Beyond 2020, the global Peptide Therapeutics market is expected to eclipse $42 billion. This dramatic market increase is driven by both growing incidences of cardiovascular and metabolic diseases, and technological enhancements in peptide synthesis that include high-throughput approaches. Hybrid technology combining solid and liquid syntheses is also contributing to the growth of peptide therapeutics, as are novel modes of conjugation.

To date, there are just over 100 therapeutic peptides (mostly innovative synthetic ones) are on the market in the USA, Europe and Japan, including those for diagnostics applications. With hundreds of protein and peptide drugs in clinical trials and many more in preclinical development, this market is expected to continue grow over the next 5-10 years.

However, targeted delivery of peptide drugs within the therapeutic range remains a significant challenge to the biopharmaceutical industry. Effective delivery systems are fundamental to enable peptides to overcome their inherent structural instability, diffuse across physical barriers, and achieve the desired bioavailability.

Advances in Nanoparticle Delivery
Encapsulating peptides into drug carrier systems improves bioavailability. Microparticles, nanoparticles, liposomes, solid lipid nanoparticles, and a variety of polymer-based materials can be used for carrier construction. Nanoparticles have been an extremely active area for developing novel drug-delivery carriers with advantages over other systems. The physiochemical properties of nanoparticles can be adjusted to fit their desired use by altering their sizes, surface charges, and hydrophobicity. Moreover, nanoparticles can be engineered to encapsulate a broad range of molecules. Nanoparticles also have the ability to accommodate a variety of functions, such as targeted delivery and sustained release through surface modifications.

Parenteral Delivery
Parenteral administration (including intravenous, subcutaneous, and intramuscular) remains the primary method for commercialized therapeutic peptides currently, but challenges such as patient compliance hinder product advancements. Improved parenteral formulations (e.g., pre-filled syringes and auto injectors) and noninvasive delivery methods are much preferred. An efficacious delivery system with better patient compliance over existing treatments could be the key to extend patent protection, as well as develop differentiated products.

Transdermal & Micro-needle Delivery
Off the bat, transdermal routes offer better patient compliance. Due to their large molecular size, peptide therapeutics usually require chemical or physical interventions to increase skin permeability transiently. Among the many technologies in development to achieve this goal, micro-needle systems pose a promising commercial delivery system. Peptides can be delivered in several ways: topical administration after micro-needle treatment, infusion through hollow micro-needles, or the slow release of encapsulated drugs into biodegradable micro-needles.