A timed-release drug delivery assembly includes an expandable structure and drug microparticles. The expandable structure is defined by host material that causes expansion of the expandable structure. The expandable structure has a non-expanded state prior to exposure to a gastric environment during which a size of the expandable structure enables entry of the expandable structure into a stomach of a patient, and an expanded state after exposure to the gastric environment during which the size and shape of the expandable structure prevents exit of the expandable structure from the stomach. The drug microparticles are held at least in part by the host material to enable release of the drug microparticles into the gastric environment over a predefined period of time. The expandable structure may include, in the expanded state, a substantially hollow framework to avoid blocking a pyloric valve of the stomach.
