A method for testing the permeation effect of a cosmetic product

Abstract

The present application relates to a kind of test methods of cosmetic penetration promotion effect, belong to cosmetic detection technical field.The present application provides a kind of test methods of cosmetic penetration promotion effect, the method includes the following steps: (1) adding colorant in the cosmetic to be tested;(2) the cosmetic of step (1) is applied to skin;(3) respectively at multiple time points, test the yellow blue chromaticity component b of skin * Value;The time point is not less than three;(4) setting negative control group, by comparison with negative control group to evaluate the percutaneous penetration promotion effect of the cosmetic to be tested.The test method of the present application avoids the invasiveness and complexity of existing detection means, significantly shortens the test cycle, does not need expensive instrument auxiliary analysis, is suitable for the rapid screening and evaluation of various cosmetic formulations.

Description

Technical Field

[0001] This invention relates to the field of cosmetic testing technology, and in particular to a test method for the penetration-enhancing effect of cosmetics. Background Technology

[0002] With the development of functional cosmetics, evaluating the skin permeability of active ingredients is crucial. Currently, existing methods for detecting penetration-enhancing effects mainly include: 1) Diffusion cell method: A skin model separates the diffusion cell and the receiving cell. Skin models include mouse abdominal skin, pig abdominal skin, pig ear skin, human skin, and artificial models. Liquid is collected from the receiving cell at regular intervals, and the content of the target substance is measured using methods such as high-performance liquid chromatography (HPLC) and gas chromatography (GC), calculating the transdermal drug delivery during that time period. 2) Skin resistance measurement: The resistance value reflects the integrity of the skin barrier; the lower the value, the stronger the skin permeability. Rat transdermal resistance measurement can replace the diffusion cell method to measure skin permeability. 3) Parallel artificial membrane permeability measurement method: An artificial membrane made of lecithin simulates the in vivo permeability barrier, separating the recipient and donor compartments to simulate the passive absorption of drugs in the body. This can simulate absorption through pathways such as intestinal absorption, the blood-brain barrier, and the skin barrier. 4) Adhesive Tape Peeling Method: After the drug is applied to the skin for a period of time, the stratum corneum is peeled off with adhesive tape. High-performance liquid chromatography (HPLC) and spectrophotometry are used to measure the peeled-off substances, revealing the amount of substance not absorbed by the skin, and further calculating the amount of substance that has entered the skin. 5) Microdialysis Method: A microcatheter with a semi-permeable membrane is inserted into the dermis or subcutaneous tissue, filling the catheter with perfusion fluid (physiological saline). The drug in the skin tissue passively diffuses through the semi-permeable membrane into the catheter due to its concentration gradient. The drug-containing solution is collected, and the drug content in the catheter is detected using colorimetry and HPLC to obtain the drug distribution and content in the skin tissue. This method is mainly used to evaluate the therapeutic effect of drugs. 6) Vasoconstriction Measurement Method: After the application of drugs (such as glucocorticoids), microvascular constriction occurs, leading to skin pallor. The degree of pallor is positively correlated with the drug's efficacy. The degree of pallor can be measured using a reflectance spectrophotometer, colorimeter, and color analysis software to compare drug efficacy. 7) Spectroscopic methods: such as Attenuated Total Reflectance Infrared Spectroscopy (ATR-FTIR), Fluorescence Lifetime Imaging (FLIM), and Raman Confocal Microscopy (CRM). These methods utilize the unique spectra formed by the excitation and absorption of substances to analyze them, pinpointing the depth of substances within the skin and allowing for visual study of drug transdermal absorption. 8) Perfusion-vascularized full-thickness skin models: These emerging commercially available perfusion-vascularized full-thickness skin models feature highly differentiated multilayered epidermal structures, including three vascular channels, neovascular buds, and microvascular networks. The permeability of substances is studied by examining their barrier function and permeation levels after application to the model. This method is currently still under development.

[0003] In summary, testing the penetration-enhancing effect of a product generally requires a characteristic substance, which is then sampled through various methods such as in vitro transdermal testing, local in vivo testing, in vitro receiving cells, in vivo tape peeling, and semi-permeable membrane microcatheters. Quantification is then achieved using analytical instruments or by directly characterizing changes in skin indicators using colorimetric instruments and spectrometers. However, these methods have several drawbacks: 1) In vitro testing results are complex and lack good correlation, failing to fully represent the effects of in vivo testing; 2) The tape peeling method is suitable for testing the amount of a specific substance retained in the skin after transdermal penetration, but it cannot be used for substances that damage the stratum corneum, and is affected by adhesion pressure, peeling speed, skin condition, and tape adhesiveness, resulting in significant individual differences; 3) The vasoconstriction assay is only applicable to cases where skin vasoconstriction is caused by glucocorticoids, and the accuracy of the test method is limited; 4) Spectroscopic testing methods are highly accurate but the instruments are expensive; 5) The perfusion vascularized full-thickness skin model method has not yet been widely used; and the microdialysis method is an invasive test and is not suitable for the cosmetics field. It is evident that existing testing methods have long testing cycles, require pretreatment and quantification using expensive analytical instruments, and involve complex analytical processes. These methods are suitable for the field of dermatological drugs, but not for the field of cosmetics.

[0004] Therefore, there is an urgent need to develop a simple, non-invasive, rapid method for evaluating transdermal absorption in the cosmetics field. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for testing the penetration-enhancing effect of cosmetics.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a method for testing the penetration-enhancing effect of cosmetics, comprising the following steps: (1) Add coloring agents to the cosmetic to be tested; (2) Apply the cosmetic from step (1) to the skin; (3) Test the yellow-blue component of the skin at multiple time points. Value; the specified time points are no less than three; (4) A negative control group was set up, and the transdermal penetration enhancement effect of the cosmetics to be tested was evaluated by comparison with the negative control group.

