title: Insulin has never become a cheap generic drug in the US because of companies' small changes to "evergreen" the patent.
authors: London.
authors: Susan
authors: S
authors: Mayor
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000191:economics; D004345:Drug Industry; D016568:Drugs, Generic / Q000191:economics*; D004465:Economic Competition; D006801:Humans; D007328:Insulin / Q000191:economics*; D010330:Patents as Topic; D014481:United States
chemical_list: D016568:Drugs, Generic; D007328:Insulin