Tablets and Capsules: Special Delivery

December 1, 2010

Like any good partnership, delivery systems and ingredients must work together seamlessly.

Like any good partnership, delivery systems and ingredients must work together seamlessly. As ingredients advance, so must delivery vehicles to ensure efficacy.

Managing Fat-Soluble Ingredients
When it comes to delivering fat-soluble ingredients, such as CoQ10; vitamins A, D, E and K; flavanoids like resveratrol; and carotenoids like lutein, astaxanthin, and zeaxanthin, form might matter. According to Matt Richardson, PhD, business development manager for Capsugel (Greenwood, SC), developing a delivery system that takes advantage of the body’s natural absorption pathways can enable better product absorption.

Because oil-soluble ingredients will not mix with the water in the body, these nutrients are not easily absorbed. The body requires some fat to solubilize the ingredient and to create a micelle, which acts as an emulsifier as well as a carrier to take the ingredient through the intestinal wall, where the nutrient is absorbed.

By encapsulating liquid preconcentrates in a self-emulsifying system, formulators can produce micelles that mimic the ones the body creates with bile salts. When the capsule opens, the self-emulsifying or microemulsifying formula mixes with the water that a consumer takes with the capsule. The formula then becomes a stable emulsion of the tiny micelle droplets.  The micelles transport the oil-soluble nutrient through the body and are small enough to pass through the intestinal wall.

To create such micelles, a fat-soluble ingredient is often dissolved using fat or oil, and a surfactant is added to break the resulting oil into tiny droplets after the capsule opens in the stomach. Droplets can be broken down so small and ingredients dispersed on such a microscopic scale that the resulting formula is completely clear. Notably, beneficial oils such as omega-3 can also be used as the emulsion base, providing added nutritional benefits to the consumer.

Richardson adds that by preemptively dissolving a fat-soluble ingredient, consumers no longer need to take a supplement with a meal-which is usually advised to ensure there will be sufficient fat in the stomach in which the ingredient can dissolve. Because the amount of fat intake can vary from meal to meal or across various diets, a more-consistent delivery of ingredients is possible when using a self-emulsifying system, he says.

Acid Resistance
Many ingredients must be protected from the acidity of the stomach. An example would be probiotics, for which ensuring live bacteria survive the trip to the intestine is vital.

This year, Capsugel introduced DRcaps, acid-resistant capsules made from hydroxypropyl methylcellulose (HPMC). While not enteric technology, the capsule can provide some protection for ingredients in a pH of 1.2. Thus, it can help protect contents while in the stomach, until the contents reach the higher pH of the intestine.

Capsugel says that in laboratory tests, DRcaps showed no disintegration at a pH of 1.2 in the first 30 minutes and less than 20% dissolution of the encapsulated ingredients after the first two hours. At a pH of 6.8, or generally at the end of four hours, the capsule completely dissolved.

Well Paired
Technologies that combine more than one product formula in a single delivery vehicle are also helping to advance delivery systems. In some cases, such as prebiotics and probiotics, or calcium and vitamin D, this can directly impact the way ingredients work.

In the capsules industry, capsule-in-capsule or beadlets-in-a-capsule technology, such as those provided by Capsugel, have been popular for this purpose.

In the tablets market, bi-layer technology is on the rise. This summer, supplements marketer USANA Health Sciences began using a bi-layer tableting process it developed for its own products. “We recognized the immediate uses and benefits of putting two formulations into one tablet,” says Tim Wood, PhD, USANA’s executive vice president of research and development. The company calls its technique Nutritional Hybrid Technology (NHT).

The tablet is created in two halves that are pressed together. Each half contains one formula. The tablet press is key to achieving this, says Wood. “The formulations are created, then fed into the machine,” explains Wood. “One side is pressed/created, then the other is pressed on. The tablet is coated once both formulations have been pressed together.” He says that virtually any hard, solid material used in a standard tablet could be made into this type of hybrid.

The company says there are many benefits for supplement users. First, Wood says, “NHT allows us to create ingredient combinations that were not previously available because some were cross-reactive and their stability would decline as they reacted. Now, we can separate the ingredients and maintain stability.”

NHT also allows consumers to take in one dose what they would usually have to take in two. “This means fewer tablets and more convenience for customers,” says Wood. NHT also creates a distinctive look in the marketplace.

Wood says that USANA is looking at using the technology to create controlled-release tablets, as well. So far the company has released two products featuring NHT: Proflavanol C100 and Hepasil DTX.

Wood explains that for Proflavanol C100, NHT provided a direct benefit that involved clearing up consumer confusion. “Our consumer data revealed that many customers were using our previous Proflavanol formulas and our Poly C, a stand-alone vitamin C product, together. It appeared that many were unaware that Proflavanol already contained Poly C…which meant many consumers were taking more vitamin C than they needed and were buying a product they didn’t need as well.” He says that the company now uses NHT to visibly highlight that there are two ingredients in the formula.

For Hepasil DTX, Wood says that NHT helped solve a stability issue that involved cross-interaction between the formula’s alpha-lipoic acid and other ingredients. “Our original blended formulation of Hepasil DTX was extremely moisture sensitive and would break apart if the moisture balance was not maintained….By separating the ingredients using NHT, the product is much more stable. Consumers are now less likely to lose tablets due to product disintegration.”

Ingredient Challenges
Manufacturers are continually running into unique challenges presented by their customers’ ingredients. Eugene Ung, CEO of contract manufacturer Best Formulations (City of Industry, CA), provides some examples: “No excipients allowed or the addition of unreasonable amounts of non-solid material or large amounts of non-compressible material.”

Some ayurvedic ingredients, such as Commiphora mukul (gugulipid), as well as some Chinese medicinal ingredients, are tacky formulations that tend to stick to the tablet press, says Shaheen Majeed, director of marketing for Sabinsa (East Windsor, NJ). Other ingredients, such as Boswellin serata, are “fluffy” in nature and thus difficult to compress.

Sometimes, ingredient challenges are purely the result of desired aesthetics. Majeed describes an incident in which a company asked Sabinsa to create a pure white tablet made from curcumin, which is bright orange.

Sabinsa’s technicians knew the tablet would have to be coated, with the additional step of a primer coat, in order to mask the bright orange shade. “We used a proprietary base coat, and then we went in with the white.” He says that doing this without driving up costs was an achievement.

And, he says, “We can say to the market, yes, we can deliver curcumin as a white tablet.”