Delivering Macromolecules: Challenges Associated with the Delivery of Biologic Drugs

Biologic drugs, rather than being synthesized from other compounds, are generally made using human or animal proteins. At the molecular level, they’re usually larger and much more complex than regular drugs. Routine oral administration of biologics has not been mastered as there is enzymatic and pH-dependent degradation of drugs in the stomach and intestines. Low permeability of epithelial cells that line the gastrointestinal tract means that proteins and peptides typically have extremely low bioavailability in the range of around 0-2% when taken by mouth.