The present invention in general relates to pharmaceutical formulations and methods for oral delivery of biologically active ingredients to a vertebrate host via receptors present in the gastro intestinal tract. The invention also relates to processes for preparing suitable complex for oral delivery of biologically active ingredients to a vertebrate host. Specifically, a new set of oral biologically active ingredient to which a biotin molecule, or analogue thereof, has been conjugated is provided, thereby facilitating oral delivery of biologically active ingredients which may or may not have their own receptors in the gastrointestinal tract.