Aqueous-based formulation containing vitamin c and composition including the same
Patent Information
- Application Number
- TW114109010
- Authority / Receiving Office
- TW · TW
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2025-03-11
- Publication Date
- 2026-09-16
- Estimated Expiration
- 2045-03-10
AI Technical Summary
Vitamin C in existing products faces challenges with instability, browning, reduced activity, skin irritation, and sensitization, particularly in long-term storage and diverse applications, despite current methods like antioxidants, pH adjustment, and encapsulation.
An aqueous base containing vitamin C and poly(ethylene ether carbonate) (PEEC) stabilizes vitamin C, reducing irritation and allergenicity while lowering carbon emissions, with a molecular structure comprising polyethylene ether units and carbon dioxide units.
The aqueous base significantly improves vitamin C stability, maintains antioxidant capacity, reduces skin irritation, and lowers carbon footprint, suitable for skin care and medical applications.
Smart Images
Figure TWG2TA001075823_001 
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Abstract
Description
Technical Field
[0001] This invention relates to water-soluble active ingredients, and in particular to an aqueous base containing vitamin C and its composition. Prior Technology
[0002] In existing technologies, Vitamin C, due to its instability, frequently suffers from browning and reduced activity. Vitamin C applied topically alone often causes skin irritation and sensitization due to its acidic nature, leading to undesirable user experiences. To overcome these problems, existing solutions include using antioxidants in Vitamin C products, adjusting pH levels, using high concentrations of low-carbon polyols as solvents, or employing encapsulation and modification technologies to reduce Vitamin C's instability. While these methods can improve Vitamin C's stability, they still face many challenges in long-term storage and diverse applications, particularly in addressing multiple objectives such as product color stability, hydrophilicity, environmental friendliness, irritation and sensitization, and cost control.
[0003] Therefore, it is necessary to provide a novel and progressive aqueous base containing vitamin C and its composition to solve the above-mentioned problems. Summary of the Invention
[0004] The main objective of this invention is to provide an aqueous base containing vitamin C and its composition, which can effectively stabilize the activity of vitamin C and has low irritation, low allergenicity and carbon reduction properties.
[0005] To achieve the above objectives, the present invention provides an aqueous base containing vitamin C, comprising: at least one water-soluble active ingredient, including at least one of vitamin C and its derivatives; water; and a poly(ethylene ether carbonate), PEEC, the molecular structure of which comprises a plurality of polyethylene ether units and a plurality of carbon dioxide structural units.
[0006] To achieve the above objectives, the present invention further provides a composition comprising an aqueous base containing vitamin C as described above, for application to the skin for skin care purposes.
[0007] To achieve the above objectives, the present invention further provides a composition comprising an aqueous base containing vitamin C as described above, for use in a medical implant. Simple Explanation of the Diagram
[0008] Figure 1 shows the appearance of a preferred embodiment of the present invention and a control group under normal temperature storage. Figure 2 shows the appearance of a preferred embodiment of the present invention and a control group under high temperature storage. Figures 3 and 4 show the experimental results of the free radical scavenging rate of vitamin C aqueous solution at different concentrations. Figures 5 and 6 show the experimental results of free radical scavenging rate at different concentrations of a preferred embodiment of the present invention. Figure 7 shows the experimental results of the inhibition rate of tyrosinase at different concentrations in a preferred embodiment of the present invention. Figure 8 shows the experimental results of the half-maximal inhibitory rate of vitamin C aqueous solution on tyrosinase over time in a preferred embodiment of the present invention. Figure 9 shows the experimental results of the inhibition rate of tyrosinase by a preferred embodiment of the present invention and vitamin C aqueous solution at high temperature over time. Figure 10 shows the experimental results of skin irritation of a preferred embodiment of the present invention and different control groups. Figure 11 shows the experimental results of the eye irritation of a preferred embodiment of the present invention and different control groups. Implementation
[0009] The following examples illustrate possible implementations of the present invention, but are not intended to limit the scope of protection of the present invention. The use of "a" or "at least one" before the terms mentioned herein is not a limitation on the quantity, and may also be "multiple" depending on the requirements. Such variations in quantity are also within the scope of protection, and are therefore stated in advance.
