31037 Assessment of actives and formula on antipigmentation efficacy

Abstract

Hyperpigmentation is a skin condition resulting from overproduction of melanin, the pigment produced by melanocytes. Melanocytes reside at the basal layer of the epidermis, producing melanin and transferring it to surrounding keratinocytes to protect the skin from UV damage. As we get older, irregularities develop, such as dark spots and uneven skin tone. Simple topical treatments against melanin overproduction are not always effective, due to skin irritability of potent ingredients or lack of penetration into the skin. A two-step approach was designed to screen for efficacious antipigmentation actives and validate performance in a finished formulation. First, potentially effective ingredients were screened for cytotoxicity and melanin synthesis inhibition using darkly pigmented normal human melanocytes. One of the efficacious ingredients identified without causing melanocyte cytotoxicity is bisabolol. Next, bisabolol is formulated into formulas with additional beneficial ingredients, and assessed on a 3D skin model for antipigmentation efficacy as well as skin irritability. MelanoDerm model was used to evaluate two different finished formulations that include bisabolol. MelanoDerm was treated with 2 final formulas as well as 2 placebo control formulas, which lacked bisabolol. The positive control was 2% kojic acid. The efficacy was assessed after 2 weeks of treatments. Compared with placebo controls, formula with bisabolol inhibited melanin synthesis. Additionally, collected media was used to evaluate skin irritation potential by assessing IL-1a release by ELISA. Final formulas had minimal impact on IL-1a release. Utilizing both monolayer melanocytes and MelanoDerm, efficacious anti-pigmentation products were validated without concerns on skin irritation.