Study of the preparation of a multiparticulate drug delivery system with a layering technique

The properties of a fully formulated enteric coating system were examined on a model multiparticulate formulation. Samples containing the model drug diltiazem hydrochloride were made in a fluid bed chamber with different amounts of Acryl-EZE, a ready-to-use coating dispersion. The effects of the film thickness on the dissolution profile were determined. While all samples yielded satisfactory release results in simulated intestinal fluid, the results in simulated gastric acid were worse than expected. The scanning electron microscopic images suggested that coating problems were not responsible for this behaviour.