Method for determining oil control efficacy of cosmetics based on oil adsorption and decomposition detection

Abstract

The present application relates to the technical field of in-vitro evaluation of cosmetic efficacy, and discloses a cosmetic oil control efficacy determination method based on oil adsorption and decomposition detection, which comprises the following steps: providing a biomimetic membrane coated on a substrate, wherein the biomimetic membrane comprises biomimetic sebum, lipase, a pH indicator for characterizing the amount of sebum decomposition products, and an enzyme activity probe for characterizing the activity of lipase; after applying the sample to be tested and incubating, performing three modalities detection in a specific order: determining the physical adsorption index by physical transfer and weighing method; measuring the biomimetic membrane after physical transfer to obtain the biochemical regulation index reflected by the pH indicator; adding a non-water activator to activate the enzyme activity probe, and measuring to obtain the enzyme activity influence index. The present application generates three independent quantitative indicators for the same sample through a single continuous detection process, which can comprehensively and quickly characterize the oil control efficacy of the sample, and accurately distinguish various action mechanisms such as physical adsorption and biochemical regulation.

Description

Technical Field

[0001] This invention relates to the field of in vitro evaluation technology of cosmetic efficacy, specifically a method for determining the oil-controlling efficacy of cosmetics based on the detection of oil adsorption and decomposition. Background Technology

[0002] Oil-controlling efficacy is one of the key functional claims of cosmetics, and its mechanism of action typically involves both physical and biochemical aspects. Physical action mainly refers to the absorption of excess oil from the skin's surface through porous powders and other ingredients; biochemical action refers to the regulation of sebum decomposition processes by active ingredients influencing the activity of enzymes related to sebum metabolism (such as lipases) in the skin's surface microecology. Therefore, a comprehensive and accurate evaluation of oil-controlling efficacy requires consideration of both mechanisms.

[0003] However, existing methods for evaluating oil-control efficacy are insufficient in terms of comprehensiveness, accuracy, and ease of operation. Current testing systems are typically separate, meaning that physical adsorption performance and biochemical regulatory performance need to be evaluated separately using two or more completely independent experimental methods. This separate testing approach not only fails to achieve simultaneous characterization of multi-dimensional efficacy on the same sample, leading to fragmented evaluation results, but also makes it difficult to reflect the comprehensive effects of different mechanisms in a complex product.

[0004] Furthermore, existing methods suffer from mechanistic ambiguity when evaluating biochemical regulatory effects. For example, some methods assess sample efficacy by measuring the amount of sebum breakdown products (such as free fatty acids), but the reduction in product amount could stem from the sample's direct inhibition of lipase activity, or it could simply be due to physical adsorbents in the sample reducing the sebum substrate available for enzymatic reactions. Current techniques struggle to clearly distinguish between these two intrinsic mechanisms in a single test, thus limiting the depth of understanding and accuracy of evaluation of sample action.

[0005] Meanwhile, many methods for determining the biochemical decomposition of sebum are quite cumbersome. These methods often rely on solvent elution and chemical derivatization of the reaction system, and require large analytical instruments such as gas chromatography for final quantification. The entire process involves many steps, is time-consuming, and has high requirements for experimental conditions and personnel, making it unsuitable for rapid screening and evaluation of large numbers of samples. Therefore, developing a method for determining sebum control efficacy that integrates multi-dimensional detection, accurately elucidates the mechanism of action, and is easy to operate is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] This application aims to provide a method for comprehensively, rapidly, and accurately determining the oil-controlling efficacy of cosmetics, particularly addressing the technical problem that existing technologies struggle to simultaneously distinguish between multiple complex oil-controlling mechanisms such as physical adsorption, biochemical inhibition, or promotion on a single sample.

[0007] Firstly, this application provides a method for determining the oil-controlling efficacy of cosmetics based on the detection of oil adsorption and decomposition, employing the following technical solution:

[0008] A method for determining the oil-controlling efficacy of cosmetics based on the detection of oil adsorption and decomposition includes the following steps:

[0009] S1. A biomimetic membrane coated on a substrate is provided, the biomimetic membrane comprising biomimetic sebum, lipase, a pH indicator for characterizing the amount of sebum decomposition products generated, and an enzyme activity probe for characterizing lipase activity.

