BPS Sterile Compounding Practice Exam

Sodium benzoate is classified as a preservative typically used for its antibacterial and antifungal properties, but it does not primarily function as a bacteriostatic agent. Bacteriostatic agents specifically inhibit bacterial growth and reproduction without killing the bacteria outright. While sodium benzoate can help preserve the integrity of formulations by preventing microbial proliferation, it does not exert a clear mechanism of action that fits into the definition of a bacteriostatic agent in the same way that methylparaben, benzyl alcohol, and propylparaben do.

Methylparaben and propylparaben, both part of the paraben family, and benzyl alcohol are traditional bacteriostatic agents that effectively inhibit the growth of bacteria, allowing for extended shelf life and safety in pharmaceutical formulations. Their primary action is to disrupt cellular processes of the microorganisms, thereby inhibiting their ability to reproduce.

By contrast, sodium benzoate serves more as a general preservative. It operates well at acidic pH levels and protects against the growth of fungi and bacteria but does not specifically act to inhibit bacterial reproduction in the same consistent manner as the others listed; hence, it is the choice that does not fit the criteria of a bacteriostatic agent.