Levigation uses a liquid in which the solid is not soluble. Which option correctly describes this?

• A. Using a solvent in which the solid is highly soluble
• B. Using a liquid that dissolves the solid completely
• C. Using a liquid in which the solid is not soluble
• D. Using heat to dissolve

Answer: (C)

Levigation aims to grind a solid with a small amount of liquid while keeping the solid undissolved. The liquid is chosen so the drug is insoluble or only sparingly soluble in it, which allows the particles to be wetted and dispersed without forming a true solution. This creates a smooth paste that can be more easily incorporated into a final dosage form. If the liquid dissolved the solid, you’d be making a solution rather than a levigated paste, which is not how levigation works. Similarly, using heat to dissolve would also produce a solution, not a fine dispersed solid. So the description that fits levigation is using a liquid in which the solid is not soluble.