FPGEE for National Association of Boards of Pharmacy (NABP) Practice Exam 2026 - Free NABP Practice Questions and Study Guide

The correct choice is levigating agents. Levigating agents are substances used to reduce the size of solid particles and aid in the uniform dispersion of these particles in a liquid medium. They play a crucial role in preparing emulsions and suspensions by preventing the particles from settling, thereby keeping them evenly distributed throughout the solution.

Levigating agents often form a viscous layer around the drug particles, which aids in their suspension and minimizes clumping, ultimately allowing for a smooth and stable formulation. This makes them particularly valuable in pharmaceutical preparations where consistent dosing and homogeneity are critical.

Other options, such as foaming agents, wetting agents, and coloring agents, serve different purposes. Foaming agents create bubbles and stabilize foam rather than suspending particles, while wetting agents facilitate the spreading of liquids on solid surfaces but don't specifically maintain particles in suspension over time. Coloring agents are used to impart specific colors to products and have no role in maintaining the physical state or distribution of drug particles within a solution. Therefore, levigating agents are the most appropriate answer regarding the suspension of drug particles.