Skin-nourishing and moisturizing sunscreen cream and preparation method thereof

Abstract

The invention provides a skin-nourishing and moisturizing sunscreen cream and a preparation method thereof, and the sunscreen cream comprises the following components in percentage by weight: 8-12% of a composite sunscreen system, 7-11% of a moisturizing system, 5-9% of an emulsifying and stabilizing system, 0.8-2.0% of a rheological modifier, 2.5-5.0% of an anticorrosive and antioxidant system, 0.5-3.0% of an active additive and the balance of water. The active additive is composed of a skin barrier repairing component, a soothing component and a biological protection component which are compounded according to a specific proportion and generate synergistic interaction with a sunscreen system. During preparation, a unique gradient cooling two-step adding method is adopted, biological protection and repairing components are added firstly, then a relieving and corrosion preventing system is added, and the efficiency of active matter is effectively protected. The product has multiple effects of stable high-power broad-spectrum sunscreen, excellent moisturizing, anti-inflammatory soothing and biological repairing, is high in safety and good in skin feeling, and solves the problems that a traditional sunscreen product is single in function, poor in stability and high in potential irritation.

Description

Technical Field

[0001] This invention relates to the field of cosmetic technology, and in particular to a skin-nourishing and moisturizing sunscreen and its preparation method. Background Technology

[0002] With the increasing awareness of sun protection, the market demand for sunscreen products has risen from basic protection to skin-nourishing effects. However, traditional sunscreens are mostly single-function, and high SPF formulas often come with an oily feel and stability challenges, easily burdening the skin. Furthermore, in pursuit of preservative effects, preservatives that can cause allergies are often added, making them unfriendly to sensitive skin. Although current technologies attempt to add active ingredients to sunscreen systems, these are mostly simple layerings, lacking synergy between components, making it difficult to achieve a true breakthrough in skin-nourishing protection. Moreover, active ingredients are easily deactivated during high-temperature emulsification. Therefore, developing a skin-nourishing sunscreen that is highly stable, has comprehensive effects, and is gentle and safe has become a pressing technical challenge for the industry. Summary of the Invention

[0003] In view of this, the present invention proposes a skin-nourishing and moisturizing sunscreen and its preparation method to solve the above problems.

[0004] The technical solution of the present invention is achieved as follows: a skin-nourishing, moisturizing and sun-protecting composition, comprising the following components by weight percentage: 8-12% of a composite sunscreen system, 7-11% of a moisturizing system, 5-9% of an emulsification stabilizing system, 0.8-2.0% of a rheology modifier, 2.5-5.0% of an antiseptic and antioxidant system, 0.5-3.0% of an active additive, and excipients or auxiliary ingredients acceptable for cosmetics or daily chemical products.

[0005] Preferably, the sunscreen system comprises ethylhexyl triazine ketone and methylene bis-benzotriazolyl tetramethyl butylphenol, wherein the weight percentage of ethylhexyl triazine ketone is 2.5-4.5% and the weight percentage of methylene bis-benzotriazolyl tetramethyl butylphenol is 5.0-7.5%.

[0006] Preferably, the moisturizing system comprises the following components: 3-7% glycerin, 1-4% butylene glycol, 0.5-2% 1,3-propanediol, and 0.1-1.0% sodium hyaluronate.

[0007] Preferably, the emulsifying stabilizing system comprises the following components by weight percentage: 2-5% polyglycerol-3-methylglucose distearate, 1-3% behenol, and 1-3% decyl glucoside.

[0008] Preferably, the rheology modifier comprises the following components by weight percentage: 0.2-1.0% carbomer, 0.2-1.0% acrylate / C10-30 alkanol acrylate crosspolymer, and 0.1-0.5% xanthan gum.

[0009] Preferably, the anti-corrosion and antioxidant system comprises the following components by weight percentage: 1.5-4.0% of a compound consisting of 1,2-hexanediol and 1,2-pentanediol, 0.3-1.0% of ethylhexylglycerin, and 0.3-1.0% of vitamin E.

[0010] Preferably, the active additive comprises the following components by weight percentage: 0.1-1.0% skin barrier repair component, 0.1-0.8% soothing component, and 0.05-0.5% bioprotective component.

