BAC Water

BAC Water Product Profile

BAC Water is an essential laboratory and formulation supply item required for professional peptide research and cosmetic compounding applications.

Product Specifications

Parameter	Value
Composition	H₂O + 0.9% Benzyl Alcohol
Mol. Weight	18.02 g/mol (solvent)
Grade	USP Grade
Appearance	Crystal clear sterile solution

Figure 1: BAC Water Overview

Application Details

1. Serves as the universal, sterile reconstitution solvent for all lyophilized peptide vials.
2. Contains precisely 0.9% benzyl alcohol as a bacteriostatic preservative agent.
3. The benzyl alcohol prevents microbial contamination across multiple needle entries.
4. Allows a single reconstituted vial to be safely used over multi-day dosing schedules.
5. Maintains the structural integrity of peptide bonds during the dissolution process.

Figure 2: Quality Metrics

Key Notes

• 1: The industry-standard solvent required before any lyophilized peptide can be administered.
• 2: Multi-dose vial safety: prevents bacterial growth for up to 28 days post-reconstitution.
• 3: Must be stored refrigerated (2-8°C) after opening to maintain sterility.

What Is Bacteriostatic Water?

Bacteriostatic water (BAC water) is sterile water that contains 0.9% benzyl alcohol as an antimicrobial preservative. Unlike sterile water for injection, which must be discarded after a single puncture, BAC water can be used for multiple withdrawals over a 28-day period without microbial contamination. This makes it the standard reconstitution solvent for lyophilized (freeze-dried) peptide vials in research settings.

Proper Reconstitution Protocol

1. Remove the flip-off cap from both the peptide vial and the BAC water vial. Swab each rubber stopper with a fresh 70% isopropyl alcohol pad.
2. Using a sterile syringe (insulin-type, 1 mL), draw the desired volume of BAC water. Common reconstitution volumes are 1–2 mL per vial depending on the peptide mass and desired concentration.
3. Insert the needle into the peptide vial at an angle and allow the water to trickle slowly down the inside wall of the glass. Do not inject directly onto the lyophilized cake, as high-pressure streams can denature fragile peptide bonds.
4. Allow the vial to sit for 60–90 seconds. Gently swirl in a circular motion until the powder is fully dissolved. Never shake vigorously—mechanical agitation causes peptide aggregation and loss of bioactivity.
5. Once reconstituted, store the peptide solution at 2–8°C (standard refrigerator). Use within 28 days for optimal stability and sterility.

Storage & Safety Considerations

• Temperature: Store unopened BAC water at controlled room temperature (20–25°C). Once opened, refrigeration extends usable life.
• Benzyl Alcohol Sensitivity: A small percentage of individuals exhibit sensitivity to benzyl alcohol. In such cases, sterile water for injection or GAC water may be substituted.
• Multi-Dose Use: Each puncture of the rubber stopper should use a fresh, sterile needle to maintain the closed-system integrity of the vial.
• Expiry: Discard any BAC water vial 28 days after the first puncture, regardless of remaining volume, to comply with USP <797> beyond-use dating guidelines.
• Compatibility: BAC water is compatible with the vast majority of research peptides. Exceptions include GLP-1 agonists supplied in pre-buffered formulations that specify their own diluent.