Novel carboxymethylcellulose-based microporous hydrogels suitable for drug delivery.

Several materials capable of acting as structures for controlled release were analysed for the fabrication of matrices. Among those used, hydrophilic polysaccharides appeared to be the most suitable materials. Carboxymethylcellulose (a semi-synthetic polysaccharide) was chemically cross-linked with a 60% and 90% cross-linking degree in order to obtain hydrogels and utilised as matrix for the realisation of controlled drug release systems. The morphology of the gels was changed in order to obtain a microporous structure with different porosity (14, 30 and 40 microm). The obtained porous matrices were characterised in terms of pore density, dimension and swelling behaviour. The influence of both the pore dimension and technique of loading on the release kinetics was analysed. By increasing the pore dimension the release of ibuprofen-lysin was slower. Inducing the microporous structure after the loading of the hydrogel with the drug resulted in a slower release.