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between the treated and untreated hind paws to the weight of the untreated hind paw was used as
an index of paw edema.
A histologic analysis was performed to observe the aerosol effect on the mice lungs morphol-
ogy. The mice were killed 6.3 h after exposure. Lungs were ixed in 4% paraformaldehyde in
phosphate buffer (pH 7.2-7.4). The ixed tissues were treated in a standard way using histological
equipment “MICROM” (Carl Zeiss) and then embedded to parafin. Sections 3-4 μm thick were
stained with hematoxylin and eosin. Slides were examined under the light microscope Axioskop
40 (Carl Zeiss).
11.1.2.1 Aerosol Size, Concentration, and Composition
A typical example of the mean particle size and number concentration (as measured at the WB
chamber inlet) is shown in Figure 11.4 as a function of generator temperature. As seen in the plot,
the range of the particle diameter is 20-100 nm under the standard operating conditions. Changing
the vapor to air mixing conditions, it was possible to decrease the mean particle diameter to 10 nm.
The particle size distribution was well described by the lognormal function. For the whole range of
the particle diameters, the geometric standard deviation was 1.4. The typical particle size distribu-
tion is shown in Figure 11.5.
Chromatographic analysis of the aerosol particles was performed to make sure that there was
no thermal decomposition of the maternal substance during evaporation-condensation. The chro-
matographic analysis showed that the chromatograms from nanoparticles of both indometacin and
90
80
70
60
50
40
30
20
10
7
10
6
10
5
10
4
10
3
10
2
360
370
380
390
T
(K)
400
410
420
FIGURE 11.4
Mean diameter
d
of ibuprofen particles and number concentration versus temperature in the
saturated vapor zone (as measured by the aerosol spectrometer).
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