Biomedical Engineering Reference
In-Depth Information
Table 12.1 Mass salbutamol per actuation (
g) for the ACI-USP/Ph.Eur. induction port and AIM-
pHRT with USP/Ph.Eur. and AIT inlets ( From [ 42 ] —used with permission )
Apparatus
µ
AIM-pHRT
ACI
Location
AIT
AIT
USP/Ph.Eur.
Inhaler mouthpiece + inlet
54.7 ± 3.6
52.9 ± 2.3
55.0 ± 4.9
Stage 0
2.3 ± 0.3
5.4 ± 0.9
Stage 1
1.4 ±7 0.1
2.5 ± 0.2
Stage 2
4.5 ± 0.7
1.9 ± 0.1
2.6 ± 0.4
Stage 3
8.4 ± 0.6
9.6 ± 1.0
Stage 4
17.9 ± 1.3
15.7 ± 2.2
Stage 5
39.6 ± 4.0
10.5 ± 1.3
8.5 ± 0.8
Stage 6
1.0 ± 0.1
1.0 ± 0.1
Stage 7
0.3 ± 0.1
0.3 ± 0.1
Filter
1.7 ± 0.3
0.7 ± 0.3
0.8 ± 0.2
TM exMVM
100.5 ± 7.7
97.2 ± 4.9
101.5 ± 9.5
IM
45.8 ± 4.9
44.2 ± 3.0
46.5 ± 4.6
n = 5 replicates per apparatus/inlet confi guration; mean ± SD
important range from 1 to 5 µm aerodynamic diameter [ 42 ]. A detailed description
of the testing and data that were obtained is provided below, as this type of informa-
tion is a good guide as to the amount of detail that will be required when introducing
the AIM-pHRT approach into routine use with whatever OIP class to which this
apparatus is being applied.
In this investigation, the interior surfaces of the AIT were coated with a thin layer
of silicone oil to simulate the mucosa, as was done by Ehtezazi et al., investigating
the MDI-delivered medication to a cascade impactor via different anatomically cor-
rect oropharyngeal models [ 43 ]. The CI collection plates were also oil coated to
mitigate particle bounce and re-entrainment, in accordance with the practice estab-
lished in previous AIM-based studies [ 44 ]. The comparative data obtained from the
full-resolution ACI as control system with either USP/Ph.Eur. induction port or with
AIT and the AIM-pHRT apparatus with AIT are summarized in Table 12.1 .
Individual total mass recovery values for salbutamol were within ±16 % of the
label claim (100 µg/actuation), with most values lying within ±10 % label claim.
The grouped mass recovery values (µg/actuation; mean ± SD) were equivalent at
100.5 ± 7.7, 97.2 ± 4.9, and 101.5 ± 9.5 for the AIM-pHRT, ACI-AIT, and ACI-Ph.
Eur./USP confi gurations, respectively (1-way anova , p = 0.64). These system suit-
ability data were close to expectations for the particular OIP, indicating that internal
losses of API were minimal, whichever confi guration was being evaluated.
Individual stage deposition data were highly reproducible, with their coeffi cients
of variation ( C-of-V ) being comparable across confi gurations, and increasing in
magnitude with decreasing absolute mass as would be expected as these values
approached closer to the lower limit of detection of 0.1 µg salbutamol/actuation.
The corresponding APSDs, normalized either to total mass of salbutamol ex-
inhaler ( TM exMVM , Fig. 12.12a ) or just to the mass recovered from the full-resolution
 
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