Particle interactions involved in aerosol dispersion of ternary interactive mixtures.
OBJECTIVE
To investigate the mechanism of action of ternary components within dry powder aerosols.


METHODS
Ternary interactive mixtures were prepared containing salbutamol sulphate (SS), coarse lactose carriers and either micronized lactose (ML) or micronized glucose (MG). In vitro drug and excipient aerosol deposition was performed using a twin-stage impinger (TSI) at 60 L/min with a Rotahaler device. Adhesional properties of the lactose carrier were examined using an atomic force microscope (AFM) colloidal probe technique.


RESULTS
The fine particle fraction (FPF) from ternary mixtures were dependent upon carrier type (p < 0.001), ternary concentration (p < 0.001) and ternary component type (p < 0.05). Ternary mixtures produced higher FPF than binary mixtures, except those containing Superfine (SF), which was attributed to the high proportion of intrinsic fine carrier particles. The higher FPF obtained from ternary mixtures was independent of the mixing order (p = 0.08). Increased adhesion force was observed on the carrier surface following the addition of ternary components (p < 0.001).


CONCLUSIONS
The results confirm that ternary components increase aerosol deposition of powder mixtures. Some results were not entirely consistent with the saturation of active site theory and a hypothesis involving competitive and multilayer adhesion was proposed and requires further testing.
Louey
Margaret D
MD
Department of Pharmaceutics, Victorian College of Pharmacy, Monash University, Melbourne, Australia.
Stewart
Peter J
PJ
D000336:Aerosols / Q000737:chemistry* / Q000493:pharmacokinetics; D004337:Drug Carriers / Q000737:chemistry / Q000493:pharmacokinetics; D010316:Particle Size; D004364:Pharmaceutical Preparations / Q000737:chemistry*
D000336:Aerosols; D004337:Drug Carriers; D004364:Pharmaceutical Preparations