Differences in inhaled fluticasone bioavailability between holding chambers in children with asthma

Area of Science:

• Pharmacology
• Pediatric Pulmonology
• Drug Delivery Systems

Background:

• Asthma management in children often relies on inhaled corticosteroids.
• Holding chambers are crucial for optimizing drug delivery to the lungs.
• Previous in vitro studies suggested differences in aerosol delivery between various holding chambers.

Purpose of the Study:

• To compare the in vivo bioavailability of inhaled fluticasone propionate delivered via two different holding chambers (InspirEase and E-Z Spacer) in children with asthma.
• To determine if in vitro findings regarding aerosol deposition translate to differences in drug bioavailability.

Main Methods:

• A double-blind, randomized, crossover study was conducted with eight children (aged 5-9 years) with stable asthma.
• Participants inhaled fluticasone propionate (110 microg puffs) twice daily through either the InspirEase or E-Z Spacer holding chamber.
• Plasma fluticasone concentrations were measured over 6 hours post-dose using high-performance liquid chromatography-mass spectrometry.

Main Results:

• The peak plasma concentration (Cmax) of fluticasone was 18% higher with InspirEase compared to E-Z Spacer (p < 0.05).
• The area under the concentration-time curve (AUC0-6) for fluticasone was 22% higher with InspirEase, though this did not reach statistical significance (p = 0.06).

Conclusions:

• The observed differences in fluticasone bioavailability between the InspirEase and E-Z Spacer holding chambers in children with asthma are consistent with prior in vitro aerosol studies.
• Holding chamber selection may influence the efficacy of inhaled fluticasone propionate therapy in pediatric asthma patients.