NebuChamber^® is made from stainless steel and is not susceptible to electrostatic charge, unlike many plastic spacers and valved holding chambers. Electrostatic charges act as interfering forces on the drug particles released into plastic spacers or valved holding chambers when the pMDI is actuated. The electrostatic effects are most pronounced for the first doses released in the chamber.

In contrast to traditional plastic holding chambers, NebuChamber does not need to be “primed”, i.e. NebuChamber delivers a full dose already from the first actuation of the pMDI.

The effects of priming were investigated in vivo in a study by Kenyon et al comparing NebuChamber with Nebuhaler^® and Volumatic™. Priming NebuChamber with 20 doses of placebo aerosol did not result in any substantial increase in total lung deposition compared with an unprimed NebuChamber.

Active doses consisted of budesonide 200 µg labelled with 99mTc. “Priming” consisted of firing 20 doses into the valved holding chamber. Lung deposition was measured by gamma scintigraphy. Adapted from Kenyon et al (1998).

Volumatic™ is a trademark owned by the GlaxoSmithKline group of companies.

References

Further reading:

Kenyon CJ, et al. The effects of static charge in valved holding chambers on glucocorticosteroid aerosol deposition in asthmatic patients. Eur Respir J 1998;11:606-10.

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