Composition for improving stability of L-ascorbic acid in cosmetics, cosmetics and preparation method

Abstract

The invention discloses a composition for improving the stability of L-ascorbic acid in cosmetics, the cosmetics and a preparation method, and the composition for improving the stability of the L-ascorbic acid is prepared from 1-5 parts of acrylate copolymer, 0.1-0.5 part of chromanol and 30-60 parts of polyhydric alcohol. By using the compound composition with the specific proportion in cosmetics, the synergistic effect can be achieved, oxidative degradation and activity loss of L-ascorbic acid can be remarkably inhibited, the product discoloration phenomenon can be effectively delayed, meanwhile, the stability of L-ascorbic acid can be effectively improved, the stable active ingredient content can be kept, and high biological activity can be maintained.

Description

Technical Field

[0001] This application belongs to the field of daily cosmetic technology, and particularly relates to a composition, cosmetic, and preparation method for improving the stability of L-ascorbic acid in cosmetics. Background Technology

[0002] Vitamin C, also known as L-ascorbic acid, is a widely used water-soluble active ingredient in cosmetics. It can not only achieve antioxidant and age spot fading effects by scavenging free radicals and inhibiting tyrosinase activity, but also stimulate collagen production at high concentrations, thus exerting anti-aging effects.

[0003] Currently, products containing L-ascorbic acid generally suffer from problems such as short shelf life, rapid discoloration, and easy oxidation and degradation, making it difficult to balance long-term stability and efficacy, which greatly limits their further application in the cosmetics field. Summary of the Invention

[0004] This application provides a composition, cosmetic, and preparation method for improving the stability of L-ascorbic acid in cosmetics, which can prevent the inactivation of L-ascorbic acid and ensure both long-term stability and efficacy.

[0005] In a first aspect, this application provides a composition for improving the stability of L-ascorbic acid, comprising, by weight parts: 100 parts of a polyol; 0.5 to 15 parts of an acrylate compound based on 100 parts of the polyol; and 0.1 to 1.5 parts of a chromol based on 100 parts of the polyol.

[0006] In any embodiment of this application, the acrylate compound is present in parts by weight of 1 to 13; and / or, the chromol is present in parts by weight of 0.5 to 1.3.

[0007] In any embodiment of this application, the acrylate compound includes α-cyano-β,β-diphenyl ethyl acrylate; and / or, the chromol includes at least one of dimethylmethoxybenzodihydropyranol, γ-chromol, 6-hydroxy-2,5,7,8-tetramethylchromol-2-carboxylic acid, and chromol palmitate; and / or, the polyol includes at least one of 1,3-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-propanediol, and methylpropanediol.

[0008] In a second aspect, this application provides a cosmetic comprising L-ascorbic acid, the cosmetic comprising the composition described in the first aspect; and / or, based on the total mass of the cosmetic, the mass percentage of L-ascorbic acid in the cosmetic is 10% to 40%; and / or, based on the total mass of the cosmetic, the mass percentage of the composition in the cosmetic is 10% to 55%.

[0009] In any embodiment of this application, the cosmetic also includes cosmetic excipients.

[0010] In any embodiment of this application, acceptable excipients in cosmetics include at least one of solubilizers, emulsifiers, pH adjusters, emollients, humectants, preservatives, chelating agents, and skin conditioning agents; and / or, solubilizers include at least one of isosorbide dimethyl ether, ethoxydiethylene glycol, and bis-diethoxydiethylene cyclohexane 1,4-dicarboxylic acid ester; and / or, emulsifiers include at least one of complex nonionic emulsifiers, lecithin, lanolin, and lanolin alcohol, wherein the complex nonionic emulsifier comprises 54% PPG-26-butanol polyether-26, 36% PEG-40 hydrogenated castor oil, and 10% water; and / or, pH adjusters include sodium hydroxide, potassium hydroxide, and arginine. The ingredients include at least one of sodium citrate, triethanolamine, and tromethamine; and / or, emollients include at least one of squalene, jojoba seed oil, castor oil, shea butter, beeswax, and shea butter; and / or, moisturizers include at least one of glycerin, hyaluronic acid, trehalose, honey, inositol, urea, panthenol, and betaine; and / or, preservatives include at least one of p-hydroxyacetophenone, 1,2-hexanediol, 1,2-pentanediol, ethylhexylglycerin, and phenoxyethanol; and / or, chelating agents include at least one of disodium ethylenediaminetetraacetate, ethylenediaminetetraacetic acid, and tetrasodium ethylenediaminetetraacetate; and / or, skin conditioning agents include at least one of vitamin E, ceramide, and p-hydroxyacetophenone.

[0011] In any embodiment of this application, the particle size distribution of the particles in the cosmetic satisfies: Dv(95)≤150nm and Dv(2)≥10nm.

