Dapsone is a white crystalline powder, used in combination with pyrimethamine in the treatment of malaria. It is a very weak Lewis base which finds use as a leprostatic drug. Dapsone is 4-(4-aminophenylsulfonyl)aniline, which has a chemical structure very similar to sulfonamines. Like sulfonamines, its antibacterial property is due to inhibiting folic acid synthesis. Although it is most often used in multidrug therapy, it has numerous other applications. As an anti-infective agent, it is also utilized in the treatment of malaria and Pneumocystis cariniipneumonia. In dermatology, it has been found helpful in the treatment of numerous non-infectious, inflammatory, autoimmune and bullous diseases. The structure of the Dapsone 0.33 hydrate is known