[0010] Please refer to Figures 1 to 11, which show a preferred embodiment of the present invention. The water-based base and composition of the present invention containing vitamin C include: at least one water-soluble active ingredient, water, and poly(ethylene ether carbonate) (PEEC).
[0011] The at least one water-soluble active ingredient includes at least one of vitamin C (ascorbic acid) and its derivatives; the molecular structure of the polyvinyl ether polycarbonate includes a plurality of polyvinyl ether units and a plurality of carbon dioxide structural units. The at least one water-soluble active ingredient may also include at least one of lactic acid, glycolic acid, salicylic acid, hydroquinone, nicotinamide, and retinoic acid, which can be selected according to product requirements, and the polyvinyl ether polycarbonate also helps to increase its stability.
[0012] The polyvinyl ether polycarbonate is represented by the following chemical formula, where R is a polyethylene glycol group with a molecular weight between 100 and 1000, and t, n, and m are integers.
[0013] In detail, the polyethylene ether polycarbonate is synthesized by ring-opening polymerization of ethylene carbonate. The molecular weight of the polyethylene ether polycarbonate is between 1,000 and 6,000, preferably between 2,000 and 4,000. Preferably, the weight percentage of carbonate groups in the polyethylene ether polycarbonate is not less than 15%. It should be noted that ethylene carbonate is one of the commercially available carbon dioxide capture and utilization (CCU) products. By ring-opening polymerization of ethylene carbonate under catalysis, a long-chain hydrophilic polymer PEEC with both ether and carbonate groups can be obtained.
[0014] The weight ratio of water to the at least one water-soluble active ingredient is greater than 2; the weight ratio of polyvinyl ether polycarbonate to the at least one water-soluble active ingredient is also greater than 2, to achieve a protective effect on the at least one water-soluble active ingredient. Therefore, the proportion of polyvinyl ether polycarbonate in the solid content of the water-based base of the present invention is generally above 60%, thereby reducing carbon emissions by more than 10%. The weight of the polyvinyl ether polycarbonate is preferably 2 to 20 times the weight of the at least one water-soluble active ingredient to effectively stabilize the at least one water-soluble active ingredient. Relevant experimental results are provided below.
[0015] In this embodiment, the aqueous base agent includes 5% by weight of vitamin C, and uses water and polyvinyl ether polycarbonate as solvents. The ratio of water to polyvinyl ether polycarbonate in the aforementioned solvent is 1:1 and is referred to as HM2450. A control group is prepared by mixing 5% by weight of vitamin C with water as a solvent. The aqueous base agent and the control group are stored at room temperature for 29 days, and their appearance is shown in Figure 1, where the left side of Figure 1 represents the control group and the right side represents the aqueous base agent. As can be clearly seen from Figure 1, compared to the control group, the aqueous base agent exhibits significantly lower levels of yellowing and browning.
[0016] In another embodiment, the aqueous base comprises 5% by weight of vitamin C, 38% by weight of water, and 57% by weight of polyethylene ether polycarbonate, wherein the mixed water and polyethylene ether polycarbonate are referred to as HM2460. The aqueous base and the control group were stored in an oven at 50°C for 6 days, and the results are shown in Figure 2, where the left side of Figure 2 represents the control group and the right side represents the aqueous base. Compared to the control group, the aqueous base showed significantly lower levels of yellowing and browning, indicating that the polyethylene ether polycarbonate does indeed help maintain the color of vitamin C.
