Bacteriostatic Water
Unopened vials of bacteriostatic water can be stored at room temperature for up to 2 years from the date they were manufactured and should not be used beyond the labeled expiration date.
After opening a vial, record the date and discard any remaining solution after 28 days at most. If the fluid becomes cloudy, changes color, or shows any signs of contamination, it should be discarded immediately.
Why the 28-Day Limit?
According to USP <797> guidelines on sterile compounding, a standard beyond-use date of 28 days is applied to any multi-dose container that contains an antimicrobial preservative. This is also supported by safety recommendations from the CDC.
Bacteriostatic water falls into this category due to its content of 0.9% benzyl alcohol (9 mg/mL), which acts as a preservative. While it helps limit bacterial growth, it does not completely eliminate it. The preservative’s effectiveness can diminish each time the vial is accessed.
Storage of Sterile Lyophilized Peptides
Sterile freeze-dried peptides should be stored in a freezer to maintain stability. To minimize exposure to moisture during storage, they are sealed under vacuum or filled with nitrogen. This vacuum seal may sometimes make it difficult to withdraw reconstituted peptide from the vial.
Before use, allow the vial to reach room temperature prior to mixing with appropriate laboratory solvents or reagents.
After reconstitution, store the solution in a refrigerator between 2 and 8 degrees Celsius, keeping it above freezing.