USP 797: Sterile Compounding Requirements Explained

USP General Chapter <797>, "Pharmaceutical Compounding — Sterile Preparations," is the United States Pharmacopeia standard that sets facility, personnel, and process requirements for compounding sterile preparations (CSPs) — IV admixtures, injectables, ophthalmics, and other dosage forms that must be sterile at the point of administration. The current version of the chapter was published in USP-NF 2023 Issue 1 on November 1, 2022, and became official on November 1, 2023, replacing the prior 2008 version and restructuring the chapter around a new Category 1/2/3 framework in place of the older low/medium/high compounding-risk levels. This guide covers what the current chapter requires, and links out to USP <795> (nonsterile compounding) and USP <800> (hazardous drugs) for how the three chapters fit together.

What USP <797> covers

USP <797> applies whenever a healthcare setting prepares a compounded sterile preparation — a sterile dosage form assembled, diluted, or otherwise altered from one or more sterile or nonsterile components outside the scope of an FDA-approved manufacturing process. Typical triggers include preparing patient-specific IV admixtures and total parenteral nutrition, combining or reconstituting sterile injectables in nonstandard combinations or ratios, repackaging a manufacturer-prepared sterile product into a different container ahead of use, and compounding ophthalmic, intrathecal, or other sterile-route preparations.

The chapter also defines narrow exclusions, most notably an "immediate use" provision for a small number of simple preparations administered promptly at the bedside under specific conditions, and administration of a conventionally manufactured sterile product exactly per its own labeling (which is not compounding at all). Where a given preparation falls relative to those exclusions is one of the most frequently disputed parts of the chapter in practice — a pharmacy or health system in doubt should check the current chapter text directly, or its state board of pharmacy’s guidance, rather than assume an exclusion applies.

The Category 1 / 2 / 3 CSP structure

The 2023 revision replaced the older low/medium/high compounding-risk-level system with three categories defined primarily by where and under what conditions a CSP is compounded, rather than by the complexity of the preparation alone:

• Category 1 CSPs are compounded in an unclassified, contained Segregated Compounding Area (SCA) using an ISO Class 5 primary engineering control (a laminar airflow workbench, biological safety cabinet, or compounding aseptic containment isolator). This is the least controlled of the three environments and carries the shortest beyond-use dates of the three categories.
• Category 2 CSPs are compounded inside a classified cleanroom suite — an ISO Class 7 buffer room served by an ISO Class 8 (or cleaner) anteroom, each with its own primary engineering control. The added, verified environmental control supports longer beyond-use dates than Category 1.
• Category 3 CSPs are compounded under the full set of Category 2 facility requirements plus additional controls — more frequent personnel competency retesting and, for many preparations, sterility testing of the specific compounded batch among them. Category 3 is the only category eligible for beyond-use dates beyond the Category 2 limits, up to a chapter-defined maximum, and only when every applicable Category 3 requirement is met.

See Cleanroom Classifications: ISO 14644-1 and the FED-STD-209E Equivalents, ISO Class 7 Cleanroom Requirements, and ISO Class 8 Cleanroom Requirements for the particle-count and air-change specifics behind each ISO class referenced above.

Facility and engineering controls

A Category 2 or 3 operation needs a physically separated buffer room and anteroom, each independently classified, with the primary engineering control (PEC) — the device the compounder works directly in — sited inside the buffer room. Category 1 compounding can take place in a properly configured SCA without a full cleanroom suite, provided the ISO Class 5 PEC and the SCA’s own siting, airflow, and cleanliness requirements are met. Across all three categories, the chapter also specifies requirements for surface cleaning and disinfection, certification of the PEC and room, and HEPA filtration. See HEPA Filter Certification for Cleanrooms and Controlled Environments and Cleanroom Checklist: Facility Compliance & Qualification for the certification side of this.

Personnel training, garbing, and competency testing

Anyone compounding CSPs must complete initial and ongoing hands-on competency assessment before compounding independently, and periodically thereafter: garbing/gowning procedure observation, hand hygiene, gloved fingertip sampling, and media-fill testing (a simulated compound using microbial growth medium in place of the actual drug, to verify the compounder’s aseptic technique doesn’t introduce contamination). The chapter sets minimum retesting intervals that differ by category, with Category 3 personnel retested more frequently than Category 1 or 2 — confirm the exact current interval against the chapter text or the USP Compounding Compendium before building a training calendar around it. See Cleanroom Gowning Procedure: Donning, Doffing, and Training for the mechanics of garbing itself.