[0007] This invention constructs a non-invasive detection model based on changes in skin optical properties. It utilizes the differences in light scattering caused by changes in the hydration state and arrangement structure of the stratum corneum after the action of penetration-enhancing ingredients. A high-precision colorimeter is used to collect data on the skin surface under a standard light source. The dynamic evolution of color difference values ​​was investigated. Big data analysis established a strong correlation between color difference changes and transdermal absorption rate, and a low-permeability control sample was used to determine the level of penetration. This method avoids the invasiveness and complexity of traditional detection methods, significantly shortens the testing cycle, requires no expensive instruments for analysis, and is suitable for the rapid screening and evaluation of various cosmetic formulations, especially for functional products such as moisturizing, nourishing, repairing, soothing, whitening, and anti-aging products.

[0008] As a preferred embodiment of the first aspect, step (4) determines the transdermal penetration effect of the cosmetic by the following method: (1) Obtain Δb at multiple time points using Formula 1 Value, when the Δb of the tested cosmetic product at at least one time point When there is a significant difference compared to the negative control group, the transdermal penetration enhancement effect of the cosmetic is determined to be significantly better than that of the negative control group; the Δb of the tested cosmetic When the value is not significantly different from that of the negative control group, the transdermal penetration enhancement effect of the cosmetic is determined to be equal to or lower than that of the negative control group; Formula 1: Δb =b x -b 0, b 0 represents the yellow-blue hue component measured before the use of cosmetics or the negative control group. Value, i.e., basic value; b X b is the yellow-blue tint component measured X hours after using cosmetics or as a negative control group. Value; X is 0.5 ≤ X ≤ 24; or / and; (2) Obtain b at multiple time points using Formula 2 Rate of change, these b The rate of change was linearly fitted to obtain the absolute value of the linear fitting slope |K|. The |K| value of the cosmetic to be tested was compared with the |K| value of the negative control group. When the |K| value of the cosmetic to be tested was greater than the |K| value of the negative control group, the transdermal penetration enhancement effect of the cosmetic to be tested was determined to be significantly better than that of the negative control group; when the |K| value of the cosmetic to be tested was less than or equal to the |K| value of the negative control group, the transdermal penetration enhancement effect of the cosmetic to be tested was determined to be equal to or less than that of the negative control group. Formula 2: b rate of change = (b Y -b 0.5 ) / (b 0.5 -b 0)×100%; b 0 represents the value of b measured before using the tested cosmetic or the negative control group. Value, i.e., basic value; b 0.5 represents the result of using the tested cosmetic or the negative control group within 0.5 hours. value; b Y represents the value of b measured Y hours after using the tested cosmetic or the negative control group. Value; Y is 1≤Y≤24.

[0009] This invention is based on the color difference value Δb of the colorant on the skin. b The dynamic change in the rate of change directly reflects the transdermal penetration process of the colorant over time, through Δb =b x -b 0 or / and b rate of change = (b Y -b 0.5 ) / (b 0.5 -b The percentage (0) × 100% is used to characterize the transdermal penetration effect of the test sample within a specific time period; it can intuitively distinguish the relative penetration capacity of different test samples.

[0010] For example, X is the set detection time, which can be any value among 0.5h, 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, or 24h; Y is the set detection time, which can be any value among 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, 13h, 14h, 15h, 16h, 17h, 18h, 19h, 20h, 21h, 22h, 23h, or 24h.

[0011] As a preferred embodiment of the first aspect, it further includes the following step: when Δb at two consecutive time points When the value is less than 0.5 (including negative values), the test is stopped, and the previous time point is the duration of the penetration effect of the cosmetic product being tested.

[0012] In this invention, Δb at two consecutive preset sampling time points A value <0.5 (including negative values) indicates recovery to the baseline standard (unsmeared state), and the test can be stopped. The test can be terminated when the sample has recovered to the unsmeared baseline state from the second time point onwards. The last Δb before baseline recovery is considered the baseline recovery determination. The sampling time point with a value ≥0.5 is taken as the longest permeation time of the sample, such as 4 hours Δb =0.5, Δb during 8-hour test =0.3, then the sample is determined to have a continuous penetration effect for 4 hours.

[0013] In a preferred embodiment of the first aspect, the amount of colorant added is 0.5% to 1.5% of the total mass of the cosmetic. Research by this invention has found that when the amount of colorant added is within the range of 0.5% to 1.5%, a good color development effect can be achieved. This ensures that the colorimeter can accurately capture color changes on the skin surface, without causing skin irritation or affecting the properties of the cosmetic itself due to excessive addition. This addition range has been verified through multiple experiments. At 0.5%, the colorant can be evenly dispersed in the cosmetic and initially show color. As the amount added increases, the color development effect gradually strengthens. When it reaches 1.0%, the color depth is moderate, and there is no color agglomeration or unevenness due to excessive concentration. At the same time, the stability and repeatability of the test results are also guaranteed.

[0014] In a preferred embodiment of the first aspect, the colorant is a water-soluble or oil-soluble pigment. The present invention selects a suitable type of colorant based on the dosage form characteristics of the cosmetic to be tested. For water-based cosmetics, such as toners and serums, water-soluble pigments are selected because they can dissolve uniformly in the aqueous system, ensuring uniform dispersion in the cosmetic. For oil-based cosmetics, such as essential oils and creams, oil-soluble pigments are selected to ensure good dispersion in the oil matrix, avoiding stratification or precipitation, thereby ensuring uniform distribution of the colorant in the cosmetic and thus guaranteeing the accuracy of subsequent color difference measurements.

