Bacteriostatic Water
Stocked in 3ml, 10ml, 30ml at MontanaPep in Great Falls, Montana. Sold for laboratory research use only.
| Size | Catalog no. | Price per vial |
|---|---|---|
| 3ml | BW3 | $5 |
| 10ml | BW10 | $10 |
| 30ml | BW30 | $15 |
Classification
Laboratory reconstitution diluent — sterile water preserved with 0.9% benzyl alcohol; not a peptide or research compound
Structure and chemistry
Bacteriostatic water is sterile water containing 0.9% (9 mg/mL) benzyl alcohol as a preservative. Benzyl alcohol (phenylmethanol, C7H8O, molecular weight about 108.1 g/mol) is a simple aromatic alcohol. The solution contains no buffer or other added solute; pharmacopeial bacteriostatic water is specified at a pH of about 5.7, within a range of 4.5 to 7.0.
What the published research shows
Not a research subject in its own right. Its relevance is practical: when a reconstituted research material will be sampled repeatedly over a period of time, a preserved diluent limits the growth of microorganisms introduced by repeated vial entry. Peptide handling guidance treats it as the preserved alternative to plain sterile water for multi-withdrawal work, with one caveat: compatibility depends on the material, because formulation studies have shown that benzyl alcohol can promote aggregation of some proteins.
Mechanism of action
Water is the solvent; benzyl alcohol is the preservative. At 0.9% it is bacteriostatic rather than sterilizing: it suppresses microbial growth, largely by disrupting microbial cell membranes, but it does not sterilize a solution that is already contaminated. Like other alcohol preservatives it can also interact with hydrophobic regions of some proteins, which is the basis of the aggregation effects reported in formulation research.
Development history
A standard laboratory and pharmacopeial reagent rather than a developed product. Bacteriostatic water is described by a United States Pharmacopeia (USP) monograph, and preservative performance in multiple-withdrawal containers is assessed under USP general chapter <51>, Antimicrobial Effectiveness Testing.
Current regulatory status
A laboratory reagent for reconstituting and diluting research materials, supplied for research use only. Because it is preserved, a vial can be entered more than once; it should still be handled aseptically, and compatibility with a given material should be confirmed before use in a protocol.
Analytical testing
Relevant specifications are sterility, bacterial endotoxin, benzyl alcohol content (typically assayed by gas or liquid chromatography), pH and, for the preservative system, antimicrobial effectiveness. HPLC peptide analysis is not applicable to a diluent; a certificate of analysis should state the benzyl alcohol concentration and the endotoxin limit.
Ordering from Great Falls
MontanaPep, also known as Montana Peptides, is an independently owned supplier based at 715 13th Ave S, Great Falls, Montana. Local pickup is available by arrangement, and we ship to research addresses across Montana including Billings, Missoula, Bozeman, Helena, Butte, Kalispell and Havre. Call (406) 799-0812 or email customerservice@montanapep.com.