Sunscreen composition as well as preparation method and application thereof

Abstract

The invention relates to the technical field of cosmetic preparation, in particular to a sunscreen composition and a preparation method thereof. The sunscreen composition disclosed by the invention is moderate in pasty fluid hardness, not easy to break, free of oil at high temperature, and convenient to carry and use. Through the synergistic effect of the microsphere particles, the free sun-screening agent, the sun-screening enhancer and other components, the composition can have a high SPF value and a high PFA value, full-wave band protection on UVA, UVB, HEV and IRA is achieved, the skin barrier function is improved, the water locking and moisturizing capacity is enhanced, skin injuries caused by ultraviolet rays are reduced, and light aging is prevented.

Description

Technical Field

[0001] The present invention relates to the technical field of cosmetic preparation, and in particular to a sunscreen composition and a preparation method thereof. Background Art

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

[0003] There are many sunscreen products on the market. For example, CN102302417A discloses a sunscreen lotion, which mainly protects against UVA and UVB by adding specific organic and inorganic sunscreens. However, this product has obvious deficiencies in protecting against HEV and IRA, and cannot meet the needs of modern consumers for full-band protection. In addition, CN110251406A discloses a sunscreen spray, which has certain advantages in terms of ease of use, but is prone to nozzle clogging and uneven spray in high temperature environments, and its effect on improving the skin barrier function is not good.

[0004] In addition, many sunscreen products have problems such as inconvenient to carry or restricted by public transportation due to their dosage forms. For example, traditional bottled sunscreens are large in size and inconvenient to carry when traveling or doing outdoor activities, while some sunscreen sprays may be restricted when taking public transportation such as airplanes due to their pressure tank design. At the same time, the skin feel of existing sunscreen products needs to be improved. Some products feel greasy, heavy, or cause skin discomfort after application, affecting consumers' experience.

[0005] In summary, it is of great practical significance to develop a sunscreen product that can achieve full-band protection, has a good skin feel, is easy to carry and can enhance the skin barrier function. Summary of the invention

[0006] The purpose of the present invention is to provide a sunscreen composition that is easy to carry and use, can achieve effective protection against the full bands of UVA, UVB, HEV and IRA, and solve the technical problems that existing sunscreen products have poor skin feel such as greasy and heavy, and have no obvious effect on improving the skin barrier function.

[0007] To achieve the above object, the present invention adopts the following technical solutions: A sunscreen composition comprises the following ingredients by weight percentage: 20%-40% oil, 5%-20% wax, 5%-20% emollient, 1%-3% preservative, 4%-10% vitamin E, 3%-8% skin conditioner, 5%-15% sunscreen, 1%-4% sunscreen enhancer, and 0.5%-2% fragrance; wherein the sunscreen comprises microsphere particles and free sunscreen agent, and the microsphere particles are loaded with sunscreen ingredients.

[0008] As a preferred embodiment, the oil is one or more of olive oil, jojoba oil, and meadowfoam seed oil; and the emollient is one or more of glycerol and propylene glycol.

[0009] 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.

[0010] Furthermore, the free sunscreen is selected from organic sunscreen and / or inorganic sunscreen, wherein the organic sunscreen is one or more of ethylhexyl methoxycinnamate and octocrylene, and the inorganic sunscreen is one or more of nano titanium dioxide and nano zinc oxide.

[0011] In order to further improve the sunscreen performance of the composition, the weight ratio of the organic sunscreen to the inorganic sunscreen in the free sunscreen is preferably 1:0.5-2.

[0012] Furthermore, the sunscreen enhancer is one or more of marigold extract, calendula extract, kale extract, and blueberry extract.

[0013] The sunscreen enhancer of the present invention contains a specific chemical structure that can absorb the energy of HEV and IRA. For example, carotenoids with a conjugated double bond system have absorption peaks in the blue light and near-infrared light regions, and the conjugated double bonds in the molecules can absorb photon energy through electronic transitions, converting light energy into other forms of energy such as heat energy, thereby reducing the harmful light dose reaching the skin.

