USP <797>: Sterile Compounding Readiness for State Board Inspections
USP General Chapter <797> Pharmaceutical Compounding — Sterile Preparations is the US standard governing sterile compounding in hospitals, infusion pharmacies, 503A outsourcers and 503B facilities.
In Short
- The 2023 revision restructured CSPs into three categories.
- Category 2 requires a buffer room at ISO Class 7 with an anteroom at ISO Class 8 (or better if compounding requires), with the PEC (typically an LAFW or BSC)…
- The 2023 revision requires viable air sampling (impactor or settling plate) at minimum every 6 months for Category 1 and 2, monthly for Category 3; surface sampling…
The major revision became official on 1 November 2023 after multiple appeals and delays, and is now actively enforced by state boards of pharmacy with reference by FDA for 503A and 503B inspections. The revision restructured Compounded Sterile Preparations into Category 1, Category 2 and Category 3, redefined Beyond-Use Dates, sharpened the cleanroom design and environmental monitoring expectations, and elevated training and competency. State-board enforcement varies but the direction is uniform — the bar in 2026 is materially higher than the 2008 version that many sites were still operating to as late as 2022. This guide walks through the CSP categories, the cleanroom and air quality requirements, the BUD assignment logic, training and competency, and a practical readiness path. It is written for pharmacy directors, compounding supervisors, quality leads and consultants at sites compounding sterile preparations.
The three Categories: 1, 2 and 3 CSPs
The 2023 revision restructured CSPs into three categories. Category 1 — prepared in an ISO Class 5 PEC located in a segregated compounding area (SCA), short BUD (12 hours room temperature, 24 hours refrigerated).
More on the three Categories: 1, 2 and 3 CSPs
Category 2 — prepared in an ISO Class 5 PEC located in a classified buffer room (ISO Class 7) with an anteroom (ISO Class 8 or better), longer BUD assignments depending on sterility testing and storage. Category 3 — Category 2 conditions plus additional controls (more rigorous sterility testing, garbing, surface sampling, training, longer cleaning and sanitisation), allowing the longest BUDs. The category drives every downstream requirement — environmental monitoring frequency, cleaning, garbing, BUD assignment, sterility testing. Sites that operate at Category 2 conditions but assign Category 3 BUDs without the Category 3 controls produce immediate findings.
Cleanroom design, air quality and pressure differentials
Category 2 requires a buffer room at ISO Class 7 with an anteroom at ISO Class 8 (or better if compounding requires), with the PEC (typically an LAFW or BSC) providing ISO Class 5 at the direct compounding area. Air changes per hour, pressure differentials (positive for non-hazardous, negative for hazardous per <800>), temperature, humidity, surface materials and the smoke-pattern verification of unidirectional flow are all defined.
More on cleanroom design, air quality and pressure differentials
Category 3 layers additional cleanroom requirements. Category 1 SCAs do not require classification but the PEC must still meet ISO Class 5. The 2023 revision tightened the air-change and pressure-differential expectations and the documented qualification thereof — state-board inspectors now arrive expecting to see the certification reports and the trended environmental data.
Environmental monitoring: viable and non-viable, surface and air
The 2023 revision requires viable air sampling (impactor or settling plate) at minimum every 6 months for Category 1 and 2, monthly for Category 3; surface sampling monthly for Category 2 and Category 3; non-viable particulate counts at minimum every 6 months for Category 2 and 3 (annually for Category 1 if compliance is otherwise demonstrated). Action levels for viable organisms are set per ISO class (1 CFU for ISO 5, 10 for ISO 7, 100 for ISO 8 per <797>) with documented response procedures including investigation, corrective action and re-monitoring.
More on environmental monitoring: viable and non-viable, surface and air
The response-to-excursion expectation is the part most sites underprepared for in their 2024 transition.
Beyond-Use Dates: the BUD table that drives everything
BUDs under the 2023 revision are determined by Category and by whether the preparation is unpreserved or preserved, refrigerated or room temperature, with or without sterility testing. Category 1: 12h room temperature / 24h refrigerated.
