A medication is ordered as 60 mg in 120 mL. What is the concentration in mg/mL?

A medication is ordered as 60 mg in 120 mL. What is the concentration in mg/mL?

• A. 0.25 mg/mL
• B. 0.75 mg/mL
• C. 1.0 mg/mL
• D. 0.5 mg/mL

Answer: (D)

Concentration is the amount of drug per unit of volume. To find mg/mL, divide the total milligrams by the total milliliters. 60 mg ÷ 120 mL = 0.5 mg/mL. So the concentration is 0.5 mg per milliliter. If the volume were larger, the concentration would be smaller (for example, 60 mg in 240 mL is 0.25 mg/mL); if the volume were smaller, the concentration would be larger (for example, 60 mg in 60 mL is 1.0 mg/mL).

Concentration is the amount of drug per unit of volume. To find mg/mL, divide the total milligrams by the total milliliters. 60 mg ÷ 120 mL = 0.5 mg/mL. So the concentration is 0.5 mg per milliliter. If the volume were larger, the concentration would be smaller (for example, 60 mg in 240 mL is 0.25 mg/mL); if the volume were smaller, the concentration would be larger (for example, 60 mg in 60 mL is 1.0 mg/mL).