Extrudable core system: development of a single-layer osmotic controlled-release tablet.

A new controlled-release, extrudable core system (ECS) tablet has been developed which osmotically delivers high doses of low solubility active pharmaceutical ingredients (API's). The tablet has a single core formed in a modified oval shape with a semi-permeable coating. The core contains hydroxyethylcellulose, which serves to entrain the API particles as they are extruded out a hole in the coating at one end of the tablet, and a sugar, which provides the osmotic driving force for water imbibing. The dosage form has been successfully shown to control delivery of API over a range of delivery rates even with 50% of the tablet being API (up to about 500 mg).