USP <797> is the standard for sterile compounding in 503A pharmacies. Plain-language explanation.
About this article
Reviewed byDr. Samuel Lora, M.D.
RolePharmacology & Compounding Reviewer
First publishedMay 20, 2026
Last reviewedMay 20, 2026
Page typeIn-depth editorial guide
Sources15+ cited sources
What USP <797> covers
Comprehensive standard for sterile preparation including: facility design (clean rooms, ISO classifications), equipment, gowning, hand hygiene, garbing, beyond-use dates, environmental monitoring, sterility testing.
ISO classifications referenced
- ISO 5 — laminar airflow workbench (LAFW), primary engineering control where compounding occurs.
- ISO 7 — buffer area surrounding ISO 5 area.
- ISO 8 — ante-room transition area.
Beyond-use dating
USP <797> specifies how long compounded sterile preparations can be stored — varies by category (immediate-use, low-risk, medium-risk, high-risk) and storage condition (controlled room temp, refrigerated, frozen).
What patients should ask
- Is the pharmacy compliant with USP <797>?
- How is environmental monitoring performed?
- What is the beyond-use date on my preparation?