A composite sunscreen composition having excellent film-forming property and sunscreen stability and a method for preparing the same

Abstract

The application discloses a kind of composite sunscreen composition with excellent film-forming property and sunscreen stability and its preparation method and application, belong to daily chemical technology field.The composite sunscreen composition includes chrysanthemum powder lauryl urethane, sodium di (lauramide glutamine) lysine, hydroxypropyl trimethyl ammonium chloride hyaluronic acid, acryloyldimethyl ammonium propionate / VP copolymer, sunscreen, base grease, and cosmetically acceptable adjuvant and solvent;Sunscreen cream prepared based on the composition can quickly form stable, light and breathable sunscreen film on the surface of skin, solve the uneven dispersion of sunscreen agglomeration in traditional sunscreen product, film-forming rigid and not breathable, sunscreen effect is easy to lose due to sweating / friction, poor skin feel and other problems, with high sunscreen stability, excellent water resistance, good skin feel, can be widely used in sunscreen product preparation with sunscreen efficacy.

Description

Technical Field

[0001] This invention belongs to the field of daily chemical products technology, specifically relating to a composite sunscreen composition with excellent film-forming properties and sun protection stability, and its preparation method. Background Technology

[0002] In recent years, with the increasing prominence of the harmful effects of ultraviolet radiation on human skin, sunscreen products have become an important part of daily skincare. Currently, most commercially available sunscreens rely on physical sunscreens (such as titanium dioxide and zinc oxide) or chemical sunscreens (such as avobenzone and octocrylene) to block ultraviolet rays. However, these sunscreen ingredients are prone to aggregation and uneven distribution in the formula, resulting in localized weaknesses in the sunscreen film, reducing its actual sun protection effect. Furthermore, they are easily rubbed off when exposed to sweat, water, or friction, resulting in poor durability.

[0003] Existing technologies often use film-forming agents to enhance the adhesion and water resistance of sunscreen ingredients. However, traditional film-forming agents such as polyvinyl alcohol and polyacrylate often suffer from problems such as stiff film formation, poor breathability, and sensitization. On the other hand, while naturally derived film-forming agents such as polysaccharides have relatively high safety, their film strength, water resistance, and compatibility with sunscreen agents are usually not ideal.

[0004] Therefore, developing a composite composition that can synergistically enhance the dispersibility, film-forming properties, durability, and comfort of sunscreens has significant practical application value. Summary of the Invention

[0005] The purpose of this invention is to overcome the technical defects of existing sunscreen compositions, such as uneven dispersion of sunscreen agents, poor film-forming properties, unpleasant skin feel, and the need to improve safety, and to provide a composite sunscreen composition with excellent film-forming properties and sun protection stability, as well as its preparation method and application.

[0006] This sunscreen composition, through the scientific formulation of key active ingredients, can quickly form a stable, thin, and breathable sunscreen film on the skin surface, effectively solving the problem of sunscreen agent aggregation, improving the durability and stability of sun protection effect, while also having excellent skin feel and high safety.

[0007] To achieve the above objectives, the present invention discloses the following technical solutions:

[0008] In a first aspect, the present invention provides a composite sunscreen composition comprising inulin lauryl carbamate, sodium di(lauramide glutamine) lysine, hydroxypropyltrimethylammonium chloride hyaluronic acid and ammonium acryloyl dimethyl taurate / VP copolymer, sunscreen agent, base oil, and cosmetic-acceptable excipients and solvents.

[0009] Preferably, the composition contains, by weight percentage, 0.05-0.15% inulin lauryl carbamate, 0.05-0.3% sodium di(lauramide-glutamine)lysine, 0.01-0.08% hydroxypropyltrimethylammonium chloride hyaluronic acid, and 0.1-0.4% ammonium acryloyldimethyl taurate / VP copolymer.

[0010] More preferably, the sunscreen agent is at least one of chemical sunscreen agents, physical sunscreen agents, and plant-based sunscreen agents.

[0011] More preferably, the chemical sunscreen agent is at least one of oil-soluble chemical sunscreen agents and water-soluble chemical sunscreen agents.

[0012] Preferably, the excipient is at least one selected from skin conditioning agents, pH adjusters, moisturizers, chelating agents, and preservatives;

[0013] The solvent is water.

[0014] Secondly, the present invention provides a sunscreen lotion with excellent film-forming properties and sun protection stability, wherein the sunscreen lotion contains the composite sunscreen composition described in the first aspect.

