A hydrogel matrix and an osmotically active material immobilized in the matrix can be combined into superabsorbent preparations that are capable of adsorbing large amounts of water. The superabsorbent preparations of the invention have advantages in the use of absorbent materials for physiological fluids, such as diapers, incontinence products, wound dressings and the like, as well as agricultural and environmental applications. In addition, biodegradable superabsorbents of the invention can be prepared.
