Evaluation of particle size distribution of albuterol sulfate hydrofluoroalkane administered via metered-dose inhaler with and without valved holding chambers

Ann Allergy Asthma Immunol. 2005 Jan;94(1):80-5. doi: 10.1016/S1081-1206(10)61290-2.


Background: Administration of inhaled medications via metered-dose inhaler (MDI) to pediatric patients younger than 4 years usually requires use of a holding chamber or spacer with an attached face mask.

Objective: To determine the particle size distribution and overall dose of albuterol from the albuterol sulfate hydrofluoroalkane delivered in conjunction with 2 US-marketed valved holding chambers (VHCs) compared with the dose delivered via MDIs without VHCs.

Methods: Cascade impaction methods with high-performance liquid chromatography were used to evaluate the fine particle mass (FPM) of albuterol administered without and with the use of 2 commercially available VHCs.

Results: Particle size distributions for the 2 VHCs and the control were similar. The mean FPM values for the 2 VHCs and the control were 32, 28, and 30 microg, respectively. Statistical comparison of the FPM shows a similar profile when differences from the albuterol hydrofluoroalkane without a spacer were evaluated.

Conclusions: In vitro results obtained under these test conditions demonstrate that all the FPM values for the VHCs tested were within 15% of the control range, a difference that is unlikely to be clinically meaningful. These results do not warrant a change in the recommended dose of albuterol hydrofluoroalkane administered when using the VHCs tested. The use of an MDI in conjunction with a VHC provides a reasonable therapeutic approach for administration of albuterol hydrofluoroalkane to young children and other patients who have difficulty administering the MDI alone.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Albuterol / administration & dosage*
  • Albuterol / chemistry
  • Asthma / drug therapy*
  • Bronchodilator Agents / administration & dosage*
  • Bronchodilator Agents / chemistry
  • Child, Preschool
  • Humans
  • Hydrocarbons, Fluorinated / administration & dosage
  • Metered Dose Inhalers / standards*
  • Particle Size


  • Bronchodilator Agents
  • Hydrocarbons, Fluorinated
  • Albuterol
  • apaflurane