What are Enteric Coated Tablets?

Enteric‑coated tablets are oral dosage forms coated with a pH dependent polymer barrier designed to withstand stomach acid and only dissolve once they reach the small intestine. Enteric coating protects the API (Active Pharmaceutical Ingredient) if it is sensitive to acidic environments and safeguards the stomach if the API can cause irritation or damage.

The global enteric coating market size was valued at $1.1 billion in 2024, and is forecasted to hit $2.3 billion by 2033, growing at a robust CAGR of 2% (source).

Common medications coated with enteric coatings include proton pump inhibitors, non-steroidal anti‑inflammatory drugs (NSAIDs), antibiotics and dietary supplements.

Key Takeaways

• Enteric‑coated tablets are designed with a pH‑dependent polymer barrier that protects APIs from stomach acid (low pH) and allows them to dissolve only once they reach the small intestine (higher pH).
• Enteric coatings help reduce gastric irritation, especially for drugs like aspirin and NSAIDs that can otherwise cause stomach discomfort.
• Enteric coatings enable targeted drug release in the intestine, improving absorption and effectiveness for acid‑sensitive or irritation‑prone medications.
• Beyond protection and release control, enteric coatings also offer taste and odor masking - reducing issues like “fishy burps” from certain supplements.
• Learn Top Tips for formulators and manufacturers of enteric products.

How Do Enteric Coated Tablets Work

Enteric coatings are polymer-based films applied to the surface of a tablet, soft gel or multiparticulate. Unlike immediate-release or aesthetic film coatings, these specialized polymers are pH‑responsive, meaning they remain intact under acidic conditions and dissolve only when they reach a higher pH environment. Read more about the film coating process.

How the Coating Interacts with Stomach Acid

Enteric coatings prevent the tablet from dissolving in the stomach by resisting the acidic pH (typically 1–3.5). As the dosage form enters the duodenum, where pH rises above 4–6.4, the coating dissolves — triggering drug release. Once the enteric coating dissolves in the small intestine, the exposed tablet core rapidly disintegrates, releasing the API for absorption.

Purpose and Benefits of Enteric Coating

Protecting Active Ingredients from Stomach Acid

Many APIs are unstable in the acidic environment of the stomach or can irritate the gastric lining. Enteric coatings prevent premature dissolution, ensuring the API reaches the small intestine intact. A common example of an API that can irritate the stomach is aspirin. Up to 27% of people report stomach irritation; enteric‑coated versions significantly reduce this risk (source). By shielding the tablet, enteric coatings support both safety and therapeutic reliability, especially for drugs known to cause gastric distress.

Targeted Drug Release

Drug release refers to the moment and location within the gastrointestinal tract where the API becomes available for absorption. Enteric coatings delay this release until the tablet reaches a higher‑pH environment — typically the small intestine. This targeted release ensures that the API reaches the optimal site for absorption and gastric side effects are significantly reduced

Improving Efficacy

By controlling where and when dissolution occurs, enteric coatings can enhance therapeutic performance. This is particularly true for medications that:

• Are degraded by stomach acid
• Require localized delivery to the intestine
• Benefit from improved bioavailability with delayed release

Taste Masking to Reduce Unpleasant Odors and “Smelly Burps”

Beyond protecting sensitive ingredients and improving targeted release, enteric coatings provide a valuable taste‑ and odor‑masking benefit — especially important for nutritional supplements known for reflux‑related aftertaste.

Certain oils, including garlic, fish oil, and other herbal extracts, can cause regurgitation after ingestion, leading to the familiar “fishy burps” or strong garlic after‑odor that many consumers find off‑putting.

