Therapeutic applications of ion exchange resins

Abstract

Ion exchange resins (IER) are water insoluble, cross-linked, chemically inert and free from local and systemic side effects. Copolymers based on vinyl, divinyl benzene and polystyrene having extensive charged functional sites have extensive binding sites leading to very high drug-loading ability. The ability of IER to bind to drug helps in masking the bitter taste of drug, drug release, drug stabilization, etc. and has made it a popular choice with pharmaceutical companies. Some IER are used as disintegrants due to their rapid water uptake. It also helps in stabilization of drug which otherwise will deteriorate on storage. Thus, IER can be used to overcome various pharmaceutical problems. IER have also found applications in parenteral drug delivery, site-specific drug delivery, as gastric retentive systems. Site-specific drug delivery is important for cancer treatment. Chewing gums also act as mobile drug delivery system specifically for treating dental caries, smoking cessation, etc. These versatile applications of IER are being used for various therapeutic applications such as neutralizing the gastric juices (hyperacidity) in treatment of gastric ulcer, Na and K supplement/depletion in oedema of cardiac, hepatic, pancreatic and nephritic origin, i.e. in a condition of Na and water retention of cardiac failure, hepatic diseases (cirrhosis of liver), pancreatic, toxaemia of pregnancy and nephritic origin. Cation-exchange resins (CER) have been used to reduce phosphate in renal end-stage disease, also as adjuvant in the treatment of hyperkalaemia associated with oliguria/anuria secondary to ARF. Anion-exchange resins (AER) have also been used in treatment of hyperglycaemia, treatment of high cholesterol level, drug-binding defects in uraemia, to reduce penicillin G binding.