[0015] In a preferred embodiment of the first aspect, the colorant is selected from one or more of carotenoids, curcumin, capsanthin, and their derivatives. These colorants are all naturally derived or stable pigments with good safety and stability. Carotenoids, such as zeaxanthin (3R,3'R-dihydroxy-β-carotene), have a bright orange-yellow color and are relatively resistant to light and heat; curcumin is a yellow pigment extracted from ginger plants, possessing good coloring ability and certain physiological activity; capsanthin is a natural red pigment extracted from chili peppers, with a bright color and good stability. Their derivatives, while retaining their original coloring properties, may exhibit superior performance in terms of solubility and stability, and can be selected according to specific needs.

[0016] In a preferred embodiment of the first aspect, the colorant is paprika oleoresin. Extensive screening experiments have revealed that paprika oleoresin has significant advantages as a colorant. First, paprika oleoresin has a bright, vivid red color; after being applied to the skin, its color change is easily identified and captured by a colorimeter, producing a relatively obvious ΔE. and Δb The change in value improves the sensitivity of the test. Secondly, capsanthin is a red, viscous, oily liquid that is easily soluble in oily products and is less affected by acids, alkalis, oxygen, visible light, and metal ions, exhibiting good stability and ensuring the reliability of the test results. Furthermore, capsanthin is widely available, relatively inexpensive, and has low skin irritation, meeting the safety requirements for cosmetic testing. Therefore, capsanthin is a relatively ideal colorant choice in the test method of this invention.

[0017] Secondly, the present invention provides the application of colorants in the preparation of formulations for detecting the penetration-enhancing effect of cosmetics.

[0018] This invention utilizes the response relationship between the color development characteristics of colorants on the skin surface and changes in the hydration state of the stratum corneum to construct a visual evaluation system. When a specific concentration of colorant is added to a cosmetic and applied to the skin, the penetration-enhancing ingredients alter the stratum corneum structure, enhancing the transdermal penetration of the cosmetic and thus affecting the diffusion behavior and color uniformity of the colorant. The color distribution changes in the skin area are recorded using an image acquisition system under standard light sources, or measured by a colorimeter. a b Value, and calculate ΔE or / and Δb value / and b This method utilizes the rate of change to dynamically track the transdermal penetration process of cosmetics. It requires no biopsy or complex pretreatment and offers high repeatability and intuitiveness. It is suitable for rapid screening and efficacy verification of penetration-enhancing formulas in everyday skincare products.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention screens out highly safe colorant ingredients suitable for the cosmetic field through extensive testing, and evaluates the difference in skin penetration between the penetration-enhancing sample group and the control group after the addition of colorant dye to characterize the skin penetration effect of the samples. A uniform co-solvent is used to pre-dissolve the colorant before mixing it with the sample to ensure thorough mixing of the colorant and to eliminate differences caused by the penetration-enhancing effect of the co-solvent.

[0020] The measurement indicators used in this invention are all color-related indicators, compared to the previous method. Change △b And compared to b 30 minutes after use The rate of change can be used to detect the penetration-enhancing effect of the cosmetic product being tested.

[0021] Pre-testing preparation is very simple, and the testing time is short. Unlike diffusion cell methods, which are limited by instrument capacity and analytical methods, or methods like tape removal combined with LC-MS or Raman spectroscopy, which are limited by expensive analytical instruments and methods, this testing method can complete multiple evaluation tests within one day. Data processing and judgment results are more intuitive, making it suitable for consumer applications in the cosmetics industry. This method requires no complex equipment; only a portable colorimeter or a system with image acquisition capabilities under standard light sources is needed for rapid on-site detection, significantly improving testing efficiency. Attached Figure Description

[0022] Figure 1 Comparison of different colorants 30 minutes after application (b) Linear fitting curve of the rate of change; Figure 2 Comparison of capsanthin concentrations at 30 minutes post-application (b) Linear fitting curve of the rate of change; Figure 3 Δb for different concentrations of capsanthin at various time points The linear fitting curve; Figure 4 Δb for different concentrations of capsanthin The linear fitting curve; Figure 5 Compared to the high-penetration group, the commercially available sample test group, and the low-penetration control group, b was applied 30 minutes later. Linear fitting curve of the rate of change; Figure 6 The standard curve fitting curve for the sample without added colorant; Figure 7 A standard curve fitting curve was obtained by adding colorant 1, capsanthin, to the sample. Figure 8 The standard curve fitting curve of zeaxanthin with added colorant 2 to the sample; Figure 9 Curcumin standard curve fitting curve after adding colorant 3 to the sample; Figure 10 Compared to the low-permeability control group and the experimental group, b was applied 30 minutes later. Linear fitting curve of the rate of change. Detailed Implementation

[0023] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0024] All raw materials used in the embodiments of this invention are commercially available analytical grade reagents. The materials and instruments used in this invention are as follows: 1. Materials: Low viscosity white mineral oil (MORESCO Co., Ltd.), curcumin (95%, Henan Zhongda Hengyuan Biotechnology Co., Ltd.), centrifuge tubes (10mL), squalane, jojoba seed oil, triglycerides (ethylhexanoate), polyglycerol-3 diisostearate, vitamin E, medium chain triglycerides (medium, MCT oil), petrolatum, eucalyptol, 1,3-propanediol, zeaxanthin (3R,3'R-dihydroxy-β-carotene, Aladdin, ≥96%), paprika oleoresin (Oterra, ≥96%).

[0025] 2. Instruments: Colorimeter (Courage+Khazakaelectronic GmbH, MPA10-Colorimeter), balance (sensitivity 0.1mg, Mettler Toledo ML204), high-speed high-resolution microconfocal Raman spectrometer.

