Colon specific delivery of fucoidan by incorporation of acidifier in enteric coating polymer

The aim of the study was to design a colon drug delivery system for fucoidan, a recently discovered material from ocean, useful in treatment of human colon cancer cells. Initial core tablets using polyethylene oxide (PEO) as a matrix former were prepared, and then, were coated with a coating formulation based on Kollicoat MAE 100P, a film former used in the pharmaceutical industry for the production of enteric coatings for solid dosage forms. Citric acid was incorporated into the above polymer coating formulation with a notice that the amount of citric acid was very crucial in preparation of the coating formulation. Interestingly, the drug release profile of coated tablets with citric acid showed sustained drug release behaviors over 15 h, expressing a promising colon specific drug delivery system; whereas, the coated tablets without citric acid showed the conventional drug release rate of an enteric film coated dosage form. In order to elucidate the effects of citric acid on the drug release rate, swelling and erosion studies, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy were conducted.