Cellulose Chemistry and Technology, cilt.46, sa.1-2, ss.35-43, 2012 (SCI-Expanded)
Chitosan-montmorillonite nanocomposite hydrogels were prepared by crosslinking chitosan nanocomposites with glutaraldehyde. The following types of clays have been used: Cloisite 15 A, Cloisite 93 A, Dellite HPS and Dellite 67G. The swelling behaviour of the crosslinked hydrogels containing nanoparticles was followed in acidic media with pH = 2.2. These hydrogels have been loaded with paracetamol, theophylline, two xanthine derivatives 7-[2-hydroxy-3-(4acethyl-amino-phenoxy)-propyl]-8-R-1, 3-dimethyl-xanthine derivatives (with R=H and NO 2 for D 1 and respectively D 2) and two corresponding new nitric oxide donors (NO-donors) as 7-[2-nitroxyacethyl-oxy-3-(4-acethyl-aminophenoxy)-propyl]-8-R-1, 3-dimethy1-xanthine compounds (R=H, NO 2 for 65 and respectively 77 compounds), their controlled release being also evaluated in an acidic solution (pH = 2.2) simulating gastric fluid. The swelling and release kinetics was studied. It has been established that almost all releases involve a non-Fickian or an anomalous transport mechanism.