Which step is NOT part of preparing a suspension?

When preparing a suspension, the primary focus is on ensuring that the solid particles are properly dispersed within a liquid medium. Each of the steps, such as adding a suspending agent, particle size reduction, and adding a vehicle or diluent, are integral to achieving a stable and uniform mixture.

Adding a suspending agent helps to maintain the dispersion of the particles and prevents them from settling out of the liquid. Reducing the particle size is crucial as smaller particles disperse more easily and suspend more effectively. The vehicle or diluent serves as the liquid medium in which the suspension is prepared, providing the necessary consistency and delivering the active ingredients.

In contrast, the addition of flavoring agents, while it can enhance the palatability of the suspension for patients, is not essential to the fundamental process of preparing a suspension. It does not contribute to the stability or suspension of the solid particles and is therefore not considered a critical step in the formulation process. This makes it the step that is not required for preparing a suspension.