Key Points in Formulating

by Joel Pettegrew

What dissolves best and is absorbed fastest--capsules, tablets, powders orliquids? Actually, it makes little difference until the stomach gets throughbreaking down the ingredient(s) to make absorption in the intestine possible.Tablets break down a little slower in the stomach than capsules because theexcipients that hold the tablet together are dissolved by stomach acids moreslowly than cellulose capsule shells; but they all reach the point of absorptionat nearly the same time. Absorption rate is what is key in formulating products,not the time it takes to travel from the mouth to the stomach.

Absorption vs. Travel Time

Data from dissolution tests, which measure the actions of many formulationsexcept for liquids, consist of USP standards and procedures that identifysolutions, equipment, temperatures and movement that simulate the peristalticaction (muscles that move food along the digestive pathway) and conditions ofthe stomach. Some lab dissolution tests show a tablet dissolves faster than acapsule and vice versa, according to the product's design.

The "travel" time from the mouth to the stomach differs for variousformulations. Common sense, combined with any simple laboratory dissolutiontest, will reveal several things. One, that a liquid will get to the intestinemore quickly than a tablet or capsule. Two, that a tablet can be made todissolve very quickly (such as by adding sodium starch) or more slowly (such asby using an enteric coating). Common sense says a liquid tincture would dissolvefaster than a soft gel, but the ingredients from either may be absorbed at asimilar rate once it reaches the intestine. Therefore, the "travel"time through the stomach to intestine of any formulation probably varies lessthan 30 minutes.

Digesting Multiple Ingredients

More important are the ingredients themselves in custom-formulated products.Today, the combination of a Specification Sheet, a copy of a recent Certificateof Analysis completed by an outside lab, an MSDS (Manufacturer's Safety DataSheet), a supplier's recommended shelf life and a sight sample prior to orderingany ingredient will help ensure the purchase of a legitimate, pure and safeingredient.

Most herbal and natural vitamin/mineral/amino acid ingredients have tacit butsynergistic properties toward each other, aiding the intentions of the composedmixture. For example, chromium seems to act as a catalyst with many ingredients.The synergistic contribution of any ingredient, similar to chromium, occurs inthe chemistry of the bloodstream and body and is not affected by formulation.However, when choosing which ingredients should go together, it is important tochoose those with similar absorption times. This is often dependent on themolecular size of the active ingredients.

The amount and number of ingredients vary the dissolution time somewhat,analogous to digesting a grape versus a pizza. The make-up of an ingredient mayalso affect the dissolution and absorption time. For example, Garcinia cambogiais very gritty and wears down tablet press punches, whereas soft and milkycolostrums dissolve more quickly in dissolution tests. An ingredient's stabilityalso comes into play; the more stable the herb, amino acid or vitamin is, theslower it is to dissolve but with a better effect in absorption and use in thebody.

Multiple vitamin/mineral products pose more of a challenge for productdesigners and formulators. A powder can contain just about everything, butvitamins in this form can taste lousy and the taste is hard to mask withoutusing a lot of sugar. Tablets can get to be huge, making them hard tomanufacture and even harder to swallow. A good choice here is to use a"00" size capsule but increase the serving size. It only takes a fewmore seconds to swallow five capsules than to choke down a horse tablet or a10-oz. powdered drink.

Indigestion of Multiple Ingredients

On the other hand, many customers want every conceivable ingredient shovedinto a formula. This results in too many ingredients with the possibility ofmismatching and loss of synergy, all put into a horse tablet, huge capsule orscoop of powder that might not dissolve.

Mega doses can cause people to burp up the ingredients and can often upsettheir stomachs. As the Greeks once said, "Everything in moderation."More is often NOT better than less. There are some ingredients in the industrythat seem to act like homeopathic tinctures in that even a moderate amount seemsto ignite a positive reaction or show nutritional support. That is not to saythat combinations are ineffective. It is better to purchase a formula with 500mg of three good ingredients than 750 mg of only one. The word "meal"commonly means a group of foods. A "formula" similarly means a groupof nutritionals; and like a meal, 55 ingredients are not needed when a veryselect few work just as well.

Buyer Beware

Another caution is the ingredient supplier who grabbed a use patent or has anexclusive marketing angle for an ingredient. Some clinical trials, either withor without double-blind protocols, are performed to develop validation recordsfor the use of these particular ingredients. To increase the chance for positiveresults, clinical trials often may use two to three times the probable effectiveamount of the recommended ingredient dosage. This ensures a good result as wellas increased quantity sales. A stand-alone ingredient may be recommended by themanufacturer to promote greater sales volume, but there are also a fewingredients (such as SAMe and DHEA) that are rarely complemented or enhanced bythe addition of other ingredients and still maintain an efficacious productdesign.

User Appeal

Sometimes user appeal may affect product design. For example, some consumerslove powders--which can contain numerous ingredients--to be mixed with theirmorning orange juice or afternoon smoothie. Other users hate the taste and messof powders, and they opt for a multi-dose tablet or capsule. Women usuallyprefer small capsules, which in terms of product design lends itself to amulti-dose. Whether it is a powder drink once a day or a multi-dose three timesa day, the ingestion, absorption and effect in the body is nearly the same--oneis just concentrated while the other is spread out. However, if the powder/drinktastes wonderful, a user could "over-dose" if intake instructions arenot followed.

When designing a formulation for a product, it is important to keep in mindthings such as price range; ease of use; user appeal (preferences concerningform, shape, taste and ingredients used); familiarity of ingredients topotential customers; effectiveness of ingredients individually and with others;cost and availability of ingredients; and supporting documentation for theingredients' functions.

Joel Pettegrew is the international marketing director at Fort Worth,Texas-based Summa Rx Laboratories Inc., a contract private label manufacturer.He has been working with formulations for more than eight years and can bereached at [email protected].