Abstract
Lactoferrin (Lf), as a therapeutic protein drug, has attracted much interest due to its many important roles in human and animal health and development. Oral delivery offers the most convenient way for supplementing Lf. However, the bioavailability of orally administered Lf is limited by a number of barriers associated with protein absorption. During the past decade, several oral delivery systems have been developed to preserve Lf stability in order to enhance gastric residence time and improve its bioavailability. This review summarizes various pharmaceutical strategies currently under investigation including: PEGylation, absorption enhancers, enzymatic inhibitors and advanced drug carrier systems.