[Problems raised by the reformulation of inhalations after the removing of propulsors "chlorofluorocarbons" (CFC)].

The application of the Montreal convention which not only plans to remove CFCs from pressurized preparations but to stop also the production, will affect companies. However, for pharmaceutical use, antiasthmatic drugs are considered as essential and at the moment the use of CFCs is allowed. But if the production stops, a reformulation will be necessary. Three solutions are conceivable: The first one is to replace CFC 11, 12 and 114 with the old well known propellants as butane, isobutane, propane but they are not very compatible with pulmonary use. The second one is the use of new official substitutes as 134a (tetrafluorethane) or R227 (heptafluoropropane). The former is immediately available and can be used because its take of toxicity has been demonstrate by an international consortium, IPACT as well as the absence of action on ozone but a light "greenhouse effect" is expected. However, the simple substitution of CFCs for those two propellants is not easy due to their physical-chemical properties which are different from the old CFCs. This reformulation is so delicate that pharmaceutical companies have chosen a third solution: precompression pumps or clever devices which can deliver directly the pure drug in powder form. The other preparations to be used for dermatological or cosmetological uses have been reformulated since a long time with original and special presentation (bags in can or volatile solvents).