Benzalkonium Chloride (BKC) is a versatile compound widely used in the pharmaceutical industry. Its potent, broad-spectrum antimicrobial and surfactant properties make it the workhorse of antimicrobials and an essential ingredient in various pharmaceutical formulations. This page provides insights into the diverse pharmaceutical uses of Benzalkonium Chloride.
In what products is Benzalkonium Chloride used?
Basically, in any pharmaceutical formulation where you need an antimicrobial, antiseptic, antifungal, antiviral, or germicidal ingredient!
Use BKC to make your product pass the mandatory Antimicrobial Efficacy Tests (AET). Its chemical structure allows it to disrupt microbial cell membranes, leading to cell death of harmful bacteria, enveloped viruses, yeast and fungi.
BKC is used as an active ingredient or as a preservative excipient across therapies, administration routes and product forms. Here are examples of product forms using BKC:
- Solutions: Washes, flushes, coatings, foams, wipes, drops, sprays, shampoos, syrups, injectables, solutions for inhalers, nebulizers, and mists.
- Semi-solids: Gels, ointments, creams, pastes, glues, and adhesives.
- Solids: Lozenges, tablets, and chewable tablets.
Ophthalmic and nasal
BKC is commonly used as a preservative in multi-dose ophthalmic and nasal formulations. Its role is crucial in maintaining the sterility, efficacy and safety of these products over the product’s shelf life before and after container opening.
Several preservatives are currently employed in topical ophthalmic formulations, including alcohols, parabens, EDTA, chlorhexidine, and quaternary ammonium compounds (Quats). Due to their high antimicrobial efficacy and relatively low toxicity, Quats are preferred preservatives with BKC as the most common choice. To achieve the required level of preservative activity in ophthalmic products, BKC is typically used at concentrations ranging from 0.001% w/w (10 ppm) to 0.025% w/w (250 ppm).
BKC is used both in human and veterinary formulations for prophylactic or treatment use. Examples are dry eye, eye infections, allergies, glaucoma, flushing, etc.
For nasal formulations, BKC concentrations will be slightly higher, ranging typically from 0.005% (50 ppm) to 0.1% (1000 ppm), also for prophylactic or treatment use. Examples are allergy treatments, cold and flu treatment or prevention, infection/COVID and flu prevention. The nasal route is likewise very effective to deliver both small molecule and large molecules drugs and vaccines.
Other products are administered through the ears (otic route), such as combination nasal and otic drops, or pure otic products for ear cleaning, ear care, otitis treatment etc. where BKC is also used as a preservative.
Topical
The topical segment can be sub-segmented into countless product forms and therapy areas. In essence, BKC is used in topical products either as a broad-spectrum preservative excipient, or as an active ingredient in antiseptic, antifungal and antiviral products, or simply in products with an antimicrobial purpose. These formulations can be for clinical or pre-surgical and surgical use, and for OTC or prescription products to prevent sepsis, treat skin conditions or other conditions using the topical drug delivery route. In both human and veterinary products, BKC concentrations as an active will typically vary from 0.1% (1000 ppm) to 0.5% (5000 ppm).
Below are examples of topical uses for BKC.
Antiseptics
Antiseptics are extensively used both in hospitals, health care settings and households, for a variety of topical applications. They can reduce the microbial count and the risk of surgical site infections (SSIs). SSIs represent one of the most common complications of dermatologic surgery, why antiseptics should be used for all procedures that enter the dermis of the skin or deeper. Broad-spectrum antiseptics are some of the most popular in dermatologic surgery and commonly include BKC, chlorhexidine, povidone-iodine, chloroxylenol, isopropyl alcohol, hexachlorophene and hydrogen peroxide.
In clinical settings, BKC is used for skin disinfection before surgical procedures or injections. Its rapid action ensures a sterile environment, reducing the risk of infections.
In both clinical and household settings, BKC is often used as an active ingredient in antiseptic solutions, rubs, wipes, foams, sanitizers and soaps. As a strong surfactant, BKC will provide residual antimicrobial activity compared to volatile compounds.
Skin condition treatments
Medicated shampoos
Cold sores and pain relieving
It is also often present in pain-relieving gels and creams in combination with benzocaine or lidocaine.
