Dry powder pharmaceutical composition, its preparation process and stable aqueous suspension obtained from such composition

Abstract

Pharmaceutical composition in a dry powder form comprising at least one hydrophobic active principle, at least one water-soluble excipient and at least one surfactant, wherein the particles in said dry powder state have a Volume Mean Diameter VMD d greater than the Volume Mean Diameter VMD w of particles in a suspension obtained from said pharmaceutical composition at standard conditions of dispersion in a water-medium. It is also disclosed a process to prepare such dry composition and an extemporaneous suspension for inhalation therapy obtainable from said dry composition.

1 . Process for the preparation of a dry powder pharmaceutical composition comprising at least one hydrophobic active principle, at least one water-soluble excipient, and at least one surfactant, in which the Volume Mean Diameter VMD d  of the particles in said solid dry composition is greater than the Volume Mean Diameter VMD w  of the particles in a suspension obtained from said pharmaceutical composition at standard conditions of dispersion in a water-medium, said process comprising the following steps:
 a) preparing a first phase (A) which is a solution of said hydrophobic active principle in an organic solvent;   b) preparing a second phase (B) in which one or more water-soluble excipients are dissolved in an aqueous medium;   c) dissolving the surfactants in either one of phase (A) or phase (B);   d) mixing said phases (A) and (B) to obtain a phase (C) in which the liquid medium is homogeneous;   e) drying said phase (C) in order to obtain a dry powder with particle size between 0.1 and 17.5 μm;   f) collecting said dry powder;   
       wherein said surfactant and active principle have a weight-to-weight ratio in said particles comprised between 0.6 and 40. 
     
     
         2 . Process according to  claim 1 , wherein said organic solvent is miscible with water. 
     
     
         3 . Process according to  claim 2 , wherein said organic solvent is an alcohol. 
     
     
         4 . Process according to  claim 3 , wherein said alcohol is ethyl alcohol. 
     
     
         5 . Process according to  claim 1 , wherein said step d) of drying said phase (C) is a spray drying process. 
     
     
         6 . Process according to  claim 1 , wherein said particle size, expressed as VMD d , is comprised between 0.1 and 175 μm.