Not Less Than - 95%
8-[4-[1-Oxido-4-(2-pyrimidinyl)-1-piperazinyl]butyl]-8-azaspiro[4.5]decane-7,9-dione; 8-[4-[4-(Pyrimidin-2-yl)piperazin-1-yl]butyl]-8-azaspiro[4.5]-decane-7,9-dione N-oxide;