The USP requires preservatives for all emulsions.

• A. True
• B. False
• C. Not specified
• D. Sometimes

Answer: (A)

Emulsions typically contain an aqueous phase, and water-rich systems are-prone to microbial growth. The USP framework treats non-sterile emulsions that are stored or dispensed in a way that can introduce microorganisms as needing a preservative to protect safety and shelf life. A preservative helps prevent contamination by bacteria, fungi, and yeast that could otherwise thrive in the aqueous environment during storage or repeated use, especially in multi-dose containers. There are exceptions—for sterile, single-dose emulsions manufactured aseptically, a preservative may not be required—but for the common non-sterile, multi-dose emulsions the preservative requirement aligns with USP expectations.