Novel drug delivery systems (NDDS) have recently gained importance for delivering a variety of therapeutic agents for both local and systemic administration. Delivery of drugs directly to targeted sites of action provides several advantages over non-specific delivery of drugs. Oral colon targeted drug delivery system is one of that NDDS which directly deliver a drug in to the colon for local treatment of a variety of colonic diseases as well as systemic absorption of proteins and peptides. The Metronidazole is the drug of choice in the treatment of the diseases like Amoebiasis, Giardiasis,...