[0017] This invention further evaluates the antioxidant effect of the aqueous base agent. In this experiment, a vitamin C aqueous solution containing 5% vitamin C (excluding the polyvinyl ether polycarbonate) was used as the control group stock solution, and the aqueous base agent (HM2460) containing 5% vitamin C was used as the experimental group stock solution. DPPH free radical scavenging experiments were conducted separately. Please refer to Figures 3 and 4, which show the DPPH scavenging rate of the control group stock solution (vitamin C aqueous solution) diluted with water to different weight percentage concentrations (X-axis). It can be seen that the DPPH scavenging rate of the control group stock solution (X-axis is 100%) can reach 89.67%, and when the control group stock solution is diluted to a weight percentage concentration of 0.092%, it can scavenge 50% of free radicals. Please also refer to Figures 5 and 6, which show the DPPH scavenging rate of the aqueous base diluted with water to different weight percentage concentrations (X-axis). It can be seen that the undiluted aqueous base (X-axis is 100%) has a DPPH scavenging rate of 96.68%, which is higher than that of the control group stock solution. Furthermore, when the aqueous base is diluted to a weight percentage concentration of 0.087%, it can scavenge 50% of free radicals, and has a lower IC50 compared to vitamin C aqueous solution with water as the solvent.
[0018] Furthermore, this experiment prepared an aqueous base containing 5% vitamin C using HM2460 as the solvent, and a control group using a 5% vitamin C aqueous solution (without the polyvinyl ether polycarbonate). Both were placed at 50°C for 0 days and 6 days, respectively, followed by a DPPH free radical scavenging experiment. The results showed that at 50°C, the IC50 of the aqueous base was 0.087% on day 0 and 0.092% on day 6, indicating a 5.75% decrease in antioxidant capacity. In contrast, the control group had an IC50 of 0.093% on day 0 and 0.104% on day 6, representing an 11.83% decrease in antioxidant capacity. Therefore, this polyvinyl ether polycarbonate can significantly slow down the oxidation rate of vitamin C under high-temperature conditions, maintaining its antioxidant capacity. Compared to water, HM2460 not only visually maintains the stability of vitamin C better, but also shows a lower IC50 change rate in antioxidant experiments, proving that this polyethylene ether polycarbonate has excellent protective effects on vitamin C.
[0019] This invention also provides a composition comprising the aqueous base containing vitamin C as described above. This composition can be used, for example but not limited to, for skin care purposes, particularly in whitening and anti-pigmentation products, anti-aging products, moisturizing and repairing products, cleansing products, and anti-sensitivity products where vitamin C stability is required. This extends the product's shelf life and ensures that at least one water-soluble active ingredient maintains its high efficacy. The hydrophilicity and skin permeability of this polyvinyl ether polycarbonate help retain moisture on the skin surface and promote skin barrier repair, achieving effects such as moisturizing, increased softness, soothing and non-tightening, easy rinsing without residue, and low foaming / easy defoaming. Furthermore, this polyvinyl ether polycarbonate has excellent surface tension and protective colloid properties, allowing it to be used in emulsions and creams to ensure a uniform mixture of oily and aqueous components to form a stable emulsion. It also improves product texture for easier application and absorption, enhancing the user experience.
[0020] This composition can also be used in medical implants, oral combination formulations, sustained-release formulations, etc. The polyvinyl ether polycarbonate is biodegradable and biocompatible, thus improving the safety of the product in vivo and reducing the risk of immune responses and allergies. The polyvinyl ether polycarbonate can also be used in sustained-release formulations to gradually release the at least one water-soluble active ingredient for a sustained therapeutic effect. On the other hand, this water-based base can also be applied in the pesticide and environmental fields, for example, to protect the at least one water-soluble active ingredient and control its release rate, reduce environmental pollution and optimize crop absorption efficiency to promote growth, or to adsorb and remove pollutants and restore damaged ecosystems.
[0021] In this regard, the present invention further evaluates the inhibitory effect of the aqueous base on tyrosinase under high temperature conditions. Tyrosinase is a key enzyme in the melanin synthesis process, and its inhibitory effect directly affects the efficacy of whitening products. In this experiment, the aqueous base (HM2460) containing 5% vitamin C was used as the experimental group, and a 5% vitamin C aqueous solution (without the polyvinyl ether polycarbonate) was used as the control group. The inhibitory effect on tyrosinase was evaluated after being stored at 50°C for 0 days, 3 days, and 6 days, respectively.
