Benzalkonium chloride is used as an antiseptic, often in combination with other antiseptic agents for inflammation of the throat and mouth. Beyond this application, it serves as a preservative and disinfectant for semisolid and liquid drug preparations.
What is benzalkonium chloride?
Benzalkonium chloride is used as an antiseptic, often in combination with other antiseptic agents for inflammation of the throat and mouth. Benzalkonium chloride belongs to the active substance group of antiseptics and has a soap-like substance. The active ingredient is a large molecule in the form of a cationic compound that is positively electrically charged. Due to shaping and charge, benzalkonium chloride is fat and water soluble. It is able to penetrate cell walls of bacteria, lodge there and kill the pathogens.
Pharmacological action
Medically, benzalkonium chloride is used as an antiseptic agent to treat inflammation of the throat and mouth. Due to its fine soap-like substance, it attaches to the inflamed mucous membrane of the mouth and throat, where it counteracts the bacteria that cause inflammation. The antiseptic contains a large molecule that registers an electric charge due to its cationic compound, making it fat and water soluble. As a cation with an electric charge, the substance has hydrophilic and lipophilic properties that enable the antiseptic agent to incorporate into the cell walls of bacteria responsible for inflammatory processes in the mouth and throat. It lodges there, making the bacteria permeable and preventing further bacterial growth. This inhibition of growth causes the death of the pathogens. Due to its broad spectrum of activity, benzalkonium chloride combats both gram-negative and gram-positive bacteria. Pharmaceutically, the active ingredient is also used as a preservative and disinfectant for semisolid and liquid medicines such as creams, sprays and eye and nose drops. The antiseptic inhibits the growth of germs and kills these pathogens during the production of drug preparations. As a disinfectant, it is effective against yeasts, algae, fungi and bacteria. To a lesser extent, benzalkonium chloride has an antiviral effect. Due to its surface-active mode of action, benzalkonium chloride is also used as a disinfectant and cleaning agent in hospitals and medical practices. It is equally suitable for laundry disinfection and as an algicide in swimming pools.
Medical application and use
The main indication for the use of this antiseptic is inflammation of the mouth and throat due to infections. Typical accompanying symptoms are difficulty swallowing, sore throat, and general malaise. When applied topically, the antiseptic is well tolerated. Even as lozenges, concentrate or spray solution, it only rarely registers dangerous side effects. Only when using eye drops containing benzalkonium chloride as a preservative should increased caution be exercised and, if in doubt, the advice of an ophthalmologist or optometrist should be sought. Antiseptic preservatives in eye drops have been used since 1978. Eye drops containing this active ingredient lead to reduced stability of the tear film and, with regular use, to inflammation of the ocular surface, causing what is known as “dry eye”. The cornea is attacked, resulting in significant damage to the deeper cell layers. If a tear substitute based on this active ingredient is used followed by eye drops containing another active pharmaceutical ingredient, the latter penetrates deeper and faster into the corneal layers. This results in undesirable effect enhancement and side effects. Eye drops that contain no preservatives or alternative preservatives are an alternative. The ophthalmologist decides in each individual case on the advantages and disadvantages and when the expected benefit is greater than any risk involved. Contact lens wearers and patients with dry eye and glaucoma should give preference to preservative-free eye drops. Information can also be obtained from the German Ophthalmological Society (DOG).
Risks and side effects
Benzalkonium chloride is generally a harmless antiseptic or disinfectant. Nevertheless, some special features must also be taken into account in this case.The antiseptic must not be used in case of known hypersensitivity to one or more of the ingredients. There are no special regulations for use in children and adolescents, pregnant women and nursing mothers can also use the antiseptic. Side effects are very few known. Moreover, they occur rarely. They include allergic skin reactions, redness or itching. The general experience is that benzalkonium chloride is well tolerated when applied to the affected mucous membranes. A contraindication is fresh and large wounds in the mouth and throat. A positive aspect is that this active ingredient does not cause cross-resistance with other antiseptics. Pathogens treated with benzalkonium chloride do not become resistant to other substances from the antiseptic group. For this reason, there are no known interactions with other substances or drug preparations.