[0014] As a preferred embodiment, the sunscreen composition of the present invention comprises the following ingredients by weight percentage: 35%-40% oil, 14%-18% wax, 16%-20% emollient, 1%-2% preservative, 6%-8% vitamin E, 3%-5% skin conditioner, 9%-13% sunscreen, 2%-3% sunscreen enhancer, and 1%-2% fragrance.

[0015] As a preferred embodiment, the sunscreen composition of the present invention comprises the following components by weight percentage: Phase A: 35%-40% oil, 16%-20% emollient, 2%-6% microsphere particles; Phase B: wax 14%-18%, preservative 1%-2%; Phase C: free sunscreen 4%-8%, vitamin E 6%-8%; Phase D: skin conditioner 3%-5%, sunscreen enhancer 2%-3%, fragrance 1%-2%.

[0016] The preparation method of the sunscreen composition of the present invention comprises the following steps: adding a phase A raw material into an emulsifying pot, heating to 40-50° C., and homogenizing at a speed of 500-1000 rpm for 5-10 minutes to make the mixture uniformly mixed; adding a phase B raw material, and stirring for 15-20 minutes until the mixture is completely dissolved; cooling to 30-40° C., adding a phase C raw material, and stirring for 10-15 minutes; cooling to below 30° C., adding a phase D raw material, and stirring for 5-10 minutes; cooling to room temperature, and discharging and filling the mixture after checking that no abnormality is found.

[0017] The method for preparing microsphere particles comprises the following steps: An appropriate amount of polylactic acid is added to ethyl acetate, and the mixture is stirred at room temperature to be uniformly dispersed. The sunscreen agent ethylhexyl methoxycinnamate is slowly added to the above polymer solution, and the mixture is stirred and dispersed uniformly to obtain an oil phase. An appropriate amount of sodium dodecyl sulfate is dissolved in deionized water, and the mixture is stirred and dispersed uniformly to obtain an aqueous phase. The oil phase is slowly added dropwise to the aqueous phase, and emulsified under high-speed stirring to form an emulsion; the organic solvent is removed by rotary evaporation to obtain a microsphere suspension, which is washed with deionized water after centrifugation, and vacuum dried to obtain microsphere particles loaded with the sunscreen agent.

[0018] Through the above preparation method, microsphere particles loaded with sunscreen agent with uniform particle size, stable loading rate and good light protection performance can be obtained, which are suitable for the preparation of sunscreen compositions and effectively improve the performance and stability of sunscreen products.

[0019] The sunscreen composition of the present invention can be used to prepare cosmetics, and has the characteristics of moderate hardness and softness, not easy to break, and no oil release at high temperature, and is therefore particularly suitable for preparing stick-shaped cosmetics.

[0020] Beneficial effects of the present invention: The sunscreen composition paste of the present invention is moderately soft and hard, not easy to break, does not produce oil at high temperature, and is convenient to carry and use. Through the synergistic effect of components such as microsphere particles, free sunscreen agents, and sunscreen enhancers, the composition can have a higher SPF value and PFA value, achieve full-band protection against UVA, UVB, HEV, and IRA, improve skin barrier function, enhance water-locking and moisturizing ability, reduce skin damage caused by ultraviolet rays, and prevent photoaging. The preparation method of the composition of the present invention is simple to operate, mild conditions and high efficiency, suitable for large-scale production, low production cost, and conducive to the promotion and application of the product. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. The following specific implementation methods further describe the present invention.

[0022] According to the specific substances and weight percentages of each component shown in Table 1, the method for preparing the sunscreen composition of Examples 1-5 includes the following steps: adding the raw materials of phase A into an emulsifying pot, heating to 45°C, and homogenizing at a speed of 700 rpm for 10 minutes to mix them evenly; adding the raw materials of phase B, stirring for 15 minutes until they are completely dissolved; cooling to 35°C, adding the raw materials of phase C, and stirring for 15 minutes; cooling to below 30°C, adding the raw materials of phase D, and stirring for 8 minutes; cooling to room temperature, and discharging and filling after checking that there are no abnormalities.

