Understanding Effervescent Tableting Technology

The dietary supplement industry is growing rapidly, with sales of more than $13 billion in 2007, and to meet market demand, the industry is spawning innovative applications in delivery technology. Many of these newly integrated applications are modeled for convenience or ease of consumer use; unfortunately, few have been focused on bioavailability, or the rate at which the active substance within the product becomes fully absorbed at the site of availability. With new ingredient discoveries and continuously added research data on pre-existing materials, the need for a readily absorbable product for consumers is the next logical step for new functional products.

Effervescent technology is a viable choice at the front of this movement. Originally popularized amongst consumers in 1931 by the German firm Bayer Corp., its Alka-seltzer® quickly became a household name. Effervescent technology was primarily used for pharmaceutical and over-the-counter (OTC) industries, and consumers were commonly confronted with bland or chalky tastes, which formulators then “enhanced” with flavored versions of prior products. Today, through modern food technology and material engineering for sweetening, flavoring and improving mouthfeel, these obstacles are essentially now a thing of the past.

Behind the Fizz

Effervescence is the chemical reaction within an aqueous solution (water) of acids and bases producing the release of carbon dioxide. Common acids utilized for these reactions are citric, malic, tartaric, adipic and fumaric acid. Citric acid is most commonly used for this application, and also adds a citrus-like taste to products. Malic acid can be implemented into an effervescent formula, adding a smoother aftertaste. However, the price difference between citric and malic acids is considerable, with malic acid significantly more expensive. Tartaric, adipic and fumaric acids are usually used in small amounts, due to their low water solubility.

Studies are examining how to maximize the delivery of actives in effervescent tablets in a cost-effective, consumer-friendly manner. One randomized, double blind, placebo-controlled study compared the time to onset of analgesia and the analgesic efficacy of two formulations of acetaminophen (1,000 mg)—effervescent tablet solution vs. standard tablet—in 242 patients with moderate or severe pain following dental surgery (J Clin Pharmacol. 2000;40:370-378). Onset of analgesia was determined using a two-stopwatch procedure and assessed over a four-hour period. Treatments were compared using standard indexes of pain intensity and pain relief and summary measures. Both acetaminophen formulations were significantly more effective than their corresponding placebo for all efficacy assessments, though the median time to onset of analgesia was significantly shorter with the effervescent tablet acetaminophen (20 minutes), in comparison to that of the standard tablet acetaminophen (45 minutes). During the initial 45 minutes of administration, tablet effervescent acetaminophen also displayed more effectiveness in patients at each scheduled assessment time than standard tablet acetaminophen. With a determined median time to meaningful pain relief achieved at a much faster rate than that of a standard tablet (up to 15 minutes faster), the conclusion was that tablet effervescent solution acetaminophen produced a significantly faster onset of analgesia than tablet acetaminophen.

Friend with Benefits

For many consumers who have problems ingesting whole tablets or capsules, effervescent applications provide a favorable alternative. After swallowing, conventional tablets and capsules are transported to the stomach where they require additional time to break down and gradually dissolve. Certain anatomical and physiological factors may hinder the dissolution process, causing irritation of mucous membranes. With a dissolved effervescent tablet, active ingredients are evenly distributed in the solution so no localized concentrations occur. The solution of the effervescent tablet also contains a buffer, a balanced ratio of acids and carbonates.

As an added convenience, makers of effervescent products are taking advantage of single serve stick pouches/packets that, when correctly formulated, are able to deliver large dosages of ingredient actives without the need to measure loose powders with a scoop, which often results in inaccurate dosing. Effervescent tablet solutions also promote adequate liquid supply, as adult liquid consumption should be 1.5 to 2 liters a day.

Whether for ease-of-use, improved absorption or even just to enjoy the bubbling display showing the product is working, effervescent tablets remain at the forefront of designer product forms for consumers today.

John Pham is the director of R&D with Santa Ana, Calif.-based Veripak Corp. (Veripak.net), a fully licensed organic and FDA-compliant contract manufacturer offering encapsulation, tableting, bottling and packaging services.