Coating Systems Excipients

Coatings are added to tablets to help make large, difficult to swallow pills easier to take. They also prevent deterioration from water and moisture. Coatings can also allow for breakdown in a specific organ in the body. For example enteric coatings allows for breakdown in the small intestine, preventing breakdown in the acidic environment of the stomach. For many coated tablets, a cellulose ether hydroxypropyl methylcellulose (HPMC) film coating is used which is free of sugar and potential allergens. Other coating materials are also used, such as synthetic polymers, shellac, corn protein zein or other polysaccharides. Capsules are coated with gelatin.