In Vitro Anti-Acne Test

Acne vulgaris is a chronic inflammatory skin disease of the follicular sebaceous glandular unit that occurs in adolescence, mainly involving the face, accompanied by erythema, hyperpigmentation and scarring. The pathogenesis of acne has not yet been fully elucidated, and is mainly thought to be related to four aspects: overproduction of lipids by sebaceous glands, abnormal keratinization of follicular sebaceous gland ducts, proliferation of follicular microorganisms, such as Propionibacterium acnes, inflammation, and immune response. CD Formulation provides in vitro anti-acne testing to help clients efficiently conduct efficacy testing of cosmetic products, which can in turn benefit the development of cosmetic products.

Test Design

If a control product is used, qualified subjects can be divided into test and control groups according to a randomized table; or if the acne areas on the left and right sides of the test site are basically symmetrical, a half-face control can be selected and divided into a test product side and a control product side. If the control product is not used, the trial design of own before and after control will be used. Subjects will use the test product or control product continuously for at least 4 weeks. Clinical assessment, subject self-assessment, image capture, and instrumental testing of the test area will be performed before and at various times after use (e.g., 2 weeks, 4 weeks after use).

In Vitro Anti-Acne Test

In vitro anti-acne tests are laboratory-based experiments that evaluate the efficacy of specific substances or products in the prevention or treatment of acne. These tests typically use cultured human skin cells or sebaceous glands that are exposed to the test substance to assess its effect on acne-related processes.

• Sebum secretion test

A sebum secretion test is an in vitro test to determine the ability of a substance to reduce the secretion of sebum, an oily substance that can contribute to the development of acne. This type of test helps to identify potential anti-acne agents that can regulate sebum production and improve the overall appearance of the skin.

In order to perform a sebum secretion test, human sebaceous glands or sebocytes (cells that produce sebum) are cultured in the presence of the test substance. The amount of sebum produced by the cells is then measured and compared to control cells that have not been exposed to the test substance.

Sebum secretion tests can be performed by lipid staining, gas chromatography, and enzyme-linked immunosorbent assay.

• Propionibacterium acnes growth inhibition test

This test evaluates the ability of a substance to inhibit the growth of Propionibacterium acnes, the bacterium that usually causes acne. To perform the P. acnes growth inhibition test, the test substance is added to a culture of P. acnes. The culture is then incubated for a period of time, after which the growth of the bacteria is measured and compared to a control culture that has not been exposed to the test substance. Bacterial growth can be measured by colony forming unit (CFU) assay, turbidimetric assay, and fluorescence detection.

• Inflammation test

This test evaluates the ability of a substance to reduce inflammation, which is a key component in the pathogenesis of acne. To perform the inflammation test, human skin cells or immune cells are cultured in the presence of a pro-inflammatory stimulus such as lipopolysaccharide or cytokines. The test substance is then added to the culture solution, and levels of inflammatory markers such as interleukin or tumor necrosis factor alpha (TNF-α) are measured and compared to control cells that have not been exposed to the test substance.

• Keratinocyte proliferation assay

This test evaluates the ability of a substance to inhibit the proliferation of keratinocytes, which can lead to the formation of pimples (clogged pores) in acne-prone skin.