To administer 900 mg using a vial of 1.5 g with a concentration of 375 mg/mL, how many milliliters should be drawn for the dose?

• A. 0.6
• B. 1.2
• C. 2.4
• D. 3.6

Answer: (C)

The amount of solution you need is found by dividing the dose by the concentration. With a dose of 900 mg and a concentration of 375 mg per mL, the required volume is 900 ÷ 375 = 2.4 mL. This ensures you deliver 2.4 mL × 375 mg/mL = 900 mg. The vial contains 1.5 g (1500 mg) total, which at this concentration is 1500 ÷ 375 = 4 mL, so drawing 2.4 mL is feasible. Therefore, you should draw 2.4 mL.