A novel breath actuated device (Autohaler) consistently actuates during the early phase of inspiration.
OBJECTIVE
To establish and quantify the point during inspiration that the Autohaler (AH) inhalation system releases a metered dose of aerosol (placebo). The second objective was to determine if the Autohaler system actuates consistently, regardless of the canister life.


METHODS
Double-blind, randomized, two-period crossover, one-day trial.


METHODS
Community based allergy and asthma clinic.


METHODS
Twelve patients with mild to moderate asthma.


RESULTS
Mean verbal training time for the AH which included the patient demonstrating their ability to correctly use the AH was approximately 6 minutes. The mean time for actuation for the AH early in its canister life ("new canister") was 195 msec compared to 205 msec for the AH late in its canister life ("old canister") (p = 0.589). This represented the early part of inspiration as patients had a mean inspiratory duration of 2231 msec for the "new" AH and 2343 msec for the "old" AH. The mean percentage of inspiration time required to actuate the "new" AH was 8.92% compared to 8.82% for the "old" AH. Patients rated the system as easier to much easier to use compared with their current standard press and breathe inhaler.


CONCLUSIONS
The AH consistently actuates early during inspiration, which is considered the optimal time for drug delivery, regardless of the canister life.
Marshik
P L
PL
College of Pharmacy University of Minnesota, Minneapolis, MN, USA.
Larsen
J S
JS
Leach
C L
CL
Halverson
P C
PC
Ekholm
B P
BP
Amies
M H
MH
Kaiser
H B
HB
Weisberg
S C
SC
Sellers
J A
JA
D000293:Adolescent; D000328:Adult; D000336:Aerosols / Q000493:pharmacokinetics*; D018927:Anti-Asthmatic Agents / Q000008:administration & dosage*; D001249:Asthma / Q000188:drug therapy; D018592:Cross-Over Studies; D004311:Double-Blind Method; D016503:Drug Delivery Systems / Q000295:instrumentation* / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009330:Nebulizers and Vaporizers; D015657:Respiratory Transport