Dissolution of aerosol particles of budesonide in Survanta (TM), a model lung surfactant

The effect of a pulmonary surfactant extract from bovine lung, Survanta(TM) , on the dissolution rate of aerosol particles of budesonide was determined . Aerosol particles of budesonide were generated from an ethanol solution, dried, and collected by a cascade impactor for characterization or by a liq uid impinger for dissolution experiments. Powder x-ray diffraction, differe ntial scanning calorimetry, differential thermal analysis, and scanning ele ctron microscopy were used to characterize the aerosol particles and starti ng material. No change in phase was detected, although the aerosol particle s appeared to contain residual solvent. The dissolution rate of the aerosol particles in saline was low and variable. Survanta(TM) increased the exten t of dissolution of budesonide in proportion to the added concentration, wh ich was also verified by equilibrium solubilization studies. Survanta(TM) a lso increased rate of dissolution, in a manner similar to sodium dodecyl su lfate. Analysis of the concentration of budesonide following ultracentrifug ation indicated that there is rapid equilibration of budesonide between the Survanta(TM) and aqueous phase. These results show that lung surfactant ha s the potential of enhancing the rate and extent of dissolution of drugs ad ministered to the lung. (C) 2001 Wiley-Liss, Inc. and the American Pharmace utical Association.