What is Enteric Coating? Benefits and How It Works

Enteric coating is an acid-resistant layer applied to tablets, capsules, or pills to prevent them from dissolving in the stomach. Its primary function is to protect sensitive active ingredients from the low pH environment of the stomach and to delay release until the dosage form reaches the small intestine, where the pH is higher and absorption often occurs.

Common polymers used for enteric coatings include cellulose acetate phthalate and methacrylic acid copolymers. These materials remain intact at acidic pH values (typically pH 1–3 in the stomach) and begin to dissolve when exposed to a higher pH (about pH 5.5–7 in the small intestine). The coating therefore provides a targeted, delayed-release mechanism without changing the core formulation of the supplement.

The digestive tract varies in acidity along its length: the stomach is highly acidic to aid digestion and defend against pathogens, while the small intestine becomes progressively less acidic. Enteric coatings exploit this pH gradient to protect ingredients that are acid-labile (easily degraded by acid) or that may cause gastric irritation if released in the stomach.

• Protection from stomach acid: Ingredients such as certain probiotics, enzymes, and some antioxidants can lose activity when exposed to gastric acid. An acid-resistant coating helps preserve potency until the active component reaches a more favourable environment.

• Improved absorption: Many nutrients and biologics are absorbed primarily in the small intestine. Delaying release until intestinal transit can increase the amount of active compound available for absorption, thereby improving bioavailability.

• Reduced gastric irritation: Some compounds can irritate gastric mucosa. Delivering these ingredients distal to the stomach can mitigate discomfort for sensitive individuals.

These advantages are consistent with basic pharmaceutical principles of enteric and delayed-release dosage forms. The degree of benefit depends on coating quality and the physicochemical properties of the active ingredient.

Not all coatings are enteric. Standard film coatings may mask taste, ease swallowing, or protect against moisture and handling; they generally dissolve in the stomach. Enteric coatings are specifically selected and tested to resist gastric pH and to dissolve at intestinal pH, so the two serve distinct functional purposes.

Supplements commonly formulated with enteric coatings include some probiotics, fish oil preparations that aim to reduce gastric reflux, and acid-labile vitamins such as certain formulations of vitamin B12.

Quality of manufacturing and proof of coating performance matter. Look for products with stability data or dissolution testing that demonstrate resistance to low pH and reliable release at intestinal pH. Independent certification and transparent manufacturing information are useful indicators; for broader context see Discover the Benefits of Dr Mercola Supplements and Understanding Supplement Certifications and Why They Matter. For an overview of formulation and benefits, consult this enteric coating guide or the related resource at detailed enteric coating resource. An additional entry point for supplier information is Topvitamine.

Enteric coating is a targeted pharmaceutical strategy to protect sensitive ingredients and to control site-specific release. When properly formulated and tested, it can preserve potency, enhance absorption, and reduce gastric irritation. Evaluating coating performance and manufacturing transparency helps ensure the expected benefits are realized.