Low-Density Microparticles with Petaloid Surface Structure for Pulmonary Drug Delivery

The morphology of spray-dried particles composed of psicose and hydroxypropyl methylcellulose was modified by adding ammonium bicarbonate (ABC) to the solution. The surface structure of the particles was altered by immediate transformation of ABC to gaseous components during the spray drying. As a result, low-density microparticles with a petaloid surface structure, which was controllable by changing the evaporation rate of ABC, was obtained. This technique should be useful for modifying characteristics of solid particles for pulmonary drug delivery. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:1309-1313, 2014