[0011] Preferably, the skin barrier repair component is selected from at least one of panthenol, ectoine, and ceramide NP; the soothing component is selected from purslane extract; and the bioprotective component is selected from *Ipomoea purpurea* extract and *Thermophilicus thermophilus* fermentation product.

[0012] The present invention also provides a skin-nourishing and moisturizing sunscreen, comprising a skin-nourishing and moisturizing composition.

[0013] Preferably, the method for preparing the moisturizing sunscreen includes the following steps: (1) Preparation of oil phase: Polyglycerol-3-methylglucose distearate and behenol in the emulsified stabilizing system are mixed with the sunscreen agent in the composite sunscreen system, heated to 75-85℃, and stirred to completely dissolve and homogenize to obtain the oil phase; (2) Preparation of aqueous phase: Deionized water, glycerol, butylene glycol, 1,3-propanediol, decyl glucoside in the moisturizing system, and carbomer and acrylate / C10-30 alkanol acrylate cross-linked polymer in the rheology modifier are mixed, heated to 75-85℃, and stirred until completely dissolved and homogeneous to obtain aqueous phase; (3) Emulsification: At a shear rate of 2000-4000 rpm, the oil phase obtained in step (1) is slowly added to the aqueous phase obtained in step (2), and homogenization is carried out at a pressure of 0.3-0.5 MPa for 5-15 minutes to form a primary emulsion. (4) Cooling and Addition: The colostrum is cooled to 40-45℃ in a gradient of 2-3℃ / min. This stage is divided into two steps: a) First add the biological protective components and skin barrier repair components, and stir at low speed for 10-15 minutes; b) Add the soothing components and the preservative and antioxidant system, and mix at low speed for 5-10 minutes; The low-speed stirring rate mentioned in steps a and b is 400-600 rpm; (5) Adjustment and post-processing: Adjust the pH to 5.5-6.5, add xanthan gum, continue to stir slowly and cool to 30-35℃, discharge the material, and the skin-nourishing and moisturizing sunscreen cream is obtained.

[0014] Compared with the prior art, the beneficial effects of the present invention are: This invention achieves a comprehensive effect of sun protection, moisturizing, anti-inflammation, and repair by scientifically combining a sunscreen system with a three-dimensional active network of "repair-soothing-biological protection." Unexpected synergistic effects are generated between the active ingredients, significantly enhancing photoprotection and skin's resistance to damage. The optimized rheological regulation system and unique preparation process, especially the two-step cooling addition method, ensure the product's long-term physicochemical stability and extremely low SPF value decay rate. This invention gives the product five core advantages: broad-spectrum high protection, 24-hour long-lasting moisturizing, gentle on sensitive skin, active skin-nourishing properties, and safety and stability. It is especially suitable for people with sensitive skin, dry skin, and other skin types who have stringent requirements for sunscreen products, demonstrating significant technological innovation and market application value. Detailed Implementation

[0015] To better understand the technical content of this invention, specific embodiments are provided below to further illustrate the invention.

[0016] Unless otherwise specified, the experimental methods used in the embodiments of this invention are all conventional methods.

[0017] Unless otherwise specified, all materials and reagents used in the embodiments of this invention are commercially available.

[0018] In this invention (1) Portulaca oleracea extract, which meets the requirements of serial number 04547 in the "Catalogue of Used Cosmetic Raw Materials (2021 Edition)", with INCI name PORTULACA oleraceaEXTRACT, is prepared by the following method: Fresh whole purslane is taken, crushed and extracted twice by reflux with 50% v / v ethanol (2h each time, material-liquid ratio g / mL=1:10), the filtrates are combined and purified by macroporous resin, concentrated and dried to obtain an extract with a total flavonoid content ≥5%.

[0019] (2) The extract of Ahnfeltiopsis concinna meets the requirements of serial number 04665 in the "Catalogue of Used Cosmetic Raw Materials (2021 Edition)" and its INCI name is Ahnfeltiopsis concinna EXTRACT. The algae were prepared by the following method: the dried algae were crushed to 40 mesh and extracted with ultrasonic-assisted extraction using 40% v / v ethanol aqueous solution (material-liquid ratio g / mL=1:15), power 300W, temperature 50℃, time 60min. After purification by 10kDa ultrafiltration membrane, the extract was concentrated under reduced pressure and freeze-dried to obtain an extract with a total polysaccharide content ≥25%.

