Method for evaluating stability of cosmetics by utilizing multiple light scattering technology and application of method

Abstract

The invention relates to a method for evaluating the stability of cosmetics by utilizing a multiple light scattering technology and application thereof, and the method comprises the following steps: carrying out influence factor test on cosmetic samples, respectively testing the cosmetic samples in an initial state before the test and in a final state after the test by adopting the multiple light scattering technology, collecting spectral signals of the cosmetic samples, and calculating the stability of the cosmetics according to the spectral signals. Calculating the initial state dispersion uniformity U0, the final state dispersion uniformity U1 and the average light intensity change rate C of the cosmetic sample, and evaluating the stability of the cosmetic sample according to the initial state dispersion uniformity U0, the final state dispersion uniformity U1 and the average light intensity change rate C. According to the method provided by the invention, a rapid, accurate and efficient cosmetic stability evaluation effect can be realized, and the product marketing period is shortened.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of cosmetic evaluation, in particular to a method for evaluating the stability of cosmetics by using multiple light scattering technology and application thereof. BACKGROUND

[0002] Cosmetic stability refers to the ability of cosmetics to maintain properties during research and development, production, storage, transportation and use, involving key indicators such as shelf life and expiration date, which need to be ensured by stability tests to meet safety and effectiveness requirements within a certain period. Cosmetic stability evaluation covers multidimensional parameters such as changes in physical and chemical properties, microbial stability and packaging compatibility.

[0003] Traditional evaluation methods of cosmetic stability rely on long-term manual stability observation, which has the characteristics of long cycle and strong subjectivity of results, and cannot meet the goal of rapid, accurate and efficient evaluation of cosmetic stability.

[0004] CN111337448A discloses a method for identifying cosmetics based on infrared spectroscopy, comprising the following steps: establishing an infrared spectrum library of cosmetics, which contains the reference infrared spectrum of several varieties of authentic cosmetics; obtaining the infrared spectrum of the cosmetic to be tested; identifying the reference infrared spectrum of the authentic cosmetic corresponding to the cosmetic to be tested from the infrared spectrum library; comparing the infrared spectrum and the reference infrared spectrum and judging the quality of the cosmetic to be tested according to the comparison result. This method is mainly used to identify the authenticity of cosmetics, and is not suitable for stability evaluation.

[0005] Therefore, it is a technical problem to be solved in the field to provide an evaluation index for quantifying the stability of cosmetics, to realize rapid, accurate and efficient evaluation of cosmetic stability, and to shorten the product marketing cycle. SUMMARY

[0006] To solve the above technical problems, the present application provides a method for evaluating the stability of cosmetics by using multiple light scattering technology and application thereof. The method provided by the present application can realize rapid, accurate and efficient evaluation of cosmetic stability, and shorten the product marketing cycle.

[0007] To achieve this purpose, the present application adopts the following technical solutions:

[0008] In a first aspect, the present application provides a method for evaluating the stability of a cosmetic product, the method comprising: performing an influencing factor test on a cosmetic product sample, testing the cosmetic product sample in an initial state before the test and in a final state after the test respectively by using a multiple light scattering technology, collecting a spectrum signal of the cosmetic product sample, calculating an initial state dispersion uniformity U0, a final state dispersion uniformity U1 and an average light intensity change rate C of the cosmetic product sample, and evaluating the stability of the cosmetic product sample according to the U0, U1 and C.

[0009] The calculation formulae of U0 and U1 are as follows:

[0010]

[0011] n is the number of collection points of the spectrum signal of the cosmetic product sample; χ i is the spectrum signal intensity of the i-th collection point; is the average value of the spectrum signal intensities of the n collection points;

[0012] The calculation formula of C is as follows:

[0013]

[0014] The spectrum signal includes backscattered light or transmitted light.

[0015] The method provided by the present application is based on the multiple light scattering technology, and can realize real-time monitoring of the internal microstructure changes (such as migration, aggregation, flocculation, coalescence, sedimentation, floating, phase separation, etc.) of the sample without contact and damage. By measuring the changes of the backscattered light (BS) or transmitted light (T) signal with time and sample height, the quantification of the stability of the sample is realized, and on this basis, the influencing factor test is carried out to simulate the change rule of the BS or T signal intensity under specific conditions, so as to realize the effect of evaluating the microstructure stability of the sample from multiple dimensions.

[0016] The method for evaluating the stability of the cosmetic product provided by the present application can replace the traditional manual visual inspection method, and realize the effect of quickly, accurately and efficiently evaluating the stability of the cosmetic product, and shorten the product marketing cycle.

[0017] Preferably, the influencing factor test comprises any one or a combination of at least two of a normal temperature test, a high temperature test, a freezing test, a refrigeration test, a variable temperature test or a simulated transportation test.