[0015] Preferably, by mass percentage, the sunscreen lotion comprises 1-9% isoamyl p-methoxycinnamate, 1-8% octocrylene, 1-8% bis-ethylhexyloxyphenol methoxyphenyl triazine, 0.05-0.15% inulin lauryl carbamate, 0.05-0.3% sodium bis(lauramide glutamine) lysine, 0.01-0.08% hydroxypropyltrimethylammonium chloride hyaluronic acid, 0.1-0.4% ammonium acryloyl dimethyl taurate / VP copolymer, 1-10% glycerin, 1-10% diisopropyl sebacate, 1-15% dioctyl carbonate, 0.01-0.5% p-hydroxyacetophenone, 0.001-1% pH adjuster, and the balance being deionized water.

[0016] Thirdly, the present invention provides a method for preparing the sunscreen lotion described in the second aspect, the method comprising the following steps:

[0017] Step 1. Heat sodium di(lauramide-glutamine)lysine, hydroxypropyltrimethylammonium chloride, hyaluronic acid, glycerol, and deionized water to 75-80℃ and stir to dissolve and mix evenly to obtain phase A;

[0018] Step 2. Heat isoamyl p-methoxycinnamate, octocrylene, bis-ethylhexyloxyphenol methoxyphenyl triazine, diisopropyl sebacate and dioctyl carbonate to 75-80℃ and stir until homogeneous to obtain phase B;

[0019] Step 3. Add phase B to phase A under homogenous stirring, maintain emulsification for 5-10 minutes, and obtain a mixed solution AB;

[0020] Step 4. Cool the mixed solution AB to 45-50℃, add inulin lauryl carbamate and ammonium acryloyl dimethyl taurate / VP copolymer, stir until uniform, then cool to 35-40℃, add p-hydroxyacetophenone, adjust the pH to 6.5±0.2 with an appropriate amount of pH adjuster, filter and discharge to obtain the sunscreen lotion.

[0021] Fourthly, the present invention provides the application of the composite sunscreen composition described in the first aspect in the preparation of skin care products with sunscreen effects.

[0022] In this invention:

[0023] The scientific formulation of inulin lauryl carbamate, sodium di(lauramide glutamine) lysine, hydroxypropyltrimethylammonium chloride hyaluronic acid, and ammonium acryloyl dimethyl taurate / VP copolymer solves the problem of sunscreen agglomeration and improves dispersion uniformity. The four components work synergistically to effectively disperse plant-based sunscreens, chemical sunscreens, or physical sunscreens, avoiding uneven dispersion caused by agglomeration. This ensures that the sunscreen ingredients are evenly distributed in the system, thereby guaranteeing the stability of the sunscreen effect and reducing the risk of skin irritation caused by excessively high local concentrations of ingredients.

[0024] Optimized film-forming properties, balancing stability, lightness, and breathability: Inulin lauryl carbamate, as a naturally derived film-forming agent, can form a dense and breathable flexible film layer, avoiding the heaviness of traditional synthetic film-forming agents; Ammonium acryloyl dimethyl taurate / VP copolymer further optimizes the flexibility and uniformity of the film layer, ensuring the integrity of the sunscreen film's coverage on the skin surface and achieving broad-spectrum blocking of UVA / UVB; the combination of these two elements gives the sunscreen film stable film-forming properties, a light texture, and good breathability, improving the user experience.

[0025] Enhancing the durability and water resistance of sunscreen film: Sodium di(lauramide-glutamine)lysine can enhance the adhesion between the sunscreen film and the stratum corneum of the skin, reducing the shedding of the sunscreen film caused by skin activity; the moisturizing film formed by hydroxypropyltrimethylammonium chloride and hyaluronic acid not only improves the skin's moisturizing feeling, but also enhances the adhesion of sunscreen agents, reducing the loss of sunscreen ingredients due to sweating or friction. The two work together to significantly improve the durability and water resistance of the sunscreen film, achieving long-lasting sun protection.

[0026] The beneficial effects of this invention are:

[0027] 1. The composite sunscreen composition provided by the present invention can effectively solve the problem of uneven dispersion and aggregation of sunscreen agents, so that the SPF value of sunscreen lotion is stable at 48.9-50.8 and the SPF value of human body reaches 30.2-36.1. It has a high SPF retention rate under high temperature storage, while reducing skin irritation caused by excessive local concentration of sunscreen agents, and improving the stability and safety of sunscreen.

