How many micrograms of digoxin are in 0.4 ml of a solution with a concentration of 50 mcg per ml?

To determine how many micrograms of digoxin are in 0.4 ml of a solution with a concentration of 50 mcg per ml, you apply the formula for calculating the amount of drug based on concentration and volume.

First, recognize that the concentration of the solution is 50 mcg per ml, meaning that each milliliter of solution contains 50 micrograms of digoxin. To find out how much is in 0.4 ml, you multiply the concentration by the volume:

Amount of digoxin = Concentration (in mcg/ml) x Volume (in ml)

= 50 mcg/ml x 0.4 ml

Carrying out the multiplication:

50 mcg/ml * 0.4 ml = 20 mcg

Thus, in 0.4 ml of the solution, there are 20 micrograms of digoxin. This matches the correct answer, confirming that the solution's concentration and the volume were applied correctly in the calculation.