[0026] Example 1: Screening of coloring dyes This invention uses coloring dyes to characterize the transdermal penetration effect of formulated products. Therefore, selecting a suitable colorant is crucial to this invention, and it must meet the following conditions: no residue on the skin surface, not easily washed away, able to penetrate into the stratum corneum along with the formulation ingredients, and stable in color development. While meeting the requirements of content and b... Based on the linear correlation of the rate of change, lipophilic colorants that are rapidly miscible with oil-based systems at room temperature are preferred. This is because readily soluble colorants require no additional heating or solubilization processes, do not alter the intrinsic permeability of the sample, and maintain a homogeneous and stable system throughout the testing period, thus maintaining good linearity, significantly reducing parallel testing errors, and improving the precision and universality of the method. For sparingly soluble solid colorants, this method can also be used, provided complete dissolution and system stability are ensured.

[0027] 1. Experimental Method: Alternative colorants: zeaxanthin (3R,3'R-dihydroxy-β-carotene), curcumin, and capsanthin, each added at a mass percentage of 0.5%.

[0028] (1) The above colorants were formulated into corresponding base skin care oils (medium permeability) to obtain base formulas 1-3. Then, the penetration-enhancing effects of different colorants were compared. The specific formulas are shown in the table below: Table 1: Basic Formula 1 Table 2: Basic Formula 2 Table 3: Basic Formula 3 (2) Apply the skin care oils 1-3 of the above basic formula to human skin respectively, and compare the effects of different colorants. The specific steps are as follows: A. Requirements for trial users: (a) Healthy individuals aged 18 to 45 (excluding pregnant women and breastfeeding mothers); (b) The skin on the inner forearm is dry, the stratum corneum is of normal thickness, there is no history of sensitivity, and there are no skin lesions, dermatitis, scars, pigmented nevi, hirsutism or other diseases or characteristics that may affect the test measurement results; all skin care products should be discontinued 12 hours before the test; (c) Skin tone requirement: HAB ≥ 45, a Value ≤ 8 (excluding excessive skin redness), skin tone is even.

[0029] Sample B: After cleaning the skin, four areas (2cm × 2cm each) were randomly marked on the inner forearm. One area served as the control group, and the other three areas served as the experimental group. During the test, the subjects were kept stable in an environment of (21±2)℃ and (50±10)% relative humidity for at least 20 minutes. Experimental group: Basic formulas 1, 2, and 3; Control group: Basic formula after removing colorants.

[0030] C-test skin baseline values: L-values ​​of skin surface area in both the control and experimental groups were measured using a colorimeter. a b value.

[0031] D. Sample application: at 1.0 mg / cm² 2 The corresponding samples were applied to the experimental group and the control group respectively.

[0032] E test after application L a b Values: L values ​​were measured on clean skin with normal activity levels at 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours after application, as well as 24 hours after application. a b The value is determined by the following steps: (a) Within 30 minutes of sample application, the skin L of the control group and the experimental group was measured using a colorimeter. a b value; (b) After application for 1 hour, 2 hours, 4 hours, and 8 hours, the skin L of the control group and the experimental group was measured using a colorimeter. a b value; (c) Subjects maintained normal daily routines and hygiene. A follow-up visit was conducted 24 hours after use, and skin L (radiochromatic aberration) was measured using a colorimeter in both the control and experimental groups. a b value.

[0033] F is calculated: (a) Calculate Δb for the control and experimental groups within 30 minutes, 1 hour, 2 hours, 4 hours, and 8 hours after sample use, and 24 hours after normal routine cleaning. value and b Rate of change; Δb The value represents the change in skin condition at the application site before and after using the tested cosmetic. b The change characterizes the relative permeability of the sample, b A larger change indicates a better absorption-promoting effect of the cosmetic. △b The formula for calculating the value is as follows: Δb =b x -b 0, b 0 represents the skin temperature (b) measured at the application site before using the cosmetic. Value, i.e., basic value; b X b is the skin color measured at the application site X hours after applying the cosmetic. value; b The formula for calculating the rate of change is as follows: b rate of change = (b Y -b 0.5 ) / (b 0.5 -b 0)×100%; b 0 represents the skin temperature (b) measured at the application site before using the cosmetic. Value, i.e., basic value; b 0.5 That is, applying b within 30 minutes. value; b Y b is the value measured on the skin at the application site Y hours after applying the cosmetic. value; (b) Color difference ΔE between the control and experimental groups within 30 minutes, 1–8 hours after application, and 24 hours after application, compared with the group without added colorant, when cleaning with normal routine. (Comparison between groups, comparison between control group and experimental group); △E The calculation formula is as follows: ΔE = ; ΔL =L x -L 0; Δa = a x -a 0; Δb =b x -b 0; L 0, a 0, b 0 represents the L measured on the skin at the application site before applying the tested cosmetic. a b Value, i.e., basic value; L x a x b x L is the amount of skin moisture measured at the application site X hours after applying the cosmetic. a b value.

[0034] G-staining agent screening criteria: A staining agent meeting the following conditions is considered a staining agent: (a) Within 30 minutes of application, the color difference between the experimental group and the control group before application was Δb*. If the difference is statistically significant, then the colorant is considered to be able to color within a short period of time; (b) Compared to within 30 minutes of application, the experimental group △b or b The larger the absolute value of the rate of change, the better the transdermal penetration effect of the test sample, and at the test endpoint, b linear fitting of rate of change R 2 The larger (R) 2 >0.9), indicating a strong correlation between the staining agent and the staining response, thus suggesting that the staining agent is more suitable for indicating changes in the permeability of skin surface samples; (c) 24 hours after application, the color difference ΔE in the experimental group compared to before application Color difference ΔE before application compared to the blank control group If the difference is not statistically significant, it is assumed that the colorant can be removed through normal cleaning within 24 hours and will not have an adverse effect on skin color.

[0035] 2. Experimental Results: The results are shown in Table 4 below: Table 4 Note: Significance: " "This means 0.01 ≤ P < 0.05;" "0.001 ≤ P < 0.01;" "This indicates that P < 0.001, meaning that the paired-samples t-test at this time point showed a statistically significant difference between the experimental group Sn and the control group S."

