Colonic targeting of aminosalicylates for the treatment of ulcerative colitis

Dig Liver Dis. 2005 Jun;37(6):381-8. doi: 10.1016/j.dld.2004.12.011. Epub 2005 Mar 2.


Aminosalicylates (5-aminosalicylic acid) represent drugs of first choice in the treatment of ulcerative colitis. Two different therapeutic approaches have been employed to target the active 5-aminosalicylic acid to its site of action. Either inactive azo-prodrugs (e.g. sulfasalazine, olsalazine, balsalazide) or special galenic formulations have been developed for topical delivery of 5-aminosalicylic acid to the colon. However, as intestinal physiology, the extent of ulcerative colitis as well as drug disposition demonstrate large interindividual differences, acute healing rates (40-80%) and the maintenance of remission are quite variable. Apparently, therapeutic effects depend on local concentrations of 5-aminosalicylic acid in the colonic mucosa whereas systemic drug exposure might be one determinant of side effects. In general, 5-aminosalicylic acid is well tolerated and withdrawal from therapy is rare. Following administration of azo-prodrugs (e.g. olsalazine), lower plasma concentrations and higher delivery into the colon of 5-aminosalicylic acid can be observed in comparison to special galenic formulations of 5-aminosalicylic acid. Whether such changes in drug disposition will affect therapeutic efficacy remains to be proved by clinical data. Consequently, selection of a particular agent should be based primarily on clinical efficacy, profile of adverse effects, patients' acceptance and economic considerations.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Administration, Oral
  • Administration, Rectal
  • Aminosalicylic Acids / administration & dosage*
  • Aminosalicylic Acids / pharmacokinetics
  • Anti-Inflammatory Agents, Non-Steroidal / administration & dosage*
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacokinetics
  • Colitis, Ulcerative / drug therapy*
  • Colitis, Ulcerative / physiopathology
  • Drug Delivery Systems
  • Humans
  • Intestines / physiology
  • Molecular Structure
  • Prodrugs / administration & dosage
  • Prodrugs / pharmacokinetics


  • Aminosalicylic Acids
  • Anti-Inflammatory Agents, Non-Steroidal
  • Prodrugs