If a single dose vial is not punctured in an ISO Class 5 or better hood, it must be used within how many hours?

The correct time frame for using a single-dose vial that remains unpunctured in an ISO Class 5 or better hood is indeed one hour. This regulation is grounded in the need to minimize the risk of contamination, which can lead to potentially harmful infections for patients.

According to the United States Pharmacopeia (USP) guidelines, specifically USP Chapter <797>, single-dose vials are intended for use immediately after opening. If they are not accessed when placed in a sterile compounding environment, the risk of microbial contamination increases over time. Therefore, to maintain the integrity of the sterility and reduce risk to patient safety, it is essential to use such vials within one hour of placement in a controlled environment, like an ISO Class 5 hood.

The other options, indicating longer time frames such as 2, 4, or 8 hours, do not align with the strict guidelines provided for the handling of single-dose preparations, which are meant to ensure the highest safety standards in pharmacy practice. Ensuring that vials are used promptly is crucial for patient health and compliance with pharmacy regulations.