US regulators have ruled that any generic forms of OxyContin must include the abuse-curbing properties of a reformulated version of the highly addictive painkiller released two and a half years ago.
Manufacturer Perdue Pharma discontinued original OxyContin (oxycodone hydrochloride) in 2010 after the US Food and Drug Administration approved a new version of the drug that is more difficult to snort or inject.
"Because original OxyContin provides the same therapeutic benefits as reformulated OxyContin, but poses an increased potential for certain types of abuse, the FDA has determined that the benefits of original OxyContin no longer outweigh its risks," the FDA said in a statement late Tuesday.
"Accordingly, the agency will not accept or approve any abbreviated new drug applications (generics) that rely upon the approval of original OxyContin."
FDA Deputy Director Douglas Throckmorton said that "while both original and reformulated OxyContin are subject to abuse and misuse," reformulated OxyContin is more difficult to crush or melt down, making it harder to snort or inject.
"When FDA finds that a new formulation has abuse deterrent properties, the agency has the authority to require generics to have abuse-deterrent properties also," regulators said, indicating the ruling could apply to other medicines.
OxyContin sales generated $2.8 billion in 2012, according to IMS Health, an industry information service. The latest FDA ruling extends Perdue Pharma's patent protection over the drug.
The original version of the drug was designed to dissolve slowly, without giving users the feeling of euphoria that leads to addiction. But addicts found they could surmount the safeguard by snorting or injecting the drug.
OxyContin shot to popularity in the last decade, largely in rural parts of the United States, gaining the nickname "Hillbilly Heroin."
The changes to the drug appear to have curbed addiction however, and a July 2012 study in the New England Journal of Medicine found that users were switching to heroin and other dangerous street drugs that give a similar high.