More on beyond-Use Dates: the BUD table that drives everything
Category 2: up to 4 days room temperature, 10 days refrigerated, 45 days frozen for aqueous preparations passing sterility testing (and shorter for those not). Category 3: significantly extended BUDs (up to 90+ days for certain conditions) with the additional Category 3 controls in place. The 'we have always used 28 days' habit from prior versions does not survive 2026 inspection — every BUD on a CSP label must be derivable from the table with the documented basis recorded.
Personnel Training, Competency and Garbing
Section 3 of the 2023 revision sets explicit training and competency requirements — initial training before independent compounding, didactic and hands-on, with documented competency assessments including gloved fingertip sampling (initial and ongoing), media-fill testing (initial and ongoing at defined frequencies per category), garbing verification, hand-hygiene technique, sterile technique. Records of competency must be maintained per compounder per competency, with retraining triggered on failure or on defined cadence.
More on personnel Training, Competency and Garbing
Garbing under section 4 is prescribed per category — and the order of garbing, the materials, and the doffing sequence all attract inspector attention.
Master Formulation Records and Compounding Records
Section 17 requires a Master Formulation Record for each unique CSP — name, strength, dosage form, identity of all components, type and size of container-closure, complete instructions, BUD and storage requirements, quality control procedures. A Compounding Record for each individual preparation captures who compounded, when, the components used with lot numbers, the equipment, the documentation of in-process checks, the BUD assigned, the QC results, the labels produced.
More on master Formulation Records and Compounding Records
The MFR / CR pair is the documentation backbone — a site that maintains MFRs in one system and CRs in another invariably has gaps that surface as inspection findings.
A 90-Day Readiness Path
Days 1 to 15: gap assessment against the 2023 revision with priority on category classification of all CSPs, BUD assignment derivation, environmental monitoring schedule and action-level response, training and competency currency. Days 16 to 45: rebuild the CSP register with Category 1/2/3 designations and BUDs derived per the current table; refresh environmental monitoring schedule per category; close competency gaps.
More on a 90-Day Readiness Path
Days 46 to 70: cleanroom re-certification if overdue; surface and viable air sampling baseline; documentation refresh on MFR/CR pairs. Days 71 to 90: internal audit covering all sections; mock state-board inspection led by an external consultant if state enforcement is aggressive; pre-inspection logistics.
Questions
Is USP <797> federally enforced?
USP <797> itself is published by USP, a private standards body. Enforcement is primarily by state boards of pharmacy under state law (most US states reference USP <797> in their pharmacy regulations) and by FDA for 503A and 503B facilities. Enforcement intensity varies by state but the trend across 2024-2026 is toward consistent and rigorous application of the 2023 revision.
How does <797> relate to <800> for hazardous drugs?
USP <800> covers handling of hazardous drugs in healthcare settings — engineering controls, personal protective equipment, work practices. <800> and <797> are designed to interoperate: a hazardous CSP must meet both standards (the <800> containment requirements layered on <797> sterile compounding). For non-hazardous CSPs only <797> applies.
What's the difference between 503A and 503B?
503A pharmacies compound pursuant to a patient-specific prescription, are regulated primarily by state boards of pharmacy, and must meet USP <797>. 503B outsourcing facilities compound in larger batches without patient-specific prescriptions, register with FDA, must meet cGMP per 21 CFR 210/211 (a higher bar than USP <797>), and are FDA-inspected. A site can be either; some entities operate parallel 503A and 503B operations.
What about <795> for non-sterile compounding?
USP <795> covers non-sterile compounding and was revised in parallel with <797>, also becoming official on 1 November 2023. The two chapters are structurally aligned (categories, BUDs, training) where the underlying science permits, with the sterile-specific elements (cleanroom, environmental monitoring, media-fill) appearing only in <797>. Sites compounding both sterile and non-sterile typically implement them together.
Practical orientation, not legal advice. Rules differ by jurisdiction; your quality and compliance team decides what applies.
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