[0022] Figure 7 shows the experimental results of the inhibition rate of the aqueous base on tyrosinase when diluted with water to different weight percentage concentrations on day 0. It can be seen that the IC50 of the aqueous base is approximately 0.38%. Referring to Figure 8, the experimental results show that the IC50 of the aqueous base is 0.38% on day 0, increasing to 0.58% on day 6, but still lower than the IC50 value (0.72%) of the control group under the same conditions, showing better stability and tyrosinase inhibition effect.
[0023] In this experiment, the aqueous base containing 5% vitamin C was stored at 50°C for 0, 3, and 6 days, and compared with a control group containing 5% vitamin C aqueous solution to evaluate its stability and inhibitory ability on tyrosinase. The results are shown in Figure 9, where the solid line represents the aqueous base and the dashed line represents the 5% vitamin C aqueous solution. As shown in Figure 9, the inhibition rate of the aqueous base on tyrosinase was 96.82% on day 0. The inhibition rate of the aqueous base on tyrosinase decreased by only 17% from day 0 to day 6, while the control group decreased by 22%. Moreover, the aqueous base maintained a relatively higher inhibition rate than the control group even on day 6. Therefore, it can be seen that the polyvinyl ether polycarbonate can effectively delay the oxidation process of vitamin C and reduce the loss of activity caused by high temperature. The polyvinyl ether polycarbonate can significantly improve the stability of vitamin C under high temperature conditions and its ability to inhibit tyrosinase. It can not only reduce the risk of browning, but also provide a longer-lasting effect in whitening skin care products. It is suitable for use in cosmetic formulations that require long-term stability.
[0024] In accordance with OECD testing guideline 439, the skin irritation of this aqueous base was assessed using the EpiDerm human epidermal tissue model, and the results are shown in Figure 10. In Figure 10, NC (negative control) is phosphate-buffered saline (DPBS), showing 100% cell viability, indicating no irritation; PC (positive control) is 5% sodium dodecyl sulfate (SDS), showing significantly reduced cell viability, far below the 50% threshold (indicated by a dashed line, which is the standard for distinguishing between irritants and non-irritants in OECD 439 testing; values below 50% are classified as irritants, while values above 50% are considered non-irritants), indicating irritation; Vic C (20%) is the control group for 20% vitamin C aqueous solution, with a cell viability of 89.6%, indicating no irritation; Vic C (20%) + HM2460 is the aqueous base containing 20% vitamin C, and its results are similar to those of Vic C. Similar to the control group C (20%), it had a cell viability as high as 92.1%, indicating that the addition of HM2460 further improved cell viability by 3%. The control group of HM2460, which was a mixture of 40% water and 60% polyvinyl ether polycarbonate, had a cell viability of 84.55%, indicating no skin irritation. The control group of Salicylic acid (10%), which was a 10% salicylic acid aqueous solution, had a cell viability slightly below the 50% threshold, indicating potential irritation. The Salicylic acid (10%) + HM2460 solution, which was a 10% salicylic acid solution with HM2460 as the solvent, had a cell viability of 78.2% compared to the Salicylic acid (10%) group, indicating that the addition of HM2460 can effectively reduce the irritation of salicylic acid and has application prospects.
