Pharmacy calculations worksheet with answers

A solution is 5% w/v. You need 170 mg of the drug. Draw up the volume in the syringe: what volume V is that?

Practice exercise (made-up values, not clinical guidance). 50 g of dextrose is dissolved in water to a total volume of 250 mL. What is the percentage strength p (% w/v)?

Practice exercise (made-up values, not clinical guidance). A vial contains ampicillin 500 mg as a powder. The practice label says to add 1.8 mL of sterile water; the powder adds 0.2 mL to the volume. What is the concentration C in mg/mL after reconstitution?

A solution has a ratio strength of 1:1000. You need 0.9 mg. Draw up the volume in the 1 mL syringe: what volume V is that?

Practice exercise (made-up values, not clinical guidance). You must prepare 600 mL of 30% dextrose by mixing 70% and 10% dextrose. How many mL V of the 70% solution do you need? Round to the nearest whole mL.

Practice exercise (made-up values, not clinical guidance). You have 100 g of 20% zinc oxide ointment. How many grams m of plain ointment base (0%) must you add to make a 10% ointment? Round to the nearest whole gram.