title: Biodegradable nanoparticle flocculates for dry powder aerosol formulation.
abstract: Uncontrolled agglomeration presents a formidable encumbrance to nanoparticle formulation as a dry powder for inhalation therapy. Spray-drying and freeze-drying of nanosuspensions has demonstrated some success in creating dry powders composed of agglomerated nanoparticles with appropriate aerodynamic properties. These controlled drying processes, however, may require an undesirable amount of excipient to maintain an active therapeutic while generating dry powders and may not offer the desired control over agglomerate size and aerosolizability. As a potential alternative approach, a method for flocculating nanoparticles in solution followed by freeze-drying is reported. Biodegradable poly(DL-lactic-co-glycolic acid) nanoparticles were self-assembled into flocs via electrostatic interactions between nanoparticles coated with oppositely charged polyelectrolytes. The size of the nanoparticle flocs was readily controlled by manipulating the mixing ratio of charged nanoparticles. Freeze-drying the flocculated nanoparticles produced dry powders exhibiting low density (approximately 0.1 g/cm3), a weblike morphology, and desirable aerodynamic properties suited for dry powder aerosols.
authors: Department of Chemical and Petroleum Engineering, The University of Kansas, Lawrence, Kansas 66047, USA.
authors: Lianjun
authors: L
authors: Shi
authors: Carl J
authors: CJ
authors: Plumley
authors: Cory
authors: C
authors: Berkland
mesh_terms: D000336:Aerosols; D001711:Biotransformation; D004339:Drug Compounding; D005427:Flocculation; D006801:Humans; D019344:Lactic Acid; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry / Q000648:ultrastructure; D036103:Nanotechnology; D010316:Particle Size; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D011208:Powders; D012138:Respiratory Therapy
chemical_list: D000336:Aerosols; D011108:Polymers; D011208:Powders; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid