Benzalkonium chloride (BAC) is widely used in antimicrobial formulations because of its broad-spectrum activity and effectiveness in microbial control. It remains one of the most commonly used preservatives in ophthalmic formulations.
As a highly cationic compound, it is not compatible with formulations containing anionic ingredients. In its concentrated form, the substance can be aggressive and is highly toxic to aquatic organisms. However, its relatively rapid degradation can help reduce its persistence in the environment.
BAC Features
- Broad-spectrum efficacy against bacteria, fungi, and enveloped viruses
- Effective across a wide pH range (4–11)
- High stability under varying temperature and pH conditions
- Non-volatile and non-flammable
- Cost-effective, requiring relatively low concentrations for effective action
- Strong surfactant properties
- Soluble in both aqueous and oily systems
The minimum inhibitory concentration (MIC) for most common Gram-positive and Gram-negative bacteria, yeasts, and molds is typically below 50 ppm (0.005%). However, higher concentrations may be recommended depending on the intended application and the desired bactericidal or antifungal effect.
