An enteric coating is a specialized protective layer applied to oral medications, such as tablets or capsules. This barrier prevents the drug from dissolving prematurely in the stomach’s acidic environment, safeguarding active ingredients from degradation. The coating also helps prevent potential irritation to the stomach lining caused by certain medications. This ensures the medication reaches its intended destination in the digestive tract before releasing its contents.
The Purpose of Enteric Coatings
Enteric coatings serve distinct purposes, protecting both the medication and the patient. One key reason for their use is to shield sensitive active ingredients from stomach acid. Many drugs, including certain proteins, enzymes, or specific medications like omeprazole, would otherwise be degraded or rendered ineffective by the highly acidic conditions of the stomach, which has a pH around 1.
The coating also safeguards the stomach lining from irritating medications. Non-steroidal anti-inflammatory drugs (NSAIDs) like aspirin or ibuprofen are common examples; these can lead to ulcers or discomfort if released directly in the stomach. Enteric coatings help mitigate these gastrointestinal side effects by preventing drug release in the stomach. Furthermore, enteric coatings enable targeted drug release, ensuring the medication is delivered to the small intestine where it can be optimally absorbed or where its action is specifically required. This is crucial for drugs treating intestinal conditions or those absorbed best in a less acidic environment.
How Enteric Coatings Function
Enteric coatings function based on the varying pH levels in the digestive system. These coatings are designed to remain stable and insoluble in the highly acidic environment of the stomach. The stomach typically maintains a pH level between 1 and 3, which is very acidic. This low pH ensures the coating does not break down, allowing the medication to pass through the stomach unharmed.
As the coated medication leaves the stomach and enters the small intestine, the environment becomes less acidic and more alkaline. The pH in the small intestine ranges from approximately 6 to 9. This significant change in pH triggers the dissolution of the enteric coating. The materials used for these coatings are typically polymers that possess these pH-dependent solubility properties, dissolving rapidly once they encounter the higher pH of the small intestine. This controlled dissolution ensures the active ingredient is released precisely where it can be absorbed or exert its therapeutic effect.
Common Examples and Important Considerations
Many common medications and supplements utilize enteric coatings. Aspirin, especially low-dose formulations taken for cardiovascular health, often comes with an enteric coating to reduce stomach irritation. Certain proton pump inhibitors, such as omeprazole, are also enteric-coated because their active ingredients are sensitive to stomach acid and require release in the small intestine for proper absorption. Additionally, some dietary supplements like fish oil and probiotics are enteric-coated to prevent degradation in the stomach and minimize issues like a fishy aftertaste or ensure the survival of beneficial bacteria.
Never crush, chew, or break enteric-coated tablets. This compromises the coating, releasing medication prematurely in the stomach. This can destroy the drug, reduce effectiveness, or cause stomach irritation. Enteric-coated tablets often have a smooth, sometimes colored, outer layer, and their packaging may include “EC” or “EN” after the drug name, indicating the presence of this specialized coating.