Browsing by Subject "ethanol-water solutions"

The aim of this study was to obtain basic knowledge of the applicability of a Büchi Spray dryer B-290 for inhalation particle production and its process parameters effects on particle physicochemical properties. The possibility to anneal the particles where also studied. The greater goal was to provide some information about the solutes' crystallization tendency related to chosen process parameters. Two active pharmaceutical ingredients, salbutamol sulphate and budesonide, where chosen as model substances. Spray drying is a suspended particle processing system which is widely applied and it has been in use from the 1940s. The processed pumpable liquid which contains chosen substances is dispersed into droplets and dried to produce particles that are later collected. Spray dryer is used to process food, biochemical and pharmaceutical substances. In the field of inhalation particle processing, however, it is rather a new technology. This is because of the quality limitations of inhalable particles and the challenges in process optimization. From the many process parameters the concentration of the solid substances, inlet temperature and concentration of organic solvent were chosen as variables for the conducted experiments due to their apparent effects on product quality and especially on solid state. A rudimentary box-annealing system was studied for spray dried substances to verify their solid state transformation tendencies. Salbutamol sulphate was annealed in a box with 65% relative humidity and budesonide in 74 % and 100% relative ethanol activities. Particle size and size distributions were measured with laser diffraction apparatus, crystallinity was analyzed with powder x-ray diffraction and particle morphology was studied with scanning electron microscope. Salbutamol sulphate turned out to be amorphous and budesonide crystalline when spray dried. Both products were within the inhalable size range (1-5µm). Under the current setup the solid state quality of the products was found dependent on the concentration of the solid substances to some extent. Spray dried amorphous salbutamol sulphate was successfully anneaed to a crystalline material and partly crystalline budesonide was annealed to a more crystalline state. Further studies are needed to utilize the full potential spray drying has to offer for inhalation formulating. The kinetics of the annealing procedure and its dependency on the method used still remain largely unexplored.