rac N-Demethyl Promethazine Hydrochloride;ProMethazine EP IMpurity C;ProMethazine IMpurity C HCl;PROMETHAZINE EP IMPURITY C HCL;(2RS)-N-Methyl-1-(10H-phenothiazin-10-yl)propan-2-amine;N-Demethyl Promethazine;10H-Phenothiazine-10-ethanamine,N,α-dimethyl-,hydrochloride (1:1);Promethazine Impurity 3(EP Impurity C)