Ensuring bioavailability of ingested active ingredients is one of the key objectives of any supplement formulator. When developing a finished product, several key issues have to be taken into consideration before selecting the final dosage form for the consumer. Only after careful examination and consideration of each question can a reasonable selection of dosage form be finalized. The general considerations for the formulator follow:
• Is the material we are attempting to deliver to the consumer sensitive to heat or inherently fragile? The compression of a powdered matrix into a solid-dose tablet often requires a ton or more of pressure, which can lead to creating heat during the compression process, and potentially reducing the efficacy or potency of sensitive compounds such as freeze-dried bacteria, phytochemicals or carotenoids.
• Do the active ingredients have particular characteristics, such as offensive odors or tastes? If that is the case, separating the material from the instant effect on human taste buds in the mouth may lead to preference for capsules versus uncoated tablets, although in some cases, coating a tablet with proteins or carbohydrate matrices can eliminate or greatly reduce the presence of unsettling aromas.
• What is the level of indicated dosage or intake that is attempting to be administered, and what is the bulk density of the material? Often, large quantities of mineral salts, such as calcium carbonate or calcium citrate, require a dosage unit favoring tablets, which can easily be more than 1.5 g of compressed materials in order to ensure adequate intake of calcium. Compressing psyllium husk powder—which has a much lower bulk density—may prove difficult indeed, and therefore this material is often sold as a powdered beverage or in two-piece capsule format.
• What is the target demographic? If the demographic is largely from 25 to 54 years and is mainly comprised of women, there may be more than just pharmacological considerations when selecting a dosage form. For example, the ability to color coordinate capsules versus tablets may be more aesthetically appealing to this target audience, as would be the perception that capsules are easier to swallow than tablets.
• What is the anticipated shelf life from a stability standpoint? Would a solid dose be preferred, or might the capsule format provide greater protection against isomerization or degradation of essential compounds in the product to be administered? Historically, this has been a mission-critical consideration for the pharmaceutical industry, leading to the creation of many pharmaceutical agents in two-piece or one-piece gelatin-type capsules designed to protect the contents from ultraviolet (UV) or other factors contributing to accelerated degradation.
• What is the environment of the region wherein these products are going to be administered? Is this a high-temperature, high-humidity environment, with rigorous packaging considerations; or is this a more moderate climate without wide swings in temperature or humidity? How are the finished products going to be handled—in a pharmacy setting, in general merchandise environments such as retail stores, or via direct to consumer means of mail order or online procurement?
Today’s consumers are much more interested in the composition and manufacturing processes deployed in their consumables, whether in the issue of foods, medicines or supplements. Considerations such as genetic modifications to raw materials or foods and their sustainability, the presence of potential allergens, the utilization of excipients or preservatives in the preparation of medicines or supplements, the anticipated and real shelf lives of these preparations, and their ultimate value in terms of bioavailability and clinically demonstrated benefit are all factors affecting the decision making process of the modern consumer.
In markets where single-entity compounds are generally presented (e.g., vitamin C), compression of consistent-dose tablets is common practice given the history of stability and accepted use. Modern derivatives of the gelatin capsule—whether in one-piece, liquid-fill presentations or in two-piece, hard-shell format—have given consumers more options. There are vegetarian capsules that have no presence of animal-derived products, made with sustainable materials, and devoid of pesticide and herbicide residues, while also remaining genetically modified organism (GMO)-free. As more consumers become aware of the world of allergens, they are gravitating to these elegant capsules which, if handled properly, can allow certain common compounding excipients to be eliminated for highly sensitive individuals.
The general acceptance of the encapsulated form of supplement has enjoyed widespread support in the past 50 years, and seems to be growing in international markets. Consumers apparently enjoy the ease of swallowing their supplements in capsules versus tablets, and the reality and perception of “protecting" sensitive compounds within the capsule have also been reinforced by multiple examples in the scientific literature of enhanced bioavailability of sensitive compounds preserved in the capsule versus alternative dosage formats.
Consumers now enjoy a wide range of options when selecting their supplements. The key concerns remain to provide consistent quality, good content uniformity, correct bioavailability patterns, and non-degraded actives, meeting the expectations of both the formulator and the consumer upon administration. With expanding technologies, the emergence of plant-based alternatives to animal gelatin has given encapsulators a new arsenal of consumer-friendly products.
Mark A. LeDoux is founder, chairman and CEO of Natural Alternatives International Inc. (nai-online.com), an organization with facilities in the United States and Switzerland engaged in the research, design and manufacture of nutritional supplement programs and products for multinational clients.