A sunscreen composition, use and sunscreen product

Abstract

This invention belongs to the field of daily chemical products and discloses a method for preparing a sunscreen composition, comprising the following steps: Step 1: mixing and dispersing sodium stearoyl glutamate, a portion of thickener, a portion of alcohol solvent, and a portion of water; Step 2: adding a sunscreen agent to the mixture from Step 1; Step 3: grinding the mixture obtained in Step 2; Step 4: emulsifying and homogenizing the remaining thickener, remaining alcohol solvent, remaining water, and the mixture obtained in Step 3; wherein the sunscreen agent contains methylene bis-benzotriazolyl tetramethylbutylphenol; the weight ratio of sodium stearoyl glutamate to methylene bis-benzotriazolyl tetramethylbutylphenol is 2-7:45-55. Through extensive experimental verification, this invention has found that sodium stearoyl glutamate and methylene bis-benzotriazolyl tetramethylbutylphenol exhibit significant synergistic sunscreen properties. This invention also discloses the composition and its uses.

Description

Technical Field

[0001] This invention relates to the field of daily chemical products, specifically to a sunscreen composition, its uses, and sunscreen products. Background Technology

[0002] In the prior art, the sun protection performance of sunscreens can be enhanced by different sunscreen synergists. Typical examples are powdered synergists, such as HDI / trimethylolhexyl lactone crosspolymer and / or lauroyl lysine (CN118105315A, sunscreen synergist, oil composition, care composition, use and preparation method), or plant-derived sunscreen synergists, such as plant root extracts and hesperidin (CN115487103A, a plant-derived sunscreen synergist composition and its application).

[0003] The following scheme uses emulsifiers as sunscreen enhancers:

[0004] Publication number CN115337227A, subject to a technical solution for a sunscreen composition and its application, mentions the use of sodium bis(lauramide-glutamine)lysine and PEG-240 / HDI copolymer bis-decyltetradecyl alcohol polyether-20 ether to enhance the inorganic sunscreen effect; its mechanism is to enhance the sunscreen effect by promoting the suspension of inorganic particles through emulsifiers;

[0005] Publication number CN117338622A discloses a technical solution for a sunscreen composition, its preparation method, and its application. It mentions the use of sodium stearoyl glutamate in the aqueous phase. By using different emulsifiers such as hydrogenated lecithin, phytosterol, squalene, and sodium stearoyl glutamate in the alcohol, aqueous, and oil phases, the stability of the obtained sunscreen composition is improved, the emulsion particle size is reduced, and layering or oil separation is avoided, thereby improving the sunscreen performance.

[0006] In the existing technology, sunscreens involving emulsified systems have many requirements for emulsifiers. It is difficult for general emulsified systems to effectively enhance the sun protection effect of sunscreens, especially chemical sunscreens.

[0007] The technical problem addressed in this case is: how to screen sunscreen agents and emulsifiers to achieve enhanced sun protection in most stable emulsion systems. Summary of the Invention

[0008] The purpose of this invention is to provide a method for preparing a sunscreen composition. Through extensive experimental verification, it has been found that sodium stearoyl glutamate and methylene bis-benzotriazolyl tetramethylbutylphenol have significant synergistic sunscreen properties. The synergistic mechanism is that sodium stearoyl glutamate can be regarded as a liquid crystal emulsifier. By grinding, sodium stearoyl glutamate is made to exhibit a liquid crystal state. The liquid crystal structure formed has birefringence, thereby improving the sunscreen effect of methylene bis-benzotriazolyl tetramethylbutylphenol.

[0009] The present invention also discloses the composition and its uses.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] A method for preparing a sunscreen composition, characterized by comprising the following steps:

[0012] Step 1: Mix and disperse sodium stearoyl glutamate, a portion of thickener, a portion of alcohol solvent, and a portion of water;

[0013] Step 2: Add sunscreen to the mixture from Step 1;

[0014] Step 3: Grind the mixture obtained in Step 2;

[0015] Step 4: Emulsify and homogenize the remaining thickener, remaining alcohol solvent, and remaining water with the mixture obtained in Step 3;

[0016] The sunscreen contains methylenebis-benzotriazolyltetramethylbutylphenol;

[0017] The weight ratio of sodium stearoyl glutamate and methylene bis-benzotriazolyl tetramethyl butylphenol is 2-7:45-55.

