What is bacteriostatic sterile water?
Two USP monographs carry “bacteriostatic” in the name and they are different products. Bacteriostatic Water for Injection is water with one or more antimicrobial agents. Bacteriostatic Sodium Chloride Injection is an isotonic salt solution with them, fixed at 0.85–0.95% NaCl.
| Published name | USP definition | Strength or antimicrobial wording | Label detail |
|---|---|---|---|
| Sodium Chloride Injection | Sterile solution of Sodium Chloride in Water for Injection. | No antimicrobial agents; NLT 95.0% and NMT 105.0% of the labeled amount of NaCl. | Hospira: sodium chloride 9 mg/mL; “no bacteriostat, antimicrobial agent or added buffer”; single-dose containers; pH 5.3 (4.5 to 7.0). Grifols: 9 g/L; 308 mOsmol/L (calc). |
| Bacteriostatic Sodium Chloride Injection | Sterile, isotonic solution of Sodium Chloride in Water for Injection. | One or more suitable antimicrobial agents; NLT 0.85% and NMT 0.95% of NaCl. | Hospira and Fresenius Kabi: sodium chloride 9 mg/mL; benzyl alcohol 0.9%. Hospira prints “NOT FOR USE IN NEONATES”. |
| Bacteriostatic Water for Injection | Prepared from Water for Injection that is sterilized and suitably packaged. | Containing one or more suitable antimicrobial agents. | — |
| Sterile Water for Injection | Prepared from Water for Injection that is sterilized and suitably packaged. | No antimicrobial agent or other added substance. | — |
What is bacteriostatic water?
The water half of this comparison is covered in bacteriostatic water vs sterile water. USP defines Bacteriostatic Water for Injection as prepared from Water for Injection that is sterilized and suitably packaged, containing one or more suitable antimicrobial agents. Sterile Water for Injection is prepared from Water for Injection that is sterilized and suitably packaged and contains no antimicrobial agent or other added substance. The distinction is the antimicrobial wording.
What is bacteriostatic sodium chloride?
USP gives the two sodium chloride monographs different kinds of salt wording. Sodium Chloride Injection is a sterile solution of Sodium Chloride in Water for Injection. It contains no antimicrobial agents. It contains NLT 95.0% and NMT 105.0% of the labeled amount of NaCl. Bacteriostatic Sodium Chloride Injection is a sterile, isotonic solution of Sodium Chloride in Water for Injection. It contains one or more suitable antimicrobial agents. It contains NLT 0.85% and NMT 0.95% of NaCl. The plain monograph expresses its range around the labeled amount, while the bacteriostatic monograph gives an absolute NaCl range. Only the latter fixes strength in its own wording.
Bacteriostatic saline vs saline: what the labels say
Hospira publishes both products, which makes the pair worth reading together. Its Bacteriostatic Sodium Chloride Injection label declares “sodium chloride 9 mg and 0.9% (9 mg/mL) benzyl alcohol added as a bacteriostatic preservative”, and prints “NOT FOR USE IN NEONATES”. Its plain 0.9% Sodium Chloride Injection label declares the same salt — “Each mL contains sodium chloride 9 mg” — and then the opposite of the rest: it “contains no bacteriostat, antimicrobial agent or added buffer and is supplied only in single-dose containers to dilute or dissolve drugs for injection”. Same company, same salt, same stated purpose. The preservative and the container are what differ.
Two other labels agree on the salt figure from their own directions. Fresenius Kabi’s bacteriostatic label gives sodium chloride 9 mg per mL with benzyl alcohol 0.9%. Laboratorios Grifols’ plain Sodium Chloride Injection gives 9 g/L — the same concentration written another way — with “no antimicrobial agents” and an osmolarity of 308 mOsmol/L (calc), against the zero osmolarity the water products print.
Common identification mistakes
Two things on this page are easy to read as more than they are. The first is the reference-standard list. The Bacteriostatic Sodium Chloride Injection monograph’s preview carries a second section the other three do not — “USP Reference Standards for purchase: USP Methylparaben RS, USP Propylparaben RS” — which reads like a statement that the product is preserved with parabens. It is not. A reference standard is what a monograph’s tests are run against. Both manufacturer labels quoted above declare benzyl alcohol, and the Fresenius Kabi label agrees with Hospira’s on both figures: sodium chloride 9 mg/mL, benzyl alcohol 0.9%.
The second is container type. None of the four USP definitions quoted above mentions a container at all; each stops at the solution itself. Single-dose and multiple-dose are what an individual label says of its own product — Grifols names single dose containers — and they are not properties of the four published names. FDA’s container-type definitions are covered in single-dose vs multi-dose vials, and the site’s method is described at how we verify.
No retail listing is linked because every product here is a prescription drug product identified by an NDC, and a retail listing would have to carry that NDC to match one.
Sources
- USP-NF — Sodium Chloride Injection
- USP-NF — Bacteriostatic Sodium Chloride Injection
- USP-NF — Bacteriostatic Water for Injection
- USP-NF — Sterile Water for Injection
- DailyMed — Bacteriostatic Sodium Chloride Injection, Hospira, Inc.
- DailyMed — Bacteriostatic Sodium Chloride Injection, Fresenius Kabi USA, LLC
- DailyMed — 0.9% Sodium Chloride Injection, USP, Hospira, Inc.
- DailyMed — Sodium Chloride Injection, Solution, Laboratorios Grifols SA
Specifications last verified: