Water and drug transport in radiation-crosslinked poly(2-methoxyethylacrylate-co-dimethyI acrylamide) and poly(2-methoxyethylacrylate-co-acrylamide) hydrogels

Hydrogels of poly(N,N'-dimethylacrylamide-co-2-methoxyethylacrylate) and poly(acrylamide-co-2-methoxyethylacrylate) have been synthesized by radiation polymerization in dimethylformamide solution with trimethylolpropane trimethacrylate as a crosslinker. In this work, some investigations on the in vitro release of gentamicin sulphate, an antibiotic entrapped in the hydrogels, are reported. The kinetics of drug release from hydrogels matrices were examined and the results indicate that the release for the proposed geometry practically occurs in the first 24 h. The fractional cumulative release of the drug from the DMAA/MOEA matrices is linear when plotted against the square root of time, pointing out a Fickian process. On the other hand, AAm/MOEA matrices showed an initial non-Fickian behaviour, probably indicating a comparable rates of Fickian diffusion and polymer relaxation. (C) 2003 Elsevier Science Ltd. All rights reserved.