[0010] S2. Apply the cosmetic sample to be tested to the surface of the biomimetic membrane and incubate it for a preset time under preset temperature and humidity conditions;

[0011] S3. After incubation, perform three-modal detection in the following order:

[0012] S3.1 First, the physical adsorption amount of oil on the sample to be tested is determined by physical transfer and weighing method to obtain the physical adsorption index (PAI).

[0013] S3.2 Next, the biomimetic membrane after physical transfer in step S3.1 is measured to obtain the degree of sebum decomposition reflected by the pH indicator, and the biochemical regulatory index BRI is obtained.

[0014] S3.3 Finally, a non-aqueous activator is added to the biomimetic membrane measured in step S3.2 to activate the enzyme activity probe, and the signal intensity of the reaction product of the enzyme activity probe is measured to obtain the enzyme activity influence index (EAI).

[0015] By adopting the above technical solution, this application integrates biomimetic sebum, lipase, pH indicator and enzyme activity probe in a biomimetic membrane, and designs a strict three-modal sequential detection process of "physical transfer first, then pH change measurement, and finally probe activation", which solves the technical problem that the existing technology cannot simultaneously and quickly distinguish multiple oil-control mechanisms on a single sample.

[0016] Specifically, the initial physical transfer and weighing step (S3.1) independently and accurately quantifies the physical adsorption capacity (PAI) of the sample without interference from subsequent biochemical detection steps. Next, the pH indicator of the remaining biomimetic membrane is measured (S3.2), and its signal reflects the cumulative amount of free fatty acids generated by lipase-catalyzed sebum decomposition during incubation, thus obtaining the biochemical regulation index (BRI), which characterizes the sample's influence on the overall biochemical decomposition process. Finally, by activating an independent enzyme activity probe with a non-aqueous activator (S3.3), the enzyme activity influence index (EAI) of the sample can be measured. This index is directly related to the activity state of the lipase itself, rather than the amount of sebum substrate. This method, through a continuous and irreversible detection process, generates three independent quantitative indicators (PAI, BRI, EAI) for the same sample, clearly distinguishing whether a sample is primarily effective through physical adsorption or by inhibiting / promoting the biochemical decomposition of sebum, and further analyzing whether the biochemical regulation stems from substrate reduction or a direct impact on enzyme activity.

[0017] Preferably, the biomimetic membrane is prepared by a working solution containing specific components, including biomimetic sebum, immobilized lipase derived from Rhizopus oryzae, bromocresol green as a pH indicator, and 4-nitrophenyl palmitate as an enzyme activity probe.

[0018] In the working solution, the concentration of the immobilized lipase is 0.1-0.3% of the total lipid mass, the concentration of bromocresol green is 0.05-0.1% of the total lipid mass, and the concentration of 4-nitrophenyl palmitate is 0.5-1.0% of the total lipid mass. The biomimetic sebum is composed of the following components in weight percentage:

[0019] Squalene 15-25%, jojoba oil 20-30%, triglycerides 35-45%, cholesterol 2-4%, oleic acid 6-8%.

[0020] By employing the above technical solution, stable components were used to construct the biomimetic membrane, ensuring the controllability and repeatability of biochemical reactions within the membrane. Bromocresol green exhibits sensitive color changes within the acidic range produced by sebum decomposition; 4-nitrophenyl palmitate is a chromogenic substrate specific to lipases, and its product shows strong absorption at a specific wavelength; specific component concentration ranges ensure that changes in various indicators remain within a precisely measurable range within the preset incubation time, thereby guaranteeing the accuracy of the measurement results.

[0021] Preferably, in step S1, the preparation step of the biomimetic membrane includes:

[0022] 50-100 μL of working solution is dropped onto the substrate, and a film is formed by spin coating, wherein the spin coating method includes:

[0023] The first stage involves a speed of 500-800 rpm and a duration of 5-10 seconds;

[0024] The second stage involves a speed of 1500-2500 rpm and a duration of 30-45 seconds;

[0025] After spin coating, let the biomimetic membrane stand for 20-40 minutes.

[0026] By adopting the above technical solution, the preparation method of the biomimetic membrane has been defined. The spin-coating parameters used can form a biomimetic membrane with uniform thickness and a smooth surface, providing a foundation for the uniformity of subsequent sample application and the accuracy of detection.

