Pharmacy calculations worksheet with answers

Practice exercise (made-up values, not clinical guidance). How many mg of bupivacaine are in 20 mL of 0.25% w/v solution? Find m.

A solution is 0.5% w/v. You need 16.5 mg of the drug. Draw up the volume in the syringe: what volume V is that?

A solution has a ratio strength of 1:1000. You need 0.87 mg. Draw up the volume in the 1 mL syringe: what volume V is that?

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. What is the concentration C in mg/mL after reconstitution?

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.

A vial holds 250 mg of powder. You add 4.5 mL of diluent, and the powder adds 0.5 mL of volume. The prescription is 120 mg. Draw up the dose: what volume V do you give?