Closed-System Transfer Devices: Understanding Key Terms and Concepts

Closed-system transfer devices (CSTDs) are adapters that connect two medication containers—vials, syringes, or IV bags—to allow a hazardous drug (HD) to be transferred between the vessels without permitting any of the drug to escape. They are used to minimize personnel environmental exposure to HDs from the time the drugs are compounded in the pharmacy to the time they are administered to the patient by the clinician.

A CSTD system comprises various components, including CSTD administration set adapters, CSTD IV bag adapters, CSTD secondary administration set adapters, CSTD**syringe adapters, and CSTD vial adapters. CSTD adapters remain closed until connected together. Connecting a male and female adapter opens a pathway between them, enabling liquid transfer access. The pathway is established using either needle-based CSTD systems or needle-free CSTD systems. Pressure equalization needs to occur when transferring fluid between containers; drug vapors that are present in the drug vial are to be released during equalization and must be contained. Two key technologies to prevent vapor escape are CSTD**barrier technology and CSTD filter technology.

Here are definitions of terms and concepts related to closed-system transfer...