[0027] Preferably, in step S2, the amount of the cosmetic sample to be tested applied is 1.5-2.5 mg / cm³. 2 The incubation temperature is 30.0-35.0℃, the relative humidity is 40-60%, and the time is 2-8 hours.

[0028] By employing the above technical solution, the application and incubation conditions of the samples were defined. These conditions simulated the temperature and humidity environment of the skin surface and ensured that the incubation time was sufficient for measurable biochemical reactions to occur, thereby guaranteeing that the test results were physiologically relevant and discriminative.

[0029] Preferably, in step S3.1, the physical transfer step specifically involves applying 40-60 g / cm³. 2 Apply uniform pressure and hold for 5-15 seconds before transferring.

[0030] By adopting the above technical solution, the operating parameters of physical transfer are limited. These parameters are optimized results that achieve a balance between ensuring transfer efficiency and avoiding excessive damage to the biomimetic membrane structure, so as to ensure the accuracy and repeatability of physical adsorption index (PAI) measurement.

[0031] Preferably, in step S3.3, the volume of the added non-aqueous activator is 8.0-12.0 μL, and the signal intensity is measured after standing for 30-90 seconds following the addition. The non-aqueous activator is composed of isopropanol, water, and Triton X-100, wherein the volume ratio of isopropanol to water is 9:1, and the mass concentration of Triton X-100 is 0.3-0.8% (w / v).

[0032] By employing the above technical solution, isopropanol in the non-aqueous activator, as the main solvent, can effectively dissolve and activate the enzyme-active probe without damaging the color of the pH indicator on the substrate; trace amounts of water are essential for the enzyme-catalyzed hydrolysis reaction; Triton X-100, as a nonionic surfactant, helps to solubilize and colorimetrically enhance the reaction products, thereby strengthening and stabilizing the detection signal. Limitations on the activator volume and reaction time ensure the efficiency of the probe reaction and the stability of the endpoint detection.

[0033] Preferably, in step S1, the substrate is a quartz substrate.

[0034] By adopting the above technical solution and using quartz as the substrate, its chemical inertness and high transmittance in the ultraviolet-visible light band provide an interference-free and stable optical background for subsequent spectroscopic color difference measurement and absorbance measurement.

[0035] This invention provides a method for determining the oil-controlling efficacy of cosmetics based on the detection of oil adsorption and decomposition. It has the following beneficial effects:

[0036] 1. This invention, through a strictly defined irreversible detection sequence within an integrated biomimetic membrane system, enables the acquisition of three independent quantitative indicators characterizing physical adsorption, biochemical decomposition processes, and enzyme activity from a single experiment. Compared to existing technologies that typically only assess a single oil control dimension or require complex experiments involving multiple separations, this invention provides a multi-dimensional quantitative data combination regarding the oil control mechanism of a sample through a single continuous operation, achieving a comprehensive characterization of the sample's oil control efficacy.

[0037] 2. This invention addresses the ambiguity of relying solely on the amount of sebum breakdown by introducing a combination of biochemical regulatory index and enzyme activity influence index, thus resolving the inaccuracy in accurately elucidating the underlying mechanism. The biochemical regulatory index reflects the overall outcome of sebum breakdown, while the enzyme activity influence index directly quantifies the activity state of the lipase itself using independent enzyme activity probes. When a sample simultaneously exhibits high physical adsorption (high PAI) and inhibited sebum breakdown (low biochemical regulatory index), the synchronous decrease in the enzyme activity influence index clearly distinguishes whether the inhibition stems from substrate reduction due to physical adsorption or from direct inhibition of lipase activity by the sample, thereby improving the accuracy of mechanism analysis.

[0038] 3. This invention significantly simplifies the operation process and improves detection efficiency by integrating detection modalities onto a single substrate and employing in-situ colorimetry / spectrophotometry. This method avoids the cumbersome and time-consuming steps required in traditional chemical analysis, such as solvent elution, sample derivatization, and chromatographic separation. It transforms complex mechanistic analysis into continuous detection on a single substrate, with rapid readings obtainable using conventional laboratory instruments. Furthermore, the established detection sequence of "physical first, then chemical, then probe" ensures no cross-interference between the detection modalities, guaranteeing the validity and reliability of the final data. Detailed Implementation

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the preparation examples, comparative examples, and test examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Preparation Examples 1-2:

[0041] Preparation Example 1: Preparation of Bionic Sebum Reserve

[0042] This preparation example provides two biomimetic sebum reservoirs with different component ratios.

