USP 825: Radiopharmaceutical Compounding Safety

Q: What is USP General Chapter 825?

USP General Chapter 825 is the U.S. Pharmacopeia standard titled Radiopharmaceuticals—Preparation, Compounding, Dispensing, and Repackaging. It sets minimum standards specific to radioactive drugs, covering personnel, facilities, engineering controls, beyond-use dating, quality assurance, and the handling steps unique to short-lived, radioactive preparations. It became an official, enforceable USP compounding standard in 2020.

Q: How is USP 825 different from USP 797?

USP 797 governs sterile compounding in general. USP 825 is written specifically for radiopharmaceuticals and adapts those controls to the realities of radioactive drugs—short half-lives, radiation shielding, contamination control, and dose-on-demand workflows. Where a radiopharmaceutical is prepared sterilely, 825 draws on 797-style engineering controls while adding the radiation-safety requirements that a general sterile-compounding chapter does not address.

Q: Who must comply with USP 825?

USP 825 applies to state-licensed activities such as the practice of pharmacy and the practice of medicine—so nuclear pharmacies, nuclear medicine departments, PET centers, and other facilities that prepare, compound, dispense, or repackage radiopharmaceuticals. USP chapters are enforced primarily through state boards of pharmacy and, where adopted, other oversight bodies.

Q: Does USP 825 replace NRC radiation safety requirements?

No. USP 825 addresses pharmaceutical quality and compounding practice; it does not replace NRC or Agreement State radiation-safety rules under 10 CFR Part 20 and Part 35. A compliant facility must satisfy both frameworks at once—the USP compounding standard and the radioactive-material license conditions that govern radiation safety.

Introduction

USP General Chapter <825> is the compounding standard written specifically for radioactive drugs. It sets minimum standards for how nuclear pharmacies and nuclear medicine departments prepare, compound, dispense, and repackage radiopharmaceuticals — reconciling the sterile-compounding engineering controls familiar from USP <797> with the radiation-safety realities of short half-lives, shielding, and contamination control. ^{1, 4}

Before <825>, radiopharmaceutical preparation was squeezed into standards designed for conventional sterile compounding, which did not fit the workflow of a drug that is radioactive, decays by the minute, must be shielded, and is often dispensed on demand. <825> was created to address that gap with a chapter tailored to radioactive drugs. It became an official, enforceable USP compounding standard in 2020, after appeals to delay it were denied in March of that year, and it sits alongside the revised sterile- and nonsterile-compounding chapters (<795>, <797>, and <800>) that reached their current official status on November 1, 2023. ^{1, 2, 3}

This guide explains what <825> covers, how it relates to the other USP compounding chapters, how it intersects NRC and FDA authority, the beyond-use-dating and engineering-control concepts that drive daily practice, and how a facility builds a compliant program. DRPS supports this work through its radioactive material license support, radiation safety officer, and PET/CT and nuclear medicine physics services.

Topic Explanation

What USP General Chapter 825 covers

USP General Chapter <825>, "Radiopharmaceuticals — Preparation, Compounding, Dispensing, and Repackaging," establishes minimum standards specific to radioactive drugs. Its scope spans the activities that a nuclear pharmacy or nuclear medicine department performs on radiopharmaceuticals: preparing kits, compounding, dispensing unit doses, and repackaging. ^{1, 4}

Because radiopharmaceuticals are simultaneously drugs and radioactive material, <825> has to serve two masters. As a pharmaceutical standard it addresses personnel training, facilities and engineering controls, quality assurance, beyond-use dating, documentation, and — for sterile products — the sterility-assurance controls adapted from sterile compounding. As a practical matter it also has to coexist with the radiation-safety program, because every one of those activities involves shielding, contamination control, and occupational-dose considerations. ^{4, 5}

For the hands-on quality side of radiopharmaceutical preparation, see our companion articles on radiopharmacy aseptic technique and QC and radiochemical purity testing.

