Premature Release from Wurster Fluid Bed Enteric Coatings

The Wurster (bottom spray) fluid bed coating process provides an optimal means to apply enteric coatings on API or API containing particles. Nevertheless, dissolution profiles can exhibit undesired API release under acidic conditions. This paper explores raw material, formulation, process, and equipment design factors that potentially contribute to unexpected early API release from Wurster coated enteric particles.