[0028] 2. The sunscreen provided by this invention can form a stable, thin and breathable sunscreen film, which has both a broad-spectrum UVA / UVB blocking effect and excellent skin feel. The overall sensory score is 4.3-4.5 points, solving the problems of stiff film formation, stuffy and sticky feeling of traditional sunscreen products. Detailed Implementation

[0029] To better illustrate the objectives, technical solutions, and advantages of this invention, the invention will be further described below with reference to specific embodiments. Those skilled in the art should understand that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0030] Unless otherwise specified, the test methods used in the examples and comparative examples are conventional methods; the materials and reagents used are commercially available unless otherwise specified; and the percentages mentioned in the examples and comparative examples are mass percentages unless otherwise specified.

[0031] Preparation of sunscreen lotion

[0032] Weigh the raw materials precisely according to the percentage of mass in Tables 1 and 2;

[0033] Step 1. Heat component 2 (lauramide glutamine), sodium lysine, hydroxypropyltrimethylammonium chloride, hyaluronic acid, glycerol, and deionized water to 75-80℃ and stir to dissolve and mix evenly to obtain phase A;

[0034] Step 2. Heat the components of the sunscreen (isoamyl p-methoxycinnamate, octocrylene, bis-ethylhexyloxyphenol methoxyphenyl triazine), diisopropyl sebacate, and dioctyl carbonate to 75-80℃ and stir until homogeneous to obtain phase B;

[0035] Step 3. Add phase B to phase A under homogenous stirring, maintain emulsification for 5-10 minutes, and obtain a mixed solution AB;

[0036] Step 4. Cool the mixed solution AB to 45-50℃, add inulin lauryl carbamate and ammonium acryloyl dimethyl taurate / VP copolymer, and stir slowly until homogeneous;

[0037] Step 5. Cool to 38°C, add p-hydroxyacetophenone, adjust the pH to 6.5±0.2 with an appropriate amount of pH adjuster, filter and discharge to obtain sunscreen lotion.

[0038] Table 1. Percentage of raw materials in the sunscreen lotion of the examples

[0039] Raw material name Example 1 Example 2 Example 3 Isoamyl p-methoxycinnamate 6 6 6 Octylene 5 5 5 bis-ethylhexyloxyphenol methoxyphenyl triazine 2 2 2 Inulin lauryl carbamate 0.08 0.1 0.12 Sodium bis(lauramide-glutamine)lysine 0.3 0.07 0.05 Hydroxypropyltrimethylammonium chloride hyaluronic acid 0.01 0.05 0.08 Acryloyldimethyltaurate ammonium / VP copolymer 0.4 0.2 0.1 glycerin 2 2 2 diisopropyl sebacate 5 5 5 dioctyl carbonate 7 7 7 p-Hydroxyacetophenone 0.1 0.1 0.1 pH adjuster Appropriate amount Appropriate amount Appropriate amount Deionized water Add to 100 Add to 100 Add to 100

[0040] Table 2. Comparative Example Sunscreen Milk Raw Material Percentage

[0041] Raw material name Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Isoamyl p-methoxycinnamate 6 6 6 6 6 6 Octylene 5 5 5 5 5 5 bis-ethylhexyloxyphenol methoxyphenyl triazine 2 2 2 2 2 2 Inulin lauryl carbamate 0.17 / 0.1 0.1 / 0.1 Hydrogenated lecithin / / / / 0.1 / Sodium bis(lauramide-glutamine)lysine / 0.17 0.07 0.07 0.07 0.07 Hydroxypropyltrimethylammonium chloride hyaluronic acid 0.05 0.05 / 0.25 0.05 / Acryloyldimethyltaurate ammonium / VP copolymer 0.2 0.2 0.25 / 0.2 0.2 Hyaluronic acid / / / / / 0.05 glycerin 2 2 2 2 2 2 diisopropyl sebacate 5 5 5 5 5 5 dioctyl carbonate 7 7 7 7 7 7 p-Hydroxyacetophenone 0.1 0.1 0.1 0.1 0.1 0.1 pH adjuster Appropriate amount Appropriate amount Appropriate amount Appropriate amount Appropriate amount Appropriate amount Deionized water Add to 100 Add to 100 Add to 100 Add to 100 Add to 100 Add to 100

[0042] Note: " / " in the table indicates no addition.

[0043] Performance testing

[0044] 1. In vitro SPF determination

[0045] Using a pipette, transfer the sunscreen samples prepared in Examples 1-3 and Comparative Examples 1-6 respectively, and evenly spot 0.0276±0.0003g of sample onto a PMMA plate (5cm×5cm). Use an index finger wearing a disposable finger cot to evenly spread the sample within a specified time. Under constant temperature and humidity conditions, avoid light and air dry for 30 minutes. Use a UV-2000s to test the SPF value of the sample. Test 3 plates for each sample, and test 5 different points on each plate. Take the average value.

