Distribution of technetium-99m-labelled QVARTMdelivered using an AutohalerTMdevice in children

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Abstract
QVARTM, an extrafine hydrofluoroalkane/beclomethasone dipropionate formulation, has been shown to double lung deposition in adults. The aim of the present study was to assess the total body deposition and distribution oftechnetium-99m-labelled (99mTc) QVARTMin children after inhalationviaan AutohalerTM.Sixteen male asthmatic children (5–14 yrs) inhaled labelled drug (99mTc; 100 µg beclomethasone dipropionate)viaan Autohaler within 30 min after salbutamol (200 µg) administration. Simultaneous anterior and posterior planar scintigraphic scans(120 s acquisition time) were collected after inhalation of labelled drug.Mean±sd lung deposition of labelled drug (attenuation-corrected; percentage of ex-actuator dose) was 36.9±9.2, 46.5±11.6 and 54.1±10.7% in children aged 5–7, 8–10 and 11–14 yrs, respectively. Combined oropharyngeal and gastrointestinal deposition was 59.7±8.2, 48.9±12.3 and 40.3±11.8%. Lung deposition positively correlated with the forced expiratory volume in one second (FEV1) and forced vital capacity (FVC). Gastrointestinal dose negatively correlated with the FEV1, FVC, height and age.In older children (11–14 yrs), lung deposition was almost identical to that reported inadults using QVARTM. In children aged 5–10 yrs, lung deposition using QVARTMwas greater than the levels measured using other commercial aerosol delivery systems. Oropharygeal and gastrointestinal deposition was inversely related toage.