Carboxymethyl cellulose (CMC) particles were synthesized in one step employing inverse micelle microemulsion polymerization using divinyl sulfone as crosslinking agent. These synthesized particles were further modified and demonstrated as drug delivery system. Acyclovir was chosen as the model drug. The synthesized CMC particles were made magnetic responsive by encasing independently prepared magnetic ferrite particles (Fe(3)O(4)) in CMC polymeric particles during the synthesis as magnetic-CMC (m-CMC). The particles were characterized by using dynamic light scattering (DLS), zeta potential measurements (ZP). FT-IR spectroscopy, scanning electron microscopy (SEM) and thermogravimetric analyzer (TGA). The synthesized particles have wide size distribution ranging from 100 to 10,000 nm. The further modification of CMC and magnetic Fe(3)O(4) containing CMC polymeric particles crosslinked at different ratios was performed successfully by introducing new functional groups to the CMC networks. It was determined that these particles obtained from the natural CMC polymers have a potential range of application as drug and targeted drug delivery system in biomedical field. (C) 2011 Elsevier Ltd. All rights reserved.