Bacteriostatic Water (often labeled Bacteriostatic Water for Injection, USP) is sterile water that contains a small amount of benzyl alcohol (0.9%) as a preservative. It is commonly used in clinical and research settings to reconstitute medications or peptides intended for multi-dose use.

What Makes It “Bacteriostatic”?

• Contains 0.9% benzyl alcohol

• Inhibits (but does not kill) bacterial growth

• Allows multiple withdrawals from the same vial when handled properly

• Extends usability after first puncture compared to sterile water without preservative

Key Characteristics

• Sterile, non-pyrogenic

• Clear, colorless solution

• Multi-dose vial

• Preservative-based antimicrobial protection

• Not intended for large-volume IV infusion

Common Uses (General)

• Reconstitution of peptides and injectable medications

• Dilution of small-dose injectable drugs

• Situations requiring multiple withdrawals from the same vial

Storage Guidelines

• Store at 20–25 °C (68–77 °F) (controlled room temperature)

• Protect from excessive heat

• Keep vial tightly sealed

• Discard according to manufacturer guidance after first puncture (often 28 days)

Important Safety Notes

• Contains benzyl alcohol, which may not be appropriate for neonates or certain sensitive populations

• Not the same as Sterile Water for Injection (which contains no preservative and is typically single-use)

• Always use sterile technique when withdrawing solution

Summary

Bacteriostatic water is sterile water containing 0.9% benzyl alcohol that inhibits bacterial growth, making it suitable for multi-dose reconstitution in medical and research environments.