[0012] Thirdly, this application provides a method for preparing a cosmetic containing L-ascorbic acid, comprising: mixing a polyol, an acrylate compound, a first excipient, and deionized water, then adding L-ascorbic acid, heating and stirring to obtain phase A; mixing chromoyl alcohol, a second excipient, and deionized water, heating and homogenizing under high pressure to obtain phase B; slowly adding phase B to phase A under stirring conditions, mixing evenly to obtain a slurry precursor, cooling the slurry precursor and adjusting the pH to 3.5-5.0, and then homogenizing under high pressure to obtain a cosmetic containing L-ascorbic acid, wherein, based on the total mass of the cosmetic, L-ascorbic acid accounts for 10%-40% of the cosmetic by mass, the polyol, acrylate compound, and chromoyl alcohol account for 10%-55% of the cosmetic by mass, the weight ratio of polyol to acrylate compound is 100:(0.5-15), and the weight ratio of polyol to chromoyl alcohol is 100:(0.1-1.5).

[0013] In any embodiment of this application, in the step of mixing polyol, acrylate compound, first excipient and deionized water and adding L-ascorbic acid, heating and stirring to obtain phase A, the heating temperature is maintained at 35°C to 45°C; and / or, in the step of mixing chromol, second excipient and deionized water, heating and performing high-pressure homogenization to obtain phase B, the heating temperature is maintained at 35°C to 45°C, and the high-pressure homogenization includes high-pressure microfluidic homogenization at a pressure of 3000 to 8000 bar, and the number of homogenization treatments is 5 to 10 times; And / or, under stirring conditions, phase B is slowly added to phase A, and after mixing evenly, a slurry precursor is obtained. The slurry precursor is then cooled and the pH is adjusted to 3.5–5.0, followed by high-pressure homogenization to obtain a cosmetic containing L-ascorbic acid. In this step, the cooling treatment includes cooling the slurry precursor to 25°C, and the high-pressure homogenization includes high-pressure microfluidic homogenization at 3000–8000 bar, with the homogenization process repeated 5–10 times. And / or, the first excipient and the second excipient each include excipients acceptable in cosmetics.

[0014] Fourthly, this application provides the use of the composition as described in the first aspect in the preparation of products that improve the stability of L-ascorbic acid, the products including at least one of cosmetics, skin care products, health products, and pharmaceuticals.

[0015] Compared to existing technologies, the composition for improving the stability of L-ascorbic acid in this application comprises 1-5 parts of acrylate copolymer, 0.1-0.5 parts of chromoyl alcohol, and 30-60 parts of polyol. By using this specific ratio of compound composition in cosmetics, a synergistic effect can be achieved, significantly inhibiting the oxidative degradation and activity loss of L-ascorbic acid, effectively delaying product discoloration, and simultaneously improving the stability of L-ascorbic acid, maintaining a stable content of active ingredients, and preserving high biological activity. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the product state of the cosmetic containing L-ascorbic acid prepared in Example 1 of this application after undergoing a high and low temperature alternating cycle test.

[0018] Figure 2 This is a schematic diagram of the product state of the cosmetic containing L-ascorbic acid prepared in Comparative Example 2 of this application after undergoing a high and low temperature alternating cycle test.

[0019] Figure 3 This is a schematic diagram of the product state of the cosmetic containing L-ascorbic acid prepared in Comparative Example 3 of this application after photostability testing. Detailed Implementation

[0020] To make the purpose, technical solution, and beneficial technical effects of this application clearer, the following detailed description is provided in conjunction with embodiments. It should be understood that the implementation details described in this specification are merely for illustrative purposes and are not intended to limit the scope of this application.

[0021] For simplicity, this application only explicitly discloses some numerical ranges. However, any lower limit can be combined with any upper limit to form a range not explicitly stated; and any lower limit can be combined with other lower limits to form a range not explicitly stated, just as any upper limit can be combined with any other upper limit to form a range not explicitly stated. Furthermore, although not explicitly stated, every point or individual value between the endpoints of the range is included within that range. Therefore, each point or individual value can be used as its own lower or upper limit and combined with any other point or individual value or with other lower or upper limits to form a range not explicitly stated.

[0022] It should be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0023] Unless otherwise stated, the values ​​of the parameters mentioned in this application can be measured using various measurement methods commonly used in the art (e.g., they can be tested according to the methods given in the embodiments of this application). Unless otherwise stated, the test temperature for all parameters mentioned in this application is 25°C and the test pressure is standard atmospheric pressure.

[0024] The foregoing description of this application is not intended to describe every disclosed implementation or method. Instead, the following description provides more specific examples of exemplary embodiments. Throughout the application, guidance is provided through a series of embodiments, which can be used in various combinations. The examples listed are representative only and should not be construed as exhaustive.

[0025] Vitamin C, a water-soluble vitamin also known as L-ascorbic acid, is a common ingredient in cosmetics. It not only has antioxidant and free radical scavenging effects, but also inhibits the formation of tyrosinase, thereby achieving whitening and spot-fading effects. There are also reports that when L-ascorbic acid reaches a certain concentration, it can promote the production of collagen in the skin and help fight aging.