Where 825 sits among the USP compounding chapters

USP compounding standards are numbered, and chapters numbered below <1000> are generally enforceable rather than merely informational. Four chapters matter for a nuclear medicine or nuclear pharmacy program:

Chapter	Title (abbreviated)	Primary scope	Current official status
USP <795>	Pharmaceutical Compounding — Nonsterile Preparations	General nonsterile compounding	Revised chapter official Nov 1, 2023
USP <797>	Pharmaceutical Compounding — Sterile Preparations	General sterile compounding, engineering controls	Revised chapter official Nov 1, 2023
USP <800>	Hazardous Drugs — Handling in Healthcare Settings	Protecting personnel/environment from hazardous drugs	Official Nov 1, 2023
USP <825>	Radiopharmaceuticals — Preparation, Compounding, Dispensing, and Repackaging	Radioactive drugs specifically	Official since 2020

The key relationship is between <797> and <825>. <797> defines how sterile preparations are made in general — the ISO-classified spaces, air-quality controls, personnel practices, and beyond-use-dating logic. <825> takes those principles and applies them to radioactive drugs, adding the radiation-safety layer and recognizing radiopharmaceutical-specific realities that a general sterile-compounding chapter cannot. ^{1, 2, 4}

Key Technical Principles

The engineering-control layer

Sterile radiopharmaceutical preparation relies on the same hierarchy of engineering controls used in sterile compounding generally: a primary engineering control (such as a shielded biological safety cabinet or compounding aseptic containment isolator) sited within an ISO-classified environment, often with an anteroom for gowning and staging. Published nuclear-pharmacy facility designs describe ISO Class 7 buffer and anteroom spaces with elevated ventilation, using lead-lined cabinets and, for generators, negative-pressure rooms. ⁵

Cleanroom air quality is maintained by high air-exchange rates. The air changes per hour (ACH) for a room of volume $V$ (m³) supplied at volumetric flow $Q$ (m³/h) is:

ACH = \frac{Q}{V}

For example, a 20 m³ buffer room supplied at 600 m³/h achieves:

ACH = \frac{600}{20} = 30 air changes per hour

ISO Class 7 buffer areas are commonly designed for at least this order of air exchange, and higher-traffic or smaller nuclear-pharmacy spaces are often ventilated more aggressively still. ⁵ The radiopharmaceutical twist is that these clean spaces must simultaneously function as radiation-controlled areas — shielded, surveyed, and contamination-controlled — which is exactly the dual demand <825> exists to address.

Beyond-use dating with decay

Every compounded preparation carries a beyond-use date (BUD) — the point after which it should not be used. For conventional drugs the BUD reflects chemical stability and, for sterile products, sterility. For radiopharmaceuticals a second clock runs in parallel: radioactive decay continuously reduces the usable activity.

Activity follows first-order decay:

A (t) = A_{0} e^{- λ t}, λ = \frac{ln 2}{T _{1/2}}

where $A_{0}$ is the calibrated activity, $λ$ the decay constant, and $T_{1/2}$ the physical half-life. Consider a fluorine-18 preparation ( $T_{1/2} = 109.77$ min) four hours (240 min) after calibration:

λ = \frac{ln 2}{109.77} \approx 0.006314 min^{- 1}

A (240) = A_{0} e^{- (0.006314) (240)} \approx A_{0} e^{- 1.515} \approx 0.22 A_{0}

Only about 22% of the calibrated activity remains after four hours. This is why radiopharmaceutical workflows are dose-on-demand and time-critical: the "beyond-use" question is inseparable from decay, and a preparation may be pharmaceutically stable yet no longer contain a useful activity. When a radionuclide is also cleared biologically, the effective half-life governs the activity retained in a patient:

\frac{1}{T _{eff}} = \frac{1}{T _{physical}} + \frac{1}{T _{biological}}

These decay realities distinguish radiopharmaceutical compounding from every other kind and are a core reason a dedicated chapter is warranted. For the isotopes involved, see common PET and radiopharmaceutical-therapy isotopes.

