Emerging Technologies for Oral Peptide Delivery: From Bioinspired Systems to Smart Device-Assisted Drug Delivery

Peptide therapeutics occupy a unique position between small organic compounds and large protein biomolecules, combining high specificity, strong pharmacological efficacy, and favourable safety profiles. Consequently, they have emerged as important therapeutic agents for a wide range of diseases, including metabolic and oncological disorders. However, oral administration of peptide drugs remains a major challenge due to extensive enzymatic degradation, low intestinal permeability, mucus entrapment, and presystemic metabolism within the gastrointestinal tract. This review provides a comprehensive overview of contemporary strategies for improving oral peptide delivery, with special emphasis on emerging pharmaceutical formulation technologies, bioinspired delivery systems and ingestible device-assisted approaches. A qualitative literature search was conducted using major scientific databases and included relevant publications available up to May 2026. The analysis identified the main barriers responsible for low oral bioavailability of peptide drugs, as well as promising approaches to overcoming these obstacles, including peptide modification, enzyme inhibition, permeation enhancement, mucolytic strategies, and advanced carrier systems. Special attention is given to multifunctional carrier systems, ingestible medical devices and bile acid-inspired technologies as emerging directions in oral peptide delivery. The convergence of pharmaceutical sciences, bioinspired formulation strategies and biomedical engineering is expected to accelerate the clinical translation of oral peptide formulations and enable their therapeutic potential to be fully exploited.