Compounding explained
Understanding
beyond-use dating.
Read the date.
Know the storage instructions.
A beyond-use date (BUD) sets a limit on using a compounded preparation. For sterile preparations, that limit can include a specific time as well as a date. [1]
Understand the datesBeyond-use
date
A use limit assigned to the compounded preparation.
Manufacturer’s
expiration date
A shelf-life limit supported by stability testing under labeled storage conditions.
At a glance
Different dates.
Different purposes.
Use the instructions supplied with your medicine. If the label is unclear, ask the dispensing pharmacy to explain it.
| What to know | Beyond-use date | Expiration date |
|---|---|---|
| What it refers to | The compounded preparation supplied by the pharmacy. | The manufacturer’s product under its labeled storage conditions. |
| What supports it | Applicable compounding standards and preparation-specific information. Sterile preparations require consideration of both stability and sterility. | Stability data supporting the product’s strength, quality and purity over its shelf life. |
| What to check next | The assigned date or time, storage requirements and any separate instructions after opening. | Storage directions and any shorter limit after opening or preparing the medicine for use. |
Background: USP’s sterile compounding FAQs and FDA’s explanation of expiration dates. For opened medication vials, see CDC’s injection safety guidance.
Putting the label into practice
Check the date,
storage and opening instructions.
The date that applies
Ask the pharmacy to identify the use limit for your preparation. Do not assume that a date on an ingredient or another prescription applies to this one.
The right storage conditions
Temperature, moisture and light can affect medicine quality. Follow the labeled conditions. If the medicine was left in a hot car or outside its required storage conditions, contact the pharmacy before using it. [2]
What changes after opening
Opening or puncturing a vial can introduce a separate use limit. Confirm whether you need to record when it was first opened and when it must be discarded. Do not treat a later printed date as permission to ignore an earlier in-use limit. [3]
Using this guide
Common questions.
Do all compounded medicines have the same BUD?
No. The appropriate limit depends on the preparation and applicable requirements. For sterile preparations, USP explains that stability or sterility considerations can require a shorter BUD. Use the date assigned to your prescription. See USP’s FAQs.
Can I extend the date by refrigerating the medicine?
Do not change the storage conditions or extend the date yourself. Follow the label and ask the pharmacy if you are unsure whether refrigeration is appropriate. A date is meaningful only with the storage conditions that support it. See FDA’s explanation.
What if the date is missing or the instructions conflict?
Contact the dispensing pharmacy before using the medicine. Have the container and prescription number ready, and mention when it was opened and how it has been stored.
Sources & further reading
- USP: General Chapter <797> FAQs — sterile compounding (PDF)
- FDA: Expiration Dates — Questions and Answers
- CDC: Preventing Unsafe Injection Practices
This overview does not assign a BUD or replace the instructions for a specific prescription. Your pharmacist can clarify the date, storage conditions and any in-use limits.