Requirements (Instruments, Chemicals & Other):
● Suspending agent (e.g., tragacanth, sodium CMC, or xanthan gum)
● Active ingredient (e.g., zinc oxide)
● Distilled water
● Measuring cylinders (25 mL, 50 mL, 100 mL)
● Beakers
● Glass rod
● Weighing balance
● Pipettes or droppers
● Stopwatch or timer
● Mortar and pestle
● Labels and marker pen
● Graduated test tubes or sedimentation bottles

Procedure:
● Weigh the required amount of drug powder for all samples (e.g., 5 g of zinc oxide per 50 mL batch).
● Prepare four suspensions with different concentrations of a single suspending agent (e.g., 0.25%, 0.5%, 1%, 1.5%).
● Disperse the suspending agent in a small quantity of water and stir until a uniform mucilage forms.
● Add the drug powder slowly into the mucilage while stirring to avoid lump formation.
● Make up the volume to 50 mL using distilled water in a graduated cylinder.
● Shake each cylinder uniformly and label according to concentration.
● Allow the suspensions to stand undisturbed.
● Record the sediment volume (Vu) at specified time intervals (e.g., 30 min, 1 h, 2 h, and 24 h).
● Calculate the sedimentation volume (F) for each suspension using the formula: F = Vu / Vo.
● Compare sedimentation volume values to determine the effect of concentration.