Concentrated suspensions of drugs and their use to produce suspensions for inhalatory administration

摘要

Concentrated suspension of water insoluble pharmaceutical substances, comprising:a) micronized particles of at least one water insoluble pharmaceutical substance with a particle size distribution in which the d(0.5) fraction is less than 3 µm, the span value is less than 2, and such features are retained upon aging the suspension for 90 days; said pharmaceutical substance being present at a concentration of from 5 to 50 times the concentration of a suspension of the same substance for inhalatory administration;b) an aqueous solution of a pharmaceutically acceptable surfactant as dispersing medium for said micronized particles of pharmaceutical substance;c) a salt dissolved in said aqueous solution, at a concentration that: i) does not cause coagulation of said particles of pharmaceutical substance; and ii) generates upon dilution an inhalatory suspension in which the concentration of salt in the aqueous phase is not higher than 10 g/l. present at a concentration of from 0.1 to 2.0 g/l.