Bacteriostatic Water
Sterile Water for Injection, USP · 0.9% (9 mg/mL) benzyl alcohol
Bacteriostatic water is sterile, non-pyrogenic water for injection to which benzyl alcohol has been added at 0.9% w/v as a bacteriostatic preservative. Benzyl alcohol inhibits the multiplication of bacteria introduced during vial entry, which is what allows a single sealed vial to be punctured repeatedly. Preservative-free sterile water for injection carries no such agent and is single-entry only.
It is used as a diluent to reconstitute lyophilized (freeze-dried) compounds. The solution is isotonic-adjusted at the point of use by the solute being dissolved; on its own it is hypotonic relative to serum. Benzyl alcohol is bacteriostatic rather than bactericidal, so it suppresses growth without sterilizing a contaminated solution.
| Composition | Water for Injection, USP + benzyl alcohol 0.9% w/v (9 mg/mL) |
|---|---|
| Preservative action | Bacteriostatic (inhibits bacterial multiplication) |
| pH | 4.5 – 7.0 |
| Sterility | Sterile, non-pyrogenic |
| Vial type | Multiple-dose; rubber septum, aluminum seal |
| In-use period after first entry | 28 days, per USP multiple-dose container convention |
| Storage | 20–25 °C (68–77 °F); excursions permitted 15–30 °C |
3 mL
10 mL
30 mL
Sold for laboratory research and development use only. Not for human or veterinary use, and not for diagnostic or therapeutic use.