RESUMEN
UNLABELLED: The aim of this study is to investigate the potential utility of some hydrogels, based on chitosan, chitosan modified with phthalic anhydride and 75/25 poly(N-isopropyl acrylamide)/alginate, for preparing drug release systems containing ketoprofen, as model drug. MATERIAL AND METHOD: The in vitro release profiles and swelling studies were done in ethanol medium, where the studied drug presents high solubility, at 25 degrees C (room temperature). The ketoprofen release was observed by monitoring the absorbance at max = 254 nm as a function of time. RESULTS: The experimental results indicated that the smallest amount of drug was released from chitosan matrices, appreciatively 31%. CONCLUSIONS: The composition of hydrogels had an important effect on ketoprofen release.