Sources familiar with the matter were quoted by Reuters as saying that the $500m-$1bn worth portfolio could be divided and sold to different parties.
Without disclosing the estimated proceeds from the sale, the sources added that the company has hired UK-based investment banking boutique DC Advisory for the transaction.
Both the company and the advisory firm declined to comment on the deal.
Protopic drug’s US patent is set to expire in 2014.
The Japansese drugmaker has $23bn in market capitalization and its dermatology portfolio sells products across the globe.