[0026] However, the stability of L-ascorbic acid in cosmetic systems has always been a key bottleneck restricting its widespread application. During storage, transportation, and use, it is highly susceptible to degradation by various environmental factors: light, such as ultraviolet radiation, accelerates its oxidation reaction; oxygen in the air can directly react with it in a redox reaction; and increased temperature significantly increases the reaction rate, promoting its decomposition. This instability is most directly manifested in the color change of cosmetics—gradually deepening from an initial pale yellow to a brownish-red. This process is not only a clear visual signal of L-ascorbic acid oxidative degradation but also signifies the loss of its active ingredients. Color changes severely impact consumers' perception of product quality, reducing market acceptance. Simultaneously, the degradation of active ingredients leads to a significant weakening or even loss of its original antioxidant, whitening, and anti-aging effects, failing to achieve the expected skincare results. Furthermore, byproducts that may be generated during degradation can potentially irritate or adversely affect the skin, compromising product safety.

[0027] In view of the above problems, the inventors propose a composition, cosmetic and preparation method for improving the stability of L-ascorbic acid in cosmetics.

[0028] The first aspect of this application provides a composition for improving the stability of L-ascorbic acid, comprising, by weight parts: 100 parts of a polyol; 0.5 to 15 parts of an acrylate compound based on 100 parts of the polyol; and 0.1 to 1.5 parts of a chromol based on 100 parts of the polyol.

[0029] For example, the weight parts of the acrylate compound can be 0.5 parts, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts or 15 parts.

[0030] For example, the weight parts of chromol can be 0.1 parts, 0.5 parts, 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts or 1.5 parts.

[0031] In some embodiments, the acrylate compound is present in parts by weight of 1 to 13; and / or, the chromol is present in parts by weight of 0.5 to 1.3.

[0032] α-Cyano-β,β-Diphenylethyl acrylate itself has sunscreen properties and can combat ultraviolet radiation; chromol is a scavenger of ROS (oxygen free radicals) and RNS (nitrogen free radicals), possessing antioxidant properties; the chemical structure of polyols contains multiple hydroxyl groups (OH groups), which have reducing properties and readily undergo redox reactions with oxygen, thereby reducing the concentration of dissolved oxygen in water. High concentrations of polyols will rapidly consume dissolved oxygen in water, thus isolating the active ingredients from contact with oxygen to a certain extent. The above-mentioned specific amounts of polyols, acrylate compounds, and chromol compound composition can exert a synergistic effect, significantly inhibiting the oxidative degradation and activity loss of L-ascorbic acid, effectively delaying product discoloration, and effectively improving the stability of L-ascorbic acid, maintaining a stable content of active ingredients, and maintaining high biological activity.

[0033] In some embodiments, the acrylate compound includes α-cyano-β,β-diphenyl ethyl acrylate; and / or, the chromol includes at least one of dimethylmethoxybenzodihydropyranol, γ-chromol, 6-hydroxy-2,5,7,8-tetramethylchromol-2-carboxylic acid, and chromol palmitate; and / or, the polyol includes at least one of 1,3-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-propanediol, and methylpropanediol.

[0034] A second aspect of the embodiments of this application provides a cosmetic comprising L-ascorbic acid, the cosmetic comprising the composition described in the first aspect; and / or, based on the total mass of the cosmetic, the mass percentage of L-ascorbic acid in the cosmetic is 10% to 40%; and / or, based on the total mass of the cosmetic, the mass percentage of the composition in the cosmetic is 10% to 55%.

[0035] For example, based on the total mass of the cosmetic, the mass percentage of L-ascorbic acid in the cosmetic can be 10%, 15%, 20%, 25%, 30%, 35%, or 40%.

[0036] This concentration range ensures that L-ascorbic acid can fully exert its antioxidant, whitening, and anti-aging bioactivities, while also being compatible with the synergistic effects of the other components in the composition. When L-ascorbic acid is at this concentration, the polyol can better form hydrogen bonds with it, avoiding molecular aggregation caused by excessive concentration and reduced stability; the network structure of acrylate compounds can also more effectively encapsulate and protect a certain amount of L-ascorbic acid, reducing its contact with oxygen, etc.; the complementary antioxidant effect of cromoglycan can also effectively scavenge free radicals that may be generated by L-ascorbic acid at this concentration, thereby synergistically maintaining its stability.

[0037] For example, based on the total mass of the cosmetic, the composition may constitute 10%, 15%, 20%, 25%, 30%, 31%, 32%, 33%, 33.1%, 33.2%, 33.3%, 33.4%, 33.5%, 34%, 35%, 40%, 45%, 50%, or 55% of the total mass of the cosmetic.

[0038] The 10%–55% proportion corresponds to the 10%–40% content of L-ascorbic acid in cosmetics, forming a reasonable ratio. This composition provides sufficient protection for the high concentration of L-ascorbic acid while avoiding redundancy due to an excessively high proportion of the compound itself. This ensures that L-ascorbic acid maintains a stable microenvironment while exerting its biological activities (such as promoting collagen synthesis and inhibiting tyrosinase), effectively delaying product discoloration and maintaining stable active ingredient content and high biological activity.