[0043] Preparation Example 1A: In a clean brown screw-top bottle, accurately weigh 25% squalene, 30% jojoba oil, 35% triglycerides, 4% cholesterol, and 6% oleic acid by mass percentage. Add cyclohexane as a solvent to the above mixture to prepare a stock solution with a total lipid concentration of 100 mg / mL. Place the stock solution on a magnetic stirrer and stir for 1 hour at room temperature (20-25°C) in the dark until a homogeneous and clear solution is formed.

[0044] Preparation Example 1B: In a clean brown screw-top bottle, accurately weigh 15% squalene, 20% jojoba oil, 45% triglycerides, 2% cholesterol, and 8% oleic acid by mass percentage. Add cyclohexane as a solvent to the above mixture to prepare a stock solution with a total lipid concentration of 150 mg / mL. Place the stock solution on a magnetic stirrer and stir for 1 hour at room temperature (20-25°C) in the dark until a homogeneous and clear solution is formed.

[0045] All the stock solutions prepared above were sealed and stored at 4°C for later use.

[0046] Preparation Example 2: Preparation of Non-Aqueous Activators

[0047] Preparation Example 2A: In a clean volumetric flask, isopropanol and deionized water were mixed at a volume ratio of 9:1. Triton X-100 was added to the mixed solvent and stirred until completely dissolved, resulting in a final mass concentration of 0.3% (w / v).

[0048] Preparation Example 2B: Repeat the steps of Preparation Example 2A, but make the final mass concentration of Triton X-100 0.5% (w / v).

[0049] Preparation Example 2C: Repeat the steps of Preparation Example 2A, but make the final mass concentration of Triton X-100 0.8% (w / v).

[0050] The non-aqueous activator solutions prepared above were all sealed and stored at room temperature for later use.

[0051] Examples 1-3:

[0052] Example 1:

[0053] 1) Preparation of working solution: Take the biomimetic sebum reserve solution described in Preparation Example 1A, and add immobilized lipase powder derived from Rhizopus oryzae, bromocresol green, and 4-nitrophenyl palmitate (4-NPP) pre-dissolved in anhydrous ethanol sequentially, so that the concentration of lipase accounts for 0.1% of the total lipid mass, the concentration of bromocresol green accounts for 0.05% of the total lipid mass, and the concentration of 4-NPP accounts for 0.5% of the total lipid mass. Vortex the mixture to obtain the working solution.

[0054] 2) Preparation of the biomimetic membrane: Take 50 μL of the working solution prepared in step 1) and drop it onto the center of a clean quartz substrate. The membrane is then formed by spin coating. The spin coater parameters are set as follows:

[0055] The first stage involves a speed of 500 rpm and a duration of 10 seconds.

[0056] The second stage involves a speed of 15,000 rpm and a duration of 45 seconds.

[0057] After spin coating, let the biomimetic film stand at room temperature for 20 minutes to allow the solvent to evaporate completely.

[0058] 3) Baseline calibration and sample application: The initial color space coordinates (L1, a1, b1) of the biomimetic film prepared in step 2) were measured using an integrating sphere spectrophotometer. Subsequently, the sample A to be tested was applied at 1.5 mg / cm². 2 The amount of product is evenly applied to the surface of the biomimetic membrane.

[0059] 4) Incubation: Place the biomimetic membrane after applying the sample in a constant temperature and humidity chamber and incubate for 2 hours at a temperature of 30.0℃ and a relative humidity of 40%.

[0060] 5) Three-modal sequential detection:

[0061] After incubation, a transfer blot was first applied, followed by the application of 40 g / cm³. 2 Apply uniform pressure and hold for 15 seconds before transferring the material, and obtain the amount of physically adsorbed oil by weighing.

[0062] Secondly, the final color space coordinates (L2,a2,b2) of the transferred substrate are measured.

[0063] Finally, 8.0 μL of the non-aqueous activator described in Preparation Example 2A was added to the substrate, and after standing for 30 seconds, its absorbance value at a wavelength of 405 nm was measured.

[0064] Through the above steps, the physical adsorption index (PAI), biochemical regulation index (BRI), and enzyme activity influence index (EAI) of the sample A under the given set of process parameters can be obtained.

