The immediate moisturizing rate and long-lasting moisturizing rate of moisturizing cosmetics can be evaluated by the following methods:
Weighing method: Moisture retention rate is calculated by placing a moisture-containing sample in a low-humidity environment and weighing the sample mass changes at regular intervals. This method can visually reflect the product's ability to moisturize for a certain period of time.
2.Subject self-assessment method: In the form of a questionnaire, subjects were asked to self-evaluate the moisturization, fine lines, and elasticity before and after using the product. This approach focuses on the user experience and allows you to evaluate the moisturizing effect of the product from the user's point of view.
3.Stratum corneum water content (mmV) test: Measure the moisture content of the stratum corneum, which is an important indicator to evaluate the moisturizing effect. Proper moisture content of the stratum corneum is a key condition for maintaining the structure and function of the **.
4.Capacitive method: Evaluate the moisturizing effect of cosmetics by measuring the moisture content of the stratum corneum. This method is suitable for the determination of the moisturizing effect of creams, lotions and gels.
5.Transepidermal water loss (TEWL) test: Evaluate the moisturizing effect by measuring the evaporation rate of surface moisture. A lower TEWL value usually means better hydration.
6.Short-term and long-term moisturizing efficacy tests: Depending on the purpose of the product and the duration of moisturizing, you can choose to undergo a short-term or long-term moisturizing efficacy test. Short-term tests focus on how long a product lasts on a surface, while long-term tests focus on how well the product moisturizes over a long period of time.
In general, in practice, the above methods are usually combined to comprehensively evaluate the timely moisturizing rate and long-term moisturizing rate of moisturizing cosmetics to ensure the accuracy and comprehensiveness of the evaluation results. At the same time, variables such as environmental factors, the type of subject, etc., need to be considered in order to more accurately evaluate the moisturizing effect of the product.