Based on the provided sources, there is no direct information indicating that the patent for tigecycline injection has been extended recently.

The first source, DrugPatentWatch, provides information on various drugs and their patents. However, it does not specifically mention any recent extension of the patent for tigecycline injection.

The second source, an article from the National Center for Biotechnology Information (NCBI), discusses the development and characteristics of tigecycline. While it provides valuable information about the drug, it does not mention any recent patent extensions.

The third source, the United States Patent and Trademark Office (USPTO), provides information about patent term extensions. However, it does not specifically mention tigecycline or any recent extensions related to the drug.

In conclusion, based on the provided sources, there is no evidence to suggest that the patent for tigecycline injection has been extended recently.

Sources:
[1] DrugPatentWatch: https://www.drugpatentwatch.com/p/tradename/TIGECYCLINE
[2] NCBI: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4037176/
[3] USPTO: https://www.uspto.gov/patents/laws/patent-term-extension/patent-terms-extended-under-35-usc-156