Polymers for colon specific drug delivery

Azo-linked polymeric prodrugs of 5-aminosalicylic acid (5-ASA) were prepared and evaluated in simulated human intestinal microbial ecosystem. Release of 5-ASA was demonstrated. Polyamides containing azo groups in the backbone were prepared and tested in vitro in a reductive buffer or in the bioreactor medium. It was demonstrated that for the hydrophobic polymer reduction stops at the hydrazine stage whereas for a hydrophilic analogue reduction with formation of amines occurred.