Sprout Pharmaceuticals didn't have to wait long for a big-name buyer to spring big bucks for the nascent drug developer.

Just two days after Sprout received U.S. Food and Drug Administration approval for its women's libido drug Addyi, hyperactive acquirer Valeant Pharmaceuticals International Inc. announced Thursday that it has agreed to pay $1 billion in cash for the Raleigh, North Carolina-based target.

Skadden, Arps, Slate, Meagher & Flom is once again taking the lead for Valeant, with Sullivan & Cromwell working on behalf of Sprout. While the high-powered Am Law 100 duo were called in for the transactional work, Addyi's approval process took some legal wrangling of its own.