According to the 2015 Supplement/OTC/Rx Database (SORD) findings, capsules remain the most popular delivery method for supplements and pharmaceuticals in the world. Among supplement users, 42% prefer capsules, citing their portability, cleanliness, and ease of swallowing. Capsule lovers are also swayed by lifestyle as it can offer clean-label promises, as well as vegan and organic options.
Soft-gel and hard-gel capsules are often the standard encapsulation vehicle for flavored nutritional oils, most commonly fish oil and krill oil. Manufacturers of the former may add flavors or fragrances to mask the odd smell from the soft-gel plasticizer. Empty pharmaceutical capsules—especially those filled with helium—can be more effective at blocking odors. Empty pharmaceutical capsules are made from fish, bovine, pig glue, and vegetarian polymers without the use of plasticizers.
Recently, a more natural capsule material has replaced the "smelly" capsule material. This is a vegetarian capsule made from naturally fermented tapioca flour, which has the highest odor barrier effect of all polymers, better than gelatin or HPMC capsules. Pullulan capsules are non-GMO projects and have a water content similar to gelatin. It is an ideal carrier for powdered products such as vitamin C because it prevents the Maillard reaction (a non-enzymatic browning phenomenon common in the food industry). Pullulan capsules are also suitable for liquid products, and they can provide excellent protection for easily oxidized ingredients, just like gelatin.
What's more, no additives are used in this capsule. This helps to further solidify its appeal to core consumers of organic food and clean labels while attracting more consumers in the growing aging and nutritious oil market – especially those looking for vegan products.
Enteric coatings have long been applied to tablets, capsules, pellets, and granules (inside the capsule shell) to delay product breakdown in the digestive tract. It protects the product from the effects and weakening of stomach acid or transports the functional ingredients within it to the most effective part of the gut. Enteric coatings can be made from fatty acids, waxes, shellac, plastics, vegetable fibers, and resinous films.
There is now also a capsule made of low-moisture hydroxypropylmethylcellulose (HPMC) that offers an alternative for enteric coating. The vegetarian capsules offer unique acid-resistant polymer properties that resist breakdown by stomach acid but break down immediately once the pH reaches above 6.8—a more acidic environment than stomach acid. A clinical study on 8 subjects confirmed the delayed-release properties of the capsules. The capsule began to disintegrate approximately 52 minutes after being ingested by the subject. For most test subjects, the capsules began to break down 20 minutes after ingestion into the intestinal environment with a pH of 5.8. Because the capsule is made from low-humidity hydroxypropylmethylcellulose (HPMC), it also stabilizes moisture-sensitive ingredients until packaging and protects them from acidic substances after consumption, making it ideal for carrying probiotics, enzymes, and many other sports nutrition ingredients.
Research has proven that this ingenious "unlocking" mechanism prevents separation or loss of the capsule's ingredients, with no opening or shattering of the capsule following normal filling, packaging, and shipping to its final destination.
As a delivery tool, capsules are always changing. For different products and different manufacturers, there is no correct delivery tool, only the most suitable one. The most important thing is to find the one that suits you best.