What Defines an Enteric Coating?
An enteric coated tablet is a medication covered with a specialized layer designed to remain intact in the acidic environment of the stomach. This coating acts as a protective barrier, preventing the tablet from dissolving prematurely. The term “enteric” refers to the small intestine, indicating the intended release site for the medication.
The materials used for enteric coatings are typically polymers that are stable at low pH levels. These polymers are engineered to dissolve only when they encounter the less acidic conditions present in the small intestine. Common examples include cellulose derivatives and methacrylic acid copolymers, which ensure the tablet bypasses the stomach without releasing its contents.
Why Enteric Coatings Are Essential
Enteric coatings play an important role in drug delivery by serving several functions. One primary purpose is to protect certain medications from degradation by stomach acid. Many active pharmaceutical ingredients, such as some antibiotics like erythromycin, enzymes like pancrelipase, and proton pump inhibitors (e.g., omeprazole, pantoprazole), are sensitive to acid and would be rendered ineffective if released in the stomach. The coating ensures these drugs reach the small intestine intact for proper absorption and therapeutic effects.
Beyond protecting the drug, enteric coatings also shield the stomach lining from potentially irritating medications. Nonsteroidal anti-inflammatory drugs (NSAIDs) like aspirin and ibuprofen are known to cause stomach upset, nausea, and even ulcers or bleeding by irritating the stomach lining. By preventing these medications from dissolving in the stomach, the coating minimizes gastrointestinal side effects, allowing the drug to pass through and release its active ingredients in the small intestine, reducing direct contact with the stomach lining.
Enteric coatings facilitate targeted drug release, ensuring medications are delivered to the specific area of the digestive tract where they are most effective. The small intestine is the primary site for absorption of most oral drugs due to its higher pH and vast surface area. For instance, certain medications for inflammatory bowel disease, like budesonide, are coated to release specifically in the small intestine or colon to act locally on the inflamed tissue, optimizing drug absorption and maximizing their intended action.
Important Considerations for Taking Enteric Coated Tablets
Enteric coated tablets should never be crushed, chewed, or broken before swallowing. The integrity of the specialized coating is fundamental to the tablet’s intended function. Compromising this coating allows the medication to be exposed to the acidic environment of the stomach.
If the coating is damaged, acid-sensitive medications will degrade, leading to reduced effectiveness or complete inactivation of the drug. Additionally, drugs designed to protect the stomach lining will release prematurely, potentially causing irritation, nausea, or even ulcers. This premature release can also alter the drug’s absorption profile, leading to either sub-therapeutic levels or, in some cases, an increased risk of side effects if the entire dose is absorbed too quickly. Always swallow enteric coated tablets whole with water to ensure the coating remains intact and the medication works as intended.