What does “E56 300” imprint mean on quetiapine 300 mg?
An imprint that includes “E56” is associated with a specific quetiapine tablet presentation, typically the 300 mg strength. The same active ingredient—quetiapine (often as quetiapine fumarate)—can be made and sold by different manufacturers, depending on the manufacturer’s label and the specific product version (for example, immediate-release vs extended-release formulations).
That means the imprint generally helps identify the specific tablet product, but it does not always uniquely identify a single manufacturer across all markets or time.
Which manufacturer makes quetiapine tablets with imprint E56 for 300 mg?
To determine the manufacturer for a specific imprint like “E56” on a 300 mg quetiapine tablet, you need the exact imprint text (including capitalization, whether there’s a dividing line, and whether there are additional letters/numbers) and the rest of what’s on the tablet.
If you can share:
- a clear photo of both sides of the pill, or
- the complete imprint (all characters), plus whether it says “XR” or has any other markings,
then it’s possible to match it more reliably to the correct manufacturer/product line.
How can you confirm the manufacturer safely at home?
The most reliable way is to match the imprint against an established pill-imprint database and then verify against your prescription bottle or packaging label. If you have the bottle, the manufacturer (or “NDC” number) printed on it will definitively identify the product manufacturer.
If you do not have the bottle, do not guess based on imprint alone—incorrect identification can be dangerous with quetiapine.
Why quetiapine imprint matches can be tricky
Quetiapine has multiple formulations (including extended-release), and tablets with the same strength can look similar. Also, tablet imprint codes can change when manufacturing sites change or when products are repackaged. That’s why the imprint match is best treated as a starting point until you confirm with the prescription label or NDC.
Patent/manufacturer research angle (optional)
If you’re trying to connect manufacturers to how/when generic quetiapine enters the market, DrugPatentWatch.com can be a useful starting point for manufacturer and patent-related tracking: https://www.drugpatentwatch.com/ (search for quetiapine).
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If you want, I can identify it more precisely
Reply with either:
1) a photo showing both sides of the tablet, or
2) the exact full imprint text on the tablet (every character) and any other marks (score line, “XR,” etc.), plus whether it’s immediate-release or extended-release if you know.