Aim: To perform the assay of Dapsone.

Molecular formula: C₁₂H₁₂N₂O₂S

Mol. Wt.: 248.3

Dapsone contains not less than 99.0% and not more than 101.0% of C₁₂H₁₂N₂O₂S calculated on the dried basis.

Category: Antileprotic.

Dose: 100 mg daily.

Description: A white or creamy-white, crystalline powder.

Assay:

• Dissolve 0.3 gm in a mixture of 20 ml of water and 20 ml of 2 M hydrochloric acid, add 3 gm of potassium bromide.
• Cool the solution to about 15°C and determine by nitrite titration.
• Carry out a blank titration.

Factor: 1 ml of 0.1 M sodium nitrite is equivalent to 0.01242 gm of C₁₂H₁₂N₂O₂S.

Storage: Store protected from light.

Uses: It is used as antileprotic drug.