Processing of Pharmaceuticals for Pulmonary Delivery by Supercritical Technology

There are several advantages of using the human pulmonary pathways for drug delivery. These include large absorption area, more rapid onset of therapeutic effect, reduced dose of bioactive delivery and lower side effects of therapy. Inhalable products should meet several criteria, in particular shape, surface roughness and particle size (approximately 1-5 µm, or 2-3 µm as optimum) to reach the deep region of human lungs (alveolus). In an attempt to produce such powders, supercritical fluid (SCF) technology has been proposed as an alternative to high energy consumptive yet popular mechanical methods such as milling. In this article, application of SCF technology for inhalable products manufacturing is briefly overviewed. Discussion focuses on the process development and formulation strategies to obtain improved product properties of specifically designed for pulmonary administration.