Abstract: A pharmaceutical composition comprising therapeutically effective amount of rifaximin or pharmaceutically acceptable salt or enantiomer or polymorph thereof, pharmaceutically acceptable excipient(s) and release controlling agent(s). Pharmaceutical composition of rifaximin comprising: at least two entities wherein one entity is an immediate release or fast release and the other is controlled release. The pharmaceutical composition in the form of multilayer tablet comprising, at least one layer comprising, therapeutically effective amount of rifaximin or pharmaceutically acceptable salt or enantiomer or polymorph thereof, pharmaceutically acceptable excipient(s); said layer providing controlled release rifaximin; and at least one layer which provides increased residence time of the dosage form in the gastrointestinal tract. The pharmaceutical formulation comprising rifaximin having an in vitro dissolution profile, wherein about 70% of rifaximin is released in about 24 hours.

Abstract: A novel pharmaceutical composition, which comprises a therapeutically effective amount of active principle(s) or a pharmaceutically acceptable salt or enantiomer or polymorph thereof, optionally one or more release controlling agent(s) and pharmaceutical acceptable excipient(s) thereof, wherein the composition is formulated to increase the residence time of the said pharmaceutical composition and/or active principle(s) in the gastrointestinal tract. A novel pharmaceutical composition comprising at least two entities wherein one entity is an immediate release/fast release and the other is controlled release. A pharmaceutical composition comprising at least two entities wherein one entity is an immediate release/fast release and the other is bioadhesive. A pharmaceutical composition comprising: at least two entities wherein one entity is controlled release and the other is bioadhesive All the three compositions are formulated to increase the residence time of active principle(s) in the gastrointestinal tract.