in vitro controlled release of colon targeted mesalamine from compritol ato 888 based matrix tablets using factorial design

a controlled release matrix formulation for mesalamine was designed and developed to achieve a 24 h release profile. using compritol 888 ato (glyceryl behenate) as an inert matrix-forming agent to control the release of mesalamine, formulation granules containing the solid dispersions were investigated. pectin, a polysaccharide, was used as bacterial dependent polymer for colon targeting. the matrix tablets for these formulations were prepared by direct compression and their in vitro release tests were carried out. a 3 2 full factorial design was used for optimization by taking the amounts of glyceryl behenate (x 1 ) and pectin (x 2 ) as independent variables and percentage drug released at 2 (q 2 ), 16 (q 16 ) and 24 (q 24 ) h as dependent variables. drug release from the matrix tablets formulations lasted for over 24 h. images of the tablet surface and cross-section were characterized by scanning electron microscopy to show the formed pores and channels in the matrices. these may provide the release pathway for the inner embedded drugs. the co-mixing of polysaccharide pectin, into the waxy matrices played a meaningful role in targeting the tablets to colon. the drug release from the novel formulation may be attributed to the diffusion-controlled mechanism. the results of the full factorial design indicated that an optimum amount of compritol ato 888 and a high amount of pectin favors the colon targeting and controlled release of mesalamine from dosage form.