[0018] Preferably, the normal temperature test comprises: standing at 25±1℃ for 1-5 days (for example, it can be 1 day, 2 days, 3 days, 4 days, 5 days, etc.).

[0019] Preferably, the high temperature test comprises: standing at 45±1℃ for 0.5-3 days (for example, it can be 0.5 days, 1 day, 2 days, 3 days, etc.), and then returning to 25±1℃.

[0020] Preferably, the freezing test comprises: standing at -18±1℃ for 0.5-3 days (for example, it can be 0.5 days, 1 day, 2 days, 3 days, etc.), and then recovering to 25±1℃.

[0021] Preferably, the temperature change test comprises: standing at 45±1℃ for 8-16h (for example, it can be 8h, 10h, 12h, 14h, 16h, etc.), standing at -18±1℃ for 8-16h (for example, it can be 8h, 10h, 12h, 14h, 16h, etc.), repeating the above steps 2-4 times (for example, it can be 2 times, 3 times, 4 times), and then recovering to 25±1℃.

[0022] Preferably, the refrigeration test comprises: standing at 4±1℃ for 0.5-3 days (for example, it can be 0.5 days, 1 day, 2 days, 3 days, etc.), and then recovering to 25±1℃.

[0023] Preferably, the simulated transportation test comprises: vibrating at 25±1℃, 250±50rpm (for example, it can be 200rpm, 220rpm, 250rpm, 280rpm, 300rpm, etc.) for 0.5-3 days (for example, it can be 0.5 days, 1 day, 2 days, 3 days, etc.).

[0024] Preferably, the light source wavelength of the multiple light scattering technology is 850-900nm (for example, it can be 850nm, 860nm, 870nm, 880nm, 890nm, 900nm, etc.).

[0025] Preferably, the bottom of the cosmetic sample is defined as 0, the height is L, and the collection area of the spectral signal is (8 / 42-33 / 42)L.

[0026] Preferably, the number of points collected for the initial state before the test and the final state after the test is independently 500-1000 (for example, it can be 500, 600, 700, 800, 900, 1000, etc.).

[0027] In the present application, the sample loading of the sample should pay attention to the following points:

[0028] (1) Check whether there are stains or scratches on the outer wall of the sample pool;

[0029] (2) When adding the sample to the sample pool, avoid wall hanging;

[0030] (3) Avoid generating bubbles when adding sample;

[0031] (4) Ensure that the sample has a good half-moon surface after adding sample, and there is no pollution around the bottle wall;

[0032] (5) The sample loading amount reaches the height of the sample cell holder (the height is about 43 mm high);

[0033] (6) The outer wall of the sample cell is cleaned before the sample loading is completed and the test is performed.

[0034] Preferably, the evaluation criteria of the cosmetic sample stability are as follows:

[0035] When U0 and U1 are both > 99%, C meets the standard of the influence factor test, the cosmetic sample is determined to be stable; otherwise, the influence factor test is repeated, when all the indexes after the second test meet the standard, the cosmetic sample is determined to be basically stable, and if any index does not meet the standard, the cosmetic sample is determined to have a stability risk;

[0036] The standard of the normal temperature test is that the absolute value of C is < 1.5;

[0037] The standard of the high temperature test is that the absolute value of C is < 1.8;

[0038] The standard of the freezing test is that the absolute value of C is < 1.8;

[0039] The standard of the refrigeration test is that the absolute value of C is < 0.9;

[0040] The standard of the variable temperature test is that the absolute value of C is < 2.0;

[0041] The standard of the simulated transportation test is that the absolute value of C is < 1.9.

[0042] In a second aspect, the present application provides an application of the method for evaluating the stability of cosmetics according to the first aspect in the quality control of cosmetics.

[0043] Compared with the prior art, the present application has at least the following beneficial effects:

[0044] The method provided by the present application is based on the multiple light scattering technology, realizes the quantification of the sample stability by measuring the changes of the backscattering light or the transmission light signal with time and sample height, and can quickly, accurately and efficiently obtain the stability result of the cosmetics, thereby shortening the product marketing cycle. DETAILED DESCRIPTION

[0045] In order to facilitate the understanding of the present application, the present application is illustrated by the following embodiments. It should be understood by those skilled in the art that the embodiments are only used to help understand the present application, and should not be regarded as a specific limitation on the present application.

