Tizanidine is the generic form of the brand-name medication Zanaflex. It is a muscle relaxant used to treat muscle spasms and reduce pain by blocking pain signals from reaching the brain.

Founded in 1983, Sun Pharmaceutical is the fourth largest maker in the U.S. and distributes about 184 drugs in the country. Sun serves more than 150 countries through its range of product offerings. The company has 40+ manufacturing sites including in India, the U.S., and Brazil.