Drug deposition is an important factor that contributes to safety and efficacy outcomes of inhaled
steroid therapy. Ciclesonide is a nonhalogenated, inhaled corticosteroid under investigation
for the treatment of asthma. Therefore, this study was performed to assess lung deposition
of ciclesonide. Technetium-99m (99mTc)–labeled ciclesonide (where the 99mTc-label is
physically dissolved in the ciclesonide–hydrofluoroalkane [HFA] solution aerosol) inhaled
by healthy volunteers was analyzed by two-dimensional (2-D) and three-dimensional (3-D)
imaging to determine lung deposition. Six healthy volunteers inhaled one puff of 40 µg (exactuator,
equivalent to 50 µg ex-valve) ciclesonide for 2-D imaging, and two healthy volunteers
inhaled 10 puffs of 40 µg ciclesonide for 2-D and 3-D imaging. The ciclesonide aerosol
was administered via metered-dose inhaler (MDI) containing HFA-134a as propellant. The
ex-actuator mean (± standard deviation) deposition of ciclesonide in the lungs was higher
(52% ± 11%) than in the mouth/pharynx (38% ± 14%). Two-dimensional and 3-D imaging
showed that ciclesonide reached all regions of the lung. Mean percent deposition in peripheral
regions (47% and 34%) was higher than in lower central regions (17% and 30%), as revealed
by 3-D and 2-D imaging, respectively. Inhalation of up to 400 µg of ciclesonide produced
no drug-related side effects. In conclusion, ciclesonide administered via metered-dose
inhaler using HFA-134a as a propellant provided high lung deposition (>50%), greater distribution
throughout peripheral regions of the lungs, and relatively low oropharyngeal deposition.