[0046] Embodiment 1

[0047] The present embodiment provides a method for evaluating the stability of cosmetics, which specifically comprises:

[0048] (1) Experimental equipment and parameters

[0049] Multiple light scattering instrument: wavelength 880 nm; scanning area: middle area, defined as the height of the bottom of the sample bottle as 0, middle area as 8-33 mm, scanning every 40 μm, a total of 626 points;

[0050] Temperature control device: temperature control accuracy ± 0.5℃;

[0051] Simulation transport vibration test bench: vibration frequency 250 rpm, acceleration reference 11.1 m / s 2 , simulation vehicle speed reference 45 km / h;

[0052] (2) Influence factor test on the cosmetic sample, using multiple light scattering technology to test the initial state and the final state of the cosmetic sample before and after the test respectively, collecting the spectral signal of the cosmetic sample, calculating the initial state dispersion uniformity U0, the final state dispersion uniformity U1 and the average light intensity change rate C of the cosmetic sample;

[0053] The influence factor test is as follows:

[0054] (a) Normal temperature test: standing at 25±1℃ for 1 day;

[0055] (b) High temperature test: standing at 45±1℃ for 1 day, and then recovering to 25℃;

[0056] (c) Freezing test: standing at -18±1℃ for 1 day, and then recovering to 25℃;

[0057] (d) Variable temperature test: standing at 45±1℃ for 12 h, standing at -18±1℃ for 12 h, repeating the above steps for 3 times, and then recovering to 25℃;

[0058] (e) Refrigeration test: standing at 4±1℃ for 1 day, and then recovering to 25℃;

[0059] (f) Simulation transport test: vibration at 25℃, 250 rpm (simulation 45 km / h transport speed) for 1 day;

[0060] The calculation formula of U0 and U1 is as follows:

[0061]

[0062] n is the number of collection points of the spectral signal of the cosmetic sample; i χi is the spectral signal intensity of the i-th collection point; χ is the average value of the spectral signal intensity of the n collection points;

[0063] The calculation formula of C is as follows:

[0064]

[0065] The spectral signal is transmitted light;

[0066] (3) The stability of the cosmetic sample is evaluated according to the initial state dispersion uniformity U0, the final state dispersion uniformity U1, and the average light intensity change rate C, and the evaluation criteria are:

[0067] When U0, U1 are both > 99%, and C meets the standard of different influence factor tests, the cosmetic sample is determined to be stable; otherwise, repeat the influence factor test, and when all indicators after the second test meet the standard, the cosmetic sample is determined to be basically stable, and if any one indicator still does not meet the standard, the cosmetic sample is determined to have a stability risk;

[0068] The standard of the influence factor test:

[0069] Normal temperature test: the absolute value of C < 1.5;

[0070] High temperature test: the absolute value of C < 1.8;

[0071] Freezing test: the absolute value of C < 1.8;

[0072] Cold storage test: the absolute value of C < 0.9;

[0073] Variable temperature test: the absolute value of C < 2.0;

[0074] Simulation transportation test: the absolute value of C < 1.9.

[0075] Example 2

[0076] The embodiment provides a method for evaluating the stability of a cosmetic, which is only different from example 1 in that the spectral signal is backscattered light, and the other parts refer to example 1.

[0077] Test Example 1

[0078] The test example uses the evaluation method of example 1 to test cosmetic sample 1 (cosmetic water 1), and simultaneously performs a traditional artificial 6-month accelerated stability test and a real transportation stability test. The traditional artificial 6-month accelerated stability test is a 6-month visual observation at normal temperature (25°C), high temperature (45°C), freezing (-18°C), variable temperature (45°C for 1 day, -18°C for 1 day, cyclically alternating), and cold storage (4°C); the real transportation stability test is a visual observation after transportation at an average speed of 45 km / h for 24 h. The results are shown in Table 1.

[0079] Table 1

[0080]

[0081] The results show that the initial and final state dispersion uniformity and the average light intensity change rate of the cosmetic sample meet the requirements, and are consistent with the traditional manual 6-month accelerated stability and real transportation stability evaluation results, indicating that the method provided by the application can realize accurate evaluation of the stability sample.

[0082] Test Example 2

[0083] The evaluation method of Example 1 was used to test the cosmetic sample 2 (cosmetic water 2) in this test example, and the results are shown in Table 2.

[0084] Table 2

[0085]

[0086] The test shows that the average light intensity change rate under high temperature test and variable temperature test does not meet the standard, so the accelerated test, i.e. repeated impact factor test, is carried out, and the second test results are shown in Table 3.

[0087] Table 3

[0088]

[0089]

[0090] After the repeated impact factor test, it is shown that the initial and final state dispersion uniformity and the average light intensity change rate of the cosmetic sample meet the requirements, and it is determined that the cosmetic sample is basically stable.

[0091] Test Example 3

[0092] The evaluation method of Example 1 was used to test the cosmetic sample 3 (cosmetic water 3) in this test example, and the results are shown in Table 4.