Wound cleaning and wound healing
It is also used in products such as wound irrigation or flush solutions, antiseptic foams, antiseptic plasters and bandages, tissue adhesives and hemostatic pastes.
Women’s hygiene, spermicides, other
Oral and respiratory
Antimicrobial actives are often found in oral health products, as antiseptics (actives) or preservatives. Examples of antimicrobials found in oral formulations are BKC, Benzyl Alcohol, Cetylpyridinium Chloride, Chlorhexidine, Chloroxylenol, Ethanol, Parabens (Methylparaben, propylparaben), various Potassium and Sodium salts and Triclosan, and natural ingredients.
Below are examples of oral and respiratory products where BKC is used.
- Throat lozenges: BKC is often included in throat lozenges to provide antimicrobial action against bacteria and viruses in the oral cavity. This helps alleviate symptoms of sore throat and reduces the risk of secondary infections. They are often used in combination with a pain-relieving agent such as benzocaine or lidocaine. The use of antimicrobial throat lozenges can be beneficial in the treatment of minor throat infections caused by bacteria or fungi. Typical BKC concentration as an active ingredient is 2 mg per lozenge.
- Chew tablets: For ulcer and blister treatment and pain relief.
- Gum gels: Designed to relieve pain, such as those used for teething or sore gums, and they may contain antimicrobials in addition to pain-relieving ingredients. Antimicrobial agents may be added to help prevent infection and reduce inflammation in the affected area. This is particularly important for teething gels, as teething can create small openings in the gums where bacteria can enter and cause infection.
- Syrups: In cough syrups as a preservative.
Adhesives: denture adhesives as a preservative.
Dentistry products: as an active or preservative in rinsing fluids, antiseptic fills, irrigation solutions. - Nebulizers, inhalers: As a preservative in formulations for respiratory condition treatment or respiratory drug delivery.
Injectables
BKC is used as a preservative in some injectable formulations to prevent microbial contamination during manufacturing and storage. Its inclusion at approx. 0.02 mg/ml (0.002% or 20 ppm) can ensure the safety and efficacy of vaccines and various biopharmaceutical drugs including mabs and hormonal preparations.
If you consider using BKC in an injectable, you can contact our experts for support in performing your preservative risk assessment.
About preservatives
It is well recognized that microbial contamination of ophthalmic, nasal, and other drug products may occur during use. Predominantly, contamination of the bottle tip or the product formulation in the bottle can arise from physical contact of the tip with fingers or eyelashes that may carry microorganisms.
Preservatives are added to the formulation to eliminate the potential for contamination after opening bottles of topical ophthalmic, nasal, or other drug formulations. Based on USP <51> requirements, the concentration of preservatives in topical ophthalmic drug products must be sufficient to achieve 1.0 and 3.0 log reduction by days 7 and 14, respectively, along with no increase in survivors from days 14–28, and no increase in survivors for the fungi from day 0 to day 28 after inoculation with 10 colony forming units (cfu)/mL.
In addition to broad antimicrobial activity, preservatives should have suitable properties such as chemical and thermal stability, compatibility with the eye drop container and other compounds in the formulation, and negligible toxicity to the ocular tissues.
Consult our white papers for preservative compatibility and comparisons, and analytical support.
Why choose Benzalkonium Chloride?
- Proven bactericide against a broad spectrum of microorganisms: Gram + and – & acid-fast bacteria, yeast, moulds, enveloped viruses.
- Effective through a wide pH range (4-11).
- Very stable at various temperatures and pH.
- Non-volatile.
- Cost-effective due to activity at low concentrations.
- Strong surfactant can support active ingredient delivery and offers residual activity.
- Safe to use, non-flammable and widely available.
- Does not add color or odor to finished formulations.
- Soluble in both aqueous and oily phases.
Conclusion
Benzalkonium Chloride plays a vital role in the pharmaceutical industry, offering antimicrobial and preservative properties that are crucial for various formulations. The pharmaceutical uses of Benzalkonium Chloride are diverse and essential for maintaining product safety and efficacy. By adhering to regulatory guidelines and understanding its applications, one can harness its benefits of while ensuring patient safety.
