Solid form of ascorbic acid carbon chain diesters and their applications

Abstract

The present invention discloses a solid form of ascorbic acid carbon chain diester and its applications. Specifically, the X-ray powder diffraction pattern of the solid form of the ascorbic acid carbon chain diester has characteristic peaks represented by the following 2θ angles: 7.2±0.2°, 14.1±0.2°, 18.5±0.2°, 18.7±0.2°, 19.8±0.2°, 22.4±0.2°, 23.9±0.2°, and 25.4±0.2°.

Description

[Technical Field]

[0001] [Cross-reference of related applications] This application claims priority to application number 63 / 626,547, titled "Solid Form of Ascorbic Acid Carbon Chain Diester and its Applications," filed with the United States Patent and Trademark Office on 30 January 2024, the entire contents of which are incorporated herein by reference.

[0002] This invention relates to a solid form of ascorbic acid carbon chain diester and its applications. The solid form of the ascorbic acid carbon chain diester has an XRPD (X-ray Powder Diffraction) pattern as shown in Figure 1. [Background technology]

[0003] In existing technological fields, many fatty acid ester derivatives of ascorbic acid are used as additives in the food industry. These ascorbic acid fatty acid esters are practically insoluble in bases such as water and polyols, and their powder form is unstable. These factors pose technical barriers to their application in other industries, such as the skincare industry.

[0004] To overcome the aforementioned technical barriers, developing innovative ascorbic acid ester derivatives applicable to the skincare industry is an urgent challenge that needs to be researched and overcome in this technological field. [Overview of the project]

[0005] In the following description of the invention and examples, "ascorbic acid carbon chain diester" and "ascorbic acid alkyl dicarboxylic acid ester (ascorbic acid alkyl dicarboxylic acid ester)" are synonyms, and the chemical structures they represent are identical.

[0006] The appearance and properties of the solid forms described below in the description of the invention and examples include, but are not limited to, lumps, powders, crystals, or mixtures thereof.

[0007] Based on the aforementioned background of the invention, the object of the present invention is to provide a solid form of ascorbic acid carbon chain diester and its applications in order to meet industrial demand, and to solve at least the following problems: namely, the current difficulty in obtaining a solid form of ascorbic acid carbon chain diester that has thermal stability, the difficulty in obtaining the technical effect of stabilizing the said solid form, and the difficulty in realizing applications of the said solid form to protect skin fibroblasts or keratinocytes from ultraviolet damage, and to promote collagen formation by skin fibroblasts or keratinocytes to achieve skin care effects.

[0008] The objectives of this invention and the resolution of its technical problems are achieved by adopting the following technical solution.

[0009] A first aspect of the present invention is to provide a solid form of ascorbic acid carbon chain diester, the X-ray powder diffraction (XRPD) pattern of the solid form having characteristic peaks represented by 2θ = 7.2±0.2°, 14.1±0.2°, 18.5±0.2°, 18.7±0.2°, 19.8±0.2°, 22.4±0.2°, 23.9±0.2°, and 25.4±0.2°.

[0010] Specifically, in the solid form of the ascorbic acid carbon chain diester, the Fourier transform infrared (FTIR) spectrum is obtained at wavenumber (cm -1 ) = 3416±2, 3172±2, 2928±2, 2857±2, 1749±2, 1737±2, 1681±2, 1347±2, 1305±2, 1146±2 and 761±2 cm -1 It has characteristic peaks.

[0011] Specifically, the differential scanning calorimetry (DSC) curve of the solid form of the ascorbic acid carbon chain diester exhibits a single characteristic peak at 150-160°C.

[0012] A second aspect of the present invention is to provide a skin care composition comprising, based on the total weight of the composition, 0.0001 to 20% by weight of the ascorbic acid carbon chain diester in solid form and 80 to 99.9999% by weight of a base, wherein the water activity value of the base is 0.7 or less.

[0013] Specifically, the base material is a water-in-oil (W / O) type, a water-in-silicone (W / Si) type, an anhydrous gel, or a gel.

[0014] Specifically, the skin care composition has the technical effect of stabilizing the solid form of the ascorbic acid carbon chain diester.

