The production of dry powder by the sonocrystallisation for inhalation drug delivery

An anti-solvent sonocrystallisation technique was applied for the production of salbutamol sulphate fine particles for the dry powder inhaler (DPI) formulations. The effects of process variables, namely sonication power (watt, W) and volume ratio of anti-solvent to solute solution on the particle characteristics of salbutamol sulphate were investigated. Depending on process variables, fine particles of salbutamol sulphate with a size distribution in a range of 2 μm to 5 μm were successfully produced. Spray drying of sonocrystallised anti-solvent suspension produced micron size crystalline salbutamol sulphate. Emitted dose of this powder was 42% that was significantly enhanced compared to amorphous form produced by spray drying technique. This value was measured by the fine particle fraction (FPFemitted) for the blend of coarse lactose (CoL) and spray-dried sonocrystallised salbutamol sulphate. The data acquired from this study demonstrates the potential of designed process for the production of particles with micron size distributions and highly crystalline form, particularly for DPI formulation.