Test of moisturizing effect of facial mask cosmetics

Test of moisturizing effect of facial mask cosmetics

Test of moisturizing effect of facial mask cosmeticsIt is a key link in evaluating the product's ability to hydrate and lock in water, directly related to consumers' intuitive experience of the product's efficacy. With the implementation of the Regulations on the Supervision and Administration of Cosmetics, claims of moisturizing efficacy need to be verified through scientific testing, which has become a core requirement for cosmetics research and development, filing, and market access. Professional testing institutions simulate the physiological environment of the skin, combine instrument analysis with human experiments, and construct a multidimensional evaluation system to provide authoritative data support for product efficacy.

Testing standards and technical framework

The moisturizing effect of facial mask should be tested in strict accordance with national standards and industry specifications, and the current main basis includes:

GB/T 35892-2018 "Guidelines for the Evaluation of Moisturizing Efficacy of Cosmetics": specifies the core methods for in vitro and human trials, and clarifies that the evaluation of moisturizing efficacy should include key indicators such as transcutaneous water loss (TEWL) and skin stratum corneum moisture content.

QB/T 4256-2011 "Moisturizing Agents for Cosmetics": A method for determining the content of moisturizing ingredients such as hyaluronic acid and ceramide, providing a basis for quantitative analysis of active ingredients.

ISO 15173:2003 "Determination of Skin Moisture Content and Transdermal Moisture Loss in Cosmetics": an internationally recognized method for detecting skin physiological indicators to ensure international comparability of data.

The detection technology framework is divided into two modules: in vitro laboratory evaluation and human efficacy evaluation. The combination of the two can comprehensively reflect the moisturizing mechanism and actual effect of the product.

Core testing items and methods

1、 In vitro moisturizing performance evaluation

Moisture retention test

Apply the facial mask essence solution evenly to the glass dish by weighing method, place it in a constant temperature and humidity environment (temperature 25 ℃± 1 ℃, humidity 43% ± 2%) for 24 hours, and calculate the water evaporation rate through the mass difference before and after. The moisture retention rate of high-quality facial mask should be ≥ 80% to ensure the slow release of effective ingredients.

Stratum corneum simulation experiment

Use the artificial skin model (such as the three-dimensional recombinant epidermis containing ceramide), treat it with facial mask essence solution, observe the changes of the cuticle structure through low-temperature scanning electron microscope, and evaluate the repair effect of the product on the skin barrier. The experiment requires the establishment of a blank control group and a positive control group (containing a standard solution of 1% hyaluronic acid).

Quantitative analysis of moisturizing ingredients

Hyaluronic acid: High performance liquid chromatography (HPLC) was used, with 0.1mol/L phosphate buffer as the mobile phase, detection wavelength at 210nm, and quantification limit up to 0.01%.

Glycerol: analyzed by gas chromatography-mass spectrometry (GC-MS) using a DB-5 capillary column (30m × 0.25mm), qualitative retention time, and quantitative external standard method.

2、 Human efficacy evaluation

Transdermal water loss (TEWL) measurement

Using the German CK MPA580 skin tester, the inner forearm skin of 20 healthy volunteers (aged 20-45 years, with normal or dry skin types) was tested in a constant temperature and humidity laboratory (temperature 22 ℃± 1 ℃, humidity 50% ± 5%). Subjects should avoid using skin care products 24 hours before the test. The area of the test area is 3cm × 3cm. The TEWL values before, 1 hour, 4 hours, 8 hours and 24 hours after the use of the facial mask should be recorded continuously. Products with moisturizing effects should reduce TEWL values by ≥ 30% (compared to the blank control group).

Skin moisture content detection

Using the Corneometer CM825 probe, measure the moisture content of the stratum corneum using the capacitance method. The testing process is synchronized with TEWL, and the qualified standard is that the moisture content of the posterior skin increases by ≥ 20% compared to the baseline value and lasts for more than 6 hours. The data needs to undergo statistical analysis (paired t-test, P<0.05 indicates significant difference).

Subjective evaluation and safety monitoring

The subjects filled out the Visual Analog Scale (VAS) and scored the skin tightness, smoothness, and other indicators on a scale of 0-10, and recorded whether there were adverse reactions such as redness and stinging. Human trials require ethical review, with participants signing informed consent forms, and the entire process following the requirements of the "Cosmetic Safety Technical Specification" (2015 edition).

