Recent advances in colon drug delivery systems.

As a result of its ability to target certain drugs and/or peptides to the colonic region for the treatment of several diseases while avoiding systemic absorption and potential side effects, colon drug delivery has become a field of research of growing interest. Developing new pharmaceutical formulations capable of reaching the colon requires a broad knowledge of natural and synthetic/semisynthetic polymers. Chitosan, polyethylene-oxide, hydroxypropyl methylcellulose, pectin, natural gums, alginates and polymethacrylates have shown promise when applied in the development of colon drug delivery systems, which range from classic formulation strategies such as tablets and capsules to more sophisticated approaches like nanosystems and integrated osmotic-like formulations. This work aims to bring together knowledge regarding the materials and processes used in the development of such pharmaceutical formulations, as well as to highlight recent advances in the field.