Chlorhexidine Gluconate Solution CAS 18472-51-0

1. Physical and Chemical Properties

Commercially, Chlorhexidine Gluconate is almost exclusively sold as a 20% aqueous solution. The pure salt is difficult to handle and dissolve, so the 20% solution offers the perfect balance of stability and ease of formulation.

Formulator’s Note: Because CHG is cationic, it is incompatible with anionic surfactants (like common soaps or SLS). Mixing the two will cause the CHG to precipitate and lose its antimicrobial activity.

2. Applications: A Versatile Guardian

The 20% solution is a raw material concentrate. It is rarely used at full strength but is the backbone for a wide array of finished products:

• Surgical Hand Scrubs & Pre-op Preps: Usually diluted to 2% or 4% formulations. It binds to the skin proteins, providing a “persistent effect” that kills bacteria for hours after application.
• Oral Hygiene: The active ingredient in prescription mouthwashes (typically 0.12% or 0.2%) to treat gingivitis and reduce plaque.
• Medical Device Disinfection: Used to disinfect catheter insertion sites and medical equipment.
• Veterinary Care: A staple in wound care sprays and shampoos for pets to treat skin infections.
• Personal Care: Increasing use in hand sanitizers (often combined with alcohol) and antibacterial wet wipes.

3. Safety Precautions: Handle with Care

While CHG is safe for end-users in diluted forms, the 20% concentrate requires professional handling protocols.

• Eye Hazard: This is the most critical risk. Concentrated CHG can cause serious, permanent eye damage. Safety goggles are non-negotiable for workers handling the raw material. If contact occurs, immediate and prolonged irrigation is vital.
• Ototoxicity (Ear Safety): CHG must not enter the middle ear. If it crosses a perforated eardrum, it can cause sensorineural deafness. Care must be taken during head and neck procedures.
• Anaphylaxis: Though rare, hypersensitivity reactions can occur.
• Incompatibility: As mentioned, keep away from inorganic anions (sulfates, chlorides) and anionic soaps to prevent deactivation.

For other cationic antimicrobial raw materials, see PHMB and Benzalkonium Chloride.

4. Storage Conditions: Protecting the API

Chlorhexidine Gluconate is a sensitive molecule. Improper storage can lead to an increase in PCA levels (degradation) or color changes.

• Light Protection: The product is photosensitive. It must be stored in opaque containers or dark areas. Exposure to direct sunlight accelerates degradation.
• Temperature Control: Store at room temperature (controlled). Do not freeze. Freezing can cause the active ingredient to precipitate, and redissolving it can be difficult and may alter the concentration uniformity. Avoid excessive heat (above 40°C).
• Container Material: High-Density Polyethylene (HDPE) drums or plastic pharmaceutical-grade bottles are standard. Avoid long-term contact with metals that might corrode or leach ions.

5. Quality Control: The Impurity Factor

When comparing quotes for CAS 18472-51-0, do not just look at the price per kg. Look at the Certificate of Analysis (COA).

The defining characteristic of high-quality CHG is the level of p-Chloroaniline (PCA).

• Standard Grade: Suitable for general disinfection.
• Pharma Grade (EP/USP): Requires PCA levels to be extremely low (often < 500 ppm or lower limits depending on the specific monograph).

We work with manufacturers who perform High-Performance Liquid Chromatography (HPLC) testing on every batch to ensure the impurity profile meets the strict requirements of export markets in Europe and the Americas.