[0018] The mechanism of the synergistic effect of sun protection in this invention is as follows:

[0019] Sodium stearoyl glutamate (SST) can be considered a liquid crystal emulsifier. Through grinding, SST is made into a liquid crystal state, and the resulting liquid crystal structure exhibits birefringence, enhancing the sun protection effect of methylenebis-benzotriazolyltetramethylbutylphenol. This property allows it to exhibit excellent emulsifying effects even at low dosages. Therefore, SST can not only be used as an emulsifier but also form a liquid crystal structure in the formulation, thereby improving product stability and performance, enhancing the dispersibility and stability of sunscreens. Simultaneously, it can form an interface layer between oily and watery components, uniformly encapsulating the sunscreen in the emulsion and reducing aggregation and precipitation. This ensures the sunscreen is evenly distributed on the skin, forming a continuous protective film, thus improving sun protection efficacy. It can also improve its stability and solubility in the formulation, further enhancing sun protection.

[0020] In the above sunscreen composition, the total amount of sodium stearoyl glutamate and methylene bis-benzotriazolyl tetramethyl butylphenol is equivalent to 47 to 62 wt% of the total amount of the product obtained in step 4.

[0021] In the above-mentioned sunscreen composition, the weight ratio of sodium stearoyl glutamate and methylene bis-benzotriazolyl tetramethylbutylphenol is 3-6:48-52.

[0022] In the above-mentioned sunscreen composition, the sunscreen agent further includes one or more combinations of ethylhexyl methoxycinnamate, ethylhexyl salicylate, ethylhexyl triazine, homosalate, and octocrylene.

[0023] In the above-mentioned sunscreen composition, the weight ratio of sodium stearoyl glutamate to sunscreen agent is 2-7:45-65.

[0024] In the above-mentioned sunscreen composition, the alcohol solvent is one or more combinations of glycerin, butylene glycol, and propylene glycol;

[0025] The amount of the alcohol solvent used is 1.5–4 wt%.

[0026] The thickener is one or more of xanthan gum, carbomer, and hydroxypropyl methylcellulose; the amount of the thickener is 0.3-1 wt%.

[0027] In this invention, step 1 uses 30-60 wt% thickener, 30-60 wt% alcohol solvent, and 30-60 wt% water, with the remainder used in step 4;

[0028] The grinding is carried out using a sand mill with a rotation speed of 1000 rpm and a material flow rate of 4000 L / 3h inside the sand mill.

[0029] In addition, the present invention also discloses a sunscreen composition prepared by any of the methods described above.

[0030] In addition, the present invention also discloses the use of sunscreen compositions as described above in the preparation of sunscreen products.

[0031] Finally, the present invention also discloses a sunscreen product containing any of the sunscreen compositions described above.

[0032] In the aforementioned sunscreen products, the amount of the sunscreen composition used in the sunscreen products is 1 to 20 wt%.

[0033] Among the aforementioned sunscreen products, the formulation of the sunscreen product is an oil-in-water sunscreen lotion, a water-in-oil sunscreen lotion, an oil-in-water sunscreen cream, a water-in-oil sunscreen cream, or a sunscreen spray.

[0034] Compared with the prior art, the beneficial effects of the present invention are:

[0035] 1. This invention effectively improves the sun protection properties of methylene bis-benzotriazolyltetramethylbutylphenol by using sodium stearoyl glutamate and methylene bis-benzotriazolyltetramethylbutylphenol in combination. This combination is applicable to most sunscreen emulsion systems and has little limitation on the type of emulsifier, thus improving the wide applicability of the formulation.

[0036] 2. This invention utilizes the liquid crystal effect of sodium stearoyl glutamate to enhance the efficacy of most chemical sunscreens, but the enhancement effect is most significant for methylene bis-benzotriazolyl tetramethylbutylphenol. Detailed Implementation

[0037] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0038] Raw material source description:

[0039] Mixed sunscreen agent 1: Ethylhexyl methoxycinnamate and ethylhexyl salicylate, with a weight ratio of 5:4;

[0040] Mixed sunscreen agent 2: Ethylhexyl methoxycinnamate and homosalate, with a weight ratio of 5:3;

[0041] Mixed sunscreen agent 3: ethylhexyl salicylate and homosalate, with a weight ratio of 4:3.