Immediate-use and category logic

USP sterile-compounding standards recognize limited immediate-use scenarios with reduced facility requirements but strict conditions and short in-use time limits. In nuclear medicine, some preparations — for example, certain kit reconstitutions used promptly — may fall under narrower handling provisions, while routine sterile preparation still requires appropriate ISO-classified engineering controls. The precise categories, conditions, and time limits are defined in the current chapter text and should be confirmed against it rather than assumed, because misapplying an immediate-use provision to routine compounding is a common compliance pitfall. ^{1, 4}

Clinical Impact

USP <825> reshapes how a nuclear medicine facility designs its space, trains its staff, and documents its work — and it does so in a way that must dovetail with the radiation-safety program. The practical consequences show up in several places:

Facility design. Sterile radiopharmaceutical preparation needs ISO-classified engineering controls that are also shielded and contamination-controlled. This shapes hot-lab layout, cabinet selection, ventilation, and workflow. See our guide to nuclear medicine hot lab design.
Personnel. Staff need competency in both aseptic technique and radiation safety — two skill sets that <825> effectively requires together.
Documentation and QA. Master formulation and compounding records, beyond-use-date justification, environmental monitoring, and quality-assurance checks become part of the routine, layered on top of the survey and contamination records the radiation-safety program already keeps.
Dose-on-demand reality. Because activity decays, the chapter's requirements have to accommodate a workflow where preparations are made close to administration time.

The overarching clinical impact is safer, more consistent radiopharmaceutical preparation — fewer contamination events, better sterility assurance for injectable products, and clearer accountability — without pretending that a radioactive drug can be handled like an ordinary sterile preparation.

Practical Optimization Tips

Build the program around the dual mandate

Map every step to a rule. For each activity — kit prep, unit-dose dispensing, PET-drug repackaging — identify whether USP <825>, USP <797>, FDA 21 CFR Part 212, and the radioactive-material license each apply, and to what. Gaps and overlaps are where compliance problems hide.
Integrate the RSO and the pharmacy. The radiation safety officer and the compounding/pharmacy lead should design the space and procedures together, because the engineering controls serve both sterility and radiation safety. Coordinate with radiation safety officer consulting.
Design the hot lab once, for both purposes. Retrofitting shielding into a cleanroom (or clean airflow into a hot lab) after the fact is expensive; plan the ISO classification, airflow, and shielding together.

Keep the documentation defensible

Justify every beyond-use date with reference to both stability and decay, and record the basis.
Run and log environmental monitoring appropriate to the ISO classification of the space.
Maintain competency and training records covering aseptic technique and radiation safety.
Keep master formulation and compounding records so each preparation is traceable.

Common pitfalls to avoid

Assuming <797> alone covers radiopharmaceuticals. It does not; <825> is the radiopharmaceutical-specific chapter.
Treating <825> as a substitute for the radioactive-material license. The USP chapter and the NRC/Agreement State rules are additive, not interchangeable.
Over-relying on immediate-use provisions to avoid engineering controls for routine preparation.
Ignoring the PET-drug boundary. Production of PET drugs falls under FDA cGMP (21 CFR Part 212); downstream compounding and dispensing fall under <825>. ⁶
Designing the cleanroom and the shielding separately, which often produces a space that satisfies one mandate and fails the other.

Regulatory Considerations

A compliant radiopharmaceutical operation satisfies several authorities at once, and USP <825> is only one layer. The frameworks stack rather than replace one another:

USP General Chapter <825> sets the compounding-quality standard for radioactive drugs and is enforced primarily through state boards of pharmacy and other bodies that adopt USP chapters. ¹
USP General Chapter <797> supplies the sterile-compounding engineering-control and beyond-use-dating framework that <825> builds on for sterile radiopharmaceuticals. ²
NRC 10 CFR Part 35 (Medical Use of Byproduct Material) and 10 CFR Part 20 (Standards for Protection Against Radiation) govern the radiation-safety program — authorized users, the RSO, surveys, dose limits, and license conditions. Part 35 requirements are in addition to Part 20, not a substitute. ^{7, 8}
FDA 21 CFR Part 212 establishes current good manufacturing practice for PET drugs, governing their production before they reach the pharmacy or clinic. ⁹
NRC medical-use licensing guidance (NUREG-1556, Volume 9) frames the radiation-safety program expectations that the compounding operation must fit within. ¹⁰

