Pharmacy calculations worksheet with answers

Practice exercise (made-up values, not clinical guidance). 20 g of glycerin is dissolved in water to a total volume of 100 mL. What is the percentage strength p (% w/v)?

A solution is 5% w/v. You need 240 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 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.

Practice exercise (made-up values, not clinical guidance). A vial contains ceftriaxone 2000 mg as a powder. The practice label says to add 19.2 mL of sterile water; the powder adds 0.8 mL to the volume. The prescribed dose is 500 mg. What volume V do you draw up? Round to one decimal place.

Practice exercise (made-up values, not clinical guidance). You have 50 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.

Practice exercise (made-up values, not clinical guidance). You must prepare 250 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.