Example 1 omitted the microspheres from Example 4 and supplemented the remaining amount with free sunscreen; Comparative Example 3 omitted the free sunscreen from Example 4 and supplemented the remaining amount with microspheres. It can be seen that the sunscreen effect of both examples is significantly lower than that of Example 4, indicating that the microspheres loaded with sunscreen ingredients and the free sunscreen have good synergistic properties, and the simultaneous addition of both to the system can achieve a significantly better sunscreen effect.

[0048] Comparative Example 2 omits the sunscreen enhancer from Example 4 and uses a free sunscreen agent to make up the difference. The sunscreen enhancer of this invention is a plant extract with certain sun protection functions, but its overall sun protection performance is generally difficult to match that of common chemical sunscreens. However, when the sunscreen enhancer in the composition of this invention is replaced with an equal amount of free sunscreen agent, the sun protection performance of the composition decreases to some extent. However, the decrease in absorbance in the HEV and IRA bands is significantly less than in other bands, indicating that the sunscreen enhancer can further improve the sun protection performance in this invention, especially exhibiting significant absorption capacity in the HEV and IRA bands, which is of great importance for achieving full-spectrum protection of the sunscreen composition.

[0049] Comparative Example 4 increased the amount of sunscreen enhancer compared to Example 4, while correspondingly reducing the amount of oil. It can be seen that further increasing the amount of sunscreen enhancer did not result in better sun protection, possibly because the change in the component ratio in the composition made it difficult for each sunscreen ingredient to achieve its optimal performance. Meanwhile, the test results in Table 4 show that although the sun protection performance of Comparative Example 4 is not as good as that of Example 4, it still has better sun protection performance than other comparative examples. This indicates that the sunscreen enhancer mainly plays an auxiliary role in the overall sun protection performance of the system in this invention, improving the composition's full-spectrum sun protection capability by absorbing HEV and IRA bands.

[0050] Comparative Example 5 increased the amount of free sunscreen agent and correspondingly reduced the amount of microspheres compared to Example 4. Comparative Example 6 increased the amount of microspheres and correspondingly reduced the amount of free sunscreen agent compared to Example 4. Due to the lack of suitable component ratios, the sun protection performance of the compositions in Comparative Examples 5 and 6 was not outstanding.

[0051] One hundred and ten volunteers with similar skin conditions were randomly divided into 11 groups. The sunscreen compositions of Examples 1-5 and Comparative Examples 1-6 were applied to the inner arms of the volunteers. Volunteers rated the oiliness, heaviness, and irritation of the products at 0.5 hours, 2 hours, and 4 hours after application, using a rating scale of 1-5, where 1 indicates no sensation and 5 indicates a very strong sensation. The average result for each group was taken. The test results are shown in Table 5.

[0052] Table 5

[0053]

[0054] The skin feel test results show that the sunscreen compositions of Examples 1-5 scored significantly lower than those of Comparative Examples 1-6 in terms of greasiness, heaviness, and irritation, indicating that the sunscreen compositions of the present invention have a better skin feel.

[0055] One hundred and ten volunteers with similar skin moisture content were randomly divided into 11 groups. The sunscreen compositions of Examples 1-5 and Comparative Examples 1-6 were applied to one side of the volunteers' face, with the other side serving as a blank control. The treatment was carried out continuously for seven days. The skin moisture content and transepidermal water loss rate were measured before and after use using a skin moisture meter and a transepidermal water loss meter, respectively. The final results for each group were averaged. The test results are shown in Table 6.

[0056] Table 6

[0057]

[0058] The skin barrier function test results show that the sunscreen compositions of Examples 1-5 significantly increased skin moisture content and significantly reduced transepidermal water loss after use, indicating that the sunscreen compositions of the present invention can effectively improve skin barrier function, while the improvement effect of Comparative Examples 1-6 is relatively weak.

[0059] It is evident that the synergistic effect of the microspheres loaded with sunscreen, the rational sunscreen agent, and the sunscreen enhancer in this invention can significantly improve the full-spectrum protection capability of the sunscreen composition, achieving full-spectrum protection against UVA, UVB, HEV, and IRA. Furthermore, the overall formulation of the composition is scientifically sound and reasonable, which, while ensuring excellent sun protection performance, can significantly improve skin barrier function, enhance water retention and moisturizing ability, reduce skin damage caused by ultraviolet rays, and prevent photoaging.

[0060] The above embodiments are preferred implementations of the present invention. In addition, the present invention can be implemented in other ways. Any obvious substitutions without departing from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A sunscreen composition, characterized in that, It includes the following components by weight percentage: Phase A: Oils 35%-40%, emollients 16%-20%, microspheres 2%-6%; Phase B: Wax 14%-18%, Preservatives 1%-2%; Phase C: 4%-8% free sunscreen, 6%-8% vitamin E; Phase D: 3%-5% skin conditioning agent, 2%-3% sun protection enhancer, 1%-2% fragrance; wherein, the microspheres are microspheres loaded with ethylhexyl methoxycinnamate; The sun protection enhancer is one or more of marigold extract, calendula extract, kale extract, and blueberry extract; The method for preparing microspheres includes the following steps: Polylactic acid was added to ethyl acetate and stirred at room temperature to disperse it evenly. Ethylhexyl methoxycinnamate was slowly added to the polymer solution and stirred to disperse it evenly to obtain an oil phase. An appropriate amount of sodium dodecyl sulfate was dissolved in deionized water and stirred to disperse it evenly to obtain an aqueous phase. The oil phase was slowly added dropwise to the aqueous phase and emulsified under high-speed stirring to form an emulsion. The organic solvent was removed by rotary evaporation to obtain a microsphere suspension. After centrifugation, the suspension was washed with deionized water and vacuum dried to obtain microspheres loaded with ethylhexyl methoxycinnamate.

2. The sunscreen composition according to claim 1, characterized in that, The oil is one or more of olive oil, jojoba oil, and meadowfoam seed oil; the emollient is one or more of glycerin and propylene glycol; the wax is one or more of beeswax, carnauba wax, and candelilla wax; the preservative is one or more of phenoxyethanol and methylparaben; and the skin conditioning agent is bisabolol.

3. The sunscreen composition according to claim 1, characterized in that, The free sunscreen agent is selected from organic sunscreen agents and / or inorganic sunscreen agents, wherein the organic sunscreen agent is octocrylene, and the inorganic sunscreen agent is one or more of nano titanium dioxide and nano zinc oxide.

4. The sunscreen composition according to claim 3, characterized in that, The weight ratio of organic to inorganic sunscreen agents in the free sunscreen agent is 1:0.5-2.

5. A method for preparing a sunscreen composition according to any one of claims 1-4, characterized in that, The process includes the following steps: Add phase A raw material to an emulsifying pot, heat to 40-50℃, and homogenize at 500-1000 rpm for 5-10 minutes to ensure uniform mixing; add phase B raw material and stir for 15-20 minutes until completely dissolved; cool to 30-40℃, add phase C raw material and stir for 10-15 minutes; cool to below 30℃, add phase D raw material and stir for 5-10 minutes; cool to room temperature, and after checking for any abnormalities, discharge and fill the product.

6. Use of the sunscreen composition according to any one of claims 1-4 in the preparation of cosmetics.

7. The use according to claim 6, characterized in that, The cosmetic product in question is a stick-shaped cosmetic product.

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