JINZHOU YICHENG CELLULOSE CO.,LTD.
A coating is a covering that is applied to the surface of walls, usually referred to as the substrate. The purpose of applying the coating may be decorative, functional, or both. The coating adds an excellent property such as anti-spattering and sagging, thickening effect, etc.
In pharmaceutical drug delivery of solid oral dosage forms film coatings are frequently applied. The motivation for coating dosage forms range from cosmetic considerations (colour, gloss), improving the stability (light protection, moisture and gas barrier) and making it easier to swallow the tablet. In addition, functional coatings can be used to modify the drug release behaviour from the dosage form. Depending on the polymers used it is possible either delay the release of the drug (such as in enteric coatings) or use the coating to sustain the release of the drug from the dosage form over extended periods of time.
A film coating is a thin polymer-based coat applied to a solid dosage form such as a tablet. The thickness of such a coating is usually between 20-100 µm.It is possible to follow the dynamic curing effect on tablet coating structure by using non-destructive analytical methodologies.