Oral Bioavailability
Oral Bioavailability — The fraction of an orally administered peptide that reaches systemic circulation intact, typically very low due to gastric degradation and poor absorption.
What Is Oral Bioavailability?
Oral bioavailability (%F) is the fraction of an orally administered peptide dose that reaches systemic circulation in intact, active form. Most peptides have < 1% oral bioavailability due to gastric acid degradation, protease digestion, poor membrane permeability, and first-pass metabolism. Achieving clinically useful oral bioavailability is the "holy grail" of peptide drug delivery.
Oral Peptide Successes
- Rybelsus (oral semaglutide): ~1% F using SNAC enhancer. First oral GLP-1 agonist
- Cyclosporine: ~30% F. N-methylated cyclic peptide. Gold standard for oral peptide design
- SNAC: Sodium N-[8-(2-hydroxybenzoyl)amino]caprylate. Enhances transcellular absorption
Frequently Asked Questions
What is Oral Bioavailability?
The fraction of an orally administered peptide that reaches systemic circulation intact, typically very low due to gastric degradation and poor absorption.
Why is Oral Bioavailability important in peptide research?
Oral Bioavailability is a fundamental concept in pharmacology as it relates to peptide science. It directly influences experimental design, compound characterization, and the reliability of research outcomes across biochemistry and molecular biology disciplines.
Authority Sources
- Oral Bioavailability on Wikipedia
- Search Oral Bioavailability on PubChem (NIH)
- Research articles on ScienceDirect