Roche, based in Basel, Switzerland, can make as many as 400 million doses of Tamiflu a year but increasing production to its maximum "takes some time", Roche is also increasing its stocks of the raw materials used in Tamiflu, including the star aniseed spice that produces shikimic acid - the major ingredient in the antiviral drug.
The dried, star-shaped fruit, mostly harvested from March to May, is a traditional ingredient in Chinese cuisine. Star aniseed exported from China reportedly accounts for 80 percent of the world's total, with the Guangxi Zhuang autonomous region one of the world's largest producers accounting for 85 percent of world's total output.