Title: Dapsone
CAS Registry Number: 80-08-0
CAS Name: 4,4¢-Sulfonylbisbenzeneamine
Additional Names: 4,4¢-sulfonyldianiline; bis(4-aminophenyl)sulfone; 4,4¢-diaminodiphenyl sulfone; DDS; diaphenylsulfone; DADPS
Manufacturers' Codes: 1358F
Trademarks: Avlosulfon (Wyeth-Ayerst); Croysulfone; Diphenasone; Disulone (Specia); Dumitone; Eporal; Novophone; Sulfona-Mae; Sulphadione; Udolac (Mallinckrodt)
Molecular Formula: C12H12N2O2S
Molecular Weight: 248.30
Percent Composition: C 58.05%, H 4.87%, N 11.28%, O 12.89%, S 12.91%
Literature References: Prepn: FR 829926 (1938 to I. G. Farbenind.), C.A. 33, 1761 (1939); Buckles, J. Chem. Educ. 31, 36 (1954); Ferry et al., Org. Synth. coll. vol. III, 239 (1955). Antibacterial action and metabolism: J. Francis, A. Spinks, Br. J. Pharmacol. 5, 565 (1950). Mechanism of toxic action: Wu, DuBois, Arch. Int. Pharmacodyn. Ther. 183, 36 (1970). Comprehensive description: C. E. Orzech et al., Anal. Profiles Drug Subs. 5, 87-114 (1976). Review of pharmacology and therapeutic use: J. Uetrecht, Clin. Dermatol. 7, 111-120 (1989). Clinical trial with chlorproguanil, q.v., in drug-resistant malaria: T. Mutabingwa et al., Lancet 358, 1218 (2001).
Properties: Crystals from 95% ethanol. mp 175-176° (also a higher melting form, mp 180.5°). pKb 13.0. Soluble in alcohol, methanol, acetone, dil hydrochloric acid. Practically insol in water.
Melting point: mp 175-176° (also a higher melting form, mp 180.5°)
pKa: pKb 13.0
Use: Hardening agent in the curing of epoxy resins.
Therap-Cat: Antibacterial (leprostatic); in treatment of dermatitis herpetiformis.
Therap-Cat-Vet: Antibacterial; coccidostat.
Keywords: Antibacterial (Synthetic); Sulfones; Antibacterial (Leprostatic); Dermatitis Herpetiformis Suppressant.
Daptomycin D-Araboflavin Darbepoetin Alfa Darifenacin Darunavir

Systematic (IUPAC) name
Clinical data
Trade names Aczone
AHFS/Drugs.com monograph
MedlinePlus a682128
Pregnancy cat. B2 (AU) C (US)
Legal status ℞-only (U.S.), POM (UK)
Routes Oral
Pharmacokinetic data
Bioavailability 70 to 80%
Protein binding 70 to 90%
Metabolism Hepatic (mostly CYP2E1-mediated)
Half-life 20 to 30 hours
Excretion Renal
CAS number 80-08-0 YesY
ATC code D10AX05 J04BA02
PubChem CID 2955
DrugBank DB00250
ChemSpider 2849 YesY
UNII 8W5C518302 YesY
KEGG D00592 YesY
Chemical data
Formula C12H12N2O2S 
Mol. mass 248.302 gmol-1
 YesY (what is this?)  (verify)

Dapsone (diamino-diphenyl sulfone) is an antibacterial most commonly used in combination with rifampicin and clofazimine as multidrug therapy (MDT) for the treatment of Mycobacterium leprae infections (leprosy). It is also second-line treatment for prophylaxis (prevention) against Pneumocystis pneumonia (PCP) caused by Pneumocystis jirovecii (formerly P. carinii) in HIV patients in whom CD4 counts are below 200/mm3.[1]

Dapsone is an odorless white to creamy-white crystalline powder with a slightly bitter taste, used in combination with pyrimethamine in the treatment of malaria.[2][3] Dapsone is commercially available in both topical and oral formulations. Topical dapsone is available in a 5% gel formulation that is sold under the brand name Aczone and is produced by Allergan. Oral dapsone is also available but is less commonly used than other sulfonamide antibiotics, many of which have a lower incidence of adverse effects.[4]