[0046] 2. Water resistance test

[0047] After the PMMA plates coated with the samples from each of the above groups were tested, they were immersed in a constant temperature water bath at 25±0.5℃ and stirred at 20r / min for 40min. After that, they were taken out and dried in the dark under constant temperature and humidity conditions, and their SPF values ​​were measured again.

[0048] 3. Centrifugal stability test

[0049] The sunscreen samples prepared in Examples 1-3 and Comparative Examples 1-6 were centrifuged at 3000 rpm for 30 min. The presence of oil phase separation, layering, precipitation, turbidity, etc. was observed. If no such phenomena were observed, the samples were considered qualified.

[0050] 4. Long-term SPF retention rate test

[0051] The sunscreen samples prepared in Examples 1-3 and Comparative Examples 1-6 were stored at 50°C for 30 days, and their SPF values ​​were tested. The long-term SPF retention rate was calculated according to the formula "Retention rate = SPF value after 30 days / Initial SPF value × 100%".

[0052] 5. Sensory Test

[0053] Fifteen volunteers, aged 25-55, half male and half female, with skin types including dry, oily, and combination, were selected. They used sunscreens prepared in Examples 1-3 and Comparative Examples 1-6, respectively, and scored them on four dimensions: spreadability, greasiness, film-forming speed, and residue. Each dimension was scored from 1 to 5, with higher scores indicating better sensory performance. The average score of each dimension was taken as the sum of the average scores of each dimension, divided by 4, and then averaged by the 20 volunteers to obtain the sensory score.

[0054] 6. Human body SPF value measurement

[0055] SPF measures the ability of a sunscreen product to protect against UVB (medium-wave ultraviolet radiation). It is calculated as the ratio of the time required for the skin to develop minimal erythema after using a sunscreen product to the time required without using one.

[0056] Healthy Asian subjects were selected for testing to predict the minimum erythema dose (MED) of their skin. The subjects' backs were treated with three methods: ① no application, ② uniform application of 2 mg of SPF standard (prepared according to the Cosmetic Safety Technical Specifications 2015), and ③ uniform application of 2 mg of the products from Examples 1-3 to designated areas. The areas were left to stand for 20 minutes to form a film. The MED values ​​were recorded after 24 hours for each of the three scenarios.

[0057] SPF = MED protection / MED no protection (average of all subjects).

[0058] The results of the above tests are shown in Tables 3 and 4.

[0059] Table 3 Test Results for Each Group

[0060] Group In vitro SPF value SPF value after water rinsing Centrifugal stability Retention rate / % Sensory score Example 1 49.5 45.2 qualified 95.2 4.5 Example 2 50.8 46.1 qualified 96.0 4.4 Example 3 48.9 44.5 qualified 94.8 4.3 Comparative Example 1 46.0 35.8 qualified 85.1 3.8 Comparative Example 2 45.2 34.0 qualified 83.5 3.6 Comparative Example 3 47.1 36.2 Slight stratification 84.3 3.9 Comparative Example 4 46.8 35.0 qualified 82.7 3.7 Comparative Example 5 44.5 32.5 Oil phase separation 80.2 3.5 Comparative Example 6 45.5 33.1 qualified 81.5 3.4

[0061] Table 4. Results of SPF value test on human body

[0062] Group SPF value Example 1 33.6 Example 2 36.1 Example 3 30.2

[0063] Results analysis:

[0064] As shown in Table 3, Examples 1-3 exhibited high and stable initial SPF values ​​and excellent water resistance. After rinsing with water, the SPF value remained above 44, with an SPF loss rate of less than 12%. This was attributed to the synergistic combination of four key ingredients: inulin lauryl carbamate formed a dense and continuous flexible film, effectively fixing the sunscreen agent; sodium di(lauramide glutamine) lysine enhanced the adhesion between the film and the interface, significantly improving the wash resistance; ammonium acryloyl dimethyl taurate / VP copolymer optimized the uniformity and flexibility of the film layer, ensuring consistent UV blocking effect; and hydroxypropyl trimethylammonium chloride hyaluronic acid, through its cationic properties and moisturizing effect, further enhanced the adhesion and durability of the sunscreen agent.