Agreement States administer their own equivalent radioactive-material programs. Of the states DRPS serves, Florida, Maryland, Virginia, California, Nevada, Pennsylvania, New York, and New Jersey are NRC Agreement States that license medical use under their own radiation-control rules, while Washington, DC and Delaware are regulated directly by the NRC for radioactive material. In Florida, the medical use of radioactive material is administered by the state radiation-control program. A facility must confirm which authority issues its license and which board of pharmacy enforces the USP chapters in its jurisdiction. For the broader compliance picture, see our guides to the radiation safety officer role and radioactive waste management in nuclear medicine.

Documented facility qualification, training records, beyond-use-date justifications, environmental monitoring, and the integration of compounding controls with the radioactive-material license are what make a radiopharmaceutical program defensible during a board-of-pharmacy inspection or an NRC/Agreement State inspection.

Frequently Asked Questions (FAQs)

What is USP General Chapter 825?

USP General Chapter <825> is the U.S. Pharmacopeia standard titled "Radiopharmaceuticals — Preparation, Compounding, Dispensing, and Repackaging." It sets minimum standards specific to radioactive drugs, covering personnel, facilities, engineering controls, beyond-use dating, quality assurance, and the handling steps unique to short-lived, radioactive preparations. It became an official, enforceable USP compounding standard in 2020.

How is USP 825 different from USP 797?

USP <797> governs sterile compounding in general. USP <825> is written specifically for radiopharmaceuticals and adapts those controls to the realities of radioactive drugs — short half-lives, radiation shielding, contamination control, and dose-on-demand workflows. Where a radiopharmaceutical is prepared sterilely, <825> draws on <797>-style engineering controls while adding the radiation-safety requirements that a general sterile-compounding chapter does not address.

Who must comply with USP 825?

USP <825> applies to state-licensed activities such as the practice of pharmacy and the practice of medicine — so nuclear pharmacies, nuclear medicine departments, PET centers, and other facilities that prepare, compound, dispense, or repackage radiopharmaceuticals. USP chapters are enforced primarily through state boards of pharmacy and, where adopted, other oversight bodies.

Does USP 825 replace NRC radiation safety requirements?

No. USP <825> addresses pharmaceutical quality and compounding practice; it does not replace NRC or Agreement State radiation-safety rules under 10 CFR Part 20 and Part 35. A compliant facility must satisfy both frameworks at once — the USP compounding standard and the radioactive-material license conditions that govern radiation safety.

What is beyond-use dating for a radiopharmaceutical?

The beyond-use date is the time or date after which a compounded preparation should not be used. For radiopharmaceuticals it must account for both pharmaceutical stability (including sterility for sterile products) and radioactive decay, since the usable activity falls continuously. The date is assigned per the applicable USP requirements and the product's stability data.

Are PET drugs covered by USP 825 or by FDA cGMP?

Both frameworks can apply at different stages. FDA current good manufacturing practice for PET drugs is codified in 21 CFR Part 212 and governs the production of PET drugs. Once a PET drug is received by a pharmacy or clinic, subsequent compounding, dispensing, and repackaging activities fall under USP <825>. Facilities should map which rule governs each step.

Does an immediate-use preparation need a full cleanroom?

USP standards recognize limited immediate-use situations with reduced facility requirements, but these carry strict conditions and short in-use time limits. Most routine sterile radiopharmaceutical preparation still requires appropriate engineering controls, such as an ISO-classified environment, rather than relying on immediate-use provisions. Confirm the specific conditions in the current chapter.