[0023] The method for preparing microsphere particles comprises the following steps: An appropriate amount of polylactic acid is added to ethyl acetate, and the mixture is stirred at room temperature to be uniformly dispersed. The sunscreen agent ethylhexyl methoxycinnamate is slowly added to the above polymer solution, and the mixture is stirred and dispersed uniformly to obtain an oil phase. An appropriate amount of sodium dodecyl sulfate is dissolved in deionized water, and the mixture is stirred and dispersed uniformly to obtain an aqueous phase. The oil phase is slowly added dropwise to the aqueous phase, and emulsified under high-speed stirring to form an emulsion; the organic solvent is removed by rotary evaporation to obtain a microsphere suspension, which is washed with deionized water after centrifugation, and vacuum dried to obtain microsphere particles loaded with the sunscreen agent.

[0024] The sunscreen composition prepared by the above method is a paste with moderate hardness and softness, is not easy to break, and does not produce oil at a high temperature of 30-40°C.

[0025] Table 1 Sunscreen performance test The test method of SPF (Sun Protection Factor) is as follows: apply a certain amount of the test sample on the skin surface of the subject; use a xenon arc light source to irradiate the test skin area with the sample and the adjacent skin area without the sample with ultraviolet light of 290nm-320nm; observe the shortest irradiation time required for erythema to appear on the test skin after irradiation (i.e., the minimum erythema dose, MED); calculate the ratio of the MED required to cause erythema on the skin protected by the sample to the MED required to cause erythema on the unprotected skin to obtain the SPF value. A total of 50 subjects were tested and divided into 5 groups. The final SPF value was the average of the SPF values ​​of the subjects in each group.

[0026] The test method of PFA (Protection Factor of UVA) is as follows: a certain amount of the test sample is applied to the skin surface of the subject; a xenon arc light source is used to irradiate the test skin area with the sample and the adjacent skin area without the sample; after irradiation, the shortest irradiation time required to produce slight melanization (i.e., minimum sustained melanization amount, MPPD) is observed on the test skin; the PFA value is obtained by calculating the ratio of the MPPD required to cause melanization of the skin protected by the sample to the MPPD required to cause melanization of 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 ​​of the subjects in each group.

[0027] In addition, the absorbance of the sunscreen compositions of Examples 1-5 in different bands of UVA, UVB, HEV and IRA was measured by spectrophotometry. The test results are shown in Table 2.

[0028] Table 2 It can be seen from the test data in Table 2 that the sunscreen compositions of Examples 1-5 have relatively high SPF values ​​and PFA values, and have excellent absorption properties in the UVA, UVB, HEV and IRA bands, indicating that the sunscreen compositions of the present invention have excellent full-band protection capabilities.

[0029] Existing sunscreen ingredients are mainly divided into organic sunscreens and inorganic sunscreens. Organic sunscreens mainly absorb the energy of ultraviolet rays and convert it into heat energy or harmless visible light to release it, thereby preventing ultraviolet rays from damaging the skin. Generally speaking, the protection band of organic sunscreens is relatively narrow. For example, ethylhexyl methoxycinnamate can absorb ultraviolet rays in the UVB band (290-320nm), and octocrylene mainly protects the UVA band (320-340nm). Inorganic sunscreens mainly play a sunscreen role by reflecting and scattering ultraviolet rays. They can provide a wider sunscreen band coverage and protect the UVA and UVB bands. The use of organic sunscreens and inorganic sunscreens in a certain proportion can obtain a wider sunscreen band, and the synergistic effect of multiple sunscreens can achieve a higher level of protection. Example 2 contains only organic sunscreens, and Example 3 contains only inorganic sunscreens. It can be seen that Example 3 is slightly better than Example 2 in terms of overall sunscreen effect, and Example 3 has a greater advantage in terms of UVA band protection effect. The free sunscreens in Examples 1 and 4 contain both organic sunscreens and inorganic sunscreens, and both the overall sunscreen effect and the protection effect in each band are better than those in Examples 2 and 3. Example 5 also contains both organic sunscreens and inorganic sunscreens, but the amount of organic sunscreens is greater than that of inorganic sunscreens. It is possible that the above-mentioned usage ratio makes the free sunscreens have no obvious synergistic effect, resulting in a significant decrease in the sunscreen performance of Example 5, and the protection ability in each band is lower than that of the sunscreen compositions of Examples 2 and 3.

