See the DrugPatentWatch profile for tigecycline

Based on the provided sources, the expiration date of the patent for injection of tigecycline, marketed as Tygacil, is not explicitly mentioned. However, we can gather some information about the patent status and availability of generic versions of the drug.

According to the first source, DrugPatentWatch, the patent status of Tygacil is listed as "expired" as of July 8, 2021. This indicates that the original patent for tigecycline has expired, allowing other manufacturers to produce generic versions of the drug.

The second source, a summary document from the U.S. Food and Drug Administration (FDA), provides information about the approval of the New Drug Application (NDA) for tigecycline. The document mentions that the NDA for Tygacil was originally approved on June 15, 2005, and the drug is indicated for the treatment of various infections. However, it does not provide specific details about the patent expiration date.

The third source, Drugs.com, states that generic versions of Tygacil are available. This suggests that the patent for tigecycline has indeed expired, allowing other manufacturers to produce generic equivalents of the drug.

While the exact expiration date of the tigecycline patent for injection is not explicitly mentioned in the provided sources, the information from DrugPatentWatch and Drugs.com suggests that the patent has already expired. This indicates that generic versions of tigecycline are now available on the market.

Sources:
[1] DrugPatentWatch: https://www.drugpatentwatch.com/p/tradename/TIGECYCLINE
[2] FDA: https://www.accessdata.fda.gov/drugsatfda_docs/nda/2016/205645Orig1s000SumR.pdf
[3] Drugs.com: https://www.drugs.com/availability/generic-tygacil.html