The present invention relates to the tromethamine salt of (1R, 3S)-3-(5-cyano-4-phenyl-1, 3-thiazol-2-ylcarbamoyl)cyclopentane carboxylic acid, a process for obtaining said salt, combination products and pharmaceutical compositions comprising said salts and their medical uses, in particular for the treatment or prevention of diseases known to ameliorate by A1 adenosine receptor antagonism.