Hydrogels are well known networks of hydrophilic polymers which can absorb a significant amount of water without dissolving or loosing their structural integrity. The water content in the hydrogels affects various properties like permeability, mechanical properties, surface properties and biocompatibility and make them technologically useful materials as biomedical devices, absorbent products and chemical separators. This book is focused on the synthesis and characterization of sodium alginate based Interpenetrating Network hydrogels and the study of transport of a cationic dye Azure-B through it. In the first section of this book the optimization of the conditions for obtaining mechanically stable IPN films of sodium alginate and gelatin and study of the influence of preparation method on film characteristics and the swelling and diffusion behaviour of the films has been reported. The second section deals with sodium alginate and sodium carboxy methyl cellulose beads. The influence of preparation method and bead characteristics on the swelling and dye release behaviour were studied.