[0015] A third aspect of the present invention is to provide a method for skin care, which includes applying a formulation containing the solid form of the ascorbic acid carbon chain diester to the surface of the skin of an individual. Specifically, based on the total weight of the formulation, the weight percentage of the solid form of the ascorbic acid carbon chain diester in the formulation is 0.0001 to 20% by weight. More specifically, the solid form of the ascorbic acid carbon chain diester has the use of protecting skin fibroblasts or keratinocytes from ultraviolet damage, and the use of promoting collagen formation by skin fibroblasts or keratinocytes.

[0016] A fourth aspect of the present invention is to provide a solid-state arrangement of ascorbic acid carbon chain diester, the arrangement having the use of protecting skin fibroblasts or keratinocytes from ultraviolet damage.

[0017] Specifically, the form of the formulation is selected from the group consisting of cream, lotion, gel, powder, paste, mask solution, and serum. The formulation of the form has the use of promoting collagen formation by skin fibroblasts or keratinocytes, based on the solid form of the ascorbic acid carbon chain diester.

[0018] As mentioned above, the technical means and effects of the present invention include the following. However, the present invention is not limited thereto. Specifically, the present invention provides a solid form of thermostable ascorbic acid carbon chain diester, stabilizes said solid form by controlling the water activity value of a composition, and achieves a skin care effect by protecting skin fibroblasts or keratinocytes from ultraviolet damage and promoting collagen formation.

[0019] The above description is merely an outline of the technical solution of the present invention. To enable a clearer understanding of the technical means of the present invention and implementation in accordance with the content of the specification, and to make the above-described structure, other objects, features and advantages of the present invention more prominent and easy to understand, preferred embodiments are given below and described in detail with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] [Figure 1] It is an XRPD pattern of the solid form of the ascorbic acid carbon chain diester of the present invention. [Figure 2] It is an FTIR spectrum of the solid form of the ascorbic acid carbon chain diester of the present invention. [Figure 3] It is a DSC curve of the solid form of the ascorbic acid carbon chain diester of the present invention. [Figure 4] It is an XRPD pattern of the solid of Experimental Example 3 of the present invention. [Figure 5] It is an XRPD pattern of the solid form of the ascorbic acid carbon chain diester of the present invention after storage in an oven at 45°C for 1 month. [Figure 6] It is an XRPD pattern of the solid of Experimental Example 3 of the present invention after storage in an oven at 45°C for 1 month. [Figure 7] It is a graph showing the recovery of cell viability after UV irradiation of the ascorbic acid carbon chain diester of the present invention. [Figure 8] It is a graph showing the reduction of intracellular ROS content after UV irradiation by the ascorbic acid carbon chain diester of the present invention. [Figure 9]This graph shows the reduction in intracellular IL-6 content after UV irradiation of the ascorbic acid carbon chain diester of the present invention. [Figure 10] This graph shows the increased collagen expression in skin fibroblasts by the ascorbic acid carbon chain diester of the present invention. [Modes for carrying out the invention]

[0021] To further elaborate on the technical means and effects employed by the present invention to achieve its objectives, specific embodiments, structures, features, and effects proposed based on the present invention will be described in detail below, in combination with the drawings and preferred embodiments.

[0022] Typically, the first embodiment of the present invention is to provide a solid form of an ascorbic acid carbon chain diester. Specifically, the composition of the solid form of the ascorbic acid carbon chain diester contains 90% by weight or more of bis-(L-ascorbic acid-6,6-) nonanedioate.

[0023] In preferred embodiments, the composition of the solid form of the ascorbic acid carbon chain diester includes 95% by weight or more of bis(L-ascorbic acid-6,6-)azelate. In more preferred embodiments, the composition of the solid form of the ascorbic acid carbon chain diester includes 99% by weight or more of bis(L-ascorbic acid-6,6-)azelate and 1% by weight or less of ascorbic acid.

[0024] In the examples, the composition of the solid form of the ascorbic acid carbon chain diester includes 5% by weight or less of bis(L-ascorbic acid-5,6-)azelate, bis(L-ascorbic acid-5,5-)azelate, or a combination thereof.

[0025] In the examples, the composition of the solid form of the ascorbic acid carbon chain diester includes 5% by weight or less of ascorbic acid-6-azelate, ascorbic acid-5-azelate, or a combination thereof.

