Bioavailability of peptide active agents to be administered orally is enhanced by a pharmaceutical composition providing targeted release of the peptide to the intestine in addition to having the active peptide linked to a membrane translocator which is capable of being at least partially cleaved in vivo by an enzyme. The composition includes an acid-resistant protective vehicle which transports components of the invention through the stomach and a sufficient amount of a pH-lowering agent to lower local intestinal pH. All components are released together into the intestine with the peptide.