[0020] (3) The thermophilic bacteria were obtained from the China Industrial Microbial Culture Collection Center, with the Latin genus name Thermusthermophilus (accession number CICC 10647). After fermentation at a constant temperature of 65℃ for 36 hours, the viable count of the fermentation broth reached 1×10⁻⁶. 8 When the concentration of CFU / mL is 10 kDa, the fermentation broth is centrifuged to remove the bacterial cells. The supernatant is collected and purified using an ultrafiltration membrane with a molecular weight cutoff of 10 kDa. The filtrate is then collected to obtain the fermentation product of Thermophilic Bacterium thermophilum.

[0021] Example 1 A skin-nourishing and moisturizing sunscreen, comprising the following components by weight percentage: Table 1:

[0022] Example 2 A skin-nourishing and moisturizing sunscreen, comprising the following components by weight percentage: Table 2:

[0023] Example 3 A skin-nourishing and moisturizing sunscreen, comprising the following components by weight percentage: Table 3:

[0024] The above Examples 1-3 were prepared using the following methods: (1) Preparation of oil phase: Polyglycerol-3-methylglucose distearate and behenol in the emulsified stabilizing system are mixed with the sunscreen agent in the composite sunscreen system, heated to 80°C, and stirred to completely dissolve and homogenize to obtain the oil phase; (2) Preparation of aqueous phase: Deionized water, glycerol, butylene glycol, 1,3-propanediol, decyl glucoside in the moisturizing system, and carbomer and acrylate / C10-30 alkanol acrylate cross-linked polymer in the rheology modifier are mixed, heated to 80°C, and stirred until completely dissolved and homogeneous to obtain the aqueous phase; (3) Emulsification: At a shear rate of 3000 rpm, the oil phase obtained in step (1) is slowly added to the aqueous phase obtained in step (2), and homogenization is carried out for 10 minutes under a pressure of 0.4 MPa to form a primary emulsion; (4) Cooling and Addition: The colostrum is cooled to 40°C in a gradient of 3°C / min. This stage is divided into two steps: a) First add the biological protective components and skin barrier repair components, and stir at low speed of 500 rpm for 12 minutes; b) Add the soothing components and the preservative and antioxidant system, and mix at a low speed of 500 rpm for 8 minutes; (5) Adjustment and post-processing: Adjust the pH to 6, add xanthan gum, continue to stir slowly and cool down to 32°C, discharge the material, and the skin-nourishing and moisturizing sunscreen cream is obtained.

[0025] Compared with Example 3, the following comparative experiments were conducted: The raw materials were weighed according to the weight percentage in Table 4, and the preparation method was carried out according to the preparation method in the example.

[0026] Table 4:

[0027] Note: "-" in the table indicates no addition.

[0028] Comparative Example 7 The difference between this comparative example and Example 3 is that in step (4), all active additives are added at 42°C at once and stirred at 500 rpm for 20 minutes; the other steps are the same as the preparation method of the example.

[0029] Performance testing 1. Sunscreen performance test 1.1 In vitro SPF value and broad spectrum: The in vitro SPF value, critical wavelength (CW, >370nm indicates broad-spectrum protection), and UVA / UVB ratio of the samples were determined using an SPF analyzer.

[0030] Table 5: Sunscreen Performance Test Results

[0031] 1.2 Conclusion Analysis: The SPF values ​​and broad-spectrum activity of Examples 1 to 3 steadily increased with increasing sunscreen agent dosage, demonstrating that the formulations have good adjustability and predictability.

[0032] Comparing Example 3 with Comparative Examples 1-5 reveals that the three-dimensional synergistic system of "repair-soothing-biological protection" of the active additives not only undertakes the repair function but also provides crucial support for the broad-spectrum protection and UVA protection efficiency of the sunscreen system. The absence of any type of active additive leads to a decrease in broad-spectrum protection performance. This indicates that the active additives not only provide skincare benefits but also have a synergistic effect with the sunscreen system. This synergy not only enhances the skincare effect of the product but also directly contributes to the stability and broad-spectrum (critical wavelength) of the sunscreen efficacy (SPF value).