[0039] In some embodiments, cosmetics also include cosmetic excipients.

[0040] In some embodiments, acceptable excipients in cosmetics include at least one of solubilizers, emulsifiers, pH adjusters, emollients, humectants, preservatives, chelating agents, and skin conditioning agents.

[0041] In some embodiments, the solubilizer includes at least one of isosorbide dimethyl ether, ethoxydiethylene glycol, and bis-diethoxydiethylene cyclohexane 1,4-dicarboxylic acid ester.

[0042] Solubilizers such as isosorbide dimethyl ether can improve the solubility and dispersibility of L-ascorbic acid and other active ingredients in the system, preventing accelerated oxidative degradation due to excessively high local concentrations. A uniform dispersion allows the hydration film protection of polyols and the network barrier of acrylate compounds to act more evenly on L-ascorbic acid molecules, reducing oxidation dead zones.

[0043] In some embodiments, the emulsifier includes at least one of a complex nonionic emulsifier, lecithin, lanolin, and lanolin alcohol, wherein the complex nonionic emulsifier comprises 54% PPG-26-butanol polyether-26, 36% PEG-40 hydrogenated castor oil, and 10% water.

[0044] Emulsifiers, especially complex nonionic emulsifiers, can stabilize the emulsion system of cosmetics and prevent local component concentration imbalances caused by layering or demulsification. A stable system environment ensures that the antioxidant effect of chromol and the protective effect of polyols are maintained and evenly, preventing L-ascorbic acid from being exposed to an adverse environment due to system instability.

[0045] pH adjusters include at least one of sodium hydroxide, potassium hydroxide, arginine, sodium citrate, triethanolamine, and tromethamine.

[0046] pH adjusters, such as sodium hydroxide and arginine, can maintain the pH of the system within a suitable range for L-ascorbic acid stability (usually an acidic environment). L-ascorbic acid is prone to structural damage under inappropriate pH conditions. pH adjusters stabilize the acid-base environment, reducing oxidative degradation caused by structural changes, and complement the antioxidant effect of cromoglyl to jointly maintain its activity.

[0047] Emollients include at least one of squalene, jojoba seed oil, castor oil, shea butter, beeswax, and shea butter.

[0048] Emollients such as squalene and jojoba seed oil can form a hydrophobic protective film on the skin's surface, reducing the contact between external oxygen and pollutants and the skin and cosmetic systems. This, combined with the physical barrier effect of acrylate compounds, further reduces the probability of L-ascorbic acid oxidation and delays discoloration.

[0049] Moisturizers include at least one of glycerin, hyaluronic acid, trehalose, honey, inositol, urea, panthenol, and betaine.

[0050] Moisturizers such as glycerin and hyaluronic acid can enhance the system's water retention capacity and maintain the stability of the hydration film formed by polyols. Adequate moisture can enhance the protection of L-ascorbic acid by the hydrogen bond network, reduce the aggregation and degradation of active ingredients caused by drying, and, in conjunction with the free radical scavenging effect of cromoglyl, maintain its biological activity.

[0051] The preservatives include at least one of p-hydroxyacetophenone, 1,2-hexanediol, 1,2-pentanediol, ethylhexylglycerin, and phenoxyethanol.

[0052] Preservatives such as p-hydroxyacetophenone and 1,2-hexanediol not only inhibit the growth of microorganisms, but some preservatives (such as p-hydroxyacetophenone) also have certain antioxidant properties, which can help chromol remove free radicals in the system and reduce the loss of activity of L-ascorbic acid due to oxidative stress caused by microbial metabolism.

[0053] The chelating agent includes at least one of disodium ethylenediaminetetraacetate, ethylenediaminetetraacetic acid, and tetrasodium ethylenediaminetetraacetate.

[0054] Chelating agents, such as disodium ethylenediaminetetraacetate, can chelate metal ions (such as iron and copper ions) in the system. These metal ions are catalysts for the oxidative degradation of L-ascorbic acid. By reducing their activity, chelating agents interrupt the catalytic pathway of the oxidation reaction and, in synergy with the protective systems of polyols and acrylate compounds, reduce the triggering factors for oxidative degradation.

[0055] Skin conditioning agents include at least one of vitamin E, ceramides, and p-hydroxyacetophenone.

[0056] Skin conditioning agents such as vitamin E are antioxidants themselves, and can form an antioxidant team with cromoglycine to enhance the ability to scavenge free radicals; ceramides can strengthen the skin barrier, reduce the impact of external stimuli on the cosmetic system, and indirectly maintain the stable environment of L-ascorbic acid.

[0057] In some embodiments, the particle size distribution of the particles in the cosmetic satisfies: Dv(95)≤150nm and Dv(2)≥10nm.

