Controlled release of chlorpheniramine maleate drug, through sodium alginate-g-methylmethacrylate (NaAlg-g-MMA) interpenetrating polymeric network beads, has been investigated. Beads were prepared by precipitating the viscous solution of NaAlg-g-MMA in acetone followed by cross-linking with glutaraldehyde. The beads were characterized by Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). Different formulations of beads were developed by varying amounts of MMA, cross-linking agent, and drug concentration. DSC thermograms of chlorpheniramine maleate drug-loaded NaAlg-g-MMA beads confirmed the molecular level distribution of drug in the polymer matrix. FTIR of beads confirm the grafting and cross-linking, SEM of the beads suggested the formation of spherical particles. Swelling experiments on the beads provided an important information on drug diffusion properties. Release data have been analyzed using an empirical equation to understand the nature of transport of drug containing solution through the polymeric matrices. The controlled release characteristics of the matrices for chlorpheniramine maleate was investigated in pH 7.4 media. Drug was released in a controlled manner upto 12 h. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 2342-2349, 2010