Based on the provided sources, there is no specific information available regarding the global extension of the patent for tigecycline injection. The sources mainly provide information about the patent term extension in the United States and do not mention its global extension.

The first source, Drug Patent Watch, provides data on the patent status of various drugs, including tigecycline. However, it does not provide any information about the global extension of the patent for tigecycline injection [1].

The second source, the United States Patent and Trademark Office (USPTO), explains the concept of patent term extension under 35 U.S.C. 156. It provides a list of patents that have been extended under this law, but it does not specifically mention tigecycline injection [2].

The third source, a research article published in the National Center for Biotechnology Information (NCBI) database, discusses the pharmacokinetics and pharmacodynamics of tigecycline. While it provides valuable information about the drug, it does not mention anything about patent extensions [3].

In conclusion, based on the provided sources, there is no clear evidence to suggest that the patent for tigecycline injection has been extended globally. It is important to note that patent information can be complex and may vary by country, so it is advisable to consult official patent databases or seek legal advice for the most accurate and up-to-date information.

Sources:
[1] Drug Patent Watch. Tigecycline - Tradename: Tigecycline. Retrieved from https://www.drugpatentwatch.com/p/tradename/TIGECYCLINE
[2] United States Patent and Trademark Office. Patent Terms Extended Under 35 USC §156. Retrieved from https://www.uspto.gov/patents/laws/patent-term-extension/patent-terms-extended-under-35-usc-156
[3] National Center for Biotechnology Information. Tigecycline: Pharmacokinetics and Pharmacodynamics. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5967687/