AR-CAPS® vs K-CAPS®: Key and uses cases | CapsCanada

The human gastrointestinal tract is a complex, dynamic system with varying pH levels that presents unique challenges to drug and supplement delivery. Formulators seeking to preserve the efficacy of acid-sensitive ingredients or to target release in specific regions of the gut often turn to two advanced technologies: acid-resistant capsules and delayed-release capsules. While sometimes confused, these systems serve distinct functional purposes. Understanding their differences is key to optimizing product performance, therapeutic impact, and consumer outcomes.

Let’s explore the complexities of these capsule technologies, highlighting their distinct functionalities and applications. 

Acid-Resistant Capsules: Protection Through the Stomach

Acid-resistant capsules are engineered to resist the low pH of gastric fluid, preserving ingredient integrity until the capsule reaches the small intestine. CapsCanada’s AR-CAPS® exemplifies this category. Made from hypromellose and proprietary polymers, AR-CAPS® creates a robust physical barrier that prevents premature release and degradation in the stomach.

Key Applications:

• Pharmaceuticals 
• NSAIDs and antibiotics: Reducing gastric irritation and preserving compound stability.

Functional Benefits:

• Resistant to gastric acids without requiring coatings.
• Low moisture content for sensitive ingredients.
• Stable across varying temperature and humidity conditions.
• Excellent compatibility with high-speed capsule-filling machines.
  
  

Delayed-Release Capsules: for Probiotics and Nutraceuticals 

K-CAPS Delayed-release capsules are designed to release enzymes and probiotic ingredients at the right place in the digestive tract. CapsCanada’s K-CAPS® Delayed-Release, made from plant-derived HPMC, is formulated to release its contents specifically in the lower intestines, where targeted absorption or local action is required.

Key Applications:

• Nutraceuticals
• Prebiotics and enzymes: Ensuring stability and activity beyond the stomach
• Gut health ingredients

Functional Benefits:

• pH-sensitive 
• No coating required, streamlining production.
• Cristal clear appearance 
• Kosher, Halal, and non-GMO.
• Enhanced bioavailability and minimized gastric irritation.
• Supports clean label positioning by offering transparency, made from HPMC, and formulations free from additives and synthetic excipients.

Industry Alignment: Pharmaceutical vs. Nutraceutical  Formulations

While both technologies support precise ingredient delivery, their adoption varies by application:

• AR-CAPS® are widely used in pharmaceutical formulations, where acid resistance is critical for drug stability. Their physical barrier function, combined with low moisture content and regulatory compliance, makes them well-suited for clinical development and commercial therapies. AR-CAPS® contain Phthalates. 
  
  
• K-CAPS® Delayed-Release are preferred in nutraceutical applications, aligning with the evolving expectations of health-conscious consumers and supplement brands.

Selecting the Right Capsule Based on Formulation Strategy

Whether you're working with probiotics, moisture-sensitive actives, or compounds targeting microbiota activity, capsule selection should align with your product’s delivery strategy and brand objectives. CapsCanada equips you with both options for both nutraceuticals and pharmaceutical formulations. Why Formulators Choose CapsCanada

CapsCanada offers a robust portfolio of empty capsule solutions backed by regulatory compliance, reliable global distribution, and technical support. Whether your goal is to protect acid-sensitive ingredients or to deliver compounds with precision, our AR-CAPS® and K-CAPS® Delayed-Release capsules provide performance, flexibility, and peace of mind.

• Manufactured in the Americas.
• Wide compatibility with capsule-filling machinery.

Precision Delivery Starts with the Right Capsule

Choosing the appropriate capsule technology is a strategic move to maximize therapeutic outcomes and consumer trust. With AR-CAPS®, you ensure survival through the stomach, making them ideal for pharmaceutical applications where regulatory frameworks may permit the use of phthalates for functional performance. In contrast,  K-CAPS® Delayed-Release are designed for nutraceutical formulations that demand clean label compliance, plant-based materials, and phthalate-free composition. Both are engineered to meet the evolving needs of health brands looking to deliver high-quality products with consistent performance.