[0058] Dv(95)≤150nm means that 95% of the particles in the system have a diameter of no more than 150nm. Smaller particle size increases the specific surface area of ​​the particles, allowing them to be more uniformly dispersed in the system. This uniform dispersion allows the particles to fully contact L-ascorbic acid molecules. On the one hand, the particles can act as a "carrier" or "barrier," encapsulating part of the L-ascorbic acid and reducing its direct contact with external oxidizing factors such as oxygen and light. Together with the network structure formed by acrylate compounds, they enhance the physical barrier effect. On the other hand, the increased specific surface area also helps polyols form a more stable hydration film on the particle surface, further strengthening the protection of L-ascorbic acid. Dv(2)≥10nm avoids the disadvantages that may be caused by excessively small particle size (such as less than 10nm). Small particles are prone to agglomeration, leading to poor dispersibility of the system, which in turn increases the local concentration of L-ascorbic acid and increases the risk of oxidative degradation. Particles with a diameter of at least 10 nm maintain good dispersion stability, ensuring uniform protection of L-ascorbic acid. This, combined with the stabilizing effect of emulsifiers, maintains system homogeneity and reduces oxidative degradation caused by local concentration imbalances. Furthermore, this particle size distribution synergizes with the antioxidant effect of cromoglyl. Uniformly dispersed particles act as "anchors" for antioxidant components, making it easier for cromoglyl to accumulate around them, increasing the local concentration of antioxidant components, enhancing the scavenging efficiency of free radicals around L-ascorbic acid, and reducing the loss of activity of L-ascorbic acid due to oxidation. Simultaneously, the suitable particle size avoids affecting the bioactivity of L-ascorbic acid, ensuring its unimpeded performance in whitening and anti-aging effects, maintaining high bioactivity. Additionally, this particle size distribution reduces abnormal light scattering and absorption in the system, minimizing the stimulation of L-ascorbic acid by light and delaying photo-induced oxidative discoloration. When used in conjunction with chelating agents, the particles can also adsorb some metal ions, assisting the chelating agents in reducing their catalytic effect on the oxidative degradation of L-ascorbic acid, and further improving stability.

[0059] A third aspect of this application provides a method for preparing a cosmetic containing L-ascorbic acid, comprising: mixing a polyol, an acrylate compound, a first excipient, and deionized water, then adding L-ascorbic acid, heating and stirring to obtain phase A; mixing chromoyl alcohol, a second excipient, and deionized water, heating and homogenizing under high pressure to obtain phase B; slowly adding phase B to phase A under stirring conditions, mixing evenly to obtain a slurry precursor, cooling the slurry precursor and adjusting the pH to 3.5-5.0, then homogenizing under high pressure to obtain a cosmetic containing L-ascorbic acid, wherein, based on the total mass of the cosmetic, L-ascorbic acid accounts for 10%-40% of the cosmetic by mass, the polyol, acrylate compound, and chromoyl alcohol account for 10%-55% of the cosmetic by mass, the weight ratio of polyol to acrylate compound is 100:(0.5-15), and the weight ratio of polyol to chromoyl alcohol is 100:(0.1-1.5).

[0060] In the preparation of phase B, the use of high-pressure microfluidic equipment has significant advantages. The high-intensity shear and impact forces generated by this equipment promote full contact and tight binding between the solubilizer and chromol, resulting in smaller product particle size and a more stable dispersion system. Simultaneously, after high-pressure microfluidic treatment, chromol is more uniformly dispersed in the system, avoiding localized excessively high or low concentrations. This allows it to more efficiently capture free radicals around L-ascorbic acid, synergistically exerting antioxidant effects with polyols and acrylate compounds, greatly improving overall antioxidant efficiency. For the same formulation, after this process, the uniform dispersion of chromol and other components, along with their full combination with other components, more continuously inhibits the oxidative degradation of L-ascorbic acid, making the formulation less prone to discoloration caused by oxidation, significantly enhancing stability, and achieving the optimal effect of inhibiting L-ascorbic acid oxidative degradation and delaying discoloration. Furthermore, in the emulsification step after adding phase B to phase A, combined with stirring and subsequent high-pressure homogenization, the distribution of active ingredients such as L-ascorbic acid in the product becomes more uniform. This uniform distribution prevents the active ingredients from precipitating due to localized aggregation, ensuring their stable presence in the cosmetic system. In contrast, if the same formulation uses a conventional emulsification process, insufficient dispersion makes it difficult to achieve a uniform distribution of active ingredients. After a period of time, the system's stability decreases, leading to particle precipitation, which in turn affects the stability and bioactivity of L-ascorbic acid. This process, tailored to the proportions and contents of each component in the formulation, ensures that L-ascorbic acid, polyols, acrylates, and chromols are in a reasonable ratio. By optimizing dispersion and emulsification, the synergistic effect of polyols, acrylates, and chromols is further enhanced, ultimately resulting in cosmetics containing L-ascorbic acid that are more stable, have a more uniform distribution of active ingredients, and are less prone to discoloration and precipitation.

