Question

As per USP, the maximum concentration of benzalkonium chloride used as a preservative in parenteral formulations is

• A. 0.01%
• B. 0.001%
• C. 0.05%
• D. 0.005%

Hint:

Always adhere to USP limits for preservatives in parenteral formulations to balance antimicrobial efficacy and patient safety.

Answer 1

The Correct Option is A

Benzalkonium chloride is a quaternary ammonium compound widely used as a preservative due to its antimicrobial properties. In parenteral formulations, preservatives are required to prevent microbial contamination during storage and use. According to the United States Pharmacopeia (USP) guidelines, the maximum permissible concentration of benzalkonium chloride in parenteral (injectable) formulations is 0.01%. Higher concentrations may pose toxicity risks such as irritation or sensitization. Therefore, strict limits ensure safety while maintaining effective antimicrobial activity. Using benzalkonium chloride within this concentration helps maintain sterility without compromising patient safety, which is crucial for injectable drug products.