Pros and Cons of Enteric Coated Tablets

Common Uses and Medications with Enteric Coating

Many commonly used APIs rely on enteric coatings for safe and effective delivery, including:

• Aspirin (enteric-coated aspirin) – Helps reduce stomach irritation and lowers the risk of gastric ulcers in long-term use.
• Diclofenac – A nonsteroidal anti-inflammatory drug (NSAID) that can irritate the stomach.
• Delayed-release antibiotics – Certain antibiotics use enteric coatings to improve stability and absorption in the intestine.
• Omeprazole – A proton pump inhibitor (PPI) that requires protection from stomach acid to ensure proper intestinal absorption. Over 50% of prescription proton pump inhibitors are enteric coated for optimal release and effectiveness. (Source)
  

Medical Conditions That Commonly Require Enteric-Coated Tablets

Enteric-coated formulations are often prescribed for conditions where stomach protection or targeted intestinal release is essential, such as:

• Gastroesophageal reflux disease (GERD) – PPIs and acid-reducing drugs benefit from delayed intestinal release
• Peptic ulcer disease – Minimizes further irritation to the stomach lining
• Chronic pain or inflammation – Long-term NSAID therapy often uses enteric-coated tablets to reduce gastric damage
• Inflammatory bowel conditions – Some medications are designed to act locally in the intestine
• Pancreatic enzyme deficiencies – Enzymes must survive stomach acid to be effective in digestion
  

Enteric Coating vs. Other Coating Types

Pharmaceutical coatings serve different functional purposes depending on the formulation needs of the API. Understanding their differences helps formulators choose the right coating to achieve optimal protection, release behavior, and patient experience.

Key Formulation Differences

Film Coatings

Film coatings area thin polymeric film applied over the tablet or capsule to enhance swallowability, protect from moisture or light, and optionally control release. They dissolve in the stomach unless designed otherwise. They may release immediately or over a prolonged period (controlled release). All film coatings contain polymers, plasticizers as a minimum.

Enteric Coatings

Enteric coatings are a type of film coating that uses pH‑responsive polymers that only dissolve in the higher‑pH environment of the small intestine. Common polymers include polyvinyl acetate phthalate (PVAP), methacrylic acid copolymers, and hypromellose phthalate. These systems often include plasticizers, alkalizing agents, detackifiers and pigment blends.

Sugar Coatings

Sugar coating involves building multiple layers of sucrose syrups, colorants, and wax polishes. This method significantly increases tablet size and weight but provides excellent taste‑masking and a glossy finish.

Comparison of Effectiveness, Safety & Cost

Effectiveness

Enteric, film, and sugar coatings each offer different levels of effectiveness depending on the needs of the formulation.

Enteric coatings ensure delayed release for acid‑sensitive APIs and for medications that may irritate the stomach, helping maintain drug stability by preventing exposure to gastric acid.

Film coatings, on the other hand, are best suited for immediate‑release or modified‑release products that do not require gastric protection, while also enhancing patient compliance and aesthetics.

Sugar coatings (this statement isn’t true since there are some OTC products (like diclofenac) that are enteric coated and sugar coated), and their lengthy, multi‑layered processing results in bulkier tablets.

Safety

Enteric coatings help reduce the risk of gastric irritation from APIs such as NSAIDs while also preventing the degradation of acid‑labile APIs, making them especially valuable for medications that require protection from stomach acidity.

Film coatings provide a protective barrier against moisture and light and are generally safe, widely used, and patient‑friendly, though they do not offer any protection from stomach acid.

Sugar coatings are also considered safe but result in larger, bulkier tablets that may be harder for some patients to swallow, and their multi‑step manufacturing process increases handling time and introduces potential process variability.

Cost Considerations

Enteric coatings tend to be more expensive because they rely on specialized polymers and require precise application controls, and in some cases the use of organic solvent–based systems which can further increase capital costs due to the need for explosion‑proof equipment and enhanced safety measures.

Film coatings are typically the most cost‑effective option, offering fast application with lower material and processing costs compared to both enteric and sugar coatings.

Sugar coatings are the most labor‑intensive and time‑consuming, making them the costliest in terms of processing time; although automation can help reduce labor demands, the multi‑stage nature of sugar coating still significantly prolongs production.

