What USP <797> actually requires
Sterile compounding is governed by a chapter most prescribers have never read. Here is what it obliges a pharmacy to do, in plain terms.
· 2 min read
USP General Chapter <797> governs the compounding of sterile preparations. It is not a marketing badge and it is not optional: it is the standard that state boards of pharmacy inspect against, and it sets out in detail how a sterile preparation must be made, where, by whom, and how long it may be used for.
Most prescribers never read it. That is reasonable — it is a technical document written for pharmacists. But a few of its requirements directly affect the prescription you write, and they are worth knowing.
The air the preparation is made in
Sterile compounding happens inside an ISO Class 5 primary engineering control — a laminar airflow hood or an isolator. That device sits inside a cleaner-than-ordinary room, and the chapter specifies the classification of that room too, along with how often the air is tested and what the particle counts have to be.
This is why a compounded sterile preparation cannot simply be mixed at a bench. The equipment is the control.
Who is allowed to make it
Personnel must pass initial and ongoing competency assessment: gloved fingertip sampling, media-fill testing that simulates the actual compounding process, and garbing observation. The frequency depends on the risk level of what is being compounded.
The practical consequence is that a pharmacy cannot surge capacity by putting an untrained person on the hood.
How long it lasts
<797> assigns beyond-use dates based on the risk level of the preparation and how it is stored — not on the stability of the drug in isolation. That distinction surprises people, and it is covered in its own article.
What to ask
If you want to know whether a pharmacy meets the chapter, three questions get you most of the way:
- How often is the primary engineering control certified, and may I see the most recent report?
- What is your media-fill failure rate, and what happens when one fails?
- Who performs your environmental monitoring, and is it an outside party?
A pharmacy that compounds sterile preparations should be able to answer all three without hesitation.