[0036] As shown in Table 4, within 30 minutes of application, the control group Δb =-0.18, colorant 1△b The value is 1.90, and the colorant is 2△b. The value is 1.09, and the colorant is 3△b. The value is 0.11, indicating that the Δb of colorant 1 is... Value and control group △b The difference in values ​​was significantly higher than that of colorants 2 and 3. This indicates that colorant 1 can color the skin in a short time and is more sensitive as a staining indicator. According to screening criterion (a), colorant 1, paprika oleoresin, is selected as a candidate colorant.

[0037] Furthermore, 24 hours after application, the control group △E The value is 0.99, and the colorant 1△E The value is 1.15, and the colorant is 2△E. The value is 1.35, and the colorant is 3△E. The value is 1.11, indicating that the ΔE for colorants 1 and 3 is... Value and control group △E The differences in values ​​were not statistically significant, and the ΔE of colorant 2 was... Value and control group △E The differences in values ​​are statistically significant. According to screening criterion (c), this indicates that both colorants 1 and 3 can be removed through normal cleansing within 24 hours without adversely affecting skin tone.

[0038] The results are as follows Figure 1 The display shows that, by Figure 1It can be seen that, with the extension of time, the sample area containing the colorant has a higher concentration of b compared to other time points within 30 minutes of application. The values ​​all showed a decreasing trend. Linear fitting was performed, and the linear R-values ​​for each experimental group were found to be... 2 The values ​​are respectively for colorant 1 R 2 =0.9558, colorant 2 R 2 =0.9986, colorant 3R 2 =0.7534, indicating that the R of colorant 1 and colorant 2 is... 2 >0.9. As shown in Table 4, the endpoint Δb of experimental group 1 at 8 hours... The absolute value is 0.39, b The absolute value of the rate of change was 120.6%, and the experimental group 2Δb The absolute value is 0.12, b The absolute value of the rate of change was 88.6%, and the experimental group 3△b The absolute value is 0.33, b The absolute value of the rate of change was 390.1%. Experimental group 3△b or b The absolute value of the rate of change was the largest, followed by the experimental group 1. Based on screening criterion (b), the overall linear relationship R... 2 Value and △b or b The absolute value of the rate of change, with paprika red as the alternative colorant.

[0039] In summary, capsanthin is more sensitive than other coloring agents as a staining indicator because it can rapidly penetrate the skin and color it within a short time. Furthermore, its linear fit R0 is superior. 2 A value greater than 0.9 indicates a high degree of agreement between the measured data points and the fitted straight line, suggesting that the staining process exhibits high regularity and predictability. Therefore, paprika oleoresin was chosen as the indicator for detecting the penetration effect of cosmetics in this invention.

[0040] Example 2: Investigation of the preferred concentration of the coloring dye Example 1 identified capsanthin as the preferred penetration indicator colorant, but its concentration needs further optimization to meet the following conditions: it should be able to penetrate the stratum corneum of the skin along with the formulation ingredients after application, and its color should remain stable during the testing period (4-8 hours). This example further tests and compares the concentration of capsanthin used.

[0041] 1. Experimental Method: (1) Using a standard medium-penetration matrix [low viscosity white mineral oil (MORESCO Co., Ltd.)], capsicum red was prepared into three mass concentrations of 0.5%, 1.0%, and 1.5%, namely test group 1, test group 2, and test group 3. The optimal working concentration of capsicum red in the skin oil system was screened to ensure that the colorant has good solubility and strong stability at this concentration, and that the skin staining Δb* value response is sensitive and linear, without saturation effect or weak signal problem. This provides a uniform and reliable colorant concentration for the penetration test of subsequent low / medium / high penetration skin oil formulations.

[0042] (2) The standard medium-permeability matrix + capsicum red solution of Example 2 was tested using the test method of Example 1; (3) Colorant concentration screening criteria: a. Linear application: Choose a period of 30 minutes to 8 hours. The overall linear relationship with the highest R² value was selected during the application period of 30 minutes to 8 hours (Δb). The linear correlation coefficient R² value is the highest. A better linear correlation indicates a stronger relationship between concentration and staining response, making it suitable as an osmosis indicator. b-sensitivity: Δb of adjacent concentrations The larger the difference (the larger the slope K value) and the statistically significant difference compared to the control group (P≤0.05), the better Δb is. The more sensitive the value response, the clearer the concentration difference can be distinguished.

[0043] c. Under the premise of meeting the above conditions, taking into account both economy and safety, and avoiding waste or potential skin irritation caused by high concentration of colorant, a medium-to-high concentration (1.0%-1.5%) is selected as the colorant concentration.

[0044] 2. Test Results: The test results are shown in Table 5 below: Table 5 Note: Significance: " "This means 0.01 ≤ P < 0.05;" "0.001 ≤ P < 0.01;" "This indicates that P < 0.001, meaning that the paired-samples t-test at this time point showed a statistically significant difference between the experimental group Sn and the control group S."