[0061] In some embodiments, in the step of mixing polyol, acrylate compound, first excipient, and deionized water, adding L-ascorbic acid, heating and stirring to obtain phase A, the heating temperature is maintained at 35°C to 45°C; and / or, in the step of mixing chromol, second excipient, and deionized water, heating, and subjecting to high-pressure homogenization to obtain phase B, the heating temperature is maintained at 35°C to 45°C, and the high-pressure homogenization includes high-pressure microfluidic homogenization at 3000 to 8000 bar, and the number of homogenization treatments is 5 to 10 times; and / or Alternatively, under stirring conditions, phase B is slowly added to phase A, and after uniform mixing, a slurry precursor is obtained. The slurry precursor is then cooled and the pH is adjusted to 3.5–5.0, followed by high-pressure homogenization to obtain a cosmetic containing L-ascorbic acid. In this step, the cooling treatment includes cooling the slurry precursor to 25°C, and the high-pressure homogenization includes high-pressure microfluidic homogenization at 3000–8000 bar, with the homogenization process repeated 5–10 times. And / or, the first excipient and the second excipient each comprise excipients acceptable for use in cosmetics.

[0062] A fourth aspect of this application provides the use of the composition as described in the first aspect in the preparation of products that improve the stability of L-ascorbic acid, the products including at least one of cosmetics, skin care products, health products, and pharmaceuticals.

[0063] Example

[0064] The following embodiments describe the disclosure of this application in more detail. These embodiments are for illustrative purposes only, as various modifications and variations will be apparent to those skilled in the art within the scope of the disclosure of this application. Unless otherwise stated, all parts, percentages, and ratios reported in the following embodiments are based on mass, and all reagents used in the embodiments are commercially available or synthesized by conventional methods and can be used directly without further processing, and the instruments used in the embodiments are commercially available.

[0065] 1,3-Propanediol was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., product number P108208;

[0066] α-Cyano-β,β-Diphenylethyl acrylate was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., item number E122424-25g;

[0067] Dimethylmethoxybenzodihydropyranol was purchased from Zhuhai Bairui Pharmaceutical Technology Co., Ltd.

[0068] L-Ascorbic acid was purchased from Senxin Flavor & Pigment Technology (China) Co., Ltd.

[0069] The composite nonionic emulsifier (i.e., LRI, consisting of 54% PPG-26-butanol polyether-26, 36% PEG-40 hydrogenated castor oil and 10% water) was purchased from DSM (DSM (China) Co., Ltd.).

[0070] γ-Chromol was purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd., product number T1782;

[0071] 1,2-Propanediol was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., product number P103433;

[0072] Butylene glycol was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., product number B111016;

[0073] 2-Ethylhexyl-2-cyano-3,3-diphenylacrylate was purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., product number E108021;

[0074] δ-Tocopherol was purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd., product number 47784.

[0075] Example 1

[0076] Example 1 of this application provides a cosmetic containing L-ascorbic acid, the preparation method of which is as follows:

[0077] S1, 1,3-propanediol, α-cyano-β,β-diphenylacrylate ethyl ester, isosorbide dimethyl ether and deionized water were mixed and then L-ascorbic acid was added. The mixture was stirred and dissolved at 40°C until no particles were present, and then kept at 40°C to obtain phase A.

[0078] S2, dimethylmethoxybenzodihydropyranol, LRI, vitamin E and deionized water are mixed and heated to 40°C, and then subjected to high pressure micro-jet 6500 bar pressure and high pressure homogenization 6 times to obtain clear and transparent phase B;

[0079] S3, under stirring conditions, phase B is slowly added to phase A and stirred until completely fused to obtain a slurry precursor. The slurry precursor is cooled to 25°C and its pH is adjusted to 4.5 using a sodium hydroxide solution with a mass fraction of 0.01% to 2%. Then, it is subjected to high-pressure micro-jet 6500 bar pressure and high-pressure homogenization 6 times to obtain a clear and transparent cosmetic containing L-ascorbic acid.

[0080] The formulation of the cosmetic containing L-ascorbic acid is shown in Table 1. The content (%) of each component in Table 1 is calculated based on the total mass of the cosmetic.

[0081] Example 2

[0082] The only difference between Example 2 and Example 1 is that dimethylmethoxybenzodihydropyranol is replaced by γ-chromanol in equal amounts.

[0083] Example 3

[0084] The only difference between Example 3 and Example 1 is that 1,3-propanediol is replaced with 1,2-propanediol in equal amounts.

[0085] Comparative Example 1

[0086] The only difference between Comparative Example 1 and Example 1 is that 1,3-propanediol is replaced with an equal amount of 1,3-butanediol.

[0087] Comparative Example 2

[0088] The only difference between Comparative Example 2 and Example 1 is that α-cyano-β,β-diphenyl acrylate is replaced in equal amounts with 2-ethylhexyl-2-cyano-3,3-diphenyl acrylate.

[0089] Comparative Example 3

[0090] The only difference between Comparative Example 3 and Example 1 is that dimethylmethoxybenzodihydropyranol is replaced with δ-tocopherol in equal amounts.

