Pharmaceutical Research

, Volume 25, Issue 1, pp 218–226

Pharmacokinetic Modeling of Absorption Behavior of 9-Aminocamptothecin (9-AC) Released from Colon-specific HPMA Copolymer–9-AC Conjugate in Rats

Authors

  • Song-Qi Gao
    • Department of Pharmaceutics and Pharmaceutical Chemistry/CCCDUniversity of Utah
  • Yongen Sun
    • Department of Obstetrics and GynecologyUniversity of Utah
  • Pavla Kopečková
    • Department of Pharmaceutics and Pharmaceutical Chemistry/CCCDUniversity of Utah
    • Department of BioengineeringUniversity of Utah
  • C. Matthew Peterson
    • Department of Obstetrics and GynecologyUniversity of Utah
    • Department of Pharmaceutics and Pharmaceutical Chemistry/CCCDUniversity of Utah
    • Department of BioengineeringUniversity of Utah
Research Paper

DOI: 10.1007/s11095-007-9465-3

Cite this article as:
Gao, S., Sun, Y., Kopečková, P. et al. Pharm Res (2008) 25: 218. doi:10.1007/s11095-007-9465-3

ABSTRACT

Purpose

To quantitate and predict colon-specific 9-aminocamptothecin (9-AC) release from the N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer–9-AC conjugate and its absorption behavior after oral administration in rats.

Methods

Drug distribution in the gastrointestinal (GI) tract and the plasma concentration-time profile of 9-AC released from the HPMA copolymer conjugate were predicted using the degradation, transit, and absorption rate constants in cecum. The fate of 9-AC in cecum and liver was measured by in-situ cecum absorption and liver perfusion.

Results

Following oral administration of the conjugate, 9-AC was released rapidly in cecum. Based on the pharmacokinetic model, up to 60% of the dose was in the cecum at ~6 h, and 7% of the dose still remained there at 24 h. The predicted plasma concentration curve for released 9-AC after an oral dose of 3 mg/kg of 9-AC equivalent increased gradually and reached a peak of 98 nM at 7 h, then started decreasing slowly to 16 nM at 24 h. The bioavailability value was estimated as 0.31 after the first-pass elimination.

Conclusions

A pharmacokinetic model delineated the impact of GI transit, drug absorption rate, and first-pass metabolism on drug disposition following oral administration of HPMA copolymer–9-AC conjugate in rats.

Key words

absorption predictioncolon-specific drug deliveryHPMA copolymer–9-aminocamptothecin conjugateoral dosingpharmacokinetic modeling

Copyright information

© Springer Science+Business Media, LLC 2007