[0026] In the example, the composition of the solid form of the ascorbic acid carbon chain diester contains 90% by weight or more of bis(L-ascorbic acid-6,6-)azelate, and the solid form of the ascorbic acid carbon chain diester has characteristic peaks represented by the following 2θ angles in the X-ray powder diffraction pattern: 7.2±0.2°, 14.1±0.2°, 18.5±0.2°, 18.7±0.2°, 19.8±0.2°, 22.4±0.2°, 23.9±0.2°, and 25.4±0.2°. In a specific example, the X-ray powder diffraction pattern of the solid form of the ascorbic acid carbon chain diester is shown in Figure 1.

[0027] In the examples, the composition of the solid form of the ascorbic acid carbon chain diester contains 90% by weight or more of bis(L-ascorbic acid-6,6-)azelate, and the Fourier transform infrared spectral spectrum of the solid form of the ascorbic acid carbon chain diester includes characteristic peaks at the following wavenumbers: 3416±2, 3172±2, 2928±2, 2857±2, 1749±2, 1737±2, 1681±2, 1347±2, 1305±2, 1146±2, and 761±2 cm⁻¹ -1 In a specific example, Figure 2 shows the Fourier transform infrared spectroscopic spectrum of the solid form of the ascorbic acid carbon chain diester.

[0028] In the example, the composition of the solid form of the ascorbic acid carbon chain diester contains 90% by weight or more of bis(L-ascorbic acid-6,6-)azelate, and the differential scanning calorimetry (DSC) curve of the solid form of the ascorbic acid carbon chain diester has a single characteristic peak between 150°C and 160°C. In a specific example, the differential scanning calorimetry curve of the solid form of the ascorbic acid carbon chain diester is shown in Figure 3.

[0029] In the examples, the solid form of the ascorbic acid carbon chain diester shown in Figure 1 is a solid form produced by recrystallization using an ester-based solvent. In specific examples, the ester-based solvent includes ethyl acetate, isopropyl acetate, or a combination thereof.

[0030] A second embodiment of the present invention provides a skin care composition comprising, based on the total weight of the composition, 0.0001 to 20% by weight of the solid form of the ascorbic acid carbon chain diester described in the first embodiment and 80 to 99.9999% by weight of a base, wherein the water activity value of the base is 0.7 or less. In one example, the base is a base with a water activity value of less than 0.6.

[0031] In specific examples, the base with a water activity value of less than 0.6 is gelatin, fatty acid (product name MBK TM ), a mixture of polyethylene glycol and mineral oil (product name Plasticized TM ), a mixture of silicone oil and vegetable oil (product name PracaSil TM -Plus), mixtures of phospholipids (trade name Anwaterus Lipoderm®), anhydrous gel (trade name PermE8 TM Or W06 TM This includes, but is not limited to, Anwaterus Topical Gel, a mixture of emulsifying waxes and fatty acid esters (trade name VersaBase Cream), or compositions similar to those described above.

[0032] In preferred embodiments, the skin care composition comprises 0.1 to 20% by weight of the ascorbic acid carbon chain diester in solid form. In more preferred embodiments, the skin care composition comprises 1 to 10% by weight of the ascorbic acid carbon chain diester in solid form.

[0033] In the examples, the base is a water-in-oil (W / O) type, a water-in-silicone (W / Si) type, an anhydrous gel, or a gel.

[0034] In specific examples, the water activity value of the water-in-oil (W / O) type is between 0.5 and 0.65. The water activity value of the anhydrous gel or gel is between 0.4 and 0.7.

[0035] In the examples, the base composition includes vegetable oil, mineral oil, polyol, silane (silicone oil), or any combination thereof.

[0036] In the examples, the vegetable oil includes jojoba oil, black cumin seed oil, grape seed oil, sunflower seed oil, olive oil, avocado oil, argan oil, macadamia nut oil, sweet almond oil, apricot kernel oil, sesame oil, bagasse fruit oil (pracaxi oil), or a combination thereof.

[0037] In the examples, the polyol includes glycerin, butylene glycol, 1,3-propanediol, 1,2-propanediol, 1,2-pentanediol, 1,2-hexanediol, polyethylene glycol, poly(1,3-propanediol), cyclodextrin and its derivatives, cellulose and its derivatives, or combinations thereof.

[0038] In specific examples, the silane includes dimethicone, cyclopentasiloxane, or a combination thereof.

