Which tool is commonly used in non-sterile compounding to grind substances?

The mortar and pestle is a fundamental tool in non-sterile compounding, primarily used for grinding and mixing solid substances into finer powders. This device allows pharmacists and technicians to achieve a consistent and desired particle size, which is essential for ensuring uniformity in the formulation of various pharmaceutical preparations. The mortar, often made of ceramic or glass, holds the materials, while the pestle serves as the grinding instrument to break down solids.

Other tools mentioned, such as a beaker, graduated cylinder, and pipette, have distinct functions that do not involve grinding. A beaker is primarily used for mixing or holding liquids, whereas a graduated cylinder is designed for precise volume measurements of liquids. A pipette is used for transferring small volumes of liquid and does not perform any grinding or powdering tasks. Therefore, the mortar and pestle stands out as the appropriate choice for the specific function of grinding in non-sterile compounding.