Despite being embroiled in many months of controversy, Zogenix Inc. is putting its full weight behind launching its new narcotic painkiller Zohydro. The company is divesting its migraine therapy business, selling it to specialty drugmaker Endo International PLC for $85 million. The deal carries a potential $20 million in milestone payments.

The agreement allows Zogenix a greater level of focus on the launch of Zohydro ER, and will help bankroll the company’s development of two abuse deterrent formulations of the drug.

Zogenix has been criticized by some for the abuse potential of this drug.

The Sumavel DosePro needle-free delivery system is part of this deal. It was launched in January 2010, and sold more than 2 million units through the end of 2013. Its net sales last year for the drug were $31.7 million, according to regulatory filings.

In other Zogenix news: The saga presses on for the company as it continues to voice objection to the new restrictions placed by the state of Massachusetts on the sale and use of Zohydro.

Massachusetts Gov. Deval Patrick is imposing new sanctions on the sale of Zohydro, after a federal judge’s recent ruling that the governor’s initial ban is preempted by federal law.

Zogenix said it was “once again disappointed” that Patrick is issuing another immediate restriction without first attempting to “discuss the facts” of how there’s a patient need for the powerful painkiller.

Patrick had banned the drug March 27, announcing that the state was in a public health emergency for its prevalence of opioid drug abuse. But the U.S. District Court of Massachusetts granted a preliminary injunction against Patrick’s ban, finding that allowing the state to overturn the FDA ruling was an obstruction of the federal agency’s authority.

This story has been updated since its original posting.