[0039] In specific examples, the components of the base further include a pH buffer (e.g., sodium citrate buffer), an antioxidant (e.g., vitamin E or sodium bisulfite), a thiol compound (e.g., cysteine ​​or cystamine), a chelating agent (e.g., ethylenediaminetetramethylenephosphonic acid (EDTMP) or its salts), water, or a combination thereof.

[0040] A third embodiment of the present invention provides a method for skin care, comprising applying a formulation (preparation) containing the solid form of the ascorbic acid carbon chain diester described in the first embodiment to the surface of the skin of an individual, wherein the form of the formulation is selected from the group consisting of cream, lotion, gel, powder, paste, mask liquid, and serum.

[0041] In the examples, based on the total weight of the formulation, the amount of the ascorbic acid carbon chain diester added in solid form is 0.0001 to 20% by weight in the formulation. In preferred examples, the weight percentage is 0.1 to 10% by weight.

[0042] In the examples, the solid form of the ascorbic acid carbon chain diester has the use of protecting skin fibroblasts or keratinocytes from ultraviolet damage. A fourth embodiment of the present invention provides a method for the solid form of the ascorbic acid carbon chain diester, the method of which has the use of protecting skin fibroblasts or keratinocytes from ultraviolet damage.

[0043] In the examples, the form of the formulation is selected from the group consisting of cream, lotion, gel, powder, paste, mask solution, and serum.

[0044] In the examples, the solid form of the ascorbic acid carbon chain diester has the use of promoting collagen formation by skin fibroblasts or keratinocytes.

[0045] In specific examples, the solid form of the ascorbic acid carbon chain diester has the effect of preventing and repairing UV-induced cell damage, and its effective concentration is greater than 125 ppm.

[0046] In specific examples, the solid form of the ascorbic acid carbon chain diester has the effect of significantly reducing intracellular reactive oxygen species (ROS), and the effective concentration is greater than 125 ppm.

[0047] In a specific embodiment, the solid form of said ascorbic acid carbon chain diester has the effect of significantly reducing intracellular inflammatory mediators, with an effective concentration of more than 125 ppm.

[0048] In an embodiment, the solid form of said ascorbic acid carbon chain diester has use for promoting collagen formation by dermal fibroblasts or keratinocytes. In a specific embodiment, the solid form of said ascorbic acid carbon chain diester has the effect of increasing the collagen expression ability of fibroblasts, with an effective concentration of more than 1 ppm.

Examples

[0049] Experimental Example 1: Method for Preparing Ascorbic Acid Carbon Chain Diester

[0050] Ascorbic acid (3 equivalents), azelaic acid (1 equivalent) and lipase (20% by weight of the total weight of reactants) are added to an aprotic reaction solvent. The reaction is carried out by heating to 60°C to 80°C under nitrogen. After completion of the reaction, lipase is removed by filtration, excess ascorbic acid is removed by water washing, and the aprotic reaction solvent is removed by concentration to obtain a crude product of diazcorbyl azelate (ascorbyl azelaate). The product is obtained after column purification, and HPLC analysis shows that its composition is more than 90% by weight of bis(L-ascorbic acid-6,6-) azelate, and the residual ascorbic acid is 0.62% by weight. Mass spectrometry (MS-ESI): 503.20. Proton nuclear magnetic resonance ( 1 H-NMR) analysis data are shown in Table 1. Its molecular formula is C 21 H 28 O 14

[0051] [Table 1] JPEG2026529540000002.jpg73141

[0052] Experimental Example 2: Recrystallization Procedure - Ester-based Crystallization Solvent ​The ascorbic acid carbon chain diester (composition: bis(L-ascorbic acid-6,6-)azelate with a composition of over 90% by weight) prepared in Experimental Example 1 was recrystallized under reflux by heating with at least four times the relative weight of an ester solvent (e.g., ethyl acetate), cooled, and filtered to obtain a filtered cake. The filtered cake was vacuum dried to obtain a solid ascorbic acid carbon chain diester. HPLC analysis revealed that its composition was within the range described in the first embodiment above. The structure of the solid form was analyzed using an X-ray powder diffractometer, and the resulting XRPD pattern is shown in Figure 1.

