What USP 797 requires
USP 797 sets standards for sterile compounding to reduce the risk of contamination, infection, and patient harm. It applies to many pharmacies, hospitals, outsourcing-related workflows where applicable, clinics, and other settings that compound sterile preparations, subject to state board rules and other regulators.
The chapter does not let a compounder choose any convenient date. The assigned BUD must be supported by the chapter's category rules, the preparation's formulation, storage condition, sterility testing where used, container-closure system, and any shorter ingredient or manufacturer limits.
- BUD is not the same as manufacturer expiration date.
- The most restrictive applicable limit controls.
- State rules and facility policies may be stricter.
How to calculate
The practical formula is BUD date and time = compounding completion date and time + allowed BUD interval for the selected category and storage condition, capped by any shorter stability, sterility, ingredient, or policy limit. For Category 1 CSPs, common maximums are short: for example, 12 hours at controlled room temperature or 24 hours refrigerated under the current chapter framework.
For a worked example, a Category 1 CSP is completed on March 10 at 14:30 and stored refrigerated under a 24-hour limit. The calculated BUD is March 11 at 14:30, unless an ingredient, device, state rule, or facility policy requires a shorter time.
Inputs that change the BUD
The assigned date can change based on whether the preparation is Category 1, Category 2, or Category 3; whether components are sterile or nonsterile; whether terminal sterilization or sterility testing applies; and whether storage is controlled room temperature, refrigerated, or frozen.
Stability is a separate limit from sterility. A CSP may have a chapter-allowed sterility BUD that is longer than the drug's chemical stability data, or the reverse. The label must use the shorter defensible limit.
- Compounding category.
- Aseptic process or terminal sterilization.
- Sterility testing status.
- Storage temperature.
- Drug stability and container compatibility.
Who needs BUD controls
Sterile compounding personnel, pharmacists, pharmacy technicians, quality managers, nursing teams, and inspectors all rely on accurate BUD labels. The date affects preparation, verification, storage, dispensing, administration, waste, and recall decisions.
Facilities should train staff to record the compounding completion time, not just the calendar date. For short BUDs, a missing time can turn an otherwise correct label into an unsafe or noncompliant one.
Common mistakes
Do not extend a BUD because a vial's manufacturer expiration date is months away. Once a sterile preparation is compounded, USP 797 BUD rules and stability support control the label. Do not ignore storage condition; moving from refrigerated to room temperature can change the permitted time.
Another mistake is using a matrix without checking whether local policy or state board rules are stricter. USP 797 is a baseline standard, but operational compliance often depends on the most conservative applicable requirement.
Frequently asked questions
Is a USP 797 BUD the same as an expiration date?
No. Manufacturer expiration dates apply to approved products in their original conditions. BUDs apply to compounded preparations and are based on sterility, stability, storage, and compounding conditions.
When does the BUD clock start?
In practice it is tied to compounding completion or the point defined by the facility's USP 797 procedure. The date and time should be documented consistently.
Can sterility testing extend a BUD?
It may support longer limits for certain categories and conditions, but only when all chapter requirements, stability data, and facility procedures support it.
What if drug stability is shorter than the USP 797 category limit?
Use the shorter limit. A preparation should not be labeled beyond the supported chemical or physical stability of the drug and container system.