The present invention includes a formulation and controlled release dosage form that enable the controlled release of therapeutic agents showing reduced absorption in the lower gastrointestinal tract. The formulation of the present invention includes a therapeutic agent that exhibits greater absorption in the upper GI tract than in the lower GI tract and a permeation enhancer, which serves to increase absorption of the therapeutic agent in the lower GI tract. The formulation of the present invention further includes a carrier that allows the formulation to transition to a bioadhesive gel in situ after the formulation is dispensed within the GI tract and has had some opportunity to reach the surface of the GI mucosal membrane. The bioadhesive gel formed by the formulation of the present invention works to present effective concentrations of both the therapeutic agent and the permeation enhancer at the surface of the GI mucosal membrane over a period. The controlled release dosage form of the present invention is designed to deliver the formulation of the present invention at a desired release rate or release rate profile over a desired period of time.