indication

For the topical treatment of comedo, papular and pustular acne (acne vulgaris) of the face, chest or back.

pharmacology

Adapalene is a chemically stable retinoid-like compound. Biochemical and pharmacological profile studies have demonstrated that adapalene is a modulator of cellular differentiation, keratinization, and inflammatory processes all of which represent important features in the pathology of acne vulgaris.

mechanism of action

Mechanistically, adapalene binds to specific retinoic acid nuclear receptors (gamma and beta) and retinoid X receptors but does not bind to the cytosolic receptor protein. Although the exact mode of action of adapalene is unknown, it is suggested that topical adapalene may normalize the differentiation of follicular epithelial cells resulting in decreased microcomedone formation.

toxicity

The acute oral toxicity of adapalene in mice and rats is greater than 10 mL/kg. Chronic ingestion of the drug may lead to the same side effects as those associated with excessive oral intake of Vitamin A.

biotransformation

Metabolized mainly by O-demethylation, hydroxylation and conjugation, and excretion is primarily by the biliary route.

absorption

Absorption of adapalene through human skin is low. Only trace amounts (<0.25 ng/mL) of parent substance have been found in the plasma of acne patients following chronic topical application of adapalene in controlled clinical trials

route of elimination

Excretion appears to be primarily by the biliary route.