[0065] Example 2:

[0066] 1) Preparation of working solution: Equal volumes of the biomimetic sebum storage solutions described in Preparation Example 1A and Preparation Example 1B were mixed. Immobilized lipase powder derived from Rhizopus oryzae, bromocresol green, and 4-NPP pre-dissolved in anhydrous ethanol were added sequentially to the mixture, such that the concentration of lipase was 0.2% of the total lipid mass, the concentration of bromocresol green was 0.08% of the total lipid mass, and the concentration of 4-NPP was 0.8% of the total lipid mass. The mixture was then vortexed to homogenize it to obtain the working solution.

[0067] 2) Preparation of the biomimetic membrane: Take 75 μL of the working solution prepared in step 1) and drop it onto the center of a clean quartz substrate. The membrane is then formed by spin coating. The spin coater parameters are set as follows:

[0068] The first stage operates at 650 rpm for 8 seconds.

[0069] The second stage involves a rotation speed of 2000 rpm for 35 seconds.

[0070] After spin coating, let the biomimetic membrane stand at room temperature for 30 minutes.

[0071] 3) Baseline calibration and sample application: The procedure is the same as step 3) in Example 1. The amount of test sample A applied is 2.0 mg / cm³. 2 .

[0072] 4) Incubation: Place the biomimetic membrane after applying the sample in a constant temperature and humidity chamber and incubate for 4 hours at a temperature of 32.0℃ and a relative humidity of 50%.

[0073] 5) Three-modal sequential detection:

[0074] After incubation, a transfer blot was first applied, followed by the application of 50 g / cm³. 2 Apply uniform pressure and hold for 10 seconds before transferring the material, and obtain the amount of physically adsorbed oil by weighing.

[0075] Secondly, the final color space coordinates (L2,a2,b2) of the transferred substrate are measured.

[0076] Finally, 10.0 μL of the non-aqueous activator described in Preparation Example 2B was added to the substrate, and after standing for 60 seconds, its absorbance value at a wavelength of 405 nm was measured.

[0077] Through the above steps, the physical adsorption index (PAI), biochemical regulation index (BRI), and enzyme activity influence index (EAI) of the sample A under the given set of process parameters can be obtained.

[0078] Example 3:

[0079] 1) Preparation of working solution: Take the biomimetic sebum reserve solution described in Preparation Example 1B, and add immobilized lipase powder derived from Rhizopus oryzae, bromocresol green, and 4-NPP pre-dissolved in anhydrous ethanol sequentially, so that the concentration of lipase accounts for 0.3% of the total lipid mass, the concentration of bromocresol green accounts for 0.1% of the total lipid mass, and the concentration of 4-NPP accounts for 1.0% of the total lipid mass. Vortex the mixture to obtain the working solution.

[0080] 2) Preparation of the biomimetic membrane: Take 100 μL of the working solution prepared in step 1) and drop it onto the center of a clean quartz substrate. The membrane is then formed by spin coating. The spin coater parameters are set as follows:

[0081] The first stage involves a rotation speed of 800 rpm for 5 seconds.

[0082] The second stage involves a rotation speed of 2500 rpm for 30 seconds.

[0083] After spin coating, the biomimetic membrane was left to stand at room temperature for 40 minutes.

[0084] 3) Baseline calibration and sample application: The procedure is the same as step 3) in Example 1. The amount of test sample A applied is 2.5 mg / cm³. 2 .

[0085] 4) Incubation: Place the biomimetic membrane after applying the sample in a constant temperature and humidity chamber and incubate for 8 hours at a temperature of 35.0℃ and a relative humidity of 60%.

[0086] 5) Three-modal sequential detection:

[0087] After incubation, a transfer blot was first applied, followed by the application of 60 g / cm³. 2Apply uniform pressure and hold for 5 seconds before transferring;

[0088] Secondly, measurements were taken of the transferred substrate;

[0089] Finally, 12.0 μL of the non-aqueous activator described in Preparation Example 2C was added to the substrate, and after standing for 90 seconds, its absorbance value was measured.

[0090] Through the above steps, the physical adsorption index (PAI), biochemical regulation index (BRI), and enzyme activity influence index (EAI) of the sample A under the given set of process parameters can be obtained.

[0091] Comparative Examples 1-4:

[0092] Comparative Example 1:

[0093] Compared to Example 2, the difference lies in that the biomimetic membrane prepared therein does not contain lipase, bromocresol green, or 4-nitrophenyl palmitate. The detection steps only include: determining the amount of physical adsorption using a transfer blot and measuring the change in gloss of the biomimetic membrane surface before and after incubation using a gloss meter.

