EST64454 hydrochloride is a selective and orally active sigma-1 receptor antagonist with a K i of 22 nM. EST64454 hydrochloride has the potential for the research of the pain. In Vivo EST64454 (10 mg/kg; p.o.; male Wistar rats) treatment shows the C max , t 1/2 , AUC 0-∞ , V ss and F% are 771 ng/mL, 3.4 hours, 1431 ng h/mL, 4.4 l/kg and 69%, respectively . EST64454 (10 mg/kg; p.o.; male CD1 mice) treatment shows the C max , t 1/2 , AUC 0-∞ , V ss and F% were 1178 ng/mL, Form:Solid