Dry Powder Coating in a Modified Wurster Apparatus

The results of dry coating of pharmaceutical materials (micro-particles), carried out in spout-fluid bed apparatus, designed by the authors are presented in the paper. The design has been developed starting from the Wurster conception device. The examination consisted of the determination of the optimal composition of coating mixture powder to plasticizer proportion, as well as the determination of basic process parameters (flow rates of individual streams). Resistance of coating on the conditions in gastrointestinal tract was chosen as optimization criterion. The purpose of the process is to defend an active substance placed in a core from the surroundings in the stomach. This active substance should be excellent dissolved only just in the small intestine (in case of an intestine medicine application).