Abstract: The invention includes an orally ingestible delivery system for releasing a therapeutic agent within an intestine of a mammal, where the system includes the therapeutic agent and a differentially permeable capsule system containing the therapeutic agent within a therapeutic agent compartment, with the differentially permeable capsule system dimensionally adapted for oral ingestion and for passage into a stomach of the mammal and thence into the intestine, wherein the differentially permeable capsule system comprises an acid-resistant shell and a dispersible acid barrier, wherein the dispersible acid barrier forms while the orally-ingestible delivery system is in the stomach; and wherein the dispersible acid barrier is dispersed in the intestine, thereby permitting enzymes in the intestine to reach the therapeutic agent compartment. The invention also includes methods of manufacturing the system and methods for its use.