Evaluation of Oil Control Efficacy

CD Formulation evaluates the effectiveness of cosmetic products in improving the oiliness of the facial skin by measuring the oil content of the subject's skin before and after using the test sample for a specified period of time. This test protocol can be applied to a wide range of cosmetics such as lotions, gels, and serums that claim to have oil control effects. Depending on the claimed oil control needs of different products, the oil control protocol can be selected to collect data at multiple time points after a certain time period of using the test sample.

Skin oil control can be achieved by using cleansers to cleanse excess oil, by using starch-synthesized polymorphic particles to adsorb oil, or by using products containing acids that dissolve keratin while constricting the opening of the hair follicle ducts, thereby reducing sebum drainage, inhibiting sebum diffusion and reducing sebum synthesis. Products can also be used to enhance the lipophilic properties of the skin and reduce the surface tension of the skin, thereby slowing down the diffusion of secreted sebum on the skin surface, i.e., changing the rheological properties of sebum on the skin surface, thereby reducing shine.

Evaluation of Oil Control Efficacy

The efficacy of sebum control can be evaluated by in vitro and in vivo methods for both the sebum production itself and the negative effects it causes.

• In Vitro Test Method

The in vitro method of oil control can be evaluated based on human immortalized sebaceous gland cells, stimulated with hormonal substances to establish an in vitro model of oil secretion, which is then processed and qualitatively analyzed to evaluate the oil control efficacy of the substance to be tested. This can be done, for example, by testing lipid droplets and genes related to oil formation.

• In vivo testing methods

There are three main methods for in vivo evaluation of the oil control efficacy of cosmetics: the skin oil tester and matte tape, the questionnaire method, and the image processing method.

Oil Control Cosmetic Efficacy Test Items

• Sebum measurement

Epidermal sebum is measured with a sebum sensor probe: the sebum secretion rate (ug/h) is calculated from the amount of sebum secreted to the skin surface in one hour, and this value is used to verify the efficacy of oil control products.

• Skin brightness

Measure the reflected light from a mirror, i.e. the light beam is reflected back at the same angle as it touches the measurement surface.

Process for Evaluating the Efficacy of Cosmetic Oil Control Products

The Cosmetic Evaluation Center requires all subjects participating in the efficacy evaluation to sit in an environment with a temperature of 21±1°C and humidity of 50±5% RH for at least 20 minutes after arriving at the laboratory, without drinking water or beverages, to ensure that the skin condition can reach a stable state and not affect the test results. In addition, the subjects were required to stay in the laboratory throughout the test for the oil control efficacy assessment and were not allowed to go outside during the test. For subjects participating in the evaluation, no cosmetics, skin care products, beauty devices, or topical medications, including cleansing products, could be used on the test area for at least 1 day prior to the test.

Based on the time points determined in the protocol, the laboratory technician measured the skin oil content of the two areas of the subject's forehead after the corresponding time period and recorded them separately.

With years of experience in the field of cosmetic development, CD Formulation provides a full range of cosmetic efficacy evaluation services from efficacy protocol design, efficacy testing to data analysis, relying on its own professional hardware and software facilities and rich, high-quality cooperation resources.