Microfabricated, asymmetrical, reservoir-containing particles for use in the oral delivery of biopolymer therapeutic agents such as peptides, proteins and oligonucleotides are disclosed. The particles are encapsulated in enteric-coated capsules or tablets to provide passage through the stomach and release of a suspension of the particles in the intestinal lumen. The particles have a selected shape, and uniform dimensions preferably in the 100 &mgr;m to 1 mm range. The reservoirs open to the face of the particle and are filled with a therapeutic agent and selected excipients. The excipients are selected to delay the dissolution/release of the agent from the particle reservoirs for 5-60 minutes after the particle is released in the intestinal lumen. Alternatively, the pore is plugged with an erodable material. The face of the particle is grafted with a layer of muco-adhesive ligands designed to quickly bind the particle to the intestinal mucosa for several minutes to several hours after release of the particles from the enteric-coated carrier.