[0053] Experimental Example 3: Recrystallization Procedure - Non-esterified crystalline solvent The ascorbic acid carbon chain diester (composition: bis(L-ascorbic acid-6,6-)azelate with a composition of over 90% by weight) prepared in Experimental Example 1 was recrystallized under reflux by heating with at least four times the relative weight of a non-esterifying crystalline solvent (ketones; e.g., acetone), cooled, and filtered to obtain a filtered cake. The filtered cake was vacuum-dried to obtain a solid ascorbic acid carbon chain diester. HPLC analysis revealed that its composition was within the range described in the first embodiment above. The structure of the solid form was analyzed using an X-ray powder diffractometer, and the resulting XRPD pattern is shown in Figure 4.

[0054] Experimental Example 4: Thermal Stability Test of Solid State The solid ascorbic acid carbon chain diesters obtained by recrystallization in Experimental Examples 2 and 3 were left in an oven at 45°C for one month. Afterward, they were removed and subjected to purity and structural analysis of the solid form. HPLC analysis revealed that the composition of each solid form was within the range described in the first embodiment. Analysis of the solid forms using an X-ray powder diffractometer yielded the XRPD patterns shown in Figures 5 and 6, respectively. Comparing Figures 1 and 5, it was shown that the solid form of ascorbic acid carbon chain diesters obtained by recrystallization using ester-based solvents exhibited high thermal stability, and its structure was unaffected and unaltered by heat. In contrast, there was a clear difference between Figures 4 and 6, suggesting that the solid form of ascorbic acid carbon chain diesters obtained by recrystallization using ether or ketone solvents that do not undergo transesterification with ascorbic acid esters exhibited poorer thermal stability. As described above, the solid form of ascorbic acid carbon chain diesters obtained by recrystallization using ester-based solvents possesses a technical advantage in structural thermal stability.

[0055] Experiment Example 5: Effect Experiment 1 (Cell Viability) Cells were seeded in 48-well plates and cultured for 24 hours at 37°C under 5% CO2 conditions. The cell line used was epidermal cells (HaCaT) (AddexBio, Cat#T0020001). The cell culture medium was DMEM medium containing 10% fetal bovine serum. The cell culture medium was replaced with a buffer solution [Sterile D-PBS (Dulbecco's phosphate buffered saline)] and the cells were irradiated with UV light. Of these, the experimental group was irradiated with a buffer solution containing the ascorbic acid carbon chain diester (alkyl ascorbate diester) of the present invention, while the positive control group and negative control group were irradiated with a buffer solution that did not contain the ascorbic acid carbon chain diester of the present invention. Only the experimental group and positive control group were irradiated with UV light, while the negative control group was kept under normal culture conditions and the cells were completely covered with aluminum foil to avoid UV irradiation. The post-UV irradiation processing steps are as follows: Specifically, the buffer solution was replaced with cell culture medium. Here, the experimental group was cultured in a cell medium containing the ascorbic acid carbon chain diester of the present invention, while the positive and negative control groups were cultured in a cell medium that did not contain the ascorbic acid carbon chain diester of the present invention. Culturing was continued for a further 24 hours at 37°C under a 5% CO2 environment. Subsequently, a cell viability assay was performed. Cell activity was detected in each experimental group using a cell activity detection reagent (Alamar Blue), and cell viability was calculated using Equation 1. Since the cell viability of the negative control group is under normal culture conditions, the cell viability of the negative control group was defined as 100% in this experiment. Intergroup comparisons were performed using an unpaired Student's t-test.

[0056] [Formula 1] JPEG2026529540000003.jpg10138

[0057] Figure 7 summarizes the results obtained by repeating the above experimental procedure multiple times. In the control group, cell viability decreased from 100% to 55±10% under UV irradiation. Compared to the control group, the ascorbic acid carbon chain diesters of the present invention at concentrations of 125, 250, 500, and 1000 ppm restored cell viability to 88±4%, 99±5%, 114±9%, and 104±7%, respectively, all of which showed statistically significant differences compared to the control group. As a result, it was shown that the ascorbic acid carbon chain diesters of the present invention have the effect of preventing and repairing UV-induced cell damage, and that the effective concentration is 125-1000 ppm.

