Isolators

General Chapter <797> defines two types of isolators and requires any isolator used for sterile compounding to maintain an ISO Class 5 environment:

1. A Compounding Aseptic Isolator (CAI) is designed to maintain an aseptic compounding environment for ingredients within the isolator throughout the compounding and material transfer processes. Air exchange into the isolator from the surrounding environment should not occur unless the air has first passed through a microbial retentive filter (HEPA minimum).
2. A Compounding Aseptic Containment Isolator (CACI) is designed to protect workers from exposure to undesirable levels of airborne drug throughout the compounding and material transfer processes and to provide an aseptic environment for compounding sterile preparations. Where volatile hazardous drugs are prepared, the exhaust air from the isolator should be appropriately removed by properly designed building ventilation.

Compounding isolators take advantage of an airtight glove/glove port design that allows the user to perform hands-on tasks inside the isolator without compromising the intended performance of the isolator. There are many variables in the design of isolators because there are no uniform industry standards for its manufacture. But they usually follow the following objectives:

• the full enclosure of the drug compounding process
• the intentional use of air pressure to define the direction of airflow in/out of the cabinet
• the use of airflow capture velocities to capture and remove aerosolized drug product near its point of generation
• the use of HEPA to capture aerosolized drug preparations and particulate contamination
• the use of external venting to remove vaporized hazardous drugs from the work chamber and from the pharmacy
• the use and material transfer processes that allow material transfer in/out of the compounding isolator without compromising worker exposure to undesirable levels of airborne drug or unwittingly compromising the sterility of the compounding environment.