The Oral Bioavailability of Peptides and Related Drugs

  • M. J. Humphrey
Part of the NATO ASI Series book series (NSSA, volume 125)


The discovery of diverse neuro- and hormonal peptides, as well as other biologically-active peptides, has prompted investigations into their therapeutic applications and to the design of peptide drugs. However a contributing factor to the therapeutic success of a drug is the availability of an oral formulation. For peptides and proteins, oral absorption and bioavailability is generally low (as shown in Table 2) relative to that expected of non-peptide drugs (for review see Humphrey & Ringrose, 1986). The purpose of this review is to describe the various barriers to, and mechanisms of absorption of peptide drugs, as well as, to discuss the relationship between physio-chemical properties and absorption (see Table 1).


Mucosal Barrier Peptide Drug Unstirred Water Layer Enalapril Maleate Mono Ethyl Ester 
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Copyright information

© Springer Science+Business Media New York 1986

Authors and Affiliations

  • M. J. Humphrey
    • 1
  1. 1.Department of Drug MetabolismPfizer Central ResearchSandwich, KentUK

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