Pharmacy calculations worksheet with answers

Practice exercise (made-up values, not clinical guidance). A solution of benzalkonium chloride has a ratio strength of 1:2 000. How many milligrams m are in 50 mL?

A solution is 2% w/v. You need 36 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 cefuroxime 750 mg as a powder. The practice label says to add 7.2 mL of sterile water; the powder adds 0.3 mL to the volume. What is the concentration C in mg/mL after reconstitution?

Practice exercise (made-up values, not clinical guidance). A vial contains oxacillin 2000 mg as a powder. The practice label says to add 11.5 mL of sterile water; the powder adds 1 mL to the volume. The prescribed dose is 600 mg. What volume V do you draw up? Round to one decimal place.

A vial holds 1000 mg of powder. You add 4.4 mL of diluent, and the powder adds 0.6 mL of volume. The prescription is 560 mg. Draw up the dose: what volume V do you give?

Practice exercise (made-up values, not clinical guidance). You must prepare 600 mL of 2% chlorhexidine from a 20% stock and purified water. How many mL V of water do you need? Round to the nearest whole mL.