What volume of a 10 mg/mL solution is needed to obtain 2 mg?

How to Calculate Volume for a Specific Medication Dose

To obtain 2 mg from a solution of 24 mg in 2.4 mL of bacteriostatic water, you need to draw up 0.2 mL of the solution.

Understanding the Calculation Process

When calculating medication doses from solutions, follow these steps:

• Identify the concentration of the solution (mg/mL) 1
• Calculate the volume needed using the formula: Volume = Desired dose ÷ Concentration 1

Step-by-Step Calculation

1. Calculate the concentration of the solution:

   • 24 mg in 2.4 mL = 24 mg ÷ 2.4 mL = 10 mg/mL 1

2. Calculate the volume needed for 2 mg:

   • Volume = Desired dose ÷ Concentration
   • Volume = 2 mg ÷ 10 mg/mL = 0.2 mL 1

Verification Method

You can verify this calculation using a proportion:

• If 24 mg is in 2.4 mL, then 2 mg is in X mL
• 24 mg : 2.4 mL = 2 mg : X mL
• X = (2 mg × 2.4 mL) ÷ 24 mg = 0.2 mL 1

Common Pitfalls to Avoid

• Confusing different concentration expressions (e.g., mg/mL vs. percentage) 1
• Miscalculating when converting between different units 1
• Failing to account for the actual concentration of the solution 1

Clinical Implications

Accurate medication dosing is critical for:

• Preventing medication errors that could lead to adverse events 1
• Ensuring therapeutic efficacy while minimizing toxicity 1
• Maintaining patient safety, especially with medications that have narrow therapeutic windows 1