Cyclic peptide oral bioavailability: Lessons from the past.

The review identifies key factors influencing the passive permeability and oral bioavailability of cyclic peptides, emphasizing structural features that enhance absorption. It highlights that cyclic peptides, unlike linear ones, can achieve drug-like oral bioavailability, as demonstrated by compounds such as cyclosporine A.

This study is a literature review analyzing past research on the oral bioavailability of peptides, focusing on passive permeability factors and comparing linear and cyclic peptide data.

Understanding what makes cyclic peptides orally bioavailable can guide the design of new peptide drugs that are easier to administer and more effective. This knowledge is crucial for advancing peptide therapeutics beyond injections to convenient oral forms.

As a review, it summarizes existing studies but does not provide new experimental data. The evidence strength and study types of included research vary and are not specified.