Embodiments of the invention provide swallowable devices, preparations, and methods for delivering drugs and other therapeutic agents within the GI tract. Particular embodiments provide a swallowable device such as a capsule for delivering drugs or other therapeutic agents (TA) into a wall of the GI tract such as the stomach or small intestine. The swallowable device comprises a sensor, a combustible propellant (CP) and a therapeutic agent preparation (TAP) comprising at least one TA. The sensor triggers the CP to ignite and propel the TAP into the wall of the GI tract in response to an external condition or change in external condition. Embodiments of the invention are particularly useful for orally delivering drugs or other TAs which are degraded within the GI tract and require parenteral injection.