[0093] Table 4

[0094]

[0095] The test shows that the final state dispersion uniformity of the cosmetic sample in the freezing test, variable temperature test, refrigeration test and simulated transportation test does not meet the standard, and the average light intensity change rate in the freezing test, variable temperature test and simulated transportation test does not meet the standard, so the accelerated test, i.e. repeated impact factor test, is carried out, and the second test results are shown in Table 5.

[0096] Table 5

[0097]

[0098] After repeating the influence factor test, it is shown that the evaluation indexes of the cosmetic sample still do not meet the standard, it is determined that the stability of the cosmetic sample is poor, and the determination is consistent with the traditional artificial 6-month accelerated stability and real transportation stability results, indicating that the method provided by the present application can realize accurate evaluation of the cosmetic sample.

[0099] Test Example 4

[0100] The cosmetic sample 4 (emulsion 1) is tested by the evaluation method of Example 2, and the results are shown in Table 6.

[0101] Table 6

[0102]

[0103]

[0104] The results show that the initial and final state dispersion uniformity and average light intensity change rate of the cosmetic sample meet the requirements, and are consistent with the traditional artificial 6-month accelerated stability and real transportation stability evaluation results, indicating that the method provided by the present application can realize accurate evaluation of the stability sample.

[0105] The applicant declares that the above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and those skilled in the art should understand that any changes or replacements within the technical scope disclosed by the present application can be easily thought of by those skilled in the art, and all fall within the protection scope and disclosure scope of the present application.

Claims

1. A method for evaluating the stability of cosmetics, characterized in that, The method includes: conducting an influencing factor test on cosmetic samples, using multiple light scattering technology to test the cosmetic samples in the initial state before the test and the final state after the test, collecting the spectral signals of the cosmetic samples, calculating the initial state dispersion uniformity U0, the final state dispersion uniformity U1 and the average light intensity change rate C of the cosmetic samples, and evaluating the stability of the cosmetic samples accordingly. The formulas for calculating U0 and U1 are both: n is the number of data collection points for the spectral signal of the cosmetic sample; χ i Let be the spectral signal intensity at the i-th acquisition point; This represents the average spectral signal intensity from n sampling points; The formula for calculating C is: The spectral signal includes either diffused light or transmitted light.

2. The method according to claim 1, characterized in that, The influencing factor test includes any one or a combination of at least two of the following: ambient temperature test, high temperature test, freezing test, refrigeration test, variable temperature test, or simulated transportation test.

3. The method according to claim 2, characterized in that, The ambient temperature test includes: standing at 25±1℃ for 1-5 days; Preferably, the high-temperature test includes: standing at 45±1℃ for 0.5-3 days, and then restoring to 25±1℃.

4. The method according to claim 2 or 3, characterized in that, The freezing test includes: standing at -18±1℃ for 0.5-3 days, and then restoring to 25±1℃; Preferably, the temperature variation test includes: standing at 45±1℃ for 8-16 hours, standing at -18±1℃ for 8-16 hours, repeating the above steps 2-4 times, and then restoring to 25±1℃.

5. The method according to any one of claims 2-4, characterized in that, The refrigeration test includes: standing at 4±1℃ for 0.5-3 days, and then restoring to 25±1℃; Preferably, the simulated transportation test includes vibration at 25±1℃ and 250±50rpm for 0.5-3 days.

6. The method according to any one of claims 1-5, characterized in that, The light source wavelength of the multiple light scattering technology is 850-900nm.

7. The method according to any one of claims 1-6, characterized in that, The bottom of the cosmetic sample is defined as 0, the height as L, and the acquisition area of ​​the spectral signal is (8 / 42-33 / 42)L.

8. The method according to any one of claims 1-7, characterized in that, The number of data points collected in the initial state before the experiment and the final state after the experiment are each independently between 500 and 1000.

9. The method according to any one of claims 2-8, characterized in that, The evaluation criteria for the stability of the cosmetic samples are as follows: When both U0 and U1 are greater than 99% and C meets the standard of the influencing factor test, the cosmetic sample is considered stable; otherwise, the influencing factor test is repeated. When all indicators meet the standard after the second test, the cosmetic sample is considered basically stable. If any indicator still does not meet the standard, the cosmetic sample is considered to have stability risk. The standard for the room temperature test is: the absolute value of C < 1.5; The standard for the high-temperature test is: the absolute value of C < 1.8; The standard for the freezing test is: the absolute value of C < 1.8; The standard for the refrigeration test is: the absolute value of C < 0.9; The standard for the variable temperature test is: the absolute value of C < 2.0; The standard for the simulated transport test is: the absolute value of C < 1.

9.

10. The application of a method for evaluating the stability of cosmetics according to any one of claims 1-9 in the quality control of cosmetics.

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