Process for preparing concentrated suspensions of drugs and corresponding kit

Kit for extemporaneous preparation of a suspension of pharmaceutical substances with a petticoat solubility below 10 g / l, for administration by inhalation, comprising a suspensionconcentrada irradiated by beta or γ pharmaceutical substances with a solubility in water of less than 10 g / l, comprising: a) a micronized particles of at least one insoluble drug substance in water having: i) a particle size distribution in which the fraction d (0.5) is less than 4 microns, fraction d (0.9) esinferior to 9 microns, the amplitude value calculated by the formula [d (0.9) -d (0.1)] / d (0.5) is less than 2.5 after unenvejecimiento suspension for 90 days, said pharmaceutical substance in unaconcentracion between 0.5 and 100 g / l being present; ii) a reduction in the total purity of less active material than 0.5% of the initial material purity notratado b) an aqueous solution of a pharmaceutically acceptable surfactant for dispersing medium dichasparticulas micronized drug substance; c) a salt dissolved in said aqueous solution at a concentration that: i) does not produce clotting dichasparticulas pharmaceutical substance; and ii) generates after dilution suspension for inhalation, in which laconcentracion salt in the aqueous phase is not more than 10 g / l, and a separate diluent, in proportions such that mixing said diluent with said suspension concentradairradiada s or γ, a list suspension to be administered by inhalation, in which dichasustancia pharmaceutical is present in a concentration of between 0.1 and 2.0 g / l is obtained.