Box-Behnken experimental design in the development of pectin-compritol ATO 888 compression coated colon targeted drug delivery of mesalamine
The aim of this study was to investigate the combined influence of 3 independent variables in the compression coated tablet of mesalamine for ulcerative colitis. A 3-factor, 3-level Box-Behnken design was used to derive a second order polynomial equation and construct contour plots to predict responses. The independent variables selected were: percentage of polymers (pectin and compritol ATO 888) in compression coating (X 1), coating mass (X 2) and coating force (X 3). Fifteen batches were prepared and evaluated for percent of drug released in 5 h (Y 5), time required for 50 % mesalamine to dissolve (t 50) with rat cecal (RC) content and without rat cecal content (t 50), percent of drug released in 24 h in the presence of rat cecal content (Y 24 with RC). Transformed values of independent and dependent variables were subjected to multiple regressions to establish a full-model second-order polynomial equation. F was calculated to confirm the omission of insignificant terms from the full-model equation. The computer optimization process and contour plots predicted the levels of independent variables X 1, X 2, and X 3 (0, 0.2 and -0.15, respectively) for colon targeting and total percent of drug released up to 24 h.