Creative Hard Capsule Technologies Enhance Efficacy

Consumers seek dietary supplements to maintain good health and promote fitness. They are increasingly gravitating toward supplements that address digestive health, active nutrition/sports nutrition and healthy aging. Among ingredients, nutritional oils are gaining interest.

The right dosage delivery form can give a product an edge with consumers. Today, three qualities are paramount: convenience, effectiveness and clean label, as driven by the healthy lifestyle market.

Hard capsules—made of gelatin, vegetarian or fish polymers—meet all check points, though enhancing effectiveness can be the most challenging to achieve. Fortunately, hard capsules present enough creative technology choices. They can bolster stability through moisture protection, enhance and preserve bioavailability, and offer timed or targeted release of ingredients for maximum effect.

Unique hard capsule technologies can address the primary delivery challenges of key ingredients in the four platforms on the rise.

Digestive Health

Sales for probiotic supplements are expected to remain robust. Currently, 15 percent of supplement users take them, up from 1 percent in 2005, according to the Natural Marketing Institute (NMI). Data from Euromonitor International revealed sales of digestive enzymes and prebiotics are expected to grow as well.

Probiotics can be harmed by moisture exposure in packaging before consumption. Both probiotics and some enzymes also can be damaged by stomach acids before they reach the intestines where they work best.

Vegetarian capsules made from hydroxypropyl methylcellulose (HPMC) can offer moisture protection because they are low in moisture content (4 to 6 percent moisture at 50 percent relative humidity compared to 12 to 14 percent for gelatin).

A unique HPMC capsule with acid-resistant polymer properties can delay the capsule’s opening in the stomach’s acidic environment. An unpublished independent in vivo gamma scintigraphy study showed the capsules begin to release in a mean time of 52 minutes after ingestion and when they were about to leave the stomach. The study was completed in 2013 by Bio-Images Research, Glasgow, Scotland.

A capsule-in-a capsule HPMC technology works well for a prebiotic-probiotic supplement. The inner capsule contains a probiotic, which is suspended in a solubilized prebiotic formula that is released first when the outer capsule dissolves and helps feed the growth for the probiotic. The inner capsule with the probiotic culture dissolves later, helping to improve its ability to reach the intestinal tract. The capsule-in-a capsule system provides an excellent moisture barrier for the inner capsule.

Active Nutrition/Sports Nutrition

The flourishing sports nutrition market is expected to catapult further as mainstream consumers flood in. A wider range of supplements are now being adopted by a market reaching beyond niche elite athletes to pull in weekend warriors, fitness enthusiasts and the over-55 who want to keep moving as long as possible.

Die-hard competitors will continue to covet ingredients such as L-carnitine, ubiquinol, L-arginine, general amino acids and creatine to aid performance and recovery. The active nutrition segment will more likely warm to supplements that can address weight control, metabolism, digestion, energy, sleep and cardiovascular health.

Low-moisture HPMC capsules and their delayed release counterparts are outstanding for enzymes including amylase, protease, lipase, alpha-galactosidase, bromelain, enzidase and isolase. They are also tremendous for delivery of amino acids such as SAMe, l-glutathione, l-carnosine and betaine hydrochloride that can be compromised by stomach acids.

A hard capsule flushed with nitrogen during filling and then hermetically sealed to block out oxygen can protect the stability and effectiveness of oxygen-sensitive liquids. Polymer choices can be gelatin or vegetarian, depending on their compatibility with the active ingredients. This technology is effective for resveratrol or red wine extract, marketed to manage weight and increase endurance;1 HMB (beta-Hydroxy-beta-methylbutyrate), shown to increase muscle mass and reduce muscle breakdown;2 L-carnitine, essential for energy production3 and important for heart4 and brain function;5 and L-arginine, which relaxes blood vessels for improved blood flow.

Healthy Aging

Aiming to prevent disease rather than treat it, mature and Boomer generation consumers dominate this category, according to NMI research. Ninety-three percent take multivitamins, 36 percent take omega-3s or lutein, and 20 percent take supplements for joint/bone health, heart health, immune health and digestive health.

With enzyme-replacement therapies and added amino acids, formulators can help ingredients withstand stomach acid and release at the appropriate time via the HPMC capsules discussed previously. The nitrogen-flushed, sealed hard capsule can enhance stability and preserve potency for many oxygen-sensitive carotenoids taken for eye and heart health, as well as coenzyme Q10 (CoQ10) taken for energy, muscle protection and inflammation.

A beads-in-a-liquid-filled capsule offers effective time release for ingredients such as melatonin for sleep support and caffeine for energy. An active ingredient solubilized in outer fill releases right away for fast effect, while the inner capsule with pelletized ingredients is formulated to release at intervals for ongoing effect.

Nutritional Oils

Euromonitor International sized the healthy oils market in the United States at approximately US$1.3 billion. New oil sources as well as new products are powering the market. Plant-based oils, in particular, are expected to jump with a compound annual growth rate (CAGR) of 8 percent from 2015 through 2020. These oils are generally used in products that target immune, eye, cardiovascular, brain and central nervous system health.

For some of the oils, the main challenge is to address burp-back without the use of additives. For others, mitigating the pungent smell in the bottlewithout additives is key. For all oils, the top priority is to minimize oxidation that produces the smell and can destabilize the ingredient and diminish its effectiveness.

Although softgels have been the standard delivery forms for nutritional oils, their plasticizers can allow entry of oxygen, seepage of strong odors, unpleasant taste of some ingredients, and the potential for ingredient migration into the shell.

A superior delivery form is a nitrogen-flushed, hermetically sealed, hard gelatin capsule. This technology protects against degradation and/or leakage, helping to promote stability for longer shelf life and odor and taste control. For non-genetically modified organism (GMO) certified vegetarian oils, there is now a HPMC capsule that is Non-GMO Project Verified, and a pullulan Non-GMO Project-Verified capsule is in development.

Dosage Delivery Form Matters

The right fit for delivery of an ingredient can make or break the success of a product. Fortunately, there are enough creative technologies for hard capsules to better meet consumer needs and demands. 

Stan Glab is a senior formulator, and Missy Lowery, senior manager, marketing, at Capsugel.

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