[0042] The differences in sun protection values ​​between the above-mentioned mixed sunscreen agents 1 to 3 and the methylene bis-benzotriazolyl tetramethylbutylphenol of the present invention are not significant.

[0043] AFSK: Potassium cetyl phosphate;

[0044] HR-S1 emulsifier: water, potassium lauryl phosphate, wherein the concentration of potassium lauryl phosphate is 48 wt%.

[0045] The formula for the sunscreen lotion is shown in Table 1 below. All subsequent cases will be implemented based on this formula.

[0046] Table 1. Sunscreen Lotion Formula Table

[0047]

[0048]

[0049] The preparation process is as follows: (1) Weigh phase A into a beaker according to the ratio and homogenize for 10 min. After mixing evenly, keep warm at 85℃ for later use. (2) Weigh phase B into another beaker according to the ratio and heat to 85-95℃ to dissolve evenly for later use. (3) Weigh phase D into another beaker and heat to 85℃ to dissolve evenly for later use. (4) Pour the prepared phase B into the beaker containing phase A and homogenize for 15 min. After homogenization, stir and cool to 60℃, add phase C and continue stirring. After cooling to 45℃, add the prepared phases D and E. (5) After adding all phases, stir for another 5 min to complete the preparation.

[0050] The testing method for SPF is as follows:

[0051] Based on the property of UV absorbers and shielding agents in sunscreen cosmetics to block ultraviolet rays, this method involves applying sunscreen cosmetics to special adhesive tape, irradiating the samples with ultraviolet light of different wavelengths, and measuring the absorbance values. The sunscreen effect is directly evaluated based on the measured values. The use of a highly stable 125-watt continuous xenon lamp light source ensures consistent light intensity throughout the experiment, guaranteeing accuracy. An XY automatic sample introduction control stage avoids errors caused by manual sample introduction. The software is easy to operate and can obtain the desired SPF value and PA critical wavelength value in a very short time. Applications: SPF value measurement of cosmetics, sunscreen products, UV-protective fabrics, photosensitive emulsions, etc.

[0052] Part 1: Preparation and Performance Testing of Sunscreen Compositions

[0053] The preparation method of the sunscreen composition is as follows:

[0054] Step 1: Mix and disperse sodium stearoyl glutamate, a portion of thickener, a portion of alcohol solvent, and a portion of water;

[0055] Step 2: Add sunscreen to the mixture from Step 1;

[0056] Step 3: The mixture obtained in Step 2 is subjected to sand milling at a speed of 1000 rpm and a circulation flow rate of 4000 L / 3h.

[0057] Step 4: Emulsify and homogenize the remaining thickener, remaining alcohol solvent, and remaining water with the mixture obtained in Step 3 at a pressure of 150 MPa for 0.5 h.

[0058] The dosage of each of the above substances can be found in Table 2; the proportions of thickener, alcohol solvent and water allocated in step 1 can be seen in the allocation ratio column of Table 2.

[0059] Table 2. Combinations of Sodium Stearoyl Glutamate with Different Sunscreen Agents (Unit: wt%)

[0060]

[0061]

[0062] Referring to the preparation method of Example 2 above, hydrogenated lecithin, a relatively typical liquid crystal emulsifier in the industry, HR-S1 and sunscreen are combined to prepare the composition. The specific formula can be found in Table 3. In Table 3, AFSK is a common emulsifier that has been reported to form a liquid crystal phase under relatively harsh processes. In this invention, it is only used as a common emulsifier.

[0063] In step 1, the ratio of thickener, alcohol solvent, and water is 50%.