Situations Where Each Type May Be Preferred

Enteric coatings are most suitable when the API is acid‑labile or loses potency in gastric acid, when the drug—such as NSAIDs or certain enzymes—may irritate the stomach, or when targeted intestinal release is required, as in the case of antibiotics or probiotics.

Film coatings are chosen when the priority is to improve swallowability, taste, or visual appeal, and when only basic protection from moisture or light is needed without the necessity for gastric protection, making them ideal for immediate‑release products.

Sugar coatings are preferred when strong taste masking is essential, or when a distinctive, visually appealing appearance supports brand identity, provided that the increased tablet size and longer processing time are acceptable trade‑offs.

Enteric Coated vs. Other Coatings

How to Take Enteric Coated Tablets

Taking enteric-coated tablets correctly is essential to ensure the medication works as intended. Because these tablets are designed to dissolve in the intestine rather than the stomach, improper use can reduce effectiveness and increase the risk of side effects.

Dos and Don’ts When Taking Enteric-Coated Tablets

To protect the enteric coating and ensure proper drug release, keep the following guidelines in mind:

Do

• Swallow the tablet whole with a full glass of water
• Follow the prescribed or labeled dosing instructions carefully
• Take the medication consistently at the same time each day, if recommended
  

Don’t

• • Do not crush, split, or chew enteric-coated tablets
  • Do not open or dissolve the tablet before swallowing
  • Do not take damaged or cracked tablets, as the coating may no longer be effective
  • Breaking or chewing an enteric-coated tablet can destroy the protective layer, causing the API to release too early in the stomach and potentially leading to irritation or reduced absorption.  A survey found that 18% of patients incorrectly split or chewed enteric-coated tablets, reducing their effectiveness. (Source)

Food and Timing Considerations

• • Food and timing can influence how enteric-coated tablets move through the stomach and reach the intestine:
  • Some enteric-coated medications work best when taken before meals, while others are recommended after food—always follow product or prescriber instructions
  • Taking the tablet with water helps it pass quickly through the stomach
  • Avoid taking enteric-coated tablets with antacids unless advised, as changes in stomach pH may affect dissolution timing
  • Delayed-release medications may take longer to provide relief compared to immediate-release forms
  • Understanding these factors helps maximize therapeutic benefit while minimizing stomach discomfort.

Side Effects and Precautions

While enteric-coated tablets are designed to improve tolerability and protect the stomach, they may still cause side effects in some individuals. Understanding potential risks helps ensure safe and effective use.

Common Side Effects

Most side effects associated with enteric-coated tablets are mild and depend on the specific medication. Commonly reported effects include:

• Nausea or upset stomach
• Abdominal pain or cramping
• Bloating or gas
• Diarrhea or constipation
• Headache (medication-dependent)

Because enteric-coated tablets delay drug release, some users may also notice a slower onset of symptom relief compared to immediate-release formulations.

Allergic Reactions to Coating Agents

In rare cases, individuals may experience allergic reactions to the materials used in enteric coatings rather than the medication itself. These coating agents may include polymers, plasticizers, or colorants.

Possible signs of an allergic reaction include:

• Skin rash or itching
• Swelling of the lips, tongue, or throat
• Difficulty breathing
• Dizziness or fainting

Anyone experiencing symptoms of a severe allergic reaction should seek immediate medical attention.

Who Should Avoid Enteric-Coated Tablets

Enteric-coated tablets may not be appropriate for everyone. Certain medical conditions or situations can interfere with how these tablets dissolve and absorb.

Individuals who may need to avoid or use caution with enteric-coated tablets include:

• People with delayed gastric emptying (gastroparesis)
• Patients with short bowel syndrome or altered intestinal anatomy
• Individuals with severe diarrhea, which may reduce drug absorption
• Patients who require rapid symptom relief
• Anyone with known hypersensitivity to coating ingredients

Healthcare providers may recommend alternative formulations, such as liquid, immediate-release, or non-coated tablets, depending on individual needs.

