ProMethazine IMpurity C HCl;ProMethazine EP IMpurity C;rac N-Demethyl Promethazine Hydrochloride;10H-Phenothiazine-10-ethanamine,N,α-dimethyl-,hydrochloride (1:1);Promethazine EP Impurity-C (HCI);Promethazine EP Impurity C (N-Desmethyl Promethazine);Promethazine Impurity 3(Promethazine EP Impurity C);Promethazine Impurity C