Alginic acid and its sodium and potassium alginates constitute a family of natural polyanionic polymers isolated from brown algae. Alginate aqueous gels can be produced by ionotropic crosslinking with different multivalent cations such as calcium and owing to the chemical structure they undergo interaction with mucus. These features together with very good biocompatibility and safety profiles and muco-adhesion make alginate particulate gels a very popular biomaterial in pharmaceutical development. The present chapter initially overviews the properties, production methods and most recent uses of alginate microparticle and nanoparticle gels for drug administration by the oral route. Then, it discusses the perspectives of this biomaterial in the future.