Multiparticulate formulation approach to colon specific drug delivery: Current perspectives

Colon specific drug delivery has gained increased importance not just for the delivery of drugs for the treatment of local diseases associated with the colon but also as potential site for the systemic delivery of therapeutic peptide and proteins. To achieve successful colon targeted drug delivery, a drug needs to be protected from degradation, release and/or absorption in the upper portion of the GI tract and then ensure abrupt or controlled release in the proximal colon. Drug modifications through covalent linkages with carrier or prodrug approach and formulation based approaches can be used for colonic delivery. Report suggests that drug carrier systems larger than 200 mu m possess very low gastric transit time due to physiological condition of the bowel in colitis. And for this reason and considering the selective uptake of micron or sub-micron particles by cancerous and inflamed cells/tissues a multiparticulate approach based on pellets, granules, microsphere or nanoparticle type formulation is expected to have better pharmacological effect in the colon. The review is aimed at understanding recent advancements made in multiparticulate formulation approach for colon specific delivery of medicaments.