The present invention relates to the stable acid addition salts of Bosentan that are useful for the purification of Bosentan base. In particular, the Bosentan acid addition salt is selected from Bosentan citrate and Bosentan tartrate.Cette invention concerne des sels daddition dacide stables de bosentan qui sont utiles pour la purification du bosentan base. En particulier, le sel daddition dacide de bosentan est choisi parmi le citrate de bosentan et le tartrate de bosentan.