[0091] Table 1

[0092]

[0093] Detection

[0094] Test methods

[0095] I. Cold Resistance Stability Test

[0096] At a test temperature of -15±1℃, the cosmetics prepared in Examples 1-3 and Comparative Examples 1-3 were tested for appearance, color, odor, and usability. Samples were taken periodically at weeks 0, 6, and 12. The test methods referred to T / SHRH058—2024 "Guidelines for Stability Testing of Cosmetics". II. Room Temperature Stability Test

[0097] The cosmetics prepared in Examples 1-3 and Comparative Examples 1-3 were tested for appearance, color, odor, and usability at a test temperature of 25℃±1℃. Samples were taken and tested periodically at weeks 0, 6, and 12. The test methods were in accordance with T / SHRH058—2024 "Guidelines for Stability Testing of Cosmetics".

[0098] III. Heat Resistance Stability Test

[0099] The cosmetics prepared in Examples 1-3 and Comparative Examples 1-3 were tested for appearance, color, odor, and usability at a test temperature of 48±1℃. Samples were taken and tested periodically at weeks 0, 6, and 12. The test methods were in accordance with T / SHRH 058—2024 "Guideline for Stability Testing of Cosmetics".

[0100] IV. Stability Test under Alternating High and Low Temperature Cyclic Conditions

[0101] Each cycle consisted of high temperature (48°C, 12h) → room temperature (25°C, 1h) → low temperature (-15°C, 12h) → room temperature (25°C, 1h), and was repeated. Under these cyclic conditions, the cosmetics prepared in Examples 1-3 and Comparative Examples 1-3 were tested for appearance, color, odor, and usability, with samples taken periodically at weeks 0, 6, and 12. The test methods followed T / SHRH058—2024, "Guidelines for Stability Testing of Cosmetics".

[0102] V. Light stability test

[0103] Under D65 light irradiation, the cosmetics prepared in Examples 1-3 and Comparative Examples 1-3 were tested for appearance, color, odor, and usability. Samples were taken periodically at weeks 0, 6, and 12. The test methods were in accordance with T / SHRH 058—2024, "Guidelines for Stability Testing of Cosmetics".

[0104] VI. L-Ascorbic Acid Content Detection

[0105] The L-ascorbic acid content was determined by high performance liquid chromatography (HPLC) to obtain the L-ascorbic acid content retention rate. The detection method is as follows:

[0106] The sample was accurately weighed, extracted with an appropriate amount of dilute acid solution and diluted to a fixed volume. After filtration through a 0.22 μm microporous membrane, the sample was injected for analysis. A C18 column was used with gradient elution using methanol-phosphate buffer solution as the mobile phase. The detection wavelength was set to 245 nm. The real-time content of L-ascorbic acid in the sample was calculated by the external standard method and compared with the initial feed content to calculate the content retention rate.

[0107] Experimental results

[0108] The results of the stability test are shown in Table 2-4, and the results of the L-ascorbic acid content detection test are shown in Table 5.

[0109] Table 2

[0110]

[0111] Table 3

[0112]

[0113] Table 4

[0114]

[0115] The results in Tables 2-4 show that the use of polyols, acrylate compounds, and chromoyl alcohols of specific amounts and types as described in this invention can have a synergistic effect, effectively improving the stability of L-ascorbic acid in cosmetics in terms of appearance, color, odor, and usability. Figure 1 This is a schematic diagram of the product state of the cosmetic containing L-ascorbic acid prepared in Example 1 of this application after high and low temperature alternating cycle test. It can be seen that the product solution is still clear and transparent. Figure 2 This is a schematic diagram of the product state of the cosmetic containing L-ascorbic acid prepared in Comparative Example 2 of this application after high and low temperature alternating cycle test. It can be seen that the product has poor stability, the solution is yellow and accompanied by precipitation. Figure 3 This is a schematic diagram of the product state of the cosmetic containing L-ascorbic acid prepared in Comparative Example 3 of this application after photostability testing. It can be seen that the solution is brownish-red and accompanied by precipitation, which further indicates that the polyols, acrylate compounds and chromols of specific amounts and types in this application, as a complex stabilizing system, significantly improve the stability of L-ascorbic acid in cosmetics through synergistic effects. This not only effectively inhibits the degradation of active ingredients, but also shows a synergistic protective effect in terms of the appearance, color retention, odor stability and performance of the formulation.

[0116] Table 5

[0117]

[0118] The results in Table 5 show that the use of polyols, acrylate compounds, and chromoyl alcohols of specific amounts and types as described in this invention can have a synergistic effect, effectively improving the retention rate of L-ascorbic acid content in cosmetics.

[0119] The above description is merely a specific implementation of this application. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here. It should be understood that the protection scope of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the protection scope of this application.

Claims

1. A composition for improving the stability of L-ascorbic acid, characterized in that, Calculated by weight, including: Polyols, 100 parts; Based on 100 parts of polyol, 0.5 to 15 parts of acrylate compounds; 0.1 to 1.5 parts of pigment alcohol based on 100 parts of polyol.

2. The composition according to claim 1, characterized in that, The acrylate compound is present in parts by weight of 1 to 13 parts; and / or, The weight of the chromoyl alcohol is 0.5 to 1.3 parts.