[0058] Experiment Example 6: Effect Experiment 2 (Intracellular Reactive Oxygen Species Amount) Cells were seeded in 48-well plates and cultured for 24 hours at 37°C under 5% CO2 conditions. The cell line used was HEKn (Gibco, Cat#C-001-5C). The cell medium was Epi-Life (HKGS, Gibco, Cat#S0015 & Cat#MEPI500CA) containing HKGS (Human Keratinocyte Growth Supplement). The cell medium was replaced, and the experimental group was cultured for 24 hours at 37°C under 5% CO2 conditions in the cell medium containing the ascorbic acid carbon chain diester of the present invention, while the positive and negative control groups were cultured for 24 hours in the cell medium without the ascorbic acid carbon chain diester of the present invention. Addition of intracellular oxidative stress detection reagent (DCFH-DA): All groups were washed with sterile D-PBS, the intracellular oxidative stress detection reagent (DCFH-DA) was added, and the cells were allowed to react for 1 hour. UV irradiation: Cells were washed with sterile D-PBS, D-PBS was added, and UV irradiation was performed. UV irradiation was performed only on the experimental group and the positive control group, while the negative control group was kept under normal culture conditions and completely covered with aluminum foil to prevent UV irradiation. Post-UV irradiation treatment: The buffer solution was replaced with cell medium. The experimental group was cultured in cell medium containing the ascorbic acid carbon chain diester of the present invention, while the positive and negative control groups were cultured in cell medium without the ascorbic acid carbon chain diester of the present invention, and cultured for a further 1 hour at 37°C in a 5% CO2 environment. Intracellular oxidative stress detection test (ROS Generation Assay): The ROS content of each experimental group was detected and calculated using Equation 2. The data from the positive control group was set to 100%. Intergroup comparisons were performed using Ampered (independent) Student's t-test.

[0059] [Formula 2] JPEG2026529540000004.jpg16138

[0060] Figure 8 summarizes the results obtained by repeating the above experimental procedure multiple times. The negative control group was the group in which the experimental material was not treated and not irradiated with UV, and its ROS content represents the normal state. The positive control group was the group in which the experimental material was not treated but irradiated with UV, and this is set to 100%. After treatment with the ascorbic acid carbon chain diester of the present invention, the ROS content was significantly reduced, showing a dose-dependent effect. 125 ppm, 250 ppm, 500 ppm, and 1000 ppm reduced ROS from 100% of the positive control group to 90±10%, 78±6%, 63±7%, and 52±3%, respectively. As a result, the ascorbic acid carbon chain diester of the present invention was shown to have a significant effect in reducing intracellular reactive oxygen species, and the effective concentration was shown to be 125 to 1000 ppm.

[0061] Experiment Example 7: Effect Experiment No. 3 (Intracellular Interleukin-6 Content) Cells were seeded in 48-well plates and cultured for 24 hours at 37°C under 5% CO2 conditions. The cell line used was HaCaT (AddexBio, Cat#T0020001). The cell medium was DMEM medium containing 10% fetal bovine serum. The cell medium was replaced with a buffer solution, and the cells were irradiated with a UV incandescent. The experimental group was given a buffer solution containing the ascorbic acid carbon chain diester of the present invention, while the positive and negative control groups were given a buffer solution without it. Only the experimental group and the positive control group were irradiated with UV, while the negative control group was kept under normal culture conditions and covered with aluminum foil to avoid irradiation. Post-UV irradiation treatment: The buffer solution was replaced with cell medium. The experimental group was given cell medium containing the ascorbic acid carbon chain diester of the present invention, while the positive and negative control groups were given cell medium without it, and culture was continued for another 24 hours at 37°C under 5% CO2 conditions. Quantitative determination of cellular interleukin-6 (IL-6): The amount of cellularly secreted IL-6 was measured using a human IL-6 enzyme-linked immunosorbent assay (ELISA) kit and calculated using Equation 3, with the positive control group set as 100%. Intergroup comparisons were performed using an Ampered (independent) Student's t-test.

[0062] [Formula 3] JPEG2026529540000005.jpg10137

[0063] Figure 9 summarizes the results obtained by repeating the above experimental procedure multiple times. The negative control group represents the normal state. The positive control group is set to 100%. After treatment with the ascorbic acid carbon chain diester of the present invention, the IL-6 content was significantly reduced, showing a dose-dependent effect. 125 ppm, 250 ppm, 500 ppm, and 1000 ppm reduced IL-6 from 100% of the positive control group to 4±1%, 1±1%, 1±1%, and 2±1%, respectively. As a result, the ascorbic acid carbon chain diester of the present invention had a significant effect in reducing intracellular inflammatory mediators, and the effective concentration was shown to be 125-1000 ppm.

