Some brands may have a pellet (spheroid) formulations (made by extrusion and spheronization) can be used for controlled<unk>  of the drug in the body whereas powder filled pellets generally cannot. The plastic spheres containing powder have micropores that open at varying PH levels, to maintain a mostly constant<unk>  during transit through the digestive tract. The spheres themselves, the outer shells, pass undigested in most patients. Other brands are thought to use ethylcellulose coatings to control drug<unk>  from pellets. Another use these style medications have is that they can be given via NG tube, the pellets being very small. This makes them one of the only<unk><unk>  oral medications that can be given by feeding tube.
Extended-release morphine
Patient-controlled analgesia
Noroxycodone
Morphine
Oxycodone
Acetylmethadol
Hydrocodone
Codeine