Synonyms: 2,4(1H,3H)-Quinazolinedione, 6,7-dimethoxy-, 6,7-Dimethoxy-2,4(1H,3H)-quinazolinedione, 2,5-Dihydroxy-6,7-dimethoxyquinazoline, 6,7-Dimethoxy-1H-quinazoline-2,4-dione, 6,7-Dimethoxyquinazoline-2,4-diol, 6,7-Dimethoxyquinazoline-2,4-dione,6,7-Dimethoxyquinazoline-2,4(1H,3H)-dione, Doxazosin Mesilate Imp. D (EP)