3. The composition according to claim 1, characterized in that, The acrylate compounds include α-cyano-β,β-diphenylethyl acrylate; and / or, The chromol comprises at least one selected from dimethylmethoxybenzodihydropyranol, γ-chromol, 6-hydroxy-2,5,7,8-tetramethylchromol-2-carboxylic acid, and chromol palmitate; and / or The polyol includes at least one of 1,3-propanediol, 1,2-butanediol, 1,2-pentanediol, 1,2-propanediol, and methylpropanediol.

4. A cosmetic product containing L-ascorbic acid, characterized in that, The cosmetic product comprises the composition according to any one of claims 1 to 3; and / or, Based on the total mass of the cosmetic product, the L-ascorbic acid constitutes 10% to 40% of the total mass of the cosmetic product; and / or, Based on the total mass of the cosmetic product, the composition constitutes 10% to 55% of the total mass of the cosmetic product.

5. The cosmetic product according to claim 4, characterized in that, The cosmetics also include cosmetic excipients.

6. The cosmetic product according to claim 4, characterized in that, Acceptable excipients in the cosmetics include at least one of the following: solubilizers, emulsifiers, pH adjusters, emollients, humectants, preservatives, chelating agents, and skin conditioning agents; and / or, The solubilizer comprises at least one of isosorbide dimethyl ether, ethoxydiethylene glycol, and bis-diethoxydiethylene cyclohexane 1,4-dicarboxylic acid ester; and / or, The emulsifier comprises at least one selected from a complex nonionic emulsifier, lecithin, lanolin, and lanolin alcohol, wherein the complex nonionic emulsifier comprises 54% PPG-26-butanol polyether-26, 36% PEG-40 hydrogenated castor oil, and 10% water; and / or, The pH adjuster includes at least one of sodium hydroxide, potassium hydroxide, arginine, sodium citrate, triethanolamine, and tromethamine; and / or, The emollient comprises at least one of squalene, jojoba seed oil, castor oil, shea butter, beeswax, and shea butter; and / or, The moisturizer includes at least one selected from glycerin, hyaluronic acid, trehalose, honey, inositol, urea, panthenol, and betaine; and / or, The preservative includes at least one selected from p-hydroxyacetophenone, 1,2-hexanediol, 1,2-pentanediol, ethylhexylglycerin, and phenoxyethanol; and / or, The chelating agent comprises at least one selected from disodium ethylenediaminetetraacetate, ethylenediaminetetraacetic acid, and tetrasodium ethylenediaminetetraacetate; and / or, The skin conditioning agent includes at least one of vitamin E, ceramide, and p-hydroxyacetophenone.

7. The cosmetic product according to claim 4, characterized in that, The particle size distribution of the particles in the cosmetic product satisfies the following conditions: Dv(95)≤150nm and Dv(2)≥10nm.

8. A method for preparing a cosmetic containing L-ascorbic acid, characterized in that, include: After mixing polyol, acrylate compound, first excipient and deionized water, L-ascorbic acid is added, and the mixture is heated and stirred to obtain phase A. The chromolyl alcohol, the second excipient, and deionized water were mixed, heated, and subjected to high-pressure homogenization to obtain phase B. Under stirring conditions, phase B is slowly added to phase A and mixed evenly to obtain a slurry precursor. The slurry precursor is then cooled and the pH is adjusted to 3.5–5.0, followed by high-pressure homogenization to obtain a cosmetic containing L-ascorbic acid. Based on the total mass of the cosmetic, the mass percentage of L-ascorbic acid in the cosmetic is 10%–40%, and the mass percentage of polyol, acrylate compound, and chromol in the cosmetic is 10%–55%. The weight ratio of polyol to acrylate compound is 100:(0.5–15), and the weight ratio of polyol to chromol is 100:(0.1–1.5).

9. The preparation method according to claim 8, characterized in that, In the step of mixing polyol, acrylate compound, first excipient and deionized water, adding L-ascorbic acid, heating and stirring to obtain phase A, the heating temperature is maintained at 35℃~45℃; and / or, In the step of mixing, heating, and homogenizing the chromoyl alcohol, the second excipient, and deionized water to obtain phase B, the heating temperature is maintained at 35°C to 45°C, and the high-pressure homogenization includes high-pressure microfluidic homogenization at 3000 to 8000 bar, and the homogenization is performed 5 to 10 times; and / or, In the step of slowly adding phase B to phase A under stirring conditions, mixing evenly to obtain a slurry precursor, cooling the slurry precursor and adjusting the pH to 3.5-5.0, and then performing high-pressure homogenization to obtain a cosmetic containing L-ascorbic acid, the cooling treatment includes cooling the slurry precursor to 25°C, and the high-pressure homogenization includes high-pressure microfluidic homogenization at 3000-8000 bar, the homogenization being performed 5-10 times; and / or, The first excipient and the second excipient each include excipients acceptable in cosmetics.

10. The use of the composition according to any one of claims 1 to 3 in the preparation of products with improved L-ascorbic acid stability, characterized in that, The products include at least one of cosmetics, skin care products, health products, and pharmaceuticals.

Images