Sterile Water for Injection
Purified water that has been sterilised and is free from preservatives, intended for single-use reconstitution of injectable medications. Unlike bacteriostatic water, it contains no preservative, so reconstituted peptides must be used promptly or discarded.
Technical Context
SWFI (USP) is purified water that has been sterilised by autoclaving or membrane filtration, packaged in single-use containers, and contains no preservatives, antimicrobials, or added substances. Specifications: pH 5.0-7.0, conductivity ≤1.3 μS/cm at 25°C, TOC (total organic carbon) ≤500 ppb, endotoxin <0.25 EU/mL. Because it lacks preservatives, reconstituted peptide solutions using SWFI should be used immediately or within 24 hours (refrigerated) — there is no antimicrobial protection against contamination during withdrawal. SWFI is required for: neonatal preparations, single-dose immediate-use products, and patients with benzyl alcohol sensitivity. For research peptide reconstitution, the choice between BWFI and SWFI depends on whether multiple withdrawals from a single reconstituted vial are planned.