Key instruments and quality control

Professional testing relies on high-precision instruments and standardized operating procedures:

Skin physiological parameter tester: such as the German Courage+Khazaka MPA series, requires daily calibration with a standard membrane to ensure TEWL measurement error ≤ 5g/(m ² · h) and moisture content measurement coefficient of variation ≤ 10%.

Constant temperature and humidity chamber: Control temperature fluctuations of ≤± 0.5 ℃ and humidity fluctuations of ≤± 2% to avoid environmental interference.

High performance liquid chromatography: equipped with a diode array detector (DAD), the column efficiency of the chromatography column must meet the requirements (theoretical number of trays ≥ 5000).

Quality control measures include:

Sample pretreatment: essence solution needs to be filtered by 0.45 μ m membrane to avoid interference of particles.

Parallel experiments: Each test should undergo at least 3 parallel experiments, with a relative standard deviation (RSD) of ≤ 8%.

Positive control: Use a standard solution containing 5% glycerol as the positive control to ensure the effectiveness of the experimental system.

Common Problems and Solutions

Inconsistencies between in vitro and human data

Some products meet the standard for in vitro moisture retention, but their human testing results are poor, mainly due to low transdermal absorption efficiency of the ingredients. It is recommended to evaluate the penetration depth of active ingredients in the stratum corneum by combining skin microscopy observation (such as VivoSight skin optical coherence layer scanner).

Lack of sustained effectiveness

If the skin moisture content drops below 50% of the baseline value after 8 hours, it may be due to insufficient addition of sealants (such as Vaseline and ceramide) in the formula. The compatibility between the product and skin lipids can be analyzed by differential scanning calorimetry (DSC) to optimize the oil ratio.

Stimulating risk

Facial mask containing alcohol and essence may cause abnormal short-term increase of TEWL. It is necessary to screen the irritation in advance through chicken embryo allantoic membrane test (HET-CAM) to ensure that the pH value is controlled within 4.0-7.0.

Testing report and market application

The testing report should include the following core contents:

Sample information: product name, batch number, manufacturer, specifications, and sampling date.

Testing method: Clearly reference standard methods, instrument models, and testing conditions.

Result and Conclusion: Present TEWL values and moisture content change rates at each time point in a table format, with statistical analysis results attached. The conclusion should clarify whether the claimed moisturizing effect has been achieved.

CMA/CNAS identification: Ensure that the report has legal validity and international recognition.

This detection is widely used in:

Product development: Guide formulators to optimize the combination of moisturizing ingredients, such as combining hyaluronic acid with panthenol, which can improve the effect by 30%.

E-commerce filing: Tmall, JD and other platforms require the moisturizing facial mask to provide a third-party test report as the basis for listing.

Consumer education: Enhance brand persuasiveness through comparative testing (such as comparing efficacy data with similar products on the market).

Industry Trends and Technological Innovation

There are three major trends in current moisturizing efficacy testing:

Microfluidic chip technology: Develop a "skin-on-a-chip" model to simulate microcirculation in the dermis layer and more accurately predict the long-term moisturizing mechanism of ingredients.

Artificial intelligence analysis: Using machine learning algorithms to process massive skin physiological data and establish personalized moisturizing effect prediction models.

No chuang imaging technology: Raman spectrometer is used to monitor the real-time vibration peak of water molecules in the stratum corneum of the skin (3200-3600 cm ⁻¹), achieving non-contact quantification of moisturizing effect.

As a third-party organization with CMA/CNAS double qualification, Zhongke Testing has established a perfect moisturizing effect testing system for facial mask, and has completed more than 2000 sample tests annually. The laboratory is equipped with Guoji Xianjin's skin testing equipment and a 100000 level cleanliness human test chamber, which can provide customized testing solutions according to customer needs, helping enterprises to quickly and compliantly launch their products.

Tip: When purchasing moisturizing facial mask, consumers can pay attention to whether the product package is marked with "through third-party moisturizing efficacy test", and give priority to products with simple ingredients, free of alcohol and essence, so as to reduce the risk of skin sensitivity.