How to Prepare 10% Dextrose from 25% Dextrose Stock
To make 10% dextrose from 25% dextrose, use the dilution formula C1×V1 = C2×V2, which means you need to mix 2 parts of 25% dextrose with 3 parts of sterile water (or 40 mL of D25 + 60 mL sterile water = 100 mL of D10).
The Dilution Calculation
The mathematical approach is straightforward:
- C1 (initial concentration) = 25%
- C2 (desired concentration) = 10%
- V2 (final volume needed) = your target volume
- V1 (volume of 25% dextrose needed) = ?
Using the formula: V1 = (C2 × V2) / C1
Practical Examples:
For 100 mL of 10% dextrose:
- Take 40 mL of 25% dextrose
- Add 60 mL of sterile water
- Total = 100 mL of 10% dextrose
For 250 mL of 10% dextrose:
- Take 100 mL of 25% dextrose
- Add 150 mL of sterile water
- Total = 250 mL of 10% dextrose
For 500 mL of 10% dextrose:
- Take 200 mL of 25% dextrose
- Add 300 mL of sterile water
- Total = 500 mL of 10% dextrose
Quick Reference Ratio
The simplest way to remember this: mix 2 parts D25 with 3 parts sterile water to get D10 (2:3 ratio).
Clinical Context
While the provided evidence focuses on clinical uses of dextrose solutions in pediatric maintenance fluids 1, DKA management 2, 3, and neonatal hypoglycemia 4, 5, the fundamental dilution principle remains constant across all applications. The 10% dextrose concentration is commonly used when initiating dextrose therapy in DKA once blood glucose falls below target levels 2, 3 and in neonatal hypoglycemia management 4, 5.
Important Caveats:
- Always use sterile water for injection when preparing IV solutions
- Label the final concentration clearly
- Document the preparation date and time
- Use appropriate aseptic technique
- Verify calculations with a second clinician when possible for patient safety