[0045] Based on the results of the linear correlation analysis, from Figure 2 It can be seen that, with the extension of time, compared with within 30 minutes of application, the levels of different concentrations of capsanthin at other time points were [lower / lower / lower / etc.]. The values ​​all showed a decreasing trend. Linear fitting was performed, and the linear R-values ​​for each experimental group were found to be... 2 The values ​​were R for experimental group 1.2 =0.9031, R in experimental group 2 2 =0.9451, R in experimental group 3 2 =0.8881, indicating that R0.8881 for experimental group 2 2 The highest value indicates that the staining response was most strongly correlated at a capsanthin concentration of 1.0%. Figure 3 It can be seen that △b at each time point After linear fitting, capsanthin showed a good linear relationship with concentration from 0.5 h after application to 4 h in the middle of the test (R0). 2 >0.9), where Δb of capsanthin (experimental group 2) at the midpoint of the 4-hour timeframe was Δb. The value showed a better linear relationship with capsaicin concentration, with R² = 0.9964, and 4 hours covered the basic penetration time of cosmetics; by Figure 4 It can be seen that Δb at each time point After linear fitting, Δb The slope |K| value was: Experimental group 3 (0.8244) > Experimental group 2 (0.4437) > Experimental group 1 (0.2257) > Control (0.0924), therefore, the preferred concentrations for testing are 1.0% and 1.5%. Figure 4 It can be seen that during the application period of 30 minutes to 8 hours, Δb in each group... The linear correlation coefficient R² values ​​showed the following order: Experimental Group 2 (0.9451) > Experimental Group 1 (0.9031) > Experimental Group 3 (0.8881) > Control (0.4587). Therefore, the R² value for Experimental Group 2 was significantly lower. 2 The highest value and the best linearity indicate that the concentration in experimental group 2 is strongly correlated with the staining response.

[0046] Therefore, based on the linear correlation of colorant concentration screening criterion (a), a capsanthin concentration of 1.0% was selected as the candidate concentration.

[0047] As shown in Table 5, the sensitivity analysis results indicate that, compared with the control group, Δb In comparison, experimental group 2 showed significant differences at 0.5h, 1h, 2h, and 4h, while experimental group 3 showed significant differences only at 0.5h, 1h, and 4h, and experimental group 1 showed a significant difference only at 0.5h. Therefore, experimental group 2 showed better sensitivity than experimental groups 1 and 3.

[0048] Therefore, based on the sensitivity of the colorant concentration screening criterion (b), a paprika red concentration of 1.0% was selected as the alternative concentration.

[0049] In summary, since experimental group 2 showed the highest linear correlation and sensitivity, a concentration of 1.0% was selected as the amount of capsanthin to be added.

[0050] Example 3: Application of the test method of the present invention in low-permeability, commercially available samples, and high-permeability formulations. This embodiment provides pure jojoba seed oil as a low-penetration moisturizing oil and pure squalane as a high-penetration skincare oil. A commercially available, high-penetration moisturizing oil, Memory Flower Extract Anti-Aging Essence Oil, is used as the test subject. The purpose is to demonstrate that the testing method of this invention is also applicable to cosmetics with both low-penetration and high-penetration formulations. Specific formulations are shown in Tables 6-8: Table 6 Table 7 Table 8 Ensure that the samples in Tables 6 to 8 are prepared as clear, uniformly mixed samples before testing, without any layering or other phenomena.

[0051] The low-penetration moisturizing oil, high-penetration skin care oil, and commercially available samples from Example 3 were tested using the test method of Example 1. The test results are shown in Table 9 below: Table 9 Note: Significance: " "This means 0.01 ≤ P < 0.05;" "0.001 ≤ P < 0.01;" "This indicates that P < 0.001, meaning that the paired-samples t-test at this time point showed a statistically significant difference between the experimental group Sn and the control group S."

[0052] As shown in Table 9 above, the test method of this invention can accurately reflect the transdermal penetration behavior of capsanthin in low-permeability, commercially available samples, and high-permeability emollient oils, and compares the commercially available samples and high-permeability emollient oils with the low-permeability ones. (b) at different time points The rate of change trend indicates that capsanthin exhibits a continuous penetration characteristic over time. Specifically, in the high-penetration formulation group, after 4 hours of application, Δb... A decrease to below 0 indicates that the sample was within approximately 4 hours. The sample was restored to baseline (untreated state), meaning it was fully permeated in approximately 4 hours; while the low-permeability group and the commercially available sample group were not fully permeated until 8 hours Δb. The temperature dropping below 0 indicates that the two samples need approximately 8 hours to complete the permeation process.

[0053] From the above Figure 5 The results show that, compared with the high-penetration group, the commercially available sample test group, and the low-penetration group, 30 minutes after application, b The rate of change is linearly fitted to obtain R. 2Values, displayed linearly: High permeability group, commercially available sample test group, low permeability group R 2 All values ​​were greater than 0.9, meeting the requirements for linear fitting of penetration rate and time; the slope of the linear fitting, |K|, was: high penetration group (0.2923) > commercially available moisturizing oil group (0.2834) > low penetration group (0.2748); it can be seen that the penetration rate of the high penetration group and the commercially available sample group was better than that of the low penetration control group; as shown in Table 9, Δb Value difference: Compared with the low-permeability control group, the high-permeability group and the commercially available sample group showed significant differences at 1 hour, that is, within 1 hour, the permeability of the high-permeability group and the commercially available sample group was better than that of the low-permeability control group.

[0054] Evaluation Result Judgment Criteria: Compared to within 30 minutes of application, the commercially available sample test group b... Rate of change (compared to 30 min after application) (Rate of change) Linear fitting R 2 >0.9. Compared to within 30 minutes of application, at least one point in test group b reached the test endpoint. The absolute value of the rate of change is greater than that of the negative control group, and Δb If the difference from the negative control group is statistically significant (P < 0.05), then the test sample is considered to have a better penetration effect than the negative control (low-permeability control group).

[0055] The results above show that the test method of this invention can accurately reflect the transdermal penetration behavior of capsicum in low-permeability skin care oils. At different time points, b... rate of change (b) rate of change = (b Y -b 0.5 ) / (b 0.5 -b The trend of changes in (0)×100%) indicates that capsanthin exhibits a continuous penetration characteristic over time.

