Stability of Dexamethasone Mixed with Bacteriostatic Water for IM Injection
Dexamethasone sodium phosphate diluted with bacteriostatic saline (0.9% NaCl) remains stable for 28 days when stored at either room temperature (22°C) or refrigerated (4°C). 1
Storage Duration and Conditions
- 28-day stability has been demonstrated for dexamethasone sodium phosphate injection (4 mg/mL) diluted to 1 mg/mL with bacteriostatic 0.9% sodium chloride 1
- Samples retained at least 97.7% of original concentration throughout the 28-day period at both storage temperatures 1
- No visual changes (discoloration or precipitation) occurred during this timeframe 1
Storage Temperature Options
- Room temperature (22°C/72°F): Stable for 28 days 1
- Refrigeration (4°C/39°F): Stable for 28 days 1
- Both storage conditions showed equivalent stability with no clinically significant difference 1
Container Considerations
When stored in syringes (if applicable for your preparation):
- Glass syringes: Stable for up to 91 days with >95% concentration retained 2
- Plastic syringes: Stable for 35-55 days (depending on syringe size) with >93% concentration retained 2
- Important caveat: After 18 months of storage in syringes, rubber plunger leachates can contaminate the solution, though this is well beyond practical clinical use 2
Critical Stability Factors
Oxidation susceptibility: Dexamethasone sodium phosphate is chemically prone to degradation by oxidation under certain conditions 3, 4
- Some commercially available dexamethasone sodium phosphate products have shown oxidative degradation issues when stored long-term in original vials 4
- The diluted preparation in bacteriostatic saline appears more stable than some commercial formulations 1
Practical Recommendations
- Label with beyond-use date: 28 days from preparation date 1
- Storage location: Either refrigerated or at controlled room temperature is acceptable 1
- Inspect before use: Check for clarity, color changes, or particulate matter before each withdrawal 1
- Avoid extended storage: Do not exceed 28 days even if solution appears clear 1
Common Pitfalls to Avoid
- Do not assume longer stability: While some studies show stability beyond 28 days in certain containers, the conservative 28-day limit is evidence-based for bacteriostatic saline dilutions 1
- Do not use if discolored: Any visual change indicates potential degradation 1
- Avoid extreme storage: Keep away from direct light and temperature extremes outside the 4-22°C range 1