2006 OPEN FORUM Abstracts
METERED DOSE INHALER OUTPUT COMPARISON BETWEEN A COLLAPSIBLE PAPERBOARD AND TWO RIGID PLASTIC HOLDING CHAMBERS
Carl Okeson, Ph.D., Kendall
Loomis, B.S., Paul McGowen, RRT
Thayer Medical Corporation, Tucson , Arizona , USA
Background: Holding chambers assist many patients with the coordination of pressurized metered-dose inhaler (pMDI) medication delivery. Our study compared the mass of albuterol sulfate delivered per actuation of Proventil HFA (Key Pharmaceuticals, Inc., Kenilworth , NJ ) by three Valved Holding Chambers (VHCs) of comparable size. The three VHCs evaluated included one collapsible VHC made from paperboard (LiteAireTM, Thayer Medical, Tucson, AZ - 160 mL chamber volume) and two VHCs made from rigid polymer (AeroChamber Plus®, Monaghan Medical Corp., Syracuse, NY - 150 mL; OptiChamber®, Respironics, Cedar Grove, NJ - 200 mL).
Method: Five of each of the three VHCs (n=5) were evaluated using a USP throat model attached via 22 mm tubing to a Harvard Apparatus (Holliston, MA) ventilator simulating tidal breathing of 750 mL at 12 breaths/minute and 1:1 I:E. Six actuations of Proventil HFA were delivered from a pre-primed and shaken pMDI canister at 10 second intervals. Each actuation occurred at the start of inspiration. Albuterol sulfate delivered through each VHC was captured on a filter connected just downstream of the throat model. Albuterol sulfate captured on the filters was eluted by rinsing with two 9 mL aliquots of 1 M KCl buffer. Albuterol sulfate concentrations in these solutions were quantified via ultraviolet spectroscopy at 276 nm, and the results analysed in Excel. Albuterol sulfate mass delivered per actuation of Proventil HFA was calculated as the mean of five unit results for each VHC tested. Device performances were compared via two-tailed T-tests; p < 0.05 indicated a significant difference in the albuterol sulfate mass output between VHCs.
Results: The results are summarized in the table below. The drug masses per pMDI dose measured for the LiteAire (75 μg/dose) and AeroChamber Plus (69 μg/dose) were not significantly different, but were both significantly higher than the yield from the OptiChamber (57 μg/dose). The correlating drug percentages delivered for the LiteAire (69%) and AeroChamber Plus (64%) were not significantly different, but were both significantly higher than the OptiChamber (53%). (Calculations based on pMDI manufacturer product information stating each mouthpiece actuation delivers 108 μg of albuterol sulfate.)
Conclusion: Under the conditions tested, the paperboard LiteAire provided drug delivery that was either statistically equivalent to or superior to the rigid plastic VHCs evaluated.
|Holding Chamber Comparisons||LiteAire||AeroChamber Plus||OptiChamber|
|Albuterol Sulfate Mass Delivered Per Actuation (μg; SDs in parentheses)||75 (± 7)||69 (± 4)||57 (± 3)*|
|Percent of Total Albuterol Sulfate Mass Delivered from pMDI Mouthpiece||69%||64%||53%*|
*Significantly lower than the other two VHCs tested