4-(Methoxycarbonyl)-1-phenethyl-4-(N-phenylpropionylamino)piperidinium dihydrogen citrate 4-Piperidinecarboxylic acid, 4-((1-oxopropyl)phenylamino)-1-(2-phenylethyl)-, methyl ester, 2-hydroxy-1,2,3-propanetricarboxylate (1:1) 59708-52-0 61380-27-6 Carfentanil citrate Carfentanil citrate [USAN] EINECS 262-748-6 Methyl 1-phenethyl-4-(N-phenylpropionamido)isonipecotate citrate (1:1) R 33799