Adapalene is a second-generation topical retinoid primarily used in the treatment of mild-moderate acne, and is also used off-label to treat keratosis pilaris as well as other skin conditions.It is effective against acne conditions where comedones are predominant. 

Function:
Adapalene is a retinoid, in vivo and in vitro models of inflammation were demonstrated to have anti-inflammatory properties. Stable chemical structure of adapalene, in the air and light without decomposing. Mechanism and adapalene with formic acid and specific nuclear retinoic acid receptor combined with retinoic acid is the combination of adapalene and protein and binding of cytoplasmic receptors.
In mice to establish animal model of skin drug test proved that adapalene can treat acne, and acne vulgaris and differentiation process as a role. The mechanism of adapalene is considered by the hair follicle epithelium of normal cell differentiation and reduce microcomedo formation.