ABSTRACT
Film coating is a process that involves the deposition of a membrane-consisting of polymer, plasticizer, colorant, and possibly other additives-onto the surface of a pharmaceutical dosage form, typically a tablet or a granule. Compared to the conventional sugar coat, the film coat is relatively thin, i.e., typically 10 to 100 μm. Although the technology involved in the application of such a thin coating to a substance is not new, having precedents in both the paints and adhesive technologies, problems do occur, resulting in a number of film defects. These can either affect the visual appearance of the coated tablet or, more importantly, result in the loss of continuity of the film and thus affect the release of the active ingredient from the preparation. Over the past two decades, with the increasing use of aqueous film coating, the number of defects reported has increased dramatically.
