ICH-2 Photoreactor
Among its line of photoreactors, we had designed a
model to comply with ICH guidelines under option 2.
This unit is equipped with sixteen T5-8Watt
fluorescent lamps providing an illuminated area of
about 144 square inches, of which an active area of
about 96 square inches (8 x 12 inches) have
fluctuations of under 10% in the incident power.
 While not required under ICH guidelines, the
excellent exhaust design of our photoreactors
allows the easy exhaust of ozone for users
employing UVC lamps at 254 nm..
A number of tools provided as standard in the ICH-2
unit allow control of the irradiation conditions and
greatly facilitate photostability work
 The brushed aluminum interior of our
photoreactors ensures quasi-spectrally neutral
reflections, thus ensuring that reflected light has
essentially the same spectral composition as
direct light.
 The recessed magnetic stirrer facilitates the
irradiation of preparative (large) solution
samples for product identification and is ideal
for stress tests.
 Complete sets of sixteen UVA and visible
lamps are provided with ICH-2 photoreactors.
UVB and UVC lamps are optionally available
from us.
 A bulkhead gas connector makes it easy to
provide controlled atmosphere (e.g., oxygen or
nitrogen) to suitable contained samples. We
manufacture an environmental chamber with
atmosphere, wavelength and temperature
control that fits in our photoreactors.
 Easily changeable lamps allow users to switch
UVA and visible lamps in minutes, or to expose
with a preferred combination of lamps. For
those choosing to have two separate
photoreactors for visible and UVA irradiations,
we will advice on how to avoid duplications of
options where this is unnecessary, and will
provide appropriate credit.
 A shutdown digital timer permits unattended
irradiation for time intervals from a few
seconds to 99 hours.
 A carousel for liquid samples (usually referred
as a merry-go-round) allows up to 16 test tubes
to be simultaneously exposed, while slow
rotation ensures that all samples receive the
same average dose. Ideal for actinometry work.
 A turntable for solid samples also provides
exposure equalization. Suitable also for Petri
dishes. Driven by the same motor as the
carousel above, they can be easily exchanged or
removed.
 Four separate switches allow different sets of
lamps to be selected for illumination.
 Temperature regulation is achieved by
controlling exhaust fan operation and heating
elements. Temperature stabilization can be
achieved at user-selected temperatures starting
about 4 degrees above room temperature and up
to about 46 Celsius.
 A power meter, pre-calibrated in the UVA and
visible regions allows light intensity
determinations in both regions with about 10%
accuracy. In order to meet more stringent
requirement we can advice customers on other
products that may meet their needs.
 Calculations made easy: we provides all the
equations for the calculations to ensure that
exposure times are compliant with ICH
guidelines under option 2, then all is needed is
to set the timer to the specific time required for
either visible or UVA exposure. An Excel file
(provided) can be used as an ICH calculator.
The lamp arrangement of the ICH-2 unit is shown in
Figure 1, where the numbers indicate sets of lamps
operated with separate control switches.
For
confirmatory studies lamp sets 1, 2 and 3 (10 lamps)
are used, while all lamps are utilized for stress tests.
1
2
1
2
1
2
1
102
2
Relative percent power across the center depth of ICH-2
4
3
3
4
4
4
4
% relative power
101
4
100
99
98
1
3
5
7
9
11
Position (in inches) from lateral edge of chamber
Figure 1: Lamp configuration for our ICH-2 model.
Typical intensities achievable in the UVA region are
between 25 and 30 watt/square meter, requiring
around 6-8 hours to achieve the ICH recommended
200 watt-hour/square meter of UVA exposure.
Visible light exposure of 1.2 million lux.hour requires
about 70 hours. The emission spectra of our UVA and
Visible lamps are shown in Figure 2.
1
Normalized data
0.8
Luzchem LZC-Vis lamps
(Sylvania cool white)
Energy
photons
0.6
0.4
Figure 3. Relative light intensity across the center
depth of the ICH-2 model. Determined
with Sylvania F8T5/CW lamps.