[0030] Table 3 Comparative Examples 1-6 were prepared according to the specific substances and weight percentages of each component shown in Table 3, and the preparation method was the same as above. The sunscreen performance of the compositions of Comparative Examples 1-6 was tested using the same method as above, and the results are listed in Table 4.

[0031] Table 4 Comparative Example 1 omits the microsphere particles on the basis of Example 4, and uses free sunscreen to make up the balance; Comparative Example 3 omits the free sunscreen on the basis of Example 4, and uses microsphere particles to make up the balance. It can be seen that the sunscreen effects of both are significantly reduced compared with Example 4, indicating that the microsphere particles loaded with sunscreen ingredients and the free sunscreen of the present invention have good synergistic performance, and adding the two into the system at the same time can obtain significantly better sunscreen effect.

[0032] Comparative Example 2 omits the sunscreen enhancer based on Example 4, and uses free sunscreen to make up the balance. The sunscreen enhancer of the present invention is a plant extract with a certain sunscreen function, and generally the overall sunscreen performance is difficult to match the common chemical sunscreen. However, when the sunscreen enhancer in the composition of the present invention is replaced with an equal amount of free sunscreen, the sunscreen performance of the composition decreases to a certain extent, but the degree of decrease in absorbance in the HEV band and IRA band is significantly less than that in other bands, indicating that the sunscreen enhancer can play a role in further improving the sunscreen performance in the present invention, especially in the HEV band and IRA band. It has a relatively obvious absorption capacity, which is of great significance to achieve full-band protection of the sunscreen composition.

[0033] Comparative Example 4 increases the amount of sunscreen enhancer on the basis of Example 4, and correspondingly reduces the amount of oil. It can be seen that further increasing the amount of sunscreen enhancer does not bring better sunscreen effect, which may be due to the change in the proportion of components in the composition, which makes it difficult for each sunscreen ingredient to exert its optimal performance. At the same time, from the test results in Table 4, it can be seen that although the sunscreen performance of Comparative Example 4 is not as good as that of Example 4, it still has better sunscreen performance than other comparative examples, indicating that the sunscreen enhancer mainly plays an auxiliary role in the overall sunscreen performance in the system of the present invention, and improves the full-band sunscreen ability of the composition by absorbing the HEV band and the IRA band.

[0034] Comparative Example 5 increases the amount of free sunscreen agent on the basis of Example 4 and correspondingly reduces the amount of microsphere particles, while Comparative Example 6 increases the amount of microsphere particles on the basis of Example 4 and correspondingly reduces the amount of free sunscreen agent. Due to the lack of appropriate component dosage ratio, the sunscreen performance of the compositions of Comparative Examples 5 and 6 is not outstanding.

[0035] 110 volunteers with similar skin conditions were selected and 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, respectively. The volunteers were asked to rate the greasy feeling, heavy feeling and irritation of the products 0.5 hours, 2 hours and 4 hours after application. The rating scale was 1-5 points, 1 point indicating no feeling and 5 points indicating very strong feeling. The final result of each group was averaged. The test results are shown in Table 5.

[0036] Table 5 From the skin feel test results, it can be seen that the sunscreen compositions of Examples 1-5 are significantly lower in greasy feel, thick feel and irritation than those of Comparative Examples 1-6, indicating that the sunscreen compositions of the present invention have better skin feel.

