A novel antileishmanial formulation containing compounds belonging to the series of (2Z,22)-3,3- (alkane-1,2- diylbis(azanediyl))bis(6-hydroxy-l- aryllfluorenyl hex-2-en-l-ones) or their salts thereof showingantileishrnanial activity under in vivo conditions against L. donovani in hamster model. These conlpounds or their fortnulation elicit anitleshmanial activity both via oral and ip routes.