Mathematical model for enteric film coating of tablets.

The enteric film coating of placebo tablets, using a methacrylic acid-methyl methacrylate copolymer as the film former in the coating solution, was studied by statistical techniques. The effects of four independent formulation and process variables on the disintegration time of the coated film in simulated intestinal fluid and on the resistance to disintegration of the coated film in simulated gastric fluid were studied. The results of a statistically designed set of experiments were used as the input data. Regression analysis of these data resulted in two first-order polynomial equations. The linear model obtained for the disintegration time of the coating in the simulated intestinal fluid was analyzed by the steepest descent method to determine the most suitable combination of the independent variables.