The interior of the chamber is constructed of
aluminum. Its surface has been designed to avoid
specular reflectance of the light, thus providing a
mechanism for diffusive reflectance and helping
achieve illumination homogeneity.
The diffuse
reflectance spectrum of the chamber walls is shown in
Figure 4. The relative small variations and the fact
that reflections only contribute to ≤ 20 % of the light
incident on samples minimizes spectral variations
across the chamber surface.
0.2
100
Aluminum
0
300
400
500
Wavelength, nm
600
700
80
Figure 2A: Emission spectrum of LZC-Vis lamps.
%R
60
40
1
Normalized data
0.8
Luzchem LZC-UVA lamps
20
Energy
Photons
0
0.6
200
300
400
500
Wavelength (nm)
600
700
0.4
Figure 4: Diffuse reflactance spectrum of the ICH-2
chamber walls.
0.2
0
300
400
500
Wavelength, nanometers
600
700
Figure 2B: Emission spectrum of LZC-UVA lamps.
The ICH-2 has its lamp configuration optimized for
best homogeneity of exposure. Figure 3 shows the
relative power across the photoreactor, as determined
at the half-depth of the chamber, i.e., 6 inches from
the front access area. The measurements where made
on the ‘floor’ of the chamber, about 9 inches from the
lamps.
Power distribution is excellent across the chamber, as
shown in Figure 3. This ensures that any group of
samples placed across the chamber at constant depth
will receive essentially identical doses. However,
there is some unavoidable drop in power towards the
back of the chamber, and near the front, where the
door access is located. Samples at these positions are
below the electrode region of the lamps, and thus the
2-inch strip nearest the back and front show
significant variations, as shown in Figure 5, where the
numbers correspond to a 2-inch grid at the floor of the
photoreactor.
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fluorescent lamps. They utilize highly efficient
ceramic xenon lamps with built-in reflectors
providing, with just 175 Watts, an illumination
intensity (34 watt radiant output) comparable with
conventional illuminators using lamps with power
ratings several times higher. This allows for forced air
cooling, avoiding the inconvenience and risks
associated with water-cooling. The ‘ozone-free’ lamp
is ideal for drug phototesting and solar simulated
radiation over 320 nm, while the full UV lamp
provides the usual xenon lamp spectrum with
significant intensity at 220 nm and up. The ‘ozone-
Figure 5: Surface plot of light distribution across an
imaginary 2-inch lattice at the floor of the
irradiation chamber. Except for the 2-inch
strips at the front and back, the remainder of
the chamber (an 8x12 inch area) shows
variations of less than 8%, with best
homogeneity achieved for horizontal strips.
Convenient add-ons for other photostability
applications (not required for ICH guidelines)
 UVB and UVC lamps
 Quartz test tubes for carousels
 Environmental chamber with atmosphere,
wavelength (via cut off filters) and
temperature control.
Xenon illumination chambers
ICH Option 1 compliance, solar simulated radiation
or full UV exposure
free’ units do not require any special concern, since
the cooling air can be readily exhausted in indooratmospheres.
Many of the convenient options of other
photoreactors will be readily available in these units,
including digital timers, power monitors, magnetic
stirrers, turntables and temperature control.
Basic units, including shutter control and filter
adaptors will list for under USD $12,000. Contact us
for inclusion in our mailing list for product release
information.
Our new exposure chambers are based on the
successful design of the photoreactors using
What’s unique about our ICH2 Photoreactor ?
LZC-ICH2 photoreactor is a unique instrument in its design, capabilities and versatility. This instrument comes fully certified for
operation under ICH guidelines for drug photostability under option 2; it is supplied with chamber mapping of power distribution
and meets our standards for illumination. Add to this the unique characteristic of our lamps, which are sold with full spectral
information allowing consistent results in any study undertaken with one of our units.
We incorporate recessed magnetic stirrers, carousels and turntables for liquid and solid samples, a digital timer, temperature
control, and brushed aluminum interior light-scattering surfaces, which allow quasi-spectrally neutral reflections, thus ensuring
that reflected light has essentially the same spectral composition as direct light, while providing a very homogeneous illumination
field.
These are NOT options. This is all standard equipment
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