Formulation and Evaluation of Anti-Inflammatory Drug Microspheres for Colon Targeted Drug Delivery

The purpose of this investigation is to prepare and evaluate colon specific microspheres of indomethacin for the treatment of colorectal cancer. sodium alginate microspheres are prepared by ionotropic gelation method using different ratios of indomethacin and sodium alginate (1:1, 1:2, 1:3, 1:4, 2:1, 2:3 & 4:1). Eudragit S-100 coating of indomethacin and sodium alginate microspheres are performed by coacervation phase separation technique. The microspheres were characterized by shape, particle size, size distribution. Entrapment efficiency, invitro drug release and stability studies. The outer surface of core and coated microspheres , which was spherical in shape, were rough and smooth respectively. The size of the core microspheres ranged from 20 -50 µm and the size of the coated microspheres ranged from 107 – 124 µm. The core microspheres sustained the release for 10 hrs in a pH progression medium mimicking the condition of GIT. The release studies of coated microspheres were performed in a similar dissolution medium as mentioned above. In acidic medium the release rate was much slower, however the drug was released quickly at pH 7.4 and their release was sustained upto 24 hrs. It is concluded from the present investigation that Eudragit coated sodium alginate microspheres are promising controlled release carriers for colon targeted delivery of indomethacin.