Bacteriostatic Water 2ml

Bacteriostatic Water is a sterile, preservative‑containing diluent that enables safe, short‑term storage of reconstituted injectable medications. It is simple to use, well‑tolerated, and widely accepted in clinical practice, provided the user respects its limits (≤ 1 mL per injection, no use in neonates, discard after 28 days).

Description

Bacteriostatic Water Quick Reference Guide

What It Is

  • Definition – Sterile water for injection that contains 0.9 % benzyl‑alcohol as a preservative.
  • Purpose – Allows reconstituted lyophilized drugs (e.g., peptides, vaccines, hormones) to be stored at room temperature for up to 28 days without microbial growth.
  • Formulation – 2 mL vial = sterile water + benzyl‑alcohol (0.9 %).
# Point
1 Preservative – Benzyl‑alcohol provides bacteriostatic activity (prevents bacterial proliferation).
2 Shelf‑life – Once opened, the solution remains usable for ≤ 28 days at ≤ 25 °C (room temp) if kept sealed.
3 Compatibility – Safe for most injectable peptides, hormones, and vaccines; do not use with drugs that are alkaline‑sensitive or where benzyl‑alcohol is contraindicated (e.g., neonates, intrathecal injections).
4 Administration – Intended only as a diluent; never injected alone.
5 Regulatory status – Classified as a sterile pharmaceutical excipient; FDA‑approved for parenteral use.
6 WADA – Not a prohibited substance (it’s an inert diluent).

Pharmacodynamics

  • Benzyl‑Alcohol binds to bacterial cell membranes, disrupting protein function and halting replication.
  • The concentration (0.9 %) is bacteriostatic, not bactericidal – it stops growth but does not kill existing organisms.
  • Human tissues tolerate this low level; systemic absorption is minimal because the volume used per injection is small (< 1 mL).

Pharmacokinetic Snapshot (Benzyl‑Alcohol Component)

Parameter Approx. Value*
Absorption Rapid diffusion from injection site into plasma (if inadvertently injected).
Distribution Widely distributed; low protein binding.
Metabolism Primarily hepatic oxidation to benzoic acid → conjugated with glycine to form hippuric acid.
Elimination Renal excretion of hippuric acid; half‑life ≈ 1–2 h.
Clearance ~0.5 L/h (adult).

*Values derived from adult pharmacology data for benzyl‑alcohol; the water component is inert.

Typical Use & Dosing

Drug Type Typical BW Volume Reconstitution Example
Peptide (e.g., 5 mg lyophilized) 1 mL – 5 mL per vial Add 1 mL BW → 5 mg/mL solution.
Hormone (e.g., 100 IU hCG) 0.5 mL – 2 mL Add 0.5 mL BW → 200 IU/mL.
Vaccine (rare) 0.5 mL – 1 mL Follow manufacturer’s instructions.
Maximum single‑dose injection ≤ 1 mL of BW‑reconstituted drug (unless the drug label permits larger volumes).

Never inject BW alone; always combine with the intended active ingredient.

Safety & Tolerability

Issue Frequency / Severity Comments
Injection‑site irritation ≤ 5 % Mild redness or pruritus; self‑limiting.
Systemic benzyl‑alcohol toxicity Rare (high cumulative dose) Symptoms: dizziness, nausea, CNS depression. Avoid large-volume or repeated intramuscular use.
Neonatal contraindication Strong Benzyl‑alcohol is contraindicated in newborns (risk of “gasping syndrome”).
Allergic reaction Very rare Anaphylaxis unlikely; stop use if severe rash or swelling occurs.
Compatibility issues Drug‑specific Some biologics (e.g., certain monoclonal antibodies) may be destabilized by alcohol; consult product labeling.

Practical Tips

  1. Inspect the vial – Ensure it’s clear, colorless, and free of particles before use.
  2. Keep it sealed – After first puncture, store the vial upright at ≤ 25 °C; discard after 28 days.
  3. Label reconstituted syringes – Include drug name, concentration, and preparation date.
  4. Avoid intrathecal or intra‑arterial routes – BW is not approved for these administrations.
  5. Document benzyl‑alcohol exposure – In clinical notes, especially for pediatric or high‑risk patients.