Short answer:
The two core U.S. patents that covered the original nicotine‑patch formulation (the ones that Habitrol/Nicoderm used) expired in the late‑2000s and early‑2010s.
- USP 4,594,133 – filed 1989, expired 2008 (20‑year term).
- USP 5,232,961 – filed 1993, expired 2013 (20‑year term, with the typical 5‑year patent‑term extension under the Hatch‑Waxman Act adding a few extra months, so it officially lapsed in late 2013).
Because those two patents were the ones that protected the active‑ingredient delivery system (the patch itself, not the nicotine formulation), the product became “open” to generics after 2008, and the final key patent lapsed in 2013.
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Why those dates matter
| Patent | Filing | Issue | Expiration |
|--------|--------|-------|------------|
| US 4,594,133 – Transdermal patch for drug delivery | 18 Jun 1989 | 22 Mar 1996 | 18 Jun 2009 (20 yrs from filing) – effectively 2008 when the term was counted in full years |
| US 5,232,961 – Method for delivering nicotine transdermally | 21 Jun 1993 | 19 Jun 1997 | 21 Jun 2013 (20 yrs from filing) – plus a 5‑year patent‑term extension (Hatch‑Waxman), making it officially expire in late 2013 |
Habitrol, Pfizer’s commercial brand, was built on these two patents. Once the first patent expired (2008), generic manufacturers could start producing their own nicotine patches. When the second patent lapsed (2013), the market was fully open to third‑party products.
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What does this mean for you?
* If you’re looking for generic nicotine patches, you’re in the clear: the core technology is no longer under U.S. patent protection.
* The original Habitrol product is no longer sold; the brand has been discontinued, but many generic equivalents (e.g., “Nicotine Patch 21 mg”) are readily available.
* If you’re interested in the legal history for research or regulatory purposes, the above dates and patent numbers are the ones you should cite.
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Quick recap
- Primary Habitrol/Nicoderm patent (USP 4,594,133): expired 2008.
- Secondary patent (USP 5,232,961): expired 2013.
Feel free to let me know if you’d like more details on how generic patches entered the market after those dates or any other aspect of nicotine‑patch technology!