Phenothiazine (Standard) is the standard substance of Phenothiazine, and it is applicable for quantitative analysis, quality control, and related research in biochemical experiments. Phenothiazine (ENT 38) is a class of agents exhibiting antiemetic, antipsychotic, antihistaminic, and anticholinergic activities. Phenothiazines antagonize the dopamine D2-receptor in the chemoreceptor trigger zone (CTZ) of the brain, potentially preventing chemotherapy-induced emesis.