Ketamine Stability in Normal Saline
Ketamine infusions mixed in normal saline are stable for 7 days when stored at room temperature (23-25°C) in IV bags, based on the highest quality pharmaceutical stability data available.
Storage and Stability Parameters
The most rigorous pharmaceutical stability studies demonstrate that ketamine maintains >95% of its initial concentration for 7 days under the following conditions 1, 2:
- Storage temperature: Room temperature (23-25°C)
- Container types: Polyvinyl chloride (PVC) IV bags, polypropylene syringes, or glass bottles
- Light exposure: Stable even when exposed to ambient light
- pH stability: No significant pH changes over 7 days
- Physical stability: No precipitation, color change, or degradation products detected
Concentration Ranges Tested
The stability data covers a wide range of ketamine concentrations commonly used in clinical practice:
- Low concentration: 0.1 mg/mL ketamine in normal saline 1
- Moderate concentration: 0.2-0.6 mg/mL ketamine in normal saline 2
- High concentration: Up to 40 mg/mL ketamine in normal saline 1
All concentrations remained chemically stable and physically compatible throughout the 7-day study period.
Practical Clinical Recommendations
For immediate use: Ketamine infusions can be prepared and used immediately without stability concerns, as the FDA label indicates ketamine is formulated as a stable sterile solution 3.
For extended storage:
- Prepare ketamine infusions in normal saline up to 7 days in advance
- Store at room temperature (no refrigeration required)
- Use standard PVC IV bags or polypropylene syringes
- No special light protection needed
- Maintain sterile technique during preparation
Important Caveats
Sterility vs. stability: While chemical stability extends to 7 days, sterility testing in one study confirmed no bacterial growth over this period when proper aseptic technique was used 2. However, institutional policies may mandate shorter hang times (typically 24-96 hours) for infection control purposes, even though the drug itself remains chemically stable.
Combination preparations: When ketamine is mixed with other medications (such as opioids), the 7-day stability window still applies, though this depends on the specific combination 1, 2.
Refrigeration not required: Unlike some parenteral preparations, ketamine in normal saline does not require refrigeration and maintains stability at room temperature, making it practical for continuous infusion protocols 1, 2.