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Absorption Revolution: CDT Nutrient Delivery |
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FEATURE
ARTICLE
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Absorption Revolution: CDT Nutrient Delivery
by William D. St. John
 By now the benefits of many nutrients and specialty supplements are well-known and widely desired, but how can you be sure your products are working?
There are many factors to the absorption equation. The ultimate goal is to get the right amount of supplement ingredient into the bloodstream and maintain an optimum level of the ingredient in the blood throughout a
specified period of time. Sound simple? It isn’t, or at least it hasn’t been until recently. To ensure optimal nutritional stores there are new innovations in the application of “smart” tablets and capsules which deliver nutrients in the proper quantity at the right place in the gastrointestinal tract over an extended period of time.
It is not enough to simply swallow a tablet or capsule containing your favorite natural ingredient. Your body has to absorb the right amount of nutrient at the right times if you are to maximize the benefits. As much as you are what you eat, you are what you absorb.
When it comes to food and digestion most people think about the stomach. In fact, most digestion and absorption of nutrients occurs in the small intestine, the maze of tubing that follows the stomach in the digestive tract. Specifically, certain nutrients are absorbed at precise locations along the intestine. This explains why people who have lost a portion of their intestinal tract due to cancer or an accident also lose the ability to absorb certain vitamins and minerals. Absorption is further complicated by the presence of food and water. For example, intestinal absorption of vitamin B6 can be negatively impacted by the presence of food. Other factors in the process of absorption are general health, age and stress.
Throughout the digestive tract various chemical and physical factors can affect the absorption of food, supplements and all other ingested substances. One of the most influential variables is pH. Each section of the digestive system has a different pH: the stomach is very acidic and has a low pH (1–3). The acidity decreases the further you go beyond the stomach, with the small intestines having a fairly neutral range of pH (5–8). Most drug and supplement delivery systems are easily broken down by the very low pH, acidic environment of the stomach, so the first goal of a delivery system is to reach the small intestine unscathed.
Water, carbohydrates and alcohol are a few of the dietary components that can be absorbed in the stomach but the rest—vitamins, minerals, proteins and fats—are not absorbed until they enter the small intestine. Hence, dietary supplements need to pass through the stomach with their active ingredient intact.
To address some of these absorption concerns, over-the-counter products have employed several main types of delivery systems: pore-forming wax, coated-beads, reservoir technology and diffusion technology.
 Pore-forming wax tablets were among the first delivery systems to be developed and are still widely used by the pharmaceutical and dietary supplement industry today because they are cheap and easy to produce. In this method the active ingredient is contained in a wax compound (paraffin or guar gum, for example), with a special polymer that dissolves out of the wax and forms pores. In the gastrointestinal (GI) tract, the pores help the GI fluid erode the wax, thereby releasing the active ingredient. While inexpensive, the accuracy and efficacy of this type of delivery is insufficient for many ingredients because the release of ingredients is dependent upon the unpredictable, non-uniform rate of erosion of the wax.
 Coated-bead systems are available as capsules and primarily involve surrounding the active ingredient with an enteric coating. The coatings allow the nutrients to reach the intestines as opposed to dissolving in the
stomach, which is highly acidic. In many cases a blend of coated-beads with different release rates is employed to create different release patterns. Manufacturers can also blend or granulate the active ingredient with special polymers before coating to provide additional levels of control.
A large portion of the active ingredient is released initially however, creating a burst or spike in blood levels and potentially wasting certain ingredients (such as water-soluble vitamin C); non-absorbed water-soluble
ingredients are excreted in the urine. Following this initial burst the release pattern continuously spikes at consecutively smaller levels, which results in an inconsistent level of the nutrient in the blood.
Reservoir systems routinely feature a semi-permeable membrane through which the active ingredient is released over an extended period of time. Most reservoir systems are osmotically-controlled: as water enters the tablet, the active ingredient is pushed into the GI tract in the intestinal environment. Such reservoir systems can achieve a replicable, linear release pattern but are extremely complex to manufacture, which renders them less cost-effective for consumers.
Diffusion technology utilizes a polymer matrix that, upon contact with water, slowly releases the active ingredient. Most systems employ one or more gel-forming polymers or fibrous polymers that will allow the active ingredient to diffuse out of the matrix as the polymer is hydrated. Known as “sustained release,” these polymer diffusion tablets have yielded constant release patterns for short time periods but fail to achieve a linear release over 12 to 24 hours due to the inconsistent swelling of the polymers.
Improving upon the sustained release diffusion systems was a challenge met by scientists at Temple University in Philadelphia when they devised CDTTM, Controlled Delivery Technology, licensed by Nutraceutix, Inc. CDT tablets and capsules were developed to allow heart patients to take a controlled delivery pill before going to bed, which releases the drug over a 12-hour period, thereby maintaining a constant blood level throughout the night. Beyond extended release, drugs have benefited from pills which release at a specific location in the gastrointestinal tract.
CDT technology offers the same great advantages of pharmaceuticals to nutritional supplements as well. Many nutrients are subject to degradation by stomach acid. Bypassing these caustic conditions is accomplished by not releasing the active ingredients until they reach the desired small intestine. The delivery is designed with pH of each part of the intestine in mind. Pills can be designed with pH-sensitive polymers which expand and release the nutrient at the specific pH of the target region of the gastrointestinal tract.
Instead of relying on the physical characteristics of the polymer, as is common in diffusion systems, they introduced additional factors that resulted in greatly increased control over active ingredient delivery. Electrolytes or acids are used to react with the active ingredient to form a “metamorphic scaffold” or crystal lattice. This molecular backbone creates a hardened outside layer that controls the rate of swelling of the various polymer systems and therefore controls the rate of diffusion or release of the vitamin, mineral, herb or other nutraceuticals.
This allows CDT to achieve many controlled-release patterns never accomplished by prior delivery systems.
About the author:
William D. St. John is director of research for Nutraceutix, Inc. He holds a master’s degree in molecular and microbiology from Ohio State University and applies this specialized scientific training to lead his company in its pioneering role of introducing cutting-edge nutritional technologies, developed through extensive research and collaboration with leading universities.
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