[0064] Experiment Example 8: Effect Experiment No. 4 (Collagen Content) Cells were seeded in 48-well plates and cultured for 24 hours at 37°C under 5% CO2 conditions. The cell line used was NHDF (PromoCell, Cat#C12302). The cell medium was FGM2 (PromoCell, Cat#C23230). Cell treatment was performed, and the cell medium was replaced. The experimental group was cultured in cell medium containing the ascorbic acid carbon chain diester of the present invention, and the control group in cell medium without it, under 37°C under 5% CO2 conditions for 24 hours. Real-time quantitative PCR: The expression levels of type I collagen and type IV collagen were measured using real-time quantitative PCR-related reagents. Relative collagen expression levels were calculated using Equation 4, with the control group set to 100%. Intergroup comparisons were performed using an unpaired (independent) Student's t-test.

[0065] [Formula 4] JPEG2026529540000006.jpg10128

[0066] Figure 10 summarizes the results obtained by repeating the above experimental procedure multiple times. The control group was set to 100%. After treatment with the ascorbic acid carbon chain diester of the present invention, the collagen content was significantly increased. 1 ppm, 10 ppm, 100 ppm, and 1000 ppm increased the type I collagen content from 100% to 328±159%, 183±87%, 163±25%, and 182±30%, respectively. The type IV collagen content was also increased from 100% to 170±15%, 173±36%, 171±12%, and 228±44%, respectively. As a result, the ascorbic acid carbon chain diester of the present invention was shown to have the ability to significantly increase the collagen expression capacity of fibroblasts, and the effective concentration was shown to be between 1 and 1000 ppm.

[0067] Experimental Example 9: Evaluation test of bases with different water activity values This experiment evaluates the stability of various skin care compositions by mixing the solid form of ascorbic acid carbon chain diester, as shown in Figure 1, with representative bases having different water activity values. Specifically, the weight percentage range of the solid form in the representative base was 0.1 to 20% by weight, and in this experiment, it was set to 1% by weight. The water activity values ​​of the bases were between 0.05 and 0.79, and specific data are shown in Table 2.

[0068] [Table 2] JPEG2026529540000007.jpg79136 Here, *Buffer (pH 4): Sodium citrate buffer; **Buffer (pH 6): Phosphate buffer

[0069] According to Table 2, when the water activity value of a typical base was 0.79, the degree of degradation (decomposition) of the ascorbic acid carbon chain diester of the present invention was high. After being left at room temperature for one month, the degradation rate, as calculated by HPLC analysis, had already reached 31%. In contrast, when the water activity value of a typical base was controlled to less than 0.7, the stability of the ascorbic acid carbon chain diester of the present invention in the aforementioned typical base was improved. Even after being left at room temperature for four months, the degradation rate was less than 20% in all cases, indicating that the content remained above 80%.

[0070] Experimental Example 10: Gel Table 3 shows the dosage form composition of this experimental example. The procedure was as follows: First, the components of group A were mixed, and after the ascorbic acid carbon chain diester was completely dissolved, group A was added to group B and mixed uniformly. The water activity value of the resulting gel was 0.75.

[0071] [Table 3] JPEG2026529540000008.jpg88151

[0072] Experimental Example 11: Water-sac oil-based formulation (O / W) Table 4 shows the dosage form composition of this experimental example. The procedure was as follows: First, xanthan gum was uniformly dispersed in water, and after dispersion was complete, group C was added. Then, groups A, C, and B were heated separately. After heating to 75 degrees Celsius, the oil phase was added to the aqueous phase, the resulting mixture was emulsified in a homogenizer, and then cooled to 40 degrees Celsius. Group E was added sequentially under stirring, and the water activity value of the final cream product was 0.91. The cream product in this experimental example discolored due to cleavage (decomposition) of ascorbic acid carbon chain diester after being left at room temperature for one month.

[0073] [Table 4] JPEG2026529540000009.jpg176147

[0074] Experimental Example 12: Silicone Oil-Efficate Water Formulation (W / Si) Table 5 shows the dosage form composition of this experimental example. The procedure was as follows: Groups A and B were mixed uniformly, then the aqueous phase was added to the oil phase, and the resulting mixture was emulsified with a homogenizer. The water activity value was less than 0.6.

