6-methyl-2-ethyl-3-hydroxypyridine [ Epigid,2-ethyl-6-methyl-3-hydroxypyridine,2-ethyl-6-methyl-3-oxypyridine,6-methyl-2-ethyl-3-hydroxypyridine hydrochloride,6-methyl-2-ethyl-3-hydroxypyridine monohydrochloride,emoxipin,emoxipine,emoxypin,emoxypine,hydroxypyridine-6 ] compound used in second source was chlorhydrate; has been used as retinoprotector