[0025] In addition, skin sensitization of HM2460 was assessed according to OECD testing guideline 442C, and the results are shown in the table below. The results indicate that HM2460 is sensitizing to Lysine peptides and Cysteine peptides. The average loss rate is less than 6.38%, and it is a non-sensitizing agent that will not cause skin allergies. Therefore, this water-based base is safe for use in skin care. [sample] [Lysine peptides, , ( ] [Blank Average] [Lysine peptides, , ( ] [Post-reaction average] [Standard deviation of repeated samples < 11.6%] [Lysine peptides, , ( ] [loss)] [Cysteine peptide, , ( ] [Blank Average] [Cysteine peptide, , ( ] [Post-reaction average] [Standard deviation of repeated samples <14.9%] [Cysteine peptide] [(] [loss)] [average] [DPRA] [Sensitivity Level] Cinnamaldehyde 2294023 1337822 0.52% 41.68 2447306 753191 0.99% 69.22 55.45 High [lactic acid] 2294023 2263064 0.88% 1.35 2447306 2515573 1.88% 0.00 0.67 Non-sensitiser [60% HM2460] 2294023 2306161 0.11% 0.00 2447306 2419188 1.33% 1.15 0.57 [Non-sensitiser]
[0026] According to OECD testing guideline 492, EpiOcular was used to assess the eye irritation of this aqueous base, and the results are shown in Figure 11. In Figure 11, NC (negative control) is water, showing 100% cell viability, indicating no irritation; PC (positive control) is methyl acetate, showing significantly reduced cell viability, far below the 60% threshold (indicated by the dashed line), indicating irritation; HM2460 is the control group of 40% water and 60% polyvinyl ether polycarbonate, with a cell viability of 94.5%, indicating no eye irritation; Vic C (20%) is the control group of 20% vitamin C aqueous solution, with a cell viability of 59.3%, indicating eye irritation; Vic C (20%) + HM2460 is the aqueous base containing 20% vitamin C, similar to the HM2460 control group, with a cell viability as high as 93.6%, indicating no eye irritation.
[0027] In addition, the minimum inhibitory concentration (MIC) was used to examine the inhibitory effect of the aqueous base on common skin pathogens, with glycerol as a control group. The experimental results showed that the MICs of the aqueous base against common skin pathogens, including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Acinetobacter niger, were 25%, 50%, 75%, and 75%, respectively, demonstrating a superior antibacterial effect compared to glycerol (which had no inhibitory effect).
[0028] In summary, the water-based base agent and its composition of the present invention possess low irritation, low allergenicity, and carbon reduction properties, making them particularly suitable for stabilizing vitamin C and solving the problems of easy oxidation, browning, and reduced activity of vitamin C in existing products. By combining this polyethylene ether polycarbonate and vitamin C, the present invention not only significantly improves the stability of vitamin C, but also, due to the carbon dioxide unit in its structure, possesses the characteristic of reducing carbon emissions and environmental impact.
[0029] none
Claims
1. A water-based base containing vitamin C, comprising: At least one water-soluble active ingredient, including vitamin C; monohydrate; And a poly(ethylene ether carbonate) (PEEC), the molecular structure of which includes a plurality of polyethylene ether units and a plurality of carbon dioxide structural units; wherein, the poly(ethylene ether carbonate) is represented by the following chemical formula: wherein, R is a polyethylene glycol group with a molecular weight between 100 and 1000, and t, n, and m are non-zero integers; the poly(ethylene ether carbonate) is formed by ring-opening polymerization of ethylene carbonate, and the molecular weight of the poly(ethylene ether carbonate) is between 1000 and 6000.
2. The aqueous base containing vitamin C as described in claim 1, wherein the weight percentage of the carbonate groups in the polyvinyl ether polycarbonate is not less than 15%.
3. The aqueous base containing vitamin C as claimed in claim 1, wherein the at least one water-soluble active ingredient further comprises at least one of lactic acid, glycolic acid, salicylic acid, hydroquinone, nicotinamide, and retinoic acid.
4. The aqueous base containing vitamin C as claimed in claim 1, wherein the weight of the polyvinyl ether polycarbonate is 2 to 20 times the weight of the at least one water-soluble active ingredient.
5. The aqueous base containing vitamin C as claimed in claim 1, wherein the weight ratio of water to the at least one water-soluble active ingredient is greater than 2.
6. The aqueous base containing vitamin C as claimed in claim 1, wherein the weight ratio of the polyvinyl ether polycarbonate to the at least one water-soluble active ingredient is greater than 2.
7. A composition comprising an aqueous base containing vitamin C as described in any one of claims 1 to 6, for application to the skin for skin care purposes.
8. A composition comprising an aqueous base containing vitamin C as described in any one of claims 1 to 6, for use in a medical implant.