A DRUG DELIVERY SYSTEM BASED ON STIMULI-RESPONSIVE ALGINATE/N-ISOPROPYLACRYL AMIDE HYDROGEL

The release kinetics of paracetamol and theophylline from pH- and temperature-responsive hydrogel matrices prepared from sodium alginate and N-isopropylacryl amide crosslinked with N,N'-methylenebisacrylamide was investigated. The drug-loaded hydrogel matrices were studied by FT-IR spectroscopy. As the release kinetics of drugs is related to the kinetics of solvent diffusion into the hydrogels, studies on the swelling behavior become of great importance for appreciating the drug release from hydrogel matrices. Swelling and release kinetic studies were performed at 37 degrees C in acid medium, at pH - 2.2, for simulating the pH of the gastric fluid in the stomach. The drug release kinetic data were analyzed and the release parameters were estimated by fitting the experimental data to three different theoretical models. The results obtained showed nearly similar release profiles for theophylline and paracetamol over a 9-day interval. The values obtained indicated an anomalous transport mechanism for both model drugs.