title: An in-vitro assessment of a NanoCrystal beclomethasone dipropionate colloidal dispersion via ultrasonic nebulization.
abstract: Short duration ultrasonic nebulization of a concentrated NanoCrystal colloidal dispersion of beclomethasone dipropionate demonstrated an increased respirable fraction and decreased throat deposition when evaluated in an Andersen 8-stage cascade impactor in comparison to the commercially available propellant-based product Vanceril. An aqueous-based 1.25% w/w colloidal dispersion of beclomethasone dipropionate when aerosolized via an Omron NE-U03 ultrasonic nebulizer generated a respirable drug dose from 22.6 to 39.4 micrograms per 2 s actuation period, compared to 12.8 micrograms for a single actuation of Vanceril. When viewed as a percentage of the emitted dose (through the actuator or mouthpiece), the respirable fraction ranged from 56 to 72% for the nanocrystalline formulation versus 36% for the propellant system. In addition, the throat deposition as seen in the induction port was 9-10% of the emitted dose for the novel suspension, as compared to 53% for the commercial product. Thus, when used with the device outlined herein, a nanocrystalline colloidal suspension of beclomethasone dipropionate affords greater potential drug delivery to the conductive airways of the lung in both quantity and as a percent of emitted dose. Additionally, lower potential throat deposition values were observed which may retard the development of undesirable side effects, such as candidiasis, when compared to a propellant based delivery system. Lastly, the ability to atomize aqueous-based nanocrystalline colloidal dispersions represents an environmentally sound alternative to the current chlorofluorocarbon (CFC)-based products and may avoid the technical difficulties of reformulating with chlorine-free propellants.
authors.affiliation: NanoSystems (Division of Elan Pharmaceutical Technologies), King of Prussia, PA 19406, USA. ostranderk@nanosys.com
authors.forename: K D
authors.initials: KD
authors.lastname: Ostrander
authors.forename: H W
authors.initials: HW
authors.lastname: Bosch
authors.forename: D M
authors.initials: DM
authors.lastname: Bondanza
mesh_terms: D000336:Aerosols; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage* / Q000737:chemistry*; D001507:Beclomethasone / Q000008:administration & dosage* / Q000737:chemistry*; D002626:Chemistry, Pharmaceutical; D003102:Colloids; D003460:Crystallization; D008855:Microscopy, Electron, Scanning; D009330:Nebulizers and Vaporizers; D010316:Particle Size; D013535:Suspensions; D014465:Ultrasonics
chemical_list: D000336:Aerosols; D018927:Anti-Asthmatic Agents; D003102:Colloids; D013535:Suspensions; D001507:Beclomethasone