| abstract |
A tablet for the controlled release of an active pharmaceutical ingredient. The tablet comprises a core having a donut-like configuration with a cylindrical hole extending through the center of the core. The core of the body comprises at least one active pharmaceutical agent and at least one hydrophilic, water-soluble, polymeric carrier. The core is coated with a hydrophobic, water-insoluble material covering all of the core except that which is defined by the cylindrical hole. Also included is a method of preparing a tablet for the controlled release of an active ingredient. The method comprises the steps of blending an active pharmaceutical ingredient, a water-soluble hydrophilic, polymeric carrier, and optionally an excipient, to form a mix; compressing the mix; punching a tablet from the mix; coating the tablet in a water insoluble, hydrophobic coating, then drilling a hole through the coated tablet. A second embodiment of this method includes drilling a first hole through the tablet before coating the tablet, placing a rod through the first hole, dipping the tablet into the coating, and then removing the rod and drilling a second hole in the tablet which is larger than the first hole. |