In which situation is it inappropriate to use a closed system transfer device?

Using a closed system transfer device (CSTD) is designed to minimize the risk of contamination and exposure when handling hazardous drugs and substances. CSTDs are especially important in situations where drugs have the potential to be toxic or hazardous, as they provide a barrier that helps to prevent leakage or aerosolization of these substances.

Testing the potency of a drug does not require the use of a CSTD because the goal is to assess the efficacy and strength of a drug in a controlled setting, typically within a laboratory environment. This process usually involves handling the drug in ways that do not necessitate the protective barriers offered by CSTDs. Moreover, the focus during potency testing is on accuracy and ensuring the integrity of the drug sample rather than minimizing exposure risks.

CSTDs are well-suited for administering hazardous agents, preparing large volume parenterals, or mixing non-hazardous solutions, as these scenarios typically involve extensive handling of drugs where safer methods would be beneficial to prevent contamination or exposure. Thus, testing the potency of a drug stands out as a situation where the use of a CSTD is not appropriate.