Carrier systems for the treatment of inflammatory bowel disease

This article reviews a number of drug carrier systems in use clinically or under development for the treatment of inflammatory bowel disease (IBD). The advantages and disadvantages of the various methods for delivering drugs to the inflamed colon are discussed, including physiological and pathophysiological problems. Local delivery of drugs to the colon was developed to improve efficacy and minimize side effect. Particularly, efforts have focused on developments for oral administration in order to adapt the carriers to the physiological requirements which would further increase the therapeutic efficacy and improve patient compliance. These conditions include variations in local pH, transit throughout the gastrointestinal tract, the potential role of gut microflora and drug dissolution in both the healthy and diseased large intestine. Effective and selective delivery of an otherwise nonspecifically acting drug could provide new therapeutic options in the treatment of IBD. New strategies for such treatments are also presented, including liposomal formulations, nanoparticles, bacterial cytokine expression and viral gene therapy.