Acedapsone (INN) is an antimicrobial drug, which also has antimalarial activity. Acedapsone, or 1399 F, is a diacetyl compound, derived from dapsone. It was synthesized and developed in 1937 by Ernest Fourneau and his team in the pharmaceutical chemistry laboratory of Pasteur Institute, and it was marketed as Rodilone by the Rhône-Poulenc company. It is a long-acting prodrug of dapsone. It is used for treating leprosy. It crystallises as pale yellow needles from diethyl ether, and as leaflets from dilute ethanol. It is slightly soluble in water.