Planes, trains, & automobiles. Buses, trucks and barges. There are many different vehicles capable of delivering people or products to their destination. Each has its own advantages and disadvantages, depending upon what is being transported and why.

A barge may not be the most comfortable nor fastest vehicle by which to travel from Minneapolis to New Orleans, but it is one of the most efficient ways to transport wheat and other commodities. A plane may be able to fly quickly between cities once airborne, but a bus or an automobile may actually be faster location to location when the time spent commuting to and from the airport and going through security is factored in.

Tablets, capsules, and liquids. Sprays, lozenges, and creams. Each vehicle has particular strengths and weaknesses. A vehicle that is the most appropriate for one situation may be totally inappropriate in another.

So it is that I alternately smile and sigh when I hear marketing claims pronouncing the superiority of one vehicle over all others. The statements are far more hype than substance and betray a basic misunderstanding of the principles involved in choosing the most appropriate vehicle to deliver the desired result.

Tablets can be highly effective delivery vehicles when manufactured with an eye toward smooth dispersion of their content. One of the advantages of tablets is that they can generally deliver more active ingredient than capsules of the same size. There is a limit on how much of a substance can be effectively delivered, however.

Calcium tablets are a good example. Some manufacturers of generic calcium tablets, knowing that consumers are looking for a bargain and that many do not want to swallow multiple pills pack a large amount of calcium in each tablet. Unfortunately, this results in such tight compression of the calcium that the tablets cannot break down in the time it takes for them to pass through the body. Reputable manufacturers produce calcium tablets that have fewer milligrams per tablet, but which disperse quickly and allow the body to effectively absorb and utilize the calcium that is present.

Tablets are the most effective vehicles in controlling where nutrients are released in the body. Enteric-coated tablets are designed to withstand the acid of the stomach and pass undissolved into the small intestine, protecting the nutrients from being inactivated by the stomach’s acidic environment. There are also tablets that are designed to remain intact throughout transit allowing the contents to seep out gradually, like tea seeping out of a tea bag.

Capsules have several advantages. They tend to be easier to swallow than tablets in most cases, and they do not require the “binders” that hold tablets together. Their contents are released very quickly after being swallowed. They can be administered easily to children or adults who cannot swallow them whole by sprinkling their contents into juice or soft food. They do not facilitate delayed release of the contents, however.

The primary advantage of liquids is that they are easy to swallow. In most cases, however, flavorings and sweeteners are required to make them palatable. These additives can at times diminish the absorption and effectiveness of the active ingredients. Liquids are also more easily contaminated than tablets or capsules. Their bulk makes liquids the least portable of all delivery vehicles. In most cases they should be refrigerated after opening, a requirement that further diminishes their portability.

Creams, patches, or troches (soft lozenges) are the most effective vehicles in the delivery of hormones, which are broken down by the liver before being sent to the rest of the body if they are swallowed. The primary disadvantage of these vehicles is that people can become allergic to them and experience a rash or itching in the application sites.

Claims that one delivery system is inherently superior to another in terms of bioavailability (the body’s ability to absorb and utilize the active ingredients) are blatantly false. Tablets that are tightly compressed will commonly affect absorption as will the use of flavorings and sweeteners to make the taste of the product appealing. The inactive ingredients in creams can either enhance or diminish the skin’s absorption of the active ingredients. Bioavailability is predominantly dependent upon the manner in which the products are manufactured rather that upon the type of delivery vehicle utilized.

Each vehicle has particular advantages and disadvantages. The chosen vehicle should provide optimum bioavailability of its active constituents. If this condition can be met in a variety of ways, the vehicle of choice becomes a matter of personal preference.