Issue link: https://www.e-digitaleditions.com/i/962670
Tablets & Capsules April 2018 25 Another strategy to aid taste masking is to add bitter blockers, which are receptor antagonists that bind competitively to specific bitter receptor sites in the patient's mouth, blocking the release of proteins responsible for taste transduction. These antagonists are often tasteless compounds that are close structural analogues of the API. coarse particles are prone to leaving a gritty mouthfeel. Irregularly shaped or rod-like particles will result in areas of thicker and thinner coating along particle surfaces, requiring greater overall coating use and film thickness to ensure adequate coverage. Flavors and sweeteners Flavors and sweeteners are adequate to mask the unpleasant taste of many drug products. Both natural and artificial flavors are available and are typically included at concentrations lower than 3 percent. Natural flavors tend to offer better taste, but artificial flavors are easier to characterize and are more chemically stable. In general, a combination of flavors may be used to complement an API's taste profile, and the flavor selection should be based on the taste characteristics of the API. Acidic APIs are more successfully masked using flavors such as citrus and berry, while alkaline APIs are better suited for flavors such as banana, caramel, cherry, and licorice. At levels of 40 to 70 percent, natural sweeteners such as mannitol, dextrose, and xylitol provide body and texture to the product, while artificial sweeteners such as sodium saccharin, acesulfame potassium, aspartame, and sucralose provide an intense sweet taste at lower concentrations (generally less than 1 percent). Each sweetener has advantages and disadvantages in terms of taste and texture, and formulators often combine sweeteners in a single dosage form to provide sufficient sweetness and intensity to mask an unpleasant-tasting API. Figure 1 Taste-masked multiparticulate bead Sugar sphere (250 to 355 microns) API layer Seal coat Barrier membrane