Influence of polymers ratio on insulin-loaded nanoparticles based on poly-ε-caprolactone and Eudragit® RS for oral administration

Abstract

Nanoparticles loaded with two different commercial insulins (Actrapid ®, Novorapid®) and based on different blends of a biodegradable polyester (poly-ε-caprolactone) and a polycationic non-biodegradable acrylic polymer (Eudragit® RS) were characterized in vitro. The zeta potential was positive whenever Eudragit ® RS was part of the nanoparticles matrix. The encapsulation efficiency was ∼ 96% except for Novorapid®-loaded particles of poly-ε-caprolactone (only 35%). In vitro release studies revealed a burst release from nanoparticles, which may be of interest for oral delivery. Novorapid-loaded nanoparticles were orally administered to diabetic rats and allowed the glycemia to be decreased when compared with free nanoparticles. © 2009 Informa UK Ltd.