126939-27-3

4-Hydroxy Ketotifen Ketotifen EP Impurity C Ketotifen Impurity 3(Ketotifen EP Impurity C） 4,9-Dihydro-4-hydroxy-4-(1-Methyl-4-piperidinyl)- 10-hydroxy-10-(1-methylpiperidin-4-yl)-5H-benzo[1,2]cyclohepta[3,4-b]thiophen-4-one 4-hydroxy-4-(1-methylpiperidin-4-yl)-4H-benzo[4,5]cyclohepta[1,2-b]thiophen-10(9H)-one