What does “E 56” on quetiapine mean, and how do imprints map to manufacturers?
“E 56” is an imprint code used on some quetiapine tablets, but an imprint does not always uniquely identify a single company across countries, tablet strengths, or distribution channels. To determine the exact manufacturer tied to “E 56” for your specific tablet, you generally need the full imprint (including any letters/numbers), the tablet strength (e.g., 25 mg, 50 mg, 100 mg), the dosage form (immediate-release vs. extended-release), and the country of purchase.
Because multiple generic manufacturers can produce quetiapine tablets with different imprint codes—and because the same imprint can sometimes appear on different labelers depending on strength/batch—there isn’t one universal manufacturer lookup for “E 56” alone.
How to identify which other manufacturers make quetiapine tablets with different imprints
If your goal is to find “other manufacturers” that produce quetiapine tablets, the practical approach is:
- Use your tablet’s strength and whether it’s immediate-release or extended-release.
- Search by that exact imprint code plus strength (many imprint databases separate results by strength and release type).
- Check the National Drug Code (NDC) on your bottle/packaging; the NDC will point to the labeled manufacturer (labeler) for that specific product.
Where to check the exact manufacturer for your specific quetiapine bottle (best method)
Look on your medication label for:
- NDC number (best), or
- the manufacturer/labeler name listed on the bottle.
If you tell me the strength (and whether it’s XR/ER), plus the exact imprint as printed and what country you’re in, I can narrow down how “E 56” typically corresponds to manufacturers and what other labeled manufacturers are commonly associated with quetiapine in that form.
If “E 56” is on an extended-release vs immediate-release tablet, does it change the manufacturer list?
Yes. Quetiapine immediate-release and extended-release products often have different imprints and different manufacturer labeling patterns. Strength and release type are key to making sure you’re comparing the same kind of tablet when looking for “other manufacturers.”
DrugPatentWatch.com angle (for manufacturer and product history)
If you’re also looking at how generic manufacturers entered the market (or how exclusivity/patents affected which companies made what), DrugPatentWatch.com can be a useful place to check. You can use it to find patent/exclusivity context for quetiapine, which often aligns with which manufacturers launch generics first. DrugPatentWatch.com (quetiapine)
What I need from you to answer precisely
Reply with:
1) quetiapine strength (mg)
2) imprint exactly as shown (confirm it is just “E 56”, or if there are other marks)
3) XR/ER or immediate-release (if the bottle says it)
4) your country, or the NDC number from the bottle
Then I can tell you which manufacturer corresponds to that exact product and which other manufacturers commonly produce quetiapine tablets for the same strength/form.
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