Mixed-interpenetrated polymeric networks based on sodium alginate (ALG) and poly(N-isopropylacryl amide) (PNIPAAm) covalently cross-linked with N,N'-methylenebisacrylamide are studied for their biocompatibility, nontoxicity, and biodegradability aiming their application in drug delivery. The presence of drug-polymeric matrix interactions and the distribution of the drug in the polymeric network for theophylline-loaded ALG/PNIPAAm hydrogels are also investigated by spectroscopic and microscopic methods. The quantitative evaluation of theophylline loaded hydrogels performed by NIR-CI technique shows a better drug entrapment and a higher homogeneity of the samples with increased alginate content. The thermal behavior of the hydrogels is significantly modified by theophylline presence. The application of the ALG/PNIPAAm hydrogels as carriers for sustained drug release formulations was assessed by the theophylline release tests performed both by in vitro and in vivo studies.
- drug delivery systems
- stimuli-sensitive polymers