Final answer:
To prepare 1 pint of a 0.1% v/v liquid drug preparation, 0.473 mL of the liquid drug is needed. The calculations are based on the desired volume of preparation and the desired concentration, assuming a negligible effect on the total volume when the drug is added.
Step-by-step explanation:
To calculate the volume of liquid drug needed to make a 1 pint (473 mL) of 0.1% v/v preparation, the formula V1 = C1V1 = C2V2 is used, where C1 is the concentration of the drug, V1 is the volume of the drug needed, C2 is the desired concentration, and V2 is the final volume of the preparation. Here, C2 is 0.1% and V2 is 473 mL, so:
V1 = (C2/100) × V2
V1 = (0.1/100) × 473 mL
V1 = 0.473 mL
This means 0.473 mL of the liquid drug is needed to make 1 pint of the 0.1% v/v preparation. This calculation assumes that the addition of the liquid drug has a negligible effect on the total volume of the preparation.