Why must the rubber stopper of a multidose vial be disinfected before use?

The rubber stopper of a multidose vial must be disinfected before use primarily to maintain sterility during each entry. This practice is crucial because each time a needle penetrates the stopper to withdraw medication, there is a potential risk of introducing pathogens or contaminants into the vial. Disinfecting the stopper effectively reduces this risk, thereby helping to preserve the integrity of the medication inside.

Maintaining sterility is essential not only for ensuring that the medication remains safe for patient use but also for preventing healthcare-associated infections that can occur from contaminated solutions. Therefore, thorough disinfection of the stopper before each use is a critical component of safe medication administration practices.