Bensalkoniumkloridi

Bensalkoniumkloridi, known in English as benzalkonium chloride (BAC), refers to a family of quaternary ammonium compounds that act as cationic surfactants with antimicrobial properties. Typical preparations are mixtures of alkylbenzyldimethylammonium chlorides, with alkyl chains commonly ranging from C8 to C18. In solution, BAC molecules carry a positive charge and interact with microbial cell membranes.

The antimicrobial action arises from disruption of lipid-containing membranes, causing increased permeability and cell death. BAC is active against many Gram-positive bacteria and some Gram-negative bacteria, certain fungi, and enveloped viruses; activity against non-enveloped viruses is generally more limited. As a preservative and antiseptic, BAC is widely used in various medicinal and consumer products at low concentrations.

Common uses include ophthalmic solutions, nasal sprays, topical antiseptics, and some disinfectants for surfaces and skin. In ophthalmology, benzalkonium chloride is frequently employed as a preservative in eye drops at small, regulated concentrations to maintain sterility between uses. It is also used in some skin cleansers, mouthwashes, and other liquid pharmaceutical formulations. As a disinfectant, BAC is valued for its broad-spectrum activity and relatively low cost, though formulations and concentrations vary by product and region.

Safety and environmental considerations are important. BAC can cause skin and eye irritation and may trigger allergic reactions in susceptible individuals; prolonged or repeated exposure can be problematic, particularly for contact lens wearers or people with sensitive eyes. Environmentally, BAC is toxic to aquatic organisms and can persist in water. Regulatory oversight in many jurisdictions governs permissible concentrations and approved uses in medicines, cosmetics, and cleaning products.

See also: quaternary ammonium compounds, antiseptics, preservatives.