[0064] Table 3. Combination of different emulsifiers and different sunscreen agents (unit: wt%)

[0065]

[0066]

[0067] Comparative Example 16

[0068] The formula is the same as in Example 2, and the preparation method is as follows:

[0069] Step 1: Mix and disperse sodium stearoyl glutamate, a portion of thickener, a portion of alcohol solvent, and a portion of water;

[0070] Step 2: Add the sunscreen agent methylenebis-benzotriazolyltetramethylbutylphenol to the mixture from Step 1;

[0071] Step 3: Emulsify and homogenize the mixture obtained in Step 2;

[0072] Step 4: Emulsify and homogenize the remaining thickener, remaining alcohol solvent, and remaining water with the mixture obtained in Step 3;

[0073] The homogenization pressure in steps 3 and 4 is 150 MPa, and the homogenization times are 0.3 h and 0.5 h, respectively.

[0074] Comparative Example 17

[0075] The formula is the same as Comparative Example 4, and the preparation method is as follows:

[0076] Step 1: Mix and disperse AFSK, a portion of thickener, a portion of alcohol solvent, and a portion of water;

[0077] Step 2: Add the sunscreen agent methylenebis-benzotriazolyltetramethylbutylphenol to the mixture from Step 1;

[0078] Step 3: Emulsify and homogenize the mixture obtained in Step 2;

[0079] Step 4: Emulsify and homogenize the remaining thickener, remaining alcohol solvent, and remaining water with the mixture obtained in Step 3;

[0080] The homogenization pressure in steps 3 and 4 is 150 MPa, and the homogenization times are 0.3 h and 0.5 h, respectively.

[0081] Comparative Example 18

[0082] The formula is the same as Comparative Example 8, and the preparation method is as follows:

[0083] Step 1: Mix and disperse HR-S1 emulsifier, part of the thickener, part of the alcohol solvent, and part of the water;

[0084] Step 2: Add the sunscreen agent methylenebis-benzotriazolyltetramethylbutylphenol to the mixture from Step 1;

[0085] Step 3: Emulsify and homogenize the mixture obtained in Step 2;

[0086] Step 4: Emulsify and homogenize the remaining thickener, remaining alcohol solvent, and remaining water with the mixture obtained in Step 3;

[0087] The homogenization pressure in steps 3 and 4 is 150 MPa, and the homogenization times are 0.3 h and 0.5 h, respectively.

[0088] Comparative Example 19

[0089] The formula is the same as that of Comparative Example 12, and the preparation method is as follows:

[0090] Step 1: Mix and disperse hydrogenated lecithin, a portion of thickener, a portion of alcohol solvent, and a portion of water;

[0091] Step 2: Add the sunscreen agent methylenebis-benzotriazolyltetramethylbutylphenol to the mixture from Step 1;

[0092] Step 3: Emulsify and homogenize the mixture obtained in Step 2;

[0093] Step 4: Emulsify and homogenize the remaining thickener, remaining alcohol solvent, and remaining water with the mixture obtained in Step 3;

[0094] The homogenization pressure in steps 3 and 4 is 150 MPa, and the homogenization times are 0.3 h and 0.5 h, respectively.

[0095] Table 4. Results of Sun Protection Performance Tests

[0096]

[0097]

[0098] Results analysis:

[0099] 1. As can be seen from Examples 1 to 5, 2 wt% sodium stearoyl glutamate can form a stable emulsion system, and increasing its amount will not have a significant impact on the sun protection SPF value; increasing the amount of methylene bis-benzotriazolyl tetramethylbutylphenol will lead to an increase in sun protection value.

[0100] 2. As can be seen from Examples 6 to 9, the use of other sunscreen agents can further increase the SPF of the formulation, but the increase is limited due to the limitation on the amount used.

[0101] 3. As can be seen from Comparative Examples 1-3, Example 2, and Comparative Examples 4-7, in the common emulsifier AFSK, the sun protection performance of most sunscreens and sodium stearoyl glutamate systems is not significantly different. Among them, the mixed sunscreen 2 has a more significant gain effect in the sodium stearoyl glutamate system. In terms of gain magnitude, methylene bis-benzotriazolyltetramethylbutylphenol is significantly better than mixed sunscreen 2.

[0102] 4. As can be seen from Examples 2, Comparative Examples 1-3, and Comparative Examples 8-11, the typical liquid crystal emulsifier HR-S1 emulsifier exhibits a significantly greater gain on mixed sunscreen agent 1 and mixed sunscreen agent 3 than the sodium stearoyl glutamate system; as can be seen from Examples 2, Comparative Examples 1-3, and Comparative Examples 12-15, the typical liquid crystal emulsifier hydrogenated lecithin exhibits a significantly greater gain on mixed sunscreen agent 1 and mixed sunscreen agent 3 than the sodium stearoyl glutamate system.

