Review article: evolutionary advances in the delivery of aminosalicylates for the treatment of ulcerative colitis

Ulcerative colitis is a chronic and debilitating disease that involves inflammation of the colonic mucosa. Current therapies aim to reduce the symptom burden of ulcerative colitis and maintain disease quiescence. The standard first-line treatment for mild-to-moderate ulcerative colitis is 5-aminosalicylate therapy, which is available in oral and rectal (topical) formulations. While current 5-aminosalicylate formulations are effective in the majority of patients, they are associated with a number of limitations including inconvenient dosing regimens and poor patient acceptability, which may lead to non-compliance with prescribed therapy. A variety of improved delivery mechanisms have been developed in an effort to overcome these limitations. Micropellet formulations and high-dose tablets appear to offer comparable efficacy and tolerability to conventional formulations, although any benefit in terms of long-term patient compliance remains to be proven. Novel methods of delivery, such as those using a combination of hydrophilic and lipophilic matrices, designed to provide once-daily dosing in a high-strength tablet, may offer a significant improvement in the therapy of active and quiescent ulcerative colitis. This review examines the limitations of current 5-aminosalicylate formulations and reports on the evolution of novel oral formulations designed to overcome these limitations, maximize patient compliance during both induction and maintenance of quiescence, and optimize overall clinical outcomes.