Antistatic treatment and salbutamol dosing have variable effect on drug delivery of valved holding chambers

Abstract

AimsOur aim was to evaluate whether the number of puffs or antistatic treatment have significant effect on drug delivery of six different valved holding chambers (VHCs). MethodsWe used simulated paediatric breathing pattern with 25/min frequency and 200 ml tidal volume. When comparing the effect of antistatic treatment, we used 100 μg of salbutamol (one puff Ventolin Evohaler 100 μg/dos) actuated into each VHC before and after detergent wash. When comparing the effect of one or two puffs (100 vs. 200 μg), all VHCs were washed prior to the measurements. ResultsAll VHC were significantly affected by antistatic treatment. Washing improved drug delivery of four VHCs (1.3–2.2 fold increase in median filter dose) but had an opposite effect in two devices (54–61% decrease). The effect of dose doubling resulted in a 2.03–2.93 fold increase on filter dose in two VHCs. Four out of the six VHC showed significantly poorer performance with two puffs as opposed to one puff (ratio of two puffs to one puff varied between 1.19 and 1.77). ConclusionVHCs marketed as antistatic are significantly affected by antistatic treatment. To ensure optimal drug delivery, salbutamol should be actuated to VHCs one puff at a time. Each VHC brand has its unique characteristic that affects drug delivery in a way that cannot be generalised to another VHC. There is a need for universal standardisation of VHCs. Key notesValved holding chambers (VHCs) that are marketed as antistatic are significantly affected by antistatic treatment. Multiple actuations before inhalation tend to decrease the drug delivery efficacy of VHCs. Each VHC brand has its unique characteristic that affects drug delivery in a way that cannot be generalised to another VHC. There is a need for comprehensive and financially independent testing and standardisation of VHCs.