[0103] 5. As can be seen from Examples 2 and Comparative Examples 16 to 19, AFSK, HR-S1 emulsifier, and hydrogenated lecithin all exhibited similar sun protection effects after homogenization and grinding. Sodium stearoyl glutamate showed better sun protection enhancement, possibly due to its better liquid crystal formation ability.

[0104] In summary, the analysis of the above results shows that the use of liquid crystal emulsifiers generally enhances the SPF of most sunscreens due to their birefringence. However, when sodium stearoyl glutamate and methylene bis-benzotriazolyl tetramethylbutylphenol are used to form an emulsion sunscreen system, a more significant sun protection effect can be achieved. This is because sodium stearoyl glutamate has stronger emulsification stability and the resulting liquid crystal phase has better birefringence. Furthermore, its stability and encapsulation properties allow for better uniform spreading and improved sun protection. In addition, methylene bis-benzotriazolyl tetramethylbutylphenol is more compatible with the aforementioned properties of sodium stearoyl glutamate, resulting in better performance.

[0105] Part 1: Safety Testing of Sunscreen Compositions

[0106] The composition of Example 3 was used in the application formulation in Table 1 for skin patch testing.

[0107] The experimental method is as follows:

[0108] Using qualified patch testing equipment, and employing the closed patch test method, place approximately 0.020 g to 0.025 g (solid) or 0.020 mL to 0.025 mL (liquid) of the test substance into the patch testing device, and apply it externally to the flexor side of the subject's forearm with hypoallergenic adhesive tape. Remove the test substance after 24 hours, and observe the skin reaction at 0.5, 24, and 48 hours after removal. Record the results according to the skin reaction grading standards in the currently effective technical specifications.

[0109] Grading criteria for skin reactions in occlusive patch testing:

[0110]

[0111] The experimental results are shown in Table 5 below;

[0112] Table 5 Patch Test Table

[0113]

[0114]

[0115] The above experiments demonstrate that the formula of this invention has a high safety factor and is non-irritating to the human body.

Claims

1. A method of preparing a sunscreen composition, characterized in that, Includes the following steps: Step 1: Mix and disperse sodium stearoyl glutamate, a portion of thickener, a portion of alcohol solvent, and a portion of water; Step 2: Add sunscreen to the mixture from Step 1; Step 3: Grind the mixture obtained in Step 2; Step 4: Emulsify and homogenize the remaining thickener, remaining alcohol solvent, and remaining water with the mixture obtained in Step 3; The sunscreen contains methylenebis-benzotriazolyltetramethylbutylphenol; The weight ratio of sodium stearoyl glutamate and methylene bis-benzotriazolyl tetramethylbutylphenol is 2-7:45-55; the total amount of sodium stearoyl glutamate and methylene bis-benzotriazolyl tetramethylbutylphenol is equivalent to 47-62 wt% of the total amount of the product obtained in step 4; the sunscreen agent also includes one or more combinations of ethylhexyl methoxycinnamate, ethylhexyl salicylate, and homosalate. The grinding is carried out using a sand mill, the rotation speed of which is 1000 rpm; the flow rate of the material inside the sand mill is 4000 L / 3h. The alcohol solvent is one or a combination of glycerol, butanediol, and propylene glycol; The amount of the alcohol solvent used is 1.5 to 4 wt%.

2. The production method according to claim 1, characterized by, The weight ratio of sodium stearoyl glutamate and methylene bis-benzotriazolyl tetramethyl butylphenol is 3-6:48-52.

3. The preparation method according to claim 1, characterized in that, The weight ratio of sodium stearoyl glutamate to sunscreen agent is 2-7:45-65.

4. The method of claim 1, wherein, The thickener is one or more of xanthan gum, carbomer, and hydroxypropyl methylcellulose; the amount of the thickener is 0.3 to 1 wt%.

5. A sunscreen composition characterized in that, It is prepared by the method described in any one of claims 1 to 4.

6. Use of the sunscreen composition as described in claim 5 to prepare a sunscreen product.

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