When does tigecycline's patent extension take effect?

I’m not sure which jurisdiction or which specific patent you mean. “Patent extension” could refer to a U.S. patent term extension (PTE) under Hatch-Waxman, an EU supplementary protection certificate (SPC), or something else.

If you can specify:
- the country/region (e.g., United States, European Union, etc.)
- the exact tigecycline patent or product (e.g., Tygacil, the core chemical patent, or a specific patent number)

I can give you a precise date. In the meantime, here’s how it generally works:

- In the United States, a patent term extension (PTE) adds time to the patent to compensate for FDA regulatory review. The extended term equals the original patent term plus the approved extension amount (up to a maximum of about five years, and subject to regulatory review timelines). The patent cannot be enforced until the new expiration date set by the USPTO. That new expiration date is shown in USPTO records and often also noted in the FDA’s Orange Book entry for the drug.

- To find the exact date for tigecycline:
- Check the FDA Orange Book entry for Tygacil (tigecycline) to see any PTE-listed patents and their new expiration dates.
- Check the USPTO Patent Center (or PatFT) for the specific tigecycline patents and any Patent Term Extension certificates, which will show the new expiration date.

If you provide the jurisdiction and any patent numbers you have, I can look up or guide you to the exact effective date.