Deformulation of dapsone gel by analytical methods

Deformulation plays an important role in ANDA submission of generic formulation. Deformulation is also known as reverse engineering. Being first to gain the most is a fundamental principle in the generics business. Though generics companies have used reverse engineering commonly, the topic is hardly discussed in the public literature. Hence, the study focuses on the reverse engineering (i.e. deformulation) method for determination of composition of commercial available dapsone gel. Deformulation of marketed formulation of Dapsone gel has been carried out by using different analytical methods like GC-FID, Karl Fischer Titration, etc. Determination of each component present in marketed formulation of Dapsone gel (Acnedap gel) has been done by development and validation of analytical method for its quantification as per ICH guidelines. The quantity of API dapsone and excipients such as DGME, methyl paraben, carbopol 980, water and sodium hydroxide obtained after decoding is 25, 0.2, 0.5, 69.2 and 0.1% respectively.