CONTROLLED RELEASE TABLETS

摘要

The invention provides a controlled release tablet for the oral administration of a pharmaceutically active ingredient comprising a controlled release core composition comprising a pharmaceutically active ingredient incorporated into a polymeric carrier and diffusable therefrom at a predetermined controlled rate upon contact with a medium of an environment of use, the polymer carrier being insoluble in the medium; and a release rate controlling coating surrounding the core, the coating comprising a water insoluble and water impermeable polymeric material having at least one channeling agent dispersed in the coating and constituting about 5-60 wt./wt.% of the total coating, the channeling agent being soluble in the medium and being leachable from the coating upon contact with the medium to form molecular channels in the coating for passive diffusion of the pharmaceutically active ingredient via the channels at a controlled rate predetermined by the channels.