Hyaluronic acid (HA) is a natural polysaccharide that is widely distributed in the human body. Its physicochemical properties and high biocompatibility make it a good candidate for biomedical and pharmaceutical uses. In the present work, we report HA-based hydrogels that could be applied as drug delivery systems or as implants for the treatment of joint diseases. We use butanediol diglycidyl ether as a chemical crosslinker to obtain HA hydrogels. Using a new dissolution tester and ketoprofen (KP) as a model drug, we study the release properties of the hydrogels. We obtain homogeneous and transparent hydrogels with high strength and elasticity. The swelling ratio (SR) depends on the crosslinker concentration and pH of the medium. We also reveal differences between the release profile of KP from swollen and unswollen hydrogels. The characteristics and differences in KP release profiles depending on the SR suggest the possibility of obtaining controlled release from HA-based hydrogels. (C) 2013 Wiley Periodicals, Inc.