Characterization of Pharmaceutical Aerosols and Dry Powder Inhalers for Pulmonary Drug Delivery
The growing use of the inhalation route for the delivery of new types of drugs, such as proteins for both local and systemic effects, and the need to manufacture and deliver fine particles to the targeted parts of the respiratory tract have led to more interest in the characterization of not only the size of the aerosol particles, but also their morphology and how they are dispersed by inhaler devices. These devices are most commonly dry powder inhalers. A fractal object, as defined by Mandelbrot, has a dimension greater than the geometric or physical dimension but less than or equal to the embedding dimension in an enclosed space. Characterization of particle surface is important because surface roughness is recognized to affect physicochemical properties of pharmaceutical products and is therefore a crucial factor in the manufacturing process and product performance.