The invention concerns pharmaceutical formulas designed for the treatment of diseases related to CFTR channel dysfunction, such as cystic fibrosis, asthma or diarrhoea. These formulas contain a molecule, coming in the form of a zwitterion at physiological pH, with the formula: where X.dbd.N or P; Y.dbd.O or S; R.sub.1 to R.sub.7 represent: --, H, or carbon chains, substituted or not, which may contain heteroatoms; except for betaine.