The US Food and Drug Administration (FDA) has approved King Pharmaceuticals’ Embeda, a long-acting opioid for the management of moderate to severe pain over an extended period of time.

Embeda (morphine sulfate and naltrexone hydrochloride) is an extended-release capsule for oral use that uses a long-acting Schedule II opioid analgesic designed to reduce drug enjoyment and euphoria when a drug is tampered with by crushing or chewing.

The drug contains extended-release morphine pellets, each with an inner core of naltrexone hydrochloride, an opioid receptor antagonist.

King chairman, president and chief executive officer Brian A Markison said that the company anticipates a September 2009 launch for Embeda.

“We are focused on developing medicines that use novel technologies designed to reduce drug enjoyment and make it more difficult to extract the active ingredient,” Markison said.

FDA approval was based on data from 12 clinical including Phase III data demonstrating efficacy and safety.

During the Phase III study, Embeda provided significant pain relief in patients with moderate to severe pain due to osteoarthritis of the hip or knee compared with placebo.

Phase III findings also showed that Embeda was safe and well tolerated in patients treated for up to 12 months, with an overall safety profile consistent with the most common opioid-related adverse events.

The most common adverse events reported in the Embeda clinical programme were consistent with the well-known adverse reactions associated with morphine, including constipation, nausea and somnolence.