This study focused on a detailed investigation of the release of the nonsteroidal anti-inflammatory drug diclofenac sodium from strong anion resin particles, entrapped in ionotropically crosslinked alginate beads, in simulated gastric and intestinal fluids at 37 degrees C. The percentage drug released from the beads in media of various pH values in 6 h was nearly 68.8 +/- 2.6%, whereas, for the same duration, the drug-resin complex particles released 87.6 +/- 3.2%, drug. The amount of drug released from the beads depended on the composition of the beads, their degree of crosslinking, and the size of the crosslinker ions. Finally, the value of the release exponent was found to be 0.56, which thus indicated the diffusion-control led mechanism of drug release from the alginate beads (c) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 112: 416-424, 2009