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Preservative-free sterile-water reconstitution diluent (single-use)
Overview
Sterile Water for Injection (SWFI) is the preservative-free, single-use reconstitution diluent. The absence of any preservative — the distinction from Bacteriostatic Water — makes it the appropriate choice in two cases: preparations intended for single use within a short window after reconstitution, where multi-use preservation is unnecessary; and peptides whose chemistry or downstream application is incompatible with benzyl alcohol or other preservatives. It is also the diluent of choice where a sterile-filled finished preparation builds its preservation system into the formulation rather than the diluent. It is supplied as a characterized ancillary diluent rather than a research-target molecule. Lyochem supplies SWFI in sterile vial formats to USP Water for Injection monograph specifications, with sterility, bacterial endotoxin (LAL), and pH documented on the release packet; EP / BP / JP equivalents are available on request. Because there is no preservative, an opened vial has a limited multi-use life (microbial ingress after septum puncture is the limiting factor), so SWFI is matched to single-use or short-window preparation. Match the diluent to the peptide's stability profile: acidic-pH-requiring peptides use the 0.6% acetic-acid diluent; preservative-incompatible peptides use SWFI; preservative-compatible peptides for multi-use can use BAC Water.
Applications & buyer fit
Solvents and ancillaries are the bench-support consumables a lab pairs with a reference standard once it leaves the freezer — bacteriostatic and sterile water, isotonic saline, 0.6% acetic-acid water, and glacial acetic acid for in-house diluent prep. These are diluents and process auxiliaries rather than research targets, so the documentation is diluent / solvent-grade (component identity, sterility, endotoxin, pH / osmolality, pharmacopeia monograph) rather than the peptide HPLC + MS + sequence packet. Diluent selection follows the peptide's stability profile: acidic-pH-requiring proteins use the acetic-acid water; preservative-incompatible peptides use sterile water; preservative-compatible peptides for multi-use vials use BAC water.
Academic Laboratories
Universities, medical schools, and government research institutes qualifying a reference standard for a method-development or in vivo workflow.
Core Facilities & Instrumentation Cores
Shared instrumentation cores, mass-spec facilities, and departmental analytical labs holding reference standards for cross-PI method validation and reagent qualification.
Contract Research Organisations (CROs)
CROs running preclinical and translational studies on behalf of academic, biotech, or pharma sponsors who need traceable reference material across multi-site campaigns.
Every release ships with its own batch-specific CoA — identity, purity, and the analytical scope agreed at quote stage, tied to the exact lot you receive.
Review a representative batch CoA before you order, so you can confirm the packet matches what your method or sponsor audit needs.
Supplied strictly as a research reagent to research institutions — not a finished dosage form and not for human administration. Buyer qualification runs at the inquiry stage.
Specifications
Documentation available on request
Regulatory note
Preservative-free reconstitution diluent for single-use preparations; supplied for Research Use Only. Verify sterility, pyrogen (LAL), and injectable-grade compliance with the destination market's requirements before use.
Frequently asked questions
Benzyl alcohol (the preservative in BAC Water) associates with the surface of some short peptides, which can shift solubility, accelerate aggregation, or interfere with benzyl-alcohol-sensitive downstream assays. Preservative-free SWFI removes that concern entirely, at the trade-off that the opened vial must be used within a short window because nothing inhibits microbial growth after septum puncture. For documented benzyl-alcohol-compatible peptides, BAC Water is operationally simpler; for new or untested peptides, SWFI is the conservative default.
Lyochem supplies SWFI to the USP Water for Injection monograph (strict limits for total organic carbon, conductivity, microbial limits, and bacterial endotoxin), with sterility and pH documented on the release packet. International equivalents (EP, BP, JP) are available on request; specify the required monograph at quote stage so the documentation references it.
SWFI is preservative-free and neutral but unbuffered and non-isotonic, suited to single-use preparation and preservative-incompatible peptides. Saline adds isotonicity (≈ 300 mOsm/L) for physiological compatibility, and BAC Water adds benzyl-alcohol preservation for multi-use vials. The peptide's recommended diluent is noted on its COA; the three cover the common reconstitution cases.
Related peptides
0.9% benzyl-alcohol bacteriostatic reconstitution diluent (multi-use)
0.9% isotonic sodium-chloride reconstitution diluent