Key Takeaways

<825> is the radiopharmaceutical-specific compounding chapter. It sets minimum standards for preparing, compounding, dispensing, and repackaging radioactive drugs, and it became official in 2020.
It builds on <797> but is not the same. Sterile radiopharmaceuticals use <797>-style engineering controls plus the radiation-safety layer that <825> adds.
The dual mandate drives design. ISO-classified clean space and radiation shielding/contamination control must be planned together, not bolted on.
Beyond-use dating includes decay. A radiopharmaceutical's usable window is limited by both stability and radioactive decay — often decay first.
The frameworks stack. USP (via boards of pharmacy), NRC/Agreement State (10 CFR Part 20/35), and FDA (21 CFR Part 212 for PET drugs) all apply; none replaces the others.
Documentation makes it defensible. Facility qualification, training, BUD justification, and environmental monitoring, integrated with the radioactive-material license, carry a facility through inspection.

Conclusion

USP General Chapter <825> exists because radiopharmaceuticals are genuinely different — they are drugs that decay, must be shielded, and are handled in a workflow no general compounding chapter anticipated. The chapter brings radiopharmaceutical preparation under a purpose-built standard that respects both pharmaceutical quality and radiation safety. For a nuclear medicine facility, compliance is not about choosing between the USP chapter and the radioactive-material license; it is about designing a program where the two reinforce each other — clean and shielded, sterile and surveyed, documented for both a board of pharmacy and a radiation-control inspector. Facilities that build that integrated program find that good radiopharmaceutical practice and good radiation safety are, in the end, the same discipline.

How DRPS Can Help

Diagnostic Radiation Physics Services helps nuclear medicine and PET facilities integrate compounding compliance with radiation safety: hot-lab and cleanroom design review, radioactive-material license support, RSO program guidance, environmental-monitoring and survey program design, and staff training that spans aseptic technique and radiation protection. Our board-certified professionals provide radioactive material license support, radiation safety officer services, PET/CT and nuclear medicine physics, and medical physicist consulting.

DRPS supports facilities across our service locations, including Florida, Maryland, Virginia, Washington DC, California, Nevada, New York, Pennsylvania, New Jersey, and Delaware.

A strong radiopharmaceutical program is not just about passing an inspection — it is about making the safe, sterile, well-documented process the easy process for the clinical team.

Related Resources

References

United States Pharmacopeia. General Chapter <825> Radiopharmaceuticals — Preparation, Compounding, Dispensing, and Repackaging. Rockville, MD: USP. usp.org
United States Pharmacopeia. General Chapter <797> Pharmaceutical Compounding — Sterile Preparations. Rockville, MD: USP. usp.org
United States Pharmacopeia. General Chapter <795> Pharmaceutical Compounding — Nonsterile Preparations. Rockville, MD: USP. usp.org
Hinkle GH. USP General Chapter <825> impact on nuclear medicine technology practice. J Nucl Med Technol. 2020;48(2):106-113. doi:10.2967/jnmt.120.243378. doi.org
Hung JC, Anderson MM. Mayo Clinic approaches to meet United States Pharmacopeia <797> requirements for facility design and environmental controls of nuclear pharmacy. J Nucl Med. 2009;50(1):156-164. doi:10.2967/jnumed.108.054742. doi.org
Norenberg JP, Petry NA, Schwarz S. Operation of a radiopharmacy for a clinical trial. Semin Nucl Med. 2010;40(5):347-356. doi:10.1053/j.semnuclmed.2010.06.002. doi.org
U.S. Nuclear Regulatory Commission. 10 CFR Part 35: Medical Use of Byproduct Material. ecfr.gov
U.S. Nuclear Regulatory Commission. 10 CFR Part 20: Standards for Protection Against Radiation. ecfr.gov
U.S. Food and Drug Administration. 21 CFR Part 212: Current Good Manufacturing Practice for Positron Emission Tomography Drugs. ecfr.gov
U.S. Nuclear Regulatory Commission. NUREG-1556, Volume 9, Revision 3: Program-Specific Guidance About Medical Use Licenses. nrc.gov