Inflammatory bowel disease: pathogenesis, causative factors, issues, drug treatment strategies, and delivery approaches

Inflammatory bowel disease (IBD) is an incessant, reverting, inflammatory disorder of the gastrointestinal tract encompassing two entities, namely, Crohn's disease (CD) and ulcerative colitis (UC). Numerous protocols have been explored to treat these dreadful diseases, including the use of different IBD drugs with different modes of action and routes of administration. Constant progression in the development of newer formulations, chemical modifications, stimuli-responsive systems, and novel approaches using colloidal and cellular carriers have led to effective treatments of gastric inflammation. Colloidal carriers including vesicular and particulate systems such as liposomes, transferosomes, solid lipid nanoparticles, microspheres; cellular carriers including erythrocytes, macrophages, and recombinant bacteria; and other systems such as osmotic pressure and plug control release have gained unique positions as drug carriers. Here, we investigate IBD in terms of its pathogenesis, role of genetic factors, currently available treatment options and their modes of action, pharmacokinetics, marketed products, side effects of individual IBD drugs, recent developments, modifications in the delivery of various drugs through novel colloidal drug carriers, and future prospects.