[0075] [Table 5] JPEG2026529540000010.jpg117151

[0076] Experimental Example 13: Oil-encapsulated aqueous formulation (W / O) Table 6 shows the dosage form composition of this experimental example. The procedure was as follows: Groups A and B were uniformly mixed, then the aqueous phase was added to the oil phase, and the resulting mixture was emulsified with a homogenizer. The water activity value of the final cream product was 0.65. The cream product in this experimental example showed no change in appearance or color even after being left at room temperature for one month.

[0077] [Table 6] JPEG2026529540000011.jpg127147

[0078] Experimental Example 14: Anhydrous Gel Table 7 shows the composition of the dosage form used in this experiment. The procedure was as follows: First, the components of group A were mixed, and after the ascorbic acid carbon chain diester was completely dissolved, groups B and C were added sequentially and mixed uniformly. Finally, an anhydrous gel was obtained, and its water activity value was less than 0.6.

[0079] [Table 7] JPEG2026529540000012.jpg89151

[0080] The foregoing are merely preferred embodiments of the Application and do not limit the Application in any formal way. While the Application is disclosed as described above with respect to preferred embodiments, this is not intended to limit the Application. Any person skilled in the art could, without departing from the scope of the proposed invention, utilize the disclosed technical content above to make equivalent variations or modifications. Any simple modifications, equivalent variations, and modifications made to the above embodiments based on the technical substance of the Application, without departing from the scope of the proposed invention, remain within the scope of the proposed invention.

Claims

1. A solid form of ascorbic acid carbon chain diester, The composition of the solid form of the ascorbic acid carbon chain diester contains 90% by weight or more of bis(L-ascorbic acid-6,6-)azelate. The solid form of the ascorbic acid carbon chain diester is characterized in that the X-ray powder diffraction pattern of the solid form of the ascorbic acid carbon chain diester has characteristic peaks represented by 2θ = 7.2±0.2°, 14.1±0.2°, 18.5±0.2°, 18.7±0.2°, 19.8±0.2°, 22.4±0.2°, 23.9±0.2°, and 25.4±0.2°.

2. The Fourier transform infrared spectral spectra of the solid form of the ascorbic acid carbon chain diester are 3416±2, 3172±2, 2928±2, 2857±2, 1749±2, 1737±2, 1681±2, 1347±2, 1305±2, 1146±2, and 761±2 cm⁻¹. －１ The solid form of the ascorbic acid carbon chain diester according to claim 1, characterized by containing a characteristic peak.

3. The solid form of the ascorbic acid carbon chain diester according to claim 1, characterized in that the solid form of the ascorbic acid carbon chain diester has a single characteristic peak in the differential scanning calorimetry curve between 150°C and 160°C.

4. A composition for skin care, Based on the total weight of the composition, it comprises 0.0001 to 20% by weight of the solid form of the ascorbic acid carbon chain diester according to any one of claims 1 to 3, and 80 to 99.9999% by weight of the base, A skin care composition characterized in that the water activity value of the base is 0.7 or less.

5. The skin care composition according to claim 4, characterized in that the base is a water-in-oil (W / O) type, a water-in-silicone (W / Si) type, an anhydrous gel, or a gel.

6. The skin care composition according to claim 4, characterized in that the base composition comprises a vegetable oil, mineral oil, polyol, silane, or any combination thereof.

7. It is a method of skin care, The method involves applying a solid form of the ascorbic acid carbon chain diester described in any one of claims 1 to 3 to the skin surface of an individual, Based on the total weight of the above formulation, the amount of the ascorbic acid carbon chain diester added in solid form is 0.0001 to 20% by weight in the above formulation. A method for caring for the skin, characterized in that the water activity value of the base of the above-mentioned formulation is 0.7 or less.

8. The skin care method according to claim 7, characterized in that the form of the formulation is selected from the group consisting of cream, lotion, gel, powder, and paste.

9. The skin care method according to claim 8, characterized in that the above-mentioned arrangement has the use of protecting skin fibroblasts or keratinocytes from ultraviolet damage.

10. The skin care method according to claim 7, characterized in that the solid form of the ascorbic acid carbon chain diester has the use of promoting collagen formation by skin fibroblasts or keratinocytes.

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