In vitro and clinical characterization of the valved holding chamber AeroChamber Plus® Flow-Vu® for administrating tiotropium Respimat® in 1-5-year-old children with persistent asthmatic symptoms.

BACKGROUND: When characterizing inhalation products, a comprehensive assessment including in vitro, pharmacokinetic (PK), and clinical data is required. We conducted a characterization of tiotropium Respimat® when administered with AeroChamber Plus® Flow-Vu® anti-static valved holding chamber (test VHC) with face mask in 1-5-year-olds with persistent asthmatic symptoms. METHODS: In vitro tiotropium dose and particle size distribution delivered into a cascade impactor were evaluated under fixed paediatric and adult flow rates between actuation and samplings. The tiotropium mass likely to reach children's lungs was assessed by tidal breathing simulations and an ADAM-III Child Model. PK exposure to tiotropium in preschool children with persistent asthmatic symptoms (using test VHC) was compared with pooled data from nine Phase 2/3 trials in older children, adolescents, and adults with symptomatic persistent asthma not using test VHC. RESULTS: At fixed inspiratory flow rates, emitted mass and fine particle dose decreased under lower flow conditions; dose reduction was observed when Respimat® was administered by test VHC at paediatric flow rates. In <5-year-old children, such a dose reduction is appropriate. In terms of dose per kg/body weight, in vitro-delivered dosing in children was comparable with adults. Transmission and aerosol holding properties of Respimat® when administered with test VHC were fully sufficient for aerosol delivery to patients. At zero delay, particles <5 µm (most relevant fraction) exhibited a transfer efficacy of ≥60%. The half-time was>10 s, allowing multiple breaths. Standardized tidal inhalation resulted in an emitted mass from the test VHC of approximately one-third of labelled dose, independent of coordination and face mask use, indicating predictable tiotropium administration by test VHC with Respimat®. Tiotropium exposure in 1-5-year-old patients using the test VHC, when adjusted by height or body surface, was comparable with that in older age groups without VHCs; no overexposure was observed. Adverse events were less frequent with tiotropium (2.5 µg, n = 20 [55.6%]; 5 µg, n = 18 [58.1%]) than placebo (n = 25 [73.5%]). CONCLUSIONS: Our findings provide good initial evidence to suggest that tiotropium Respimat® may be administered with AeroChamber Plus® Flow-Vu® VHC in 1-5-year-old patients with persistent asthmatic symptoms. To confirm the clinical efficacy and safety in these patients, additional trials are required. CLINICAL TRIALS REGISTRY NUMBER: The trial was registered under NCT01634113 at http://www.clinicaltrials.gov.

Size distribution of salbutamol/ipratropium aerosols produced by different nebulizers in the absence and presence of heat and humidification.

BACKGROUND: Few studies have evaluated the size distribution of inhaled and exhaled aerosolized drugs, or the effect of heated humidification on particle size and lung deposition. The present study evaluated these aspects of bronchodilator (salbutamol/ipratropium) delivery using a lung model in the absence and presence of heat and humidification. METHODS: We positioned filters to collect and measure the initial drug, inhaled drug, and exhaled drug. Particle size distribution was evaluated using an 8-stage Marple personal cascade impactor with 0.2-µm polycarbonate filters. RESULTS: A greater inhaled drug mass was delivered using a vibrating mesh nebulizer (VMN) than by using a small volume nebulizer (SVN), when heated humidifiers were not employed. When heated and humidified medical gas was used, there was no significant difference between the inhaled drug mass delivered by the VMN and that delivered by the SVN. A significantly greater mass of inhaled 1.55-µm drug particles was produced by the VMN than with the SVN, under heated and humidified conditions. However, the mass median aerodynamic diameters (MMADs) of the aerosolized drug produced by the SVN and VMN did not differ significantly under the same conditions. CONCLUSIONS: The VMN produced more fine particles of salbutamol/ipratropium, and the drug particle size clearly increased in the presence of heat and humidification.