[0056] In summary, the test results of Examples 1-3 demonstrate that the test method established in this invention has good applicability and accuracy, and can effectively distinguish formulations with different permeability. This is achieved through the color difference value Δb. b Rate of change (compared to b 30 minutes after application) The dynamic change of the rate of change can intuitively reflect the transdermal penetration process of colorants over time, further verifying the scientific validity and reliability of this method in assessing the permeability of cosmetics. Δb at two consecutive preset sampling time points A value <0.5 (including negative values) indicates recovery to the baseline standard (unsmeared state), and the test can be stopped. The test can be terminated when the sample has recovered to the unsmeared baseline state from the second time point onwards. The last Δb before baseline recovery is considered the baseline recovery determination. The sampling time point with a value ≥0.5 is taken as the longest permeation time of the sample, such as 4 hours Δb =0.5, Δb during 8-hour test =0.3, then the sample is determined to have a continuous penetration effect for 4 hours.

[0057] This indicates that the cosmetic penetration enhancement effect test method constructed in this invention has the following characteristics: (1) Through Δb =b x -b 0 or / and b rate of change = (b Y -b 0.5 ) / (b 0.5 -b (0)×100% characterizes the transdermal penetration effect of the test sample within a specific time; (2) It can be applied to cosmetic formulations with low, medium and high penetration effects, and predicts the duration of complete penetration effect of the sample by the total time from application to complete disappearance of the penetration effect; (3) By using fixed low-penetration reference samples (such as colorless pure products such as colorless vegetable oil, jojoba seed oil, petrolatum, white mineral oil, etc.) and high-penetration reference samples (such as colorless pure products such as squalane, isopropyl myristate, etc.) as controls, the relative penetration ability of different test samples can be intuitively distinguished.

[0058] Example 4: Verification of the test method of the present invention This embodiment uses Raman spectroscopy to detect the relative permeability of transdermal penetration for verification. The specific operation is as follows: 1. Raman spectroscopy testing procedures: (1) The subjects were instructed to use the product as instructed. After the subjects arrived, they cleaned the skin on the inside of their arms with water. After cleaning, they sat quietly in a constant temperature and humidity room for 30 minutes. After 30 minutes, the subjects used the product as instructed. The product was Memory Flower Extract Anti-Aging Essence Oil (without added colorants, main ingredients: squalane, jojoba seed oil, and the same penetrating components as in Example 1). In vivo Raman tests were performed on the subjects at 0.5h, 1h, 2h, 4h, and 8h.

[0059] (2) Calculate the relative penetration rate at each time point compared to immediate application (within 30 minutes of application): Relative penetration rate (%) = Normalized (change in Raman characteristic peaks caused by use of the test product) × 100%.

[0060] 2. Establishing the standard curve: (1) Using a colorimeter, the skin color of the test area of ​​the subject was measured at 0.5h, 1h, 2h, 4h and 8h. Value, and calculate b at each time point. The rate of change in value compared to immediately after application (within 30 minutes of application); (2) Plot a curve with the relative permeability of the Raman spectrum on the x-axis and the rate of change of b* at 0.5h, 1h, 2h, 4h, and 8h as the y-axis, using the immediate (within 30 minutes of application) change rate.

[0061] b before application The color b* is the skin's natural color. It is compared with the time immediately after application (considering that the application time is generally set to 30 minutes, representing the 0 time point after application) and the time within 30 minutes after application.

[0062] 3. Verification results: The results are shown in Table 10 and... Figures 6-9 As shown, the results obtained using the detection method of Example 1 and the Raman spectrometer show a high degree of consistency. The penetration trends of both methods at each time point are highly consistent, verifying the accuracy and reliability of the method of this invention. The Δb value of the experimental group continuously increases with time, showing a significant change after 30 minutes, and tends to stabilize after 4 hours, which is consistent with the trend of relative penetration measured by Raman spectroscopy.

[0063] from Figure 7 (Sample + colorant 1 paprika) It can be seen that the standard curve fitting equation is y = 0.3108x + 0.4198 (R²). 2 =0.9588) indicates that the relative permeability of the Raman spectrum is related to b The rate of change showed a significant linear correlation. This result verifies the scientific validity of the preferred colorant and color difference method used in this invention to reflect the degree of transdermal penetration, indicating that Δb value and b The rate of change can effectively characterize the permeation kinetics of active ingredients. Correlation analysis between the two detection methods further demonstrates that the established test model has good in vitro-in vivo correlation, providing a reliable technical basis for evaluating the permeation performance of cosmetics. The trends in the rate of change of the permeation-enhancing effect detected by the two methods are consistent, with a correlation coefficient R0. 2 Both values ​​>0.90, exhibiting typical transdermal permeation kinetics. This result further confirms that the color difference evaluation method established in this invention can accurately reflect the transdermal permeation behavior of active ingredients, possessing the advantages of non-invasiveness and real-time dynamic monitoring, and is suitable for rapid screening and evaluation of permeation performance in cosmetic formulation development. This invention demonstrates the feasibility of dynamically monitoring active ingredients in low-permeability formulations through color difference analysis, and is simple to operate and has good repeatability.

[0064] Table 10 Application examples The testing method of this invention is applied to detect commercially available cosmetics, and the specific operation is as follows: Pure petrolatum was used as a low-permeability control group, and commercially available eye creams with typical permeability were used as test subjects. The purpose was to examine whether the test method of this invention could be applied to the detection of commercially available cosmetics. Specific colorant formulations are shown in Tables 11 and 12. Table 11 Table 12 1. Ensure that the samples in Tables 11 and 12 are well mixed before testing, without any layering or other phenomena.

[0065] 2. Simple preliminary experiment to determine whether a calibration group needs to be set up: Pure sample (no colorant), b is measured before and immediately after application. Calculate the difference; if the difference is <0.3, the background color interference can be ignored and the correction group can be omitted; if the difference is ≥0.3, there is detectable interference and a correction group must be added.