Enteric Coating – Top Tips for Formulators and Manufacturers

	Partner with our technical experts Leverage the experience of our technical team, who have supported the development of enteric dosage forms across a wide range of actives and processing conditions. We offer both aqueous and organic enteric coating options to suit your project needs.
	Accelerate development with Hyperstart C2C Use Hyperstart C2C on MyColorcon—our self‑serve digital platform—to quickly identify starting formulations tailored to your specific requirements, reducing development time and improving efficiency.
	Start with a robust tablet core A strong, low‑friability core is essential for successful enteric coating performance. The tablet force should be considered to ensure that the tablet is strong enough to withstand the coating process. The use of hygroscopic materials should be minimized, including super‑disintegrants. Starch 1500 is an effective alternative that can help improve core strength and reduce variability.
	Avoid sharp edges and complex tablet designs Although embossed tablets can be enteric coated successfully, they introduce additional complexity. Enteric films must be applied as a continuous, uniform layer, and any thinner regions - such as around embossing, can compromise enteric protection. Where possible, choose simple shapes with rounded edges to support even coverage of the enteric film coating.
	Consider a seal coat for added protection If edge erosion is a concern, applying an immediate‑release seal coat can help smooth the tablet surface and protect vulnerable edges, improving overall coating robustness.
	Optimize the coating process Control key parameters such as spray rate, temperature, and airflow to ensure a uniform, defect‑free coating. Monitor coating‑solution viscosity throughout application to maintain consistency.
	Validate the analytical method Verify dissolution media preparation, including correct reagent, pH, and buffer capacity—as inadequate buffering in the intestinal stage can skew results. Remove air bubbles from the medium to prevent test interference. If compendial methods lack physiological relevance, consider biorelevant, bicarbonate‑based dissolution media when in vivo performance is a concern.
	Consider storage conditions High humidity and improper storage temperatures can cause the enteric coating to crack or agglomerate over time, compromising its integrity and leading to failure during stability testing. Use suitable packaging (e.g., blister packs or bottles with desiccants) and store products in controlled environments.

Conclusion

Enteric‑coated tablets play a critical role in ensuring medications reach the small intestine intact, improving both safety and therapeutic effectiveness. By protecting APIs from harsh gastric conditions and enabling targeted release, they enhance absorption, reduce side effects, and support better patient outcomes. While they offer valuable benefits—from gastric protection to taste and odor masking—they must be taken correctly to preserve coating integrity and maintain predictable drug performance.

For formulators and manufacturers, enteric coatings remain essential tools for optimizing drug delivery, especially when stability, tolerability, and controlled release are top priorities.

Frequently Asked Questions

• Which polymers are best for enteric protection?
  There are several polymers or fully formulated coatings available for enteric protection, including PVAP, Acryl-EZE, and Opadry Enteric. Selection will depend on the API properties, targeted release site and regulatory status for your target markets. Colorcon can assist in choosing the right enteric film coating.

• How much coating weight gain is required to ensure enteric protection?
  The amount of coating that needs to be applied will depend on the polymer chosen. As a minimum 6% weight gain is recommended.
  
  
• How can I ensure the coating does not degrade during storage?
  To maintain coating stability throughout storage, conduct appropriate stability testing to confirm long‑term quality and efficacy. Protective packaging and/or moisture‑control solutions such as desiccants (e.g., DryGuard) may also be required.
  
  
• Some of my enteric coated tablets are failing dissolution testing. What can I do to fix this problem?
  If your enteric‑coated tablets are failing dissolution testing, the issue is often related to coating uniformity, core strength, or test‑method setup. Reviewing and optimizing these factors can quickly resolve most failures. For detailed guidance, refer back to the Top Tips for Formulators and Manufacturers section in this article or contact Colorcon for advice.
  
  
• Can I crush an enteric coated tablet?
  You should never crush an enteric coated tablet because it destroys the protective coating, allowing the drug to dissolve when it enters the stomach. This may cause irritation to the stomach or result in the drug not working.