[0065] The initial SPF and post-water-resistance SPF values ​​of Comparative Examples 1-6 were significantly lower than those of the Examples. Comparative Example 1 showed a significant decrease in water resistance due to the absence of sodium bis(lauramide-glutamine)lysine, indicating that this component is crucial for enhancing film adhesion and water resistance. Comparative Example 2, lacking inulin lauryl carbamate, exhibited insufficient film density, resulting in poor sunscreen fixation and low initial and water-resistance SPF. Comparative Example 3, lacking hydroxypropyltrimethylammonium chloride hyaluronic acid, showed decreased film moisturizing properties and affinity, leading to poorer water resistance and durability, and slight delamination, indicating compromised system stability. Comparative Example 4, lacking ammonium acryloyl dimethyl taurate / VP copolymer, showed insufficient film uniformity and flexibility, resulting in uneven sunscreen distribution and decreased SPF and water resistance. Comparative Example 5, using hydrogenated lecithin instead of inulin lauryl carbamate, resulted in severe oil-phase separation due to the inability of traditional emulsifiers to form an effective continuous film in the specific system, resulting in the worst performance across all aspects. In Comparative Example 6, after replacing hydroxypropyltrimethylammonium chloride hyaluronic acid with ordinary hyaluronic acid, the adhesion and durability of the sunscreen were significantly reduced due to the lack of cationic properties and film-forming auxiliary functions.

[0066] Regarding stability, all Examples 1-3 passed, indicating that the system is emulsified stably and has good compatibility. Comparative Example 3 showed slight stratification, and Comparative Example 5 showed oil-phase separation, proving that all four components are indispensable; otherwise, the overall stability of the system would be affected. Regarding thermal stability, the retention rates of Examples 1-3 were all above 94%, indicating that the compositions of the present invention have excellent thermal storage stability, and the sunscreen agents are not easily degraded or agglomerated. Compared to Example 2, the retention rates of Comparative Examples 1-6 decreased, further confirming the role of the compound system in maintaining the long-term stability of the sunscreen agents.

[0067] Examples 1-3 all received sensory scores higher than 4.3, with volunteers generally reporting that they "form a film quickly, feel light and thin on the skin, are non-greasy, and leave no residue," indicating that the composition of the present invention improves performance while also providing an excellent skin feel. In contrast, the comparative examples generally received lower sensory scores, especially Comparative Examples 5 and 6, which again demonstrates that the absence or substitution of any key component will negatively impact the user experience of the final product.

[0068] In summary, the sunscreen-enhancing film-forming system provided by this invention, composed of inulin lauryl carbamate, sodium bis(lauramide-glutamine)lysine, hydroxypropyltrimethylammonium chloride hyaluronic acid, and ammonium acryloyldimethyltaurate / VP copolymer, exhibits significantly superior performance compared to the comparative example in terms of sun protection properties, water resistance, stability, and skin feel. The comparative data demonstrates that the absence of any one component leads to a decline in performance. This composition is suitable for the development of high-end sunscreens and makeup primers, and possesses promising prospects for industrialization.

[0069] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A sunscreen lotion with excellent film-forming properties and sun protection stability, characterized in that, By weight percentage, the sunscreen lotion comprises 1-9% isoamyl p-methoxycinnamate, 1-8% octocrylene, 1-8% bis-ethylhexyloxyphenol methoxyphenyl triazine, 0.05-0.15% inulin lauryl carbamate, 0.05-0.3% sodium bis(lauramide-glutamine)lysine, 0.01-0.08% hydroxypropyltrimethylammonium chloride hyaluronic acid, 0.1-0.4% ammonium acryloyldimethyl taurate / VP copolymer, 1-10% glycerin, 1-10% diisopropyl sebacate, 1-15% dioctyl carbonate, 0.01-0.5% p-hydroxyacetophenone, 0.001-1% pH adjuster, and the balance being deionized water.

2. The method for preparing sunscreen lotion according to claim 1, characterized in that, The preparation method includes the following steps: Step 1. Heat sodium di(lauramide-glutamine)lysine, hydroxypropyltrimethylammonium chloride, hyaluronic acid, glycerol, and deionized water to 75-80℃ and stir to dissolve and mix evenly to obtain phase A; Step 2. Heat isoamyl p-methoxycinnamate, octocrylene, bis-ethylhexyloxyphenol methoxyphenyl triazine, diisopropyl sebacate and dioctyl carbonate to 75-80℃ and stir until homogeneous to obtain phase B; Step 3. Add phase B to phase A under homogenous stirring, maintain emulsification for 5-10 minutes, and obtain a mixed solution AB; Step 4. Cool the mixed solution AB to 45-50℃, add inulin lauryl carbamate and ammonium acryloyl dimethyl taurate / VP copolymer, stir until uniform, then cool to 35-40℃, add p-hydroxyacetophenone, adjust the pH to 6.5±0.2 with an appropriate amount of pH adjuster, filter and discharge to obtain the sunscreen lotion.

3. The application of the sunscreen emulsion with excellent film-forming properties and sun protection stability as described in claim 1 in the preparation of skin care products with sun protection effects.