[0066] The low-permeability control containing colorants, commercially available eye creams, and commercially available eye cream products containing colorants in this application example were tested using the test method of Example 1. The test results are shown in Table 12 below: Table 12 Note: Significance: " "This means 0.01 ≤ P < 0.05;" "0.001 ≤ P < 0.01;" "P < 0.001 indicates that the paired-samples t-test at this time point showed a statistically significant difference between the experimental group S6 and the low-permeability control group C.

[0067] As can be seen from the results in Table 12 above: (1) Apply S (Premium Essence Anti-Wrinkle Eye Cream) and immediately △b =-0.04<0.3, indicating that the background color interference of the sample is negligible, and subsequent tests of the sample calibration group are omitted; (2) Table 12 reflects the transdermal penetration behavior of capsicum in low-permeability, commercially available eye creams, and compares commercially available eye creams with low-permeability petrolatum. b at different time points Rate of change (compared to 30 min after application) The trend of change rate indicates that capsicum red exhibits a continuous penetration characteristic over time. Specifically, in the commercially available eye cream group, △b showed a significant increase in penetration rate 8 hours after application. The value decreased to 0.1 < 0.5, indicating that the sample was within approximately 8 hours of exposure. Return to baseline standard (unsmeared state), meaning the sample completed penetration in approximately 8 hours. At 8 hours, sample b... The change rate (dye loss rate) was -98.4%.

[0068] (3) From the above Figure 10 The results show that the 30-minute time difference between the petroleum jelly group (low-osmotic control group) and the eye cream group (experimental group) was significantly reduced. The rate of change is linearly fitted to obtain R. 2 Values ​​and slopes |K| values, linear display: low permeability group (R 2 =0.9664), commercially available eye cream group (R 2 =0.9373)R 2 All values ​​were greater than 0.9, indicating that the permeability-time linear fitting requirement was met; Results: ① Slope |K| value: Commercially available eye cream group (0.2394) > Low permeability group (0.1132), indicating that the permeability of the tested eye cream was superior to that of Vaseline (low permeability control group); ② From Table 12, △b Differences: Compared with the low-penetration group, the commercially available eye cream group showed significant differences at 2h, 4h, and 8h (P < 0.05). This means that within 8 hours, the penetration rate of commercially available eye creams was significantly better than that of petroleum jelly (low penetration control group).

[0069] The final determination will be based on ① the slope |K| value or / and ② Δb. The permeability of the test sample was evaluated by assessing the significance of the difference from the low-permeability control group.

[0070] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for testing the penetration-enhancing effect of cosmetics, characterized in that, The method includes the following steps: (1) Add coloring agents to the cosmetic to be tested; (2) Apply the cosmetic from step (1) to the skin; (3) Test the yellow-blue component of the skin at multiple time points. Value; the specified time points are no less than three; (4) A negative control group was set up, and the transdermal penetration enhancement effect of the cosmetics to be tested was evaluated by comparison with the negative control group.

2. The test method as described in claim 1, characterized in that, Step (4) determines the transdermal penetration effect of the cosmetics using the following method: (1) Obtain Δb at multiple time points using Formula 1 Value, when the Δb of the tested cosmetic product at at least one time point When there is a significant difference compared to the negative control group, the transdermal penetration enhancement effect of the cosmetic is determined to be significantly better than that of the negative control group; the Δb of the tested cosmetic When the value is not significantly different from that of the negative control group, the transdermal penetration enhancement effect of the cosmetic is determined to be equal to or lower than that of the negative control group; Formula 1: Δb =b x -b 0, b 0 represents the yellow-blue hue component measured before the use of cosmetics or the negative control group. Value, i.e., basic value; b x b is the yellow-blue tint component measured X hours after using cosmetics or as a negative control group. Value; X is 0.5 ≤ X ≤ 24; or / and; (2) Obtain b at multiple time points using Formula 2 Rate of change, these b The rate of change was linearly fitted to obtain the absolute value of the linear fitting slope |K|. The |K| value of the cosmetic to be tested was compared with the |K| value of the negative control group. When the |K| value of the cosmetic to be tested was greater than the |K| value of the negative control group, the transdermal penetration enhancement effect of the cosmetic to be tested was determined to be significantly better than that of the negative control group; when the |K| value of the cosmetic to be tested was less than or equal to the |K| value of the negative control group, the transdermal penetration enhancement effect of the cosmetic to be tested was determined to be equal to or less than that of the negative control group. Formula 2: b rate of change = (b Y -b 0.5 ) / (b 0.5 -b 0)×100%; b 0 represents the value of b measured before using the tested cosmetic or the negative control group. Value, i.e., basic value; b 0.5 represents the result of using the tested cosmetic or the negative control group within 0.5 hours. value; b Y b is the result measured Y hours after using the tested cosmetic or the negative control group. Value; Y is 1≤Y≤24.

3. The test method as described in claim 2, characterized in that, It also includes the following steps: When Δb at two consecutive time points When the value is less than 0.5, the test is stopped, and the previous time point is the duration of the penetration effect of the cosmetic product being tested.

4. The test method as described in claim 1, characterized in that, The amount of colorant added is 0.5% to 1.5% of the total mass of the cosmetic.

5. The test method as described in claim 1, characterized in that, The colorant is a water-soluble or oil-soluble pigment.

6. The test method as described in claim 1, characterized in that, The colorant is selected from one or more of carotenoids, curcumin, capsanthin and their derivatives.

7. The test method as described in claim 6, characterized in that, The colorant is paprika oleoresin.

8. The test method as described in claim 1, characterized in that, The negative control group consisted of a low-permeability moisturizing oil.

9. The test method as described in claim 1, characterized in that, The low-permeability moisturizing oil is selected from colorless pure plant oil, petrolatum, and high-viscosity white mineral oil.

10. Application of colorants in the preparation of formulations for testing the penetration-enhancing effect of cosmetics.

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