Which of the following is an explicit example of a wetting agent listed in the materials?

• A. Flavorings
• B. Glycerin
• C. Distilled water
• D. Colorants

Answer: (B)

Wetting agents lower the interfacial tension between a liquid and a solid, helping the liquid spread and wet surfaces more effectively. Glycerin fits this role well because it’s a viscous, hygroscopic liquid that acts as a humectant and wetting agent in many pharmaceutical formulations, improving how liquids wet powders and other solids and aiding uniform dispersion. Flavorings and colorants are additives for taste and appearance, not for altering surface tension, and distilled water is simply the solvent or vehicle, not a dedicated wetting agent. So glycerin is the explicit wetting agent listed.