Cation Exchange Hydrogels as Platform for Loading and Controlled Delivery of Drug

Abstract

Ion exchange hydrogels are largely used in pharmaceutical field due to high loading capacity and controlled delivery of drugs. In this paper, cation exchange hydrogels based on natural polymer (sulfopropyl dextran, SPD, carboxymethyl dextran, CMD, dextran sulfate, SD) or synthetic matrix (styrene-divinylbenzene) (Vionit CS-3) were evaluated as support for loading and controlled delivery of hypoglycemic basic drug buformin, taken as model drug. The hydrogels, except dextran sulfate, proved high drug loading capacity and efficiency, due to the strong drug/cation exchange hydrogel interactions and good accessibility of the drug to the loading sites. All hydrogels released the buformin in a prolonged time. The results concerning LD50 on rats and on mice demonstrated that there is no significant difference between the toxicity of the buformin itself and its complexes with the studied cation exchange hydrogels. Also, it was demonstrated that buformin–cation exchange complexes are pharmacodynamically active and induce a significant decrease of the glycemia.