Bacteriostatic Water

Overview

Bacteriostatic water (BAC water) is sterile water for injection containing 0.9% benzyl alcohol as a preservative. It is the standard diluent for reconstituting lyophilized peptides, allowing multi-dose use from a single vial by inhibiting bacterial growth.

Mechanism of Action

BAC water is preferred over sterile water for injection when multiple draws from a reconstituted peptide vial are anticipated. The benzyl alcohol preservative maintains sterility for up to 28 days after first puncture when stored under refrigeration. Sterile water (without preservative) should be used for single-use preparations or when benzyl alcohol sensitivity is a concern.

Key Research Areas

Considerations for Researchers

Always use proper aseptic technique when drawing from BAC water vials. Inspect for particulates before each use. Discard if solution appears cloudy or discolored. Use an appropriate gauge needle to avoid coring the rubber stopper.