Abstract
Particle coating is one of the oldest pharmaceutical processes that is still in existence. It is the process of applying a thin polymer-based film to a particle or granule containing the active pharmaceutical ingredient. The widely used methods for particle coating are sugar coating, film coating, and enteric coating and the techniques are pan coating, fluidized bed coating, and compression coating. Sugar coating was the earlier coating method, and it was gradually replaced by film coating because it required skilled manipulation. With the technology developing, enteric coating draws more attention. Pan coating is the most classic coating technique, which is applied to sugar coating, film coating and enteric coating. Fluid bed coating is used for a mixture of multiple materials and medicines and keeps the bioavailability high. Compression coating can avoid the harmful effects of moisture and high temperature, while it requires highly accurate machinery.