Environmental monitoring

USP <797> requires ongoing viable (microbial) and nonviable (particle count) air and surface sampling of the compounding environment, at a frequency and using methods the chapter specifies, to verify the classified space is actually performing to its assigned ISO class on an ongoing basis rather than only at initial certification.

Beyond-use dating under USP <797>

A beyond-use date (BUD) is the date, or date and time, after which a CSP must not be used, stored, or transported. The 2023 revision changed the primary basis for assigning a BUD: rather than deriving it chiefly from the preparation’s compounding-risk complexity, the current chapter ties the maximum allowable BUD principally to the Category the preparation was compounded under (which reflects the environment’s degree of verified control), layered with the specific storage condition (controlled room temperature, refrigerated, or frozen), the dosage form, and any supporting sterility or stability testing and applicable USP monograph or manufacturer stability data. In general, Category 1 carries the shortest maximum BUDs, Category 2 allows longer BUDs reflecting the added cleanroom controls, and Category 3 is the only category that can reach the chapter’s longest allowable BUDs, and only when the full Category 3 requirement set (facility, testing, and personnel) is actually met.

The chapter’s own BUD tables specify the exact allowable periods for each category and storage condition. Because those figures are precise, category-specific, and were revised in 2023, the operating rule for any compounding pharmacy is to assign BUDs directly from the current chapter text or the USP Compounding Compendium rather than from memory, a training slide deck, or a pre-2023 reference chart, which will not reflect the current structure.

How USP <797> relates to USP <795> and USP <800>

These three chapters answer different questions and apply together, not as alternatives to one another:

• USP <797> (this chapter) governs the facility, process, and personnel requirements for compounding a preparation that must be sterile.
• USP <795> governs the equivalent requirements for compounding a preparation that is not required to be sterile — most oral liquids, creams, ointments, capsules, and suppositories.
• USP <800> governs facility engineering controls for handling drugs on the NIOSH hazardous drug list, whether the specific preparation being compounded is sterile or nonsterile. USP <800> does not replace <797> or <795> — it layers additional containment requirements on top of whichever of the two applies to the specific preparation. A pharmacy compounding a hazardous sterile drug has to satisfy both <797> and <800> at once.

For a direct side-by-side of what <797> and <795> each require, see USP 797 vs. USP 795: Sterile vs. Nonsterile Compounding Compared.

Enforcement

USP general chapters are not self-enforcing federal law. They become enforceable in a given state chiefly through incorporation into that state’s board-of-pharmacy regulations or practice act, and separately through accreditation bodies (such as the Joint Commission or ACHC) that reference current USP chapters in their own compounding-pharmacy survey standards. Adoption language, effective dates, and the degree of surveyor scrutiny vary by state and by accreditor — a pharmacy operating across state lines should confirm the specific requirements of each state board it is licensed under rather than assume uniform, federally-set enforcement.

Frequently asked questions

Is USP <797> legally mandatory?

USP <797> itself is a compendial standard, not a federal statute. It becomes mandatory in practice through state board of pharmacy regulations that incorporate it (directly or by reference to the current USP-NF), and through accreditation standards that require conformance as a condition of accreditation. Most states have adopted some form of <797> into their pharmacy practice regulations, but the exact language and timeline vary by state.

What scenario must meet USP <797>?

Any preparation of a compounded sterile preparation outside the narrow "immediate use" and conventionally-manufactured-product exclusions triggers <797> — this includes routine hospital IV admixture and TPN compounding, ophthalmic and intrathecal compounding, and outpatient sterile compounding pharmacies (including 503A and 503B facilities, which have their own additional FDA-level requirements on top of <797>).

What is the difference between USP <795> and <797>?

In short, <795> covers nonsterile compounding and <797> covers sterile compounding — see the full USP 797 vs. 795 comparison for the facility, testing, and BUD differences in detail.

Does USP <797> apply to a physician’s office?

If a physician’s office prepares a compounded sterile preparation beyond the immediate-use exclusion — for example, preparing injectables in advance of a clinic day rather than administering a conventionally manufactured product per its labeling — it is generally within scope of <797>, subject to the state board of pharmacy’s specific interpretation and any medical-practice-act exemptions that state provides. This is a genuinely state-variable area; check with the relevant state board directly.