The lack of electrostatic interference on the walls of NebuChamber^® means that the dose delivered from NebuChamber will be consistent over time.

Repeated use of a pMDI in combination with NebuChamber gave a consistent delivery of dose over 100 consecutive doses of budesonide in vitro (Berg et al, 1998).

The drug used in this study was budesonide. Adapted from Berg et al (1998).

Dose delivery from NebuChamber in asthmatic children of different ages. Doses were measured by interposing a filter between the facemask and the valve system of the holding chamber. Adapted from Bisgaard et al (1995).

In a study by Barry and O'Callaghan (1999), in which a breathing simulator mimicked the effect of breathing at tidal volumes between 50 and 300 mL with a respiratory frequency of 20 cycles/min, the delivery of budesonide from NebuChamber was constant at tidal volumes of 150 mL and above (Figure). Thus, for the youngest children with small tidal volumes (50 ml corresponds approximately to 5 kg body weight) less drug will be delivered – however, calculated per kg body weight twice as much budesonide will be delivered compared to older children.

Amounts of budesonide deposited on filters from NebuChamber and Nebuhaler at different tidal volumes after 5 inhalations. Holding chambers were washed in warm water and air-dried. Adapted from Barry and O’Callaghan (1999).

References

Berg E, et al. In vitro performance of three combinations of valved holding chambers and pressurized metered dose inhalers for treatment in children. Eur Respir J 1998;12:472-6.

Bisgaard H, et al. A non-electrostatic valved holding chamber for aerosol delivery. Arch Dis Child 1995;73:226-30.

Barry PW, O'Callaghan C. The output of budesonide from spacer devices assessed under simulated breathing conditions. J Allergy Clin Immunol 1999;104:1205-10.