[0033] Comparative Examples 1, 3, and 4 lacked bioprotective components. The main components were highly active polysaccharides and heat-resistant enzymes contained in the extract of *Euphorbia milii* and fermentation products of *Thermophila thermophila*, which can promote the formation of a dense and uniform protective film on the skin surface and reduce the gaps in UVA penetration. A single active combination cannot achieve this synergistic film-forming effect.

[0034] Comparative samples 2 and 3 lacked soothing components, indicating that their anti-inflammatory properties may have reduced the damage to the skin barrier caused by UV-induced inflammatory responses, indirectly maintaining the functional integrity of the sunscreen film.

[0035] Comparative Example 5 uses a single biological protection component, replacing the compound system with only the extract of *Pseudomonas leucosus*. The polysaccharide component of *Pseudomonas leucosus* extract and the thermostable enzyme of the fermentation product of *Thermophilus thermophilus* have a synergistic effect. The former optimizes the membrane structure, and the latter enhances the membrane stability. Using them alone cannot achieve the same UVA protection efficiency.

[0036] Comparative Example 6 showed that the lack of a moisturizing system resulted in an incomplete emulsion film, which severely weakened the actual sun protection effect.

[0037] Comparative Example 7 was caused by the one-time high-temperature addition of active additives. The heat-sensitive active ingredients were deactivated by prolonged stirring at 42°C, losing their synergistic support function for the sunscreen system. After the active ingredients were deactivated, they could not assist the sunscreen agent in film formation and dispersion, resulting in a decrease in protective efficacy.

[0038] 2. In vitro efficacy testing 2.1 Anti-inflammatory effect: Using an LPS-induced human macrophage (THP-1) model, the inhibition rate of the key inflammatory factor interleukin-1α (IL-1α) in the cell supernatant was measured.

[0039] 2.2 Barrier repair effect: The cell migration rate (wound healing rate) was measured after 24 hours using the human keratinocyte (HaCaT) scratch assay.

[0040] Table 6: Results of in vitro efficacy tests

[0041] 2.3 Results Analysis The bioprotective components not only assist purslane extract in inhibiting IL-1α release but also promote cell migration by activating migration-related proteins in keratinocytes. Their absence weakens the synergistic support between the anti-inflammatory and repair pathways. The flavonoids in purslane extract can directly block the NF-κB inflammatory pathway; their absence significantly reduces early inflammation blocking ability. Ectoin can regulate extracellular matrix adhesion, providing a migration scaffold for keratinocytes. The results show that the absence of any one component leads to a decrease in both anti-inflammatory and barrier repair effects, demonstrating a significant synergistic effect of ectoin, purslane, *Ipomoea purpurea* extract, and *Thermophilus thermophilus* in anti-inflammatory and barrier repair processes.

[0042] 3. Stability Test 3.1 Accelerated Stability Test: The samples were placed in a 45°C incubator for 30 days and in a 50°C incubator for 7 days. The appearance was observed, the SPF value was measured, the decay rate was measured, and the centrifugation stability (4000 rpm, 30 min) was evaluated at specific time points.

[0043] SPF attenuation rate = [(Initial SPF value - Post-test SPF value) / Initial SPF value] × 100% 3.2 Cold and heat resistance tests: The sample was cycled three times at -10℃ (24 hours) and 45℃ (24 hours), and its condition was observed after returning to room temperature.

[0044] Table 7: Accelerated stability test results at 45℃ (30 days)

[0045] 3.3 Results Analysis Example 3 exhibited the best stability, with almost no SPF decay and stable physical state. In Comparative Example 6, with only 7% glycerol, the viscosity of the aqueous phase decreased sharply, allowing oil droplets to move very freely after shear homogenization and quickly aggregate and demulsify; the SPF decay rate of Comparative Example 7 was much higher than that of Example 3, demonstrating that the two-step addition process is crucial for maintaining the photostability of sunscreen agents.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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 skin-nourishing, moisturizing, and sun-protective composition, characterized in that, By weight percentage, it includes the following components: 8-12% complex sunscreen system, 7-11% moisturizing system, 5-9% emulsification stabilizing system, 0.8-2.0% rheology modifier, 2.5-5.0% preservative and antioxidant system, 0.5-3.0% active additives, and excipients or auxiliary ingredients acceptable for cosmetics or daily chemical products.