[0094] Comparative Example 2:

[0095] Compared with Example 2, the difference is that the biomimetic membrane prepared therein does not contain 4-nitrophenyl palmitate as an enzyme activity probe. Therefore, its three-modal sequential detection steps do not include the steps of adding non-aqueous activator and measuring final absorbance (EAI).

[0096] Comparative Example 3:

[0097] The difference compared to Example 2 is that the biomimetic membrane prepared therein does not contain bromocresol green, which serves as a pH indicator. In its detection steps, after determining the amount of physical adsorption, the remaining biomimetic membrane on the substrate must be completely eluted with an organic solvent, and the amount of free fatty acids generated from sebum decomposition is quantified using gas chromatography-mass spectrometry (GC-MS).

[0098] Comparative Example 4:

[0099] Compared with Example 2, the difference is that the order of the three-modal sequential detection steps is reversed. After incubation, a non-aqueous activator is first added to the surface of the biomimetic membrane and its absorbance value at a wavelength of 405 nm is measured. Then, a transfer imprint is used to transfer the membrane to determine the amount of physical adsorption.

[0100] Test Example 1-2:

[0101] Test Example 1:

[0102] This test example illustrates the process and results of testing standard samples with three different mechanisms of action—physical adsorption, biochemical decomposition inhibition, and biochemical decomposition promotion—using the method described in this invention.

[0103] The testing process followed the steps and process parameters described in Example 2 exactly. The tests were conducted in four groups:

[0104] Blank control group;

[0105] Physical adsorption verification group;

[0106] Biochemical decomposition inhibition verification group;

[0107] Biochemical decomposition promotion verification group.

[0108] The blank control group had no sample applied to the biomimetic membrane. The physical adsorption validation group had a sample uniformly applied at a concentration of 2.0 mg / cm³ to the biomimetic membrane. 2 Porous silica powder. In the biochemical decomposition inhibition verification group, an isopropanol solution containing benzyl sulfonyl fluoride (PMSF) was uniformly applied to the biomimetic membrane. After solvent evaporation, the residual PMSF concentration was 0.1 mg / cm³. 2 The biochemical decomposition-promoting verification group uniformly applied an aqueous solution containing sodium taurocholate onto the biomimetic membrane. After the solvent evaporated, the residual amount of sodium taurocholate was 0.1 mg / cm³. 2 .

[0109] All samples from the above groups were incubated at 32.0℃ and 50% relative humidity for 4 hours. After incubation, the samples from each group were measured according to the three-modal sequential detection steps described in Example 2. The amount of physically adsorbed oil, the endpoint color space coordinates, and the absorbance value at a wavelength of 405nm were recorded. Based on these measurements, the physical adsorption index (PAI), biochemical regulation index (BRI), and enzyme activity influence index (EAI) for each group were calculated.

[0110] Table 1. Test data for this test case.

[0111]

[0112] Summary: As shown in Table 1, the four test groups obtained independent and significantly different combinations of three-dimensional parameters. The data from the blank control group (PAI≈0, BRI=100%, EAI=100%) formed the benchmark for subsequent comparisons. The PAI value of the physical adsorption validation group was significantly higher than the benchmark, while its BRI and EAI values ​​were close to the benchmark. The PAI values ​​of the biochemical degradation inhibition validation group and the biochemical degradation promotion validation group were close to the benchmark, but their BRI and EAI values ​​were significantly lower and higher than the benchmark, respectively. This significant numerical difference indicates that the method of this invention generates discriminative feature data vectors for samples with different mechanisms of action.

[0113] In this test, this method, through a continuous detection process, generated independent quantitative values ​​for different mechanisms of action. The physical adsorption validation group obtained a high PAI value (1.87 mg / cm³). 2 Meanwhile, the deviations in BRI and EAI were small. Mode 1 (physical transfer weighing) in the method separated and quantified the physical adsorption effect. The biochemical degradation inhibition and promotion validation groups obtained extremely low (12.6%) and extremely high (145.2%) BRI and EAI values, respectively. Mode 2 (color change monitoring) and Mode 3 (probe activation) in the method responded to changes in sebum decomposition and enzyme activity. This method distinguishes between two opposing regulatory effects on sebum metabolism: inhibition and promotion.

