USP 797: keep the drug clean
USP 797 covers sterile compounding, meaning medications that will be injected or infused and have to be free of contamination. The room exists to protect the product. It is held at positive pressure, so when a door opens, clean air pushes out instead of room air drifting in.
USP 800: keep the drug contained
USP 800 covers hazardous drugs, such as many chemotherapy agents, where the risk runs the other way. The concern is exposure for the pharmacists and staff nearby. Those rooms are held at negative pressure, so air flows in and anything airborne stays inside and is exhausted safely.
A pharmacy that does both needs both kinds of room, side by side, with air moving in opposite directions.
The Reno project
The Reno VA asked Alares to turn existing patient exam rooms in an outpatient clinic into a compounding pharmacy that complies with USP 797 and 800, including a clean room. Exam rooms are not built for any of this, so the challenge was creating controlled environments inside a building that was never meant to hold them.
We designed a new air handler to keep the compounding rooms at positive pressure, and a separate negative pressure system for the hazardous drug side. The design also covered the new room layout and wall details, new equipment with roof curbs and roof penetrations, special plumbing, a new steam generator, and building automation to manage the pressures. The renovation cost about $1.3 million.
Why automation matters
Pressure relationships are only useful if they hold. Doors open, filters load, fans drift. Tying the rooms into the building automation system is what keeps the pressures where the standard needs them, instead of relying on someone to notice when they slip.
The takeaway
A compounding room is defined by its air more than its walls. If you are planning one inside an existing building, start with the air: which way it has to move, how it gets there, and what keeps it there.