Formulation and physical characterization of large porous particles for inhalation.

摘要: Purpose. Relatively large (>5 µm) and porous (mass density < 0.4 g/cm3) particles present advantages for the delivery of drugs to lungs, e.g., excellent aerosolization properties. The aim this study was, first, formulate such with excipients that are either FDA-approved inhalation or endogenous lungs; second, compare aerodynamic size performance theoretical estimates based on bulk powder measurements. Methods. Dry powders were made water-soluble (e.g., lactose, albumin) combined water-insoluble material lung surfactant), using a standard single-step spray-drying process. Aerosolization properties assessed Spinhaler TM device in vitro both an Andersen cascade impactor AerosizerTM.. Results. By properly choosing excipient concentration varying spray drying parameters, high degree control was achieved over physical dry powders. Mean geometric diameters ranged between 3 15 µm, tap densities 0.04 0.6 g/cm3. Theoretical mass mean diameter (MMAD) rationalized calculated terms particle densities. Experimental values MMAD obtained from AerosizerTM most closely approximated estimates, as compared those impactor. Particles possessing porosity size, 1−3 exhibited emitted doses 96% respirable fractions ranging up 49% 92%, depending measurement technique. Conclusions. engineered light particles, prepared combinations GRAS (generally recognized safe) excipients, may be broadly applicable therapy.