[0114] The EAI parameter introduced in this method, along with the BRI parameter, can be used to distinguish between two situations: substrate reduction or impairment of enzyme activity itself. As shown in the data from the physical adsorption validation group, significant physical adsorption (high PAI) was accompanied by a slight decrease in BRI (85.3%), while EAI remained essentially unchanged (96.8%). In contrast, the BRI (12.6%) and EAI (9.4%) in the biochemical degradation inhibition validation group both decreased sharply. The comparison of these two groups shows that changes in the EAI parameter are directly related to the inhibition of enzyme activity, but not directly related to substrate reduction caused by physical adsorption. The three-modal sequential detection process constructed in this invention was used to analyze the oil control mechanism of the samples.

[0115] Test Example 2: Comparison Test Between the Example and the Comparative Example

[0116] This test example illustrates the process and results of testing the same sample using the method of the present invention (Example 2) and four comparative methods (Comparative Examples 1-4), to demonstrate the necessity of the structure and sequence of steps of the method of the present invention.

[0117] This test used a commercially available oil-controlling serum (denoted as Test Sample B) as the test subject. Five test groups were established: Example 2 group and Comparative Examples 1 to 4 groups. All groups used Test Sample B, and the application amount and incubation conditions were completely consistent with Example 2. Each group was operated and tested strictly according to its respective method and procedure.

[0118] Example 2 group: Perform trimodal sequential detection according to the complete steps of Example 2.

[0119] Comparative Example 1: Following the steps of Comparative Example 1, only the amount of physical adsorption and the change in gloss before and after incubation were measured.

[0120] Comparative Example 2: Following the steps of Comparative Example 2, the amount of physical adsorption and the degree of sebum decomposition were measured, without activating or measuring the enzyme activity probe.

[0121] Comparative Example 3: Following the steps of Comparative Example 3, after determining the amount of physical adsorption, the amount of free fatty acids generated was determined by solvent elution and gas chromatography-mass spectrometry (GC-MS).

[0122] Comparative Example 4: Following the steps of Comparative Example 4, the detection order was reversed. First, the enzyme activity probe was activated and measured, and then the physical transfer was performed.

[0123] Record the relevant parameters available for each group. In Table 2, the symbol " / " indicates that the indicator was not measured or was not applicable in the method of the test group. The GC-MS results of Comparative Example 3 are expressed as the free fatty acid production rate relative to the blank control group.

[0124] Table 2. Comparison of test data for this test case

[0125]

[0126] Summary: As shown in Table 2, the complete three-dimensional parameter combination of sample B was obtained using the method of Example 2 (PAI = 1.21 mg / cm²). 2 (BRI=45.8%, EAI=52.3%). This result indicates that sample B simultaneously exhibits the effect of physically adsorbing oil (significant PAI value) and inhibiting the biochemical decomposition of sebum (BRI and EAI values ​​are both well below 100%). The methods of Comparative Examples 1-4, due to differences in their composition or procedures, failed to provide complete or accurate information.

[0127] Comparative Example 1 only yielded the physical adsorption amount and surface chemical changes of the sample, failing to reveal its impact on the biochemical decomposition process of sebum. While Comparative Example 2 reflected the inhibition of sebum decomposition through BRI (43.9%), its methodology lacked the detection of enzyme activity probes, thus making it impossible to determine whether the inhibition stemmed from substrate reduction due to physical adsorption or from the sample's direct influence on lipase activity. Example 2, however, confirmed the direct inhibitory effect of the sample on enzyme activity through the measured EAI value (52.3%). Although Comparative Example 3 obtained similar conclusions to BRI using GC-MS, its procedure involved solvent elution, sample derivatization, and large-scale instrument analysis, making it complex and time-consuming. Compared to the in-situ, rapid colorimetric method in Example 2, it lacked operational convenience.

[0128] Comparative Example 4 reversed the detection order, leading to invalid and contradictory data. Because the liquid (non-aqueous activator) was added first, the physical integrity of the biomimetic membrane was compromised, making subsequent physical transfer steps inaccurate and rendering the PAI data invalid. Simultaneously, a huge, illogical difference appeared between BRI (115.7%) and EAI (28.4%), indicating that the incorrect detection order severely interfered with the measurement accuracy. This result confirms that the three-modal sequential detection process defined in this invention—"physical transfer first, then pH indicator measurement, and finally activation of enzyme activity probe"—is a necessary technical condition for obtaining accurate, reliable, and multi-dimensional information.

