Oral Delivery of Biotechnology based Drugs: Dream or Reality?

Aims & Scope: Biotechnology has provided a wide array of therapeutic agents such as peptide, protein, vaccine and gene products that are mainly administered by means of injections. Therapeutic agents produced by biotechnological processes such as recombinant DNA technology, fermentation, tissue and cell culture technology as well as genetic engineering are usually large, hydrophilic molecules facing delivery challenges, for example, these drugs are susceptible to degradation and are generally poorly membrane permeable. Since successful delivery of any drug is a pre-requisite to achieve the therapeutic goal, novel strategies have emerged in the late 20 century to overcome challenges associated with the oral route of drug administration. These strategies include, but are not restricted to: 1) microand nanotechnology including self-emulsifying lipid based formulations, dendrimers and devices, 2) permeability enhancing technology, 3) targeting of active transporters and membrane receptors, 4) use of cell penetrating peptides, 5) chemical modifications of peptides such as inclusion complex formation and peptide conjugates, 6) site-specific delivery systems, 7) muco-adhesive systems and 8) polymeric hydrogels. Despite the initial excitement regarding the potential of these technologies to provide effective oral delivery, few have advanced from the pre-clinical stage into clinical trials and very few, if any, resulted so far in registered medicinal products. Moreover, most literature provides information on effectiveness and mechanisms based on in vitro investigations without revealing the viability of these technologies in clinical practice. This special issue will critically assess the latest developments in the field of oral delivery of biotechnological therapeutic agents with specific reference to the prospects of them being successful in terms of product development.