American Society of Hirudotherapy

Pharmacodynamics and pharmacokinetics of recombinant hirudin via four non-parenteral routes

Research article published in Peptides (2005)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Observational studyDrug DevelopmentLiu et al. · Peptides, 2005

Abstract

One of recombinant hirudin variants, rHV2, a polypeptide used as an anticoagulant agent in clinic, was administered to anesthetized rats via intratracheal, buccal, nasal and rectal routes. Prolongation in clotting time and thrombin time was measured to calculate pharmacological bioavailability. Plasma concentration of rHV2 was determined using a chromogenic thrombin substrate assay and pharmacokinetic parameters were obtained on the basis of a non-compartmental model. Intravenous administration was also performed as the gold standard by which the other routes were compared. Difference in pharmacological bioavailability (P.A.), bioavailability (F) and absorption rate of rHV2 was found for the four non-parenteral routes. The rank order for both P.A. and F was intratracheal>nasal>buccal>rectal. Absorption was more rapid after both intratracheal and rectal administration (tmax approximately 20-40 min), compared with that after nasal and rectal administration. It is evident that the pulmonary route is preferable to other three routes for successful systemic delivery of rHV2.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeComparative StudyJournal Article
Indexed MeSH termsAbsorptionAdministration, BuccalAdministration, IntranasalAdministration, OralAdministration, RectalAnimalsArea Under CurveBiological AvailabilityHirudinsHumansInfusions, IntravenousMale

Summary

Peer-reviewed research on anticoagulant and antithrombotic drug development relevant to thrombin and factor inhibition. Indexed in PubMed and verified against the NCBI record.

Why This Matters for Hirudotherapy

This animal study examined the recombinant hirudin variant rHV2, a leech-derived direct thrombin inhibitor, delivered to anesthetized rats by four non-parenteral routes (intratracheal, nasal, buccal, rectal), using prolongation of clotting and thrombin time plus a chromogenic thrombin-substrate assay to estimate bioavailability against intravenous dosing; the abstract reports the rank order for both pharmacological availability and bioavailability as intratracheal > nasal > buccal > rectal and concludes the pulmonary route was preferable for systemic delivery. It is directly relevant to the medicinal-leech secretome drug-discovery narrative, addressing a core translational problem for hirudin-class peptides, namely how to administer them without injection. Caveat: this is a preclinical rat study of an isolated recombinant peptide via experimental delivery routes; it is not a clinical trial and says nothing about leech-applied hirudotherapy in patients.

Citation

Pharmacodynamics and pharmacokinetics of recombinant hirudin via four non-parenteral routes.

Liu et al. · Peptides, 2005

Added to ASH library: May 28, 2026 · Site last updated: June 18, 2026

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