Applicability of an ultrasonic nebulization system for the airways delivery of beclomethasone dipropionate in a murine model of asthma.
OBJECTIVE
We have assessed the use of an ultrasonic nebulization system (UNS), composed of ultrasonic nebulizer and diffusion dryer filled with charcoal, for the effective delivery of beclomethasone to the airways in a murine asthma model.


METHODS
Solution of beclomethasone in ethanol was aerosolized using an ultrasonic nebulizer. Passage of the aerosol through a drying column containing charcoal and deionizer produced dry beclomethasone particles. Particles were delivered to BALB/c mice placed in a whole-body exposition chamber 1 h before intranasal challenge with ovalbumine. Efficacy of beclomethasone delivery was evaluated by examining bronchoalveolar lavage fluid (BALF) cytology.


RESULTS
Effect of three UNS system parameters on aerosol particle size was investigated. The critical parameter affecting the size of dry particles was beclomethasone concentration in aerosolized solution and solution flow rate while power level of ultrasonic nebulizer generator had no effect. Administration of beclomethasone at calculated dose of 150 microg/kg to mice significantly decreased total cell number and relative eosinophil number in BALF.


CONCLUSIONS
The UNS system produces a monodisperse aerosol that can be used for inhalative delivery of poorly water soluble substances to experimental animals. The UNS system minimizes formulation requirements and allows rapid and relatively simple efficacy and toxicity testing in animals.
Hrvacić
Boska
B
PLIVA Research Institute Ltd., Prilaz baruna Filipovića 29, HR-10000, Zagreb, Croatia. boska.hrvacic@pliva.hr
Bosnjak
Berislav
B
Tudja
Marijan
M
Mesić
Milan
M
Merćep
Mladen
M
D000465:Algorithms; D000818:Animals; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage* / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy* / Q000276:immunology; D001507:Beclomethasone / Q000008:administration & dosage* / Q000627:therapeutic use*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009330:Nebulizers and Vaporizers; D010047:Ovalbumin / Q000276:immunology; D010316:Particle Size; D011208:Powders; D012130:Respiratory Hypersensitivity / Q000276:immunology; D014465:Ultrasonics
D018927:Anti-Asthmatic Agents; D011208:Powders; D010047:Ovalbumin; D001507:Beclomethasone