Abstract: A therapeutic preparation consisting of particles containing a therapeutically active material are coated with a disintegratable coating comprising zein and shellac. A first group of particles contains no coating or a coating subject to rapid disintegration upon ingestion to release an initial dose of therapeutic material and remaining groups of particles are coated with increasingly thicker coatings for delayed disintegration to release subsequent doses of therapeutic material. The coating composition may include disintegration modifiers so that thinner coatings of the zein-shellac coating material can be employed than would be required for zein shellac alone to obtain the delayed disintegration of the coating.