[0037] 110 volunteers with similar skin moisture content were selected and divided into 11 groups. The sunscreen compositions of Examples 1-5 and Comparative Examples 1-6 were applied to one side of the face of the volunteers, and the other side was used as a blank control for 7 consecutive days. The moisture content and transepidermal water loss rate of the skin before and after use were measured using a skin moisture tester and a transepidermal water loss tester, and the final results of each group were averaged. The test results are shown in Table 6.

[0038] Table 6 From the skin barrier function test results, it can be seen that the skin moisture content of Examples 1-5 is significantly increased and the transepidermal water loss rate is significantly reduced after use, indicating that the sunscreen composition of the present invention can effectively improve the skin barrier function, while the improvement effect of Comparative Examples 1-6 is relatively weak.

[0039] It can be seen that the synergistic effect of the components such as the microsphere particles loaded with sunscreen agents, rational sunscreen agents and sunscreen enhancers of the present invention can significantly improve the full-band protection ability of the sunscreen composition and achieve full-band protection against UVA, UVB, HEV and IRA. In addition, the overall formula of the composition is scientific and reasonable. On the basis of ensuring excellent sunscreen performance, it can significantly improve the skin barrier function, enhance the ability to lock in water and retain moisture, reduce skin damage caused by ultraviolet rays, and prevent photoaging.

[0040] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention may also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. A sunscreen composition, characterized in that: The composition includes the following ingredients by weight percentage: 20%-40% oil, 5%-20% wax, 5%-20% emollient, 1%-3% preservative, 4%-10% vitamin E, 3%-8% skin conditioner, 5%-15% sunscreen, 1%-4% sunscreen enhancer, and 0.5%-2% fragrance; wherein the sunscreen comprises microsphere particles and free sunscreen agent, and the microsphere particles are loaded with sunscreen ingredients.

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 is selected from organic sunscreens and / or inorganic sunscreens, wherein the organic sunscreen is one or more of ethylhexyl methoxycinnamate and octocrylene, and the inorganic sunscreen 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 the organic sunscreen to the inorganic sunscreen in the free sunscreen is 1:0.5-2.

5. The sunscreen composition according to claim 1, characterized in that The sunscreen enhancer is one or more of marigold extract, calendula extract, kale extract and blueberry extract.

6. The sunscreen composition according to claims 1-5, characterized in that: The following ingredients are included in weight percentage: 35%-40% oil, 14%-18% wax, 16%-20% emollient, 1%-2% preservative, 6%-8% vitamin E, 3%-5% skin conditioner, 9%-13% sunscreen, 2%-3% sunscreen enhancer, and 1%-2% fragrance.

7. The sunscreen composition according to claims 1-6, characterized in that: The composition includes the following components by weight percentage: Phase A: 35%-40% oil, 16%-20% emollient, 2%-6% microsphere particles; Phase B: wax 14%-18%, preservative 1%-2%; Phase C: free sunscreen 4%-8%, vitamin E 6%-8%; Phase D: skin conditioner 3%-5%, sunscreen enhancer 2%-3%, fragrance 1%-2%.

8. A method for preparing the sunscreen composition according to claim 7, characterized in that: The method comprises the following steps: adding the raw material of phase A into an emulsifying pot, heating it to 40-50°C, homogenizing it at a speed of 500-1000 rpm for 5-10 minutes to make it evenly mixed; adding the raw material of phase B, stirring it for 15-20 minutes until it is completely dissolved; cooling it to 30-40°C, adding the raw material of phase C and stirring it for 10-15 minutes; cooling it to below 30°C, adding the raw material of phase D and stirring it for 5-10 minutes; cooling it to room temperature, and discharging and filling it after checking that there is no abnormality.

9. Use of the sunscreen composition according to any one of claims 1 to 7 for preparing cosmetics.

10. The use according to claim 9, characterized in that The cosmetics are stick-shaped cosmetics.

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