There isn't one. Oxycontin was a name brand for a 12 hour time release tablet of it,and Roxicodone was the instant release version. Then Oxycodone was used for generics, desginated with either a CR or ER for the 12 hour, and IR for the instant release. But the full name of the chemical salt of the drug is
Oxycodone Hydrochloride. Many of them are shortened when released on the general market ...