Wurster Process

A technique, invented by Dale Wurster at the University of Wisconsin, for applying a coating onto particulate solids (typically 20 to 2,000 microns) in which the particles are moved in a circulating fashion using fluidizing air streams with differential velocities. The coating material is typically atomized onto the circulating particles and dried, cooled or cured to solidify the coating. The excellent drying capacity of the fluidizing air provides very rapid drying and heat transfer, minimizing potential interaction of the coating vehicle with the particles. Used for such applications as taste masking , moisture/oxygen-barriers, and oral delivery for controlled, delayed, sustained or enteric release.