The present invention provides formulations of therapeutic agents that benefit from a prolonged time of controlled release in the stomach and upper gastrointestinal (GI) tract, and from an enhanced drug exposure to the upper GI tract. The formulations of the invention comprise a therapeutic agent and one or more pH sensitive polymers that are designed for accelerated hydration, expansion, disintegration and dissolution at the higher pH of the upper GI tract, thereby, ensuring that any therapeutic agent that has not been released in the stomach is released in the upper GI tract, thus maximizing absorption of therapeutic agent that has a window of absorption located at the upper GI tract.
