United States
Hong KongLot numbers and dates
A lot number identifies a manufacturing run and is how recalls are targeted. An expiration date is the manufacturer's guarantee of potency for the unopened product stored correctly.
Three identifiers that do three different jobs, and the exam checks you have not merged them.
The three
| Identifier | Tells you |
|---|---|
| NDC | What the product is - labeler, product, package size, under 21 CFR 207.33 |
| Lot number | Which manufacturing run this package came from |
| Serial number | Which individual package this is, under serialization |
| Expiration date | How long the unopened product is guaranteed, stored as directed |
Why the lot number matters most operationally
Recalls are targeted by lot. A notice names a product and specific batches, so identifying affected stock means checking lots rather than pulling everything with that NDC.
That is why lot numbers are recorded, and it is the practical reason this sits in the syllabus.
What an expiration date actually means
The date is the manufacturer's guarantee under those conditions. Open the container, reconstitute the product, or break the cold chain and the date no longer applies - what governs then is a beyond-use date, which is a different thing and usually much shorter.
Stock rotation
First expiring, first out. Placing new stock behind existing stock is the routine control, and it is a procedure rather than a judgment.
Checking dates on receipt matters too, since short-dated stock arriving unnoticed becomes waste.
When only a month and year are given
The convention is that the product is good through the end of that month.
What a technician does
- Records lot and expiration where required
- Rotates stock by expiry
- Removes expired stock into the correct disposal stream
- Uses lot numbers to answer recall notices
Common questions
What does a lot number identify?
The manufacturing run a package came from. It is how recalls are targeted.
How is it different from an NDC?
The NDC says what the product is; the lot says which run.
What does an expiration date assume?
An unopened container stored as directed.
What if only a month and year are given?
The product is good through the end of that month.
What is stock rotation?
First expiring, first out - new stock placed behind existing stock.