The disclosure relates to a sustained-release oral dosage form for once-a-day administration comprising: a pharmaceutically acceptable sustained-release matrix comprising, as part of the sustained-release matrix, (a) an analgesially effective amount of oxycodone in the range from 1 mg to 640 mg of oxycodone or a pharmaceutically acceptable salt thereof, and (b) a sustained release material in an effective amount to render the dosage form suitable for once-a-day oral administration, the sustained-release matrix coated with a coating, wherein the dosage form provides a sustained release effect for at least about 24 hours and a mean C24/Cmax oxycodone ratio of 0.7 to 0.99 after once-a-day steady state oral administration to human patients.
