Micellization and sustained drug release behavior of EC-g-PPEGMA amphiphilic copolymers

The micellization and sustained drug release behavior of ethyl cellulose graft poly(poly(ethylene glycol) methyl ether methacrylate) (EC-g-PPEGMA) copolymers with well-defined structure were investigated by using pyrene as the fluorescent probe and model drug. It was found that the EC-g-PPEGMA copolymers have a low critical micelle concentration (CMC) at about 5 x 10(-4) mg/mL. Drug loading experiments indicate that a low graft density of the copolymers corresponds to a higher drug loading efficiency and a higher loading capacity of drug in the micelles. The release rate of the loaded pyrene depends on both the length of the side chains and the loading capacity of pryene in the micelles. A shorter side chain of the copolymer and a higher ratio of the copolymer to the pyrene in the micelles correspond to a lower release rate. The self-assembly system shows a potential application in controlled drug delivery. (C) 2010 Elsevier Ltd. All rights reserved.