Pharmacy calculations worksheet with answers

Practice exercise (made-up values, not clinical guidance). 50 g of glycerin is dissolved in water to a total volume of 500 mL. What is the percentage strength p (% w/v)?

A solution is 1% w/v. You need 22 mg of the drug. Draw up the volume in the syringe: what volume V is that?

Practice exercise (made-up values, not clinical guidance). A vial contains ampicillin 1000 mg as a powder. The practice label says to add 3.5 mL of sterile water; the powder adds 0.5 mL to the volume. What is the concentration C in mg/mL after reconstitution?

Practice exercise (made-up values, not clinical guidance). A vial of penicillin G contains 5 000 000 units. Its practice label gives three strengths (see the table). You add 3.2 mL of diluent. The prescribed dose is 600 000 units. What volume V do you draw up? Round to one decimal place.

Practice exercise (made-up values, not clinical guidance). You must prepare 450 mL of 25% dextrose by mixing 50% and 5% dextrose. How many mL V of the 50% solution do you need? Round to the nearest whole mL.

A vial holds 500 mg of powder. You add 1.2 mL of diluent, and the powder adds 0.8 mL of volume. The prescription is 300 mg. Draw up the dose: what volume V do you give?