Radiation synthesis of poly(ethylene glycol)/acrylic acid hydrogel as carrier for site specific drug delivery

Abstract pH‐sensitive hydrogels were prepared from poly(ethylene glycol) (PEG) and acrylic acid (AAc) in aqueous solution employing γ‐radiation‐induced copolymerization and crosslinking. The swelling behavior of the prepared hydrogels was determined by investigating the time and pH‐dependent swelling of the (PEG/AAc) hydrogels of different PEG content. The effect of environmental parameters such as pH and ionic strength on the swelling kinetics was studied. The results not only show the dependence of the swelling indices on the pH value of the swelling medium but also show a clear dependence of the diffusion coefficient on the ionic strength of the medium. To estimate the ability of the prepared copolymer to be used as a colon‐specific drug carrier, the release of ketoprofen was studied as a function of time at pH 1 and pH 7. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006