Claims

1. A method for determining the oil-controlling efficacy of cosmetics based on the detection of oil adsorption and decomposition, characterized in that, Includes the following steps: S1. A biomimetic membrane coated on a substrate is provided, the biomimetic membrane comprising biomimetic sebum, lipase, a pH indicator for characterizing the amount of sebum decomposition products generated, and an enzyme activity probe for characterizing lipase activity. S2. Apply the cosmetic sample to be tested to the surface of the biomimetic membrane and incubate it for a preset time under preset temperature and humidity conditions; S3. After incubation, perform three-modal detection in the following order: S3.1 First, the physical adsorption amount of oil in the sample to be tested is determined by physical transfer and weighing method to obtain the physical adsorption index; S3.2 Next, the biomimetic membrane after physical transfer in step S3.1 is measured to obtain the degree of sebum decomposition reflected by the pH indicator, and the biochemical regulation index is obtained. S3.3 Finally, a non-aqueous activator is added to the biomimetic membrane measured in step S3.2 to activate the enzyme activity probe, and the signal intensity of the reaction product of the enzyme activity probe is measured to obtain the enzyme activity influence index.

2. The cosmetic oil control efficacy measuring method based on oil adsorption and decomposition detection according to claim 1, characterized by, The biomimetic membrane is prepared by a working solution containing specific components, including biomimetic sebum, immobilized lipase derived from Rhizopus oryzae, bromocresol green as a pH indicator, and 4-nitrophenyl palmitate as an enzyme activity probe.

3. The cosmetic oil control efficacy measuring method based on oil adsorption and decomposition detection according to claim 2, characterized by, In the working solution, the concentration of the immobilized lipase is 0.1-0.3% of the total lipid mass, the concentration of bromocresol green is 0.05-0.1% of the total lipid mass, and the concentration of 4-nitrophenyl palmitate is 0.5-1.0% of the total lipid mass.

4. The cosmetic oil control efficacy measuring method based on oil adsorption and decomposition detection according to claim 3, characterized by, The biomimetic sebum is composed of the following components by weight percentage: Squalene 15-25%, jojoba oil 20-30%, triglycerides 35-45%, cholesterol 2-4%, oleic acid 6-8%.

5. The method for determining the oil-controlling efficacy of cosmetics based on the detection of oil adsorption and decomposition according to claim 1, characterized in that, In step S1, the preparation steps of the biomimetic membrane include: 50-100 μL of working solution is dropped onto the substrate, and a film is formed by spin coating, wherein the spin coating method includes: The first stage involves a speed of 500-800 rpm and a duration of 5-10 seconds; The second stage involves a speed of 1500-2500 rpm and a duration of 30-45 seconds; After spin coating, let the biomimetic membrane stand for 20-40 minutes.

6. The cosmetic oil control efficacy measuring method based on oil adsorption and decomposition detection according to claim 1, characterized by, In step S2, the amount of the cosmetic sample to be tested applied is 1.5-2.5 mg / cm³. 2 The incubation temperature is 30.0-35.0℃, the relative humidity is 40-60%, and the time is 2-8 hours.

7. The cosmetic oil control efficacy measuring method based on oil adsorption and decomposition detection according to claim 1, characterized by, In step S3.1, the physical transfer is specifically performed by applying a pressure of 40-60 g / cm 2 for 5-15 seconds after which the transfer is performed.

8. The cosmetic oil control efficacy measuring method based on oil adsorption and decomposition detection according to claim 1, characterized by, In step S3.3, the volume of the added non-aqueous activator is 8.0-12.0 μL, and the signal intensity is measured after standing for 30-90 seconds following the addition.

9. The cosmetic oil control efficacy measuring method based on oil adsorption and decomposition detection according to claim 1, characterized by, The non-aqueous activator is composed of isopropanol, water and Triton X-100, wherein the volume ratio of isopropanol to water is 9:1 and the mass concentration of Triton X-100 is 0.3-0.8% (w / v).

10. The cosmetic oil control efficacy measuring method based on oil adsorption and decomposition detection according to claim 1, characterized by, In step S1, the substrate is a quartz substrate.

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