Figures & data
Figure 1.— Tail-off characteristics of asthma medications delivered by MDIs with different valve placement. Panel A shows tail-off from 3 separate MDIs with fill holes located at the base of the retaining cup that allow formulation to enter the valve (valve-down orientation). Panel B shows more erratic tail-off characteristics of 3 separate MDIs with valve design in which the fill holes are located at higher levels relative to the base of the retaining cup (Adapted from Schultz (Citation13)).
![Figure 1.— Tail-off characteristics of asthma medications delivered by MDIs with different valve placement. Panel A shows tail-off from 3 separate MDIs with fill holes located at the base of the retaining cup that allow formulation to enter the valve (valve-down orientation). Panel B shows more erratic tail-off characteristics of 3 separate MDIs with valve design in which the fill holes are located at higher levels relative to the base of the retaining cup (Adapted from Schultz (Citation13)).](/cms/asset/046c647f-be35-45ff-bf97-6b3a641d9cc2/ijas_a_789056_f0001_b.gif)
Figure 2.— Integrated dose counter on a metered-dose inhaler. Shown here is a ProAir® metered-dose inhaler (manufactured by Teva Pharmaceutical Industries, Ltd., Horsham, PA).
![Figure 2.— Integrated dose counter on a metered-dose inhaler. Shown here is a ProAir® metered-dose inhaler (manufactured by Teva Pharmaceutical Industries, Ltd., Horsham, PA).](/cms/asset/f23099f3-f70b-4ade-be45-6b5cd0ac17e0/ijas_a_789056_f0002_b.jpg)
Table 1.— Discrepancies in patient perceptions of the number of doses of rescue medication remaining in an MDI with no dose counter. Seventeen patients with asthma who regularly use an MDI estimated the number of salbutamol doses remaining in MDIs that had been partially emptied to different degrees (Adapted from Holt et al. (Citation21)).