2. The skin-nourishing, moisturizing, and sun-protective composition as described in claim 1, characterized in that, The sunscreen system comprises ethylhexyl triazine ketone and methylene bis-benzotriazolyl tetramethyl butylphenol, wherein the weight percentage of ethylhexyl triazine ketone is 2.5-4.5% and the weight percentage of methylene bis-benzotriazolyl tetramethyl butylphenol is 5.0-7.5%.

3. The skin-nourishing, moisturizing, and sun-protective composition as described in claim 1, characterized in that, The moisturizing system comprises the following components: glycerin 3-7%, butylene glycol 1-4%, 1,3-propanediol 0.5-2%, and sodium hyaluronate 0.1-1.0%.

4. The skin-nourishing, moisturizing, and sun-protective composition as described in claim 1, characterized in that, The emulsified stabilizing system comprises the following components by weight percentage: 2-5% polyglycerol-3-methylglucose distearate, 1-3% behenol, and 1-3% decyl glucoside.

5. The skin-nourishing, moisturizing, and sun-protective composition as described in claim 1, characterized in that, The rheology modifier comprises the following components by weight percentage: 0.2-1.0% carbomer, 0.2-1.0% acrylate / C10-30 alkanol acrylate crosspolymer, and 0.1-0.5% xanthan gum.

6. The skin-nourishing, moisturizing, and sun-protective composition as described in claim 1, characterized in that, The anti-corrosion and antioxidant system comprises the following components by weight percentage: 1.5-4.0% of a compound consisting of 1,2-hexanediol and 1,2-pentanediol, 0.3-1.0% of ethylhexylglycerin, and 0.3-1.0% of vitamin E.

7. The skin-nourishing, moisturizing, and sun-protective composition as described in claim 1, characterized in that, The active additive comprises the following components by weight percentage: 0.1-1.0% skin barrier repair component, 0.1-0.8% soothing component, and 0.05-0.5% bioprotective component.

8. The skin-nourishing, moisturizing, and sun-protective composition as described in claim 7, characterized in that, The skin barrier repair component is selected from at least one of panthenol, ectoine, and ceramide NP; the soothing component is selected from purslane extract; and the bioprotective component is selected from *Ipomoea purpurea* extract and *Thermophilic bacteria* fermentation product.

9. A skin-nourishing and moisturizing sunscreen, characterized in that, It comprises a skin-nourishing and moisturizing composition as described in any one of claims 1-8.

10. The method for preparing the skin-nourishing and moisturizing sunscreen as described in claim 9, characterized in that, Includes the following steps: (1) Preparation of oil phase: Polyglycerol-3-methylglucose distearate and behenol in the emulsified stabilizing system are mixed with the sunscreen agent in the composite sunscreen system, heated to 75-85℃, and stirred to completely dissolve and homogenize to obtain the oil phase; (2) Preparation of aqueous phase: Deionized water, glycerol, butylene glycol, 1,3-propanediol, decyl glucoside in the moisturizing system, and carbomer and acrylate / C10-30 alkanol acrylate cross-linked polymer in the rheology modifier are mixed, heated to 75-85℃, and stirred until completely dissolved and homogeneous to obtain aqueous phase; (3) Emulsification: At a shear rate of 2000-4000 rpm, the oil phase obtained in step (1) is slowly added to the aqueous phase obtained in step (2), and homogenization is carried out at a pressure of 0.3-0.5 MPa for 5-15 minutes to form a primary emulsion. (4) Cooling and Addition: The colostrum is cooled to 40-45℃ in a gradient of 2-3℃ / min. This stage is divided into two steps: a) First add the biological protective components and skin barrier repair components, and stir at low speed for 10-15 minutes; b) Add the soothing components and the preservative and antioxidant system, and mix at low speed for 5-10 minutes; The low-speed stirring rate mentioned in steps a and b is 400-600 rpm; (5) Adjustment and post-processing: Adjust the pH to 5.5-6.5, add xanthan gum, continue to stir slowly and cool to 30-35℃, discharge the material, and the skin-nourishing and moisturizing sunscreen cream is obtained.

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