Poly(ethylene carbonate)s, part II: degradation mechanisms and parenteral delivery of bioactive agents

Citation
Gh. Stoll et al., Poly(ethylene carbonate)s, part II: degradation mechanisms and parenteral delivery of bioactive agents, J CONTR REL, 76(3), 2001, pp. 209-225
Citations number
46
Categorie Soggetti
Pharmacology & Toxicology
Journal title
JOURNAL OF CONTROLLED RELEASE
ISSN journal
01683659 → ACNP
Volume
76
Issue
3
Year of publication
2001
Pages
209 - 225
Database
ISI
SICI code
0168-3659(20011019)76:3<209:PCPIDM>2.0.ZU;2-W
Abstract
The degradation and drug carrier properties of poly(ethylene carbonate) (PE C) were investigated in vitro and in rats and rabbits. PEC was found to be specifically degraded in vivo and in vitro by superoxide radical anions O-2 (-)., which are, in vivo, mostly produced by inflammatory cells. No degrada tion of PEC was observed in the presence of hydrolases, serum or blood. PEC is biodegraded by surface erosion without significant change in the molecu lar weight of the residual polymer mass. The non-hydrolytic biodegradation by cells producing O-2 . is unique among the polymers used as biodegradable drug carriers. The main degradation product of PEC in aqueous systems is e thylene glycol, formed presumably by hydrolysis of ethylene carbonate. The splitting off of a five-membered ring structure from the polymer chain indi cates a chain reaction mechanism for the biodegradation. PEC is a suitable drug carrier, particularly for labile drugs. Using human interleukin-3 and octreotide as model drugs, surface erosion of the PEC formulations was indi cated by a 1:1 correlation between drug release and polymer mass loss. (C) 2001 Elsevier Science BY. All rights reserved.