Enteric coating

An enteric coating (also known as gastro-resistant drugs) is a polymer barrier applied on oral medication that prevents its dissolution or disintegration in the gastric environment. This helps by either protecting drugs from the acidity of the stomach, the stomach from the detrimental effects of the drug, or to release the drug after the stomach (usually in the upper tract of the intestine). Some drugs are, in fact, unstable at the acid gastric pH, and need to be protected from degradation. Enteric coating is also an effective method to obtain drug targeting. Other drugs such as some anthelmintics may, in fact, require to reach a high concentration in a specific district of the intestine. Enteric coating may also be used during studies as an useful research tool to determine drug absorption. Enteric coated medications pertain to the "delayed action" dosage form category. It should be noted that from a pharmacological point of view the term "enteric coating" is not entirely correct, as gastric resistance can be also obtained by adding enteric polymeric systems to the matrix of the dosage form. Tablets, mini-tablets, pellets and granules (usually filled into capsule shells) are the most common enteric-coated dosage forms.