The invention concerns a novel method for industrial preparation of disodium 2,2'-dithiobis(alkylsulphonates), and in particular disodium 2,2'-dithiobis(ethanesulphate) (dimesna).

Optically active hydroquinine (amino-3 phenyl)-1 ethanesulfonate (form A), preparation thereof and its use as an intermediate in the preparation of cholecystokinine and gastrin antagonists.

The invention provides various crystalline forms of 1-(2-methylpropyl)-1H-imidazo[4,5-c][1,5]naphthyridin-4-amine ethanesulfonate, pharmaceutical compositions, methods of making, and methods of use.

Levogyral isomers of alkylammonium (amino-3 phenyl)-1 ethanesulphonate derivatives of formula (I) in which R+ denotes a tetraalkylammonium or trialkylphenylalkylammonium residue.

The invention also concerns the preparation and use of said derivatives.