Light stress chambers

In Figure 33 is pictured Weiss Gallenkamps LSC020.STX.C (A), Light Stress Chamber (39). This unit has a metal halide lamp as its sources for irradiation. This option is also available in their custom-made, walk-in, drug stability rooms. 

Figure 33 PSC062,STX.C light stress chamber. Source. Courtesy of Weiss Gallenkamp.

Placebo and drug product will be photolytically stressed by placing it in a thermostated light chamber at 25°C and subjecting the samples to a UYA light source of not less than 200 watt h/meter and a fluorescent light source of not less than 1.2 million lux h. 

Oxidation -t light Depending on which oxidative stress causes most oxidation, a new solution is prepared and is put in light chamber. 6 hr, 24 hr... 

Resistance to Photochemical Reaction Initiated by U.V. Light (the sun). With the Introduction and acceptance of silicone sealants the stress tests have had to be made more stringent. Filters are removed from the Weather-O-Meter tests so some change can be noted in 6000 hours. Previously, sealants were considered good if performance changes were not significant after 250 hours. In fact, silicone sealants are now used to seal the test chamber of weather-simulating machines.—... 

The in-line window arrangement ensures that the fluids in the chamber can be seen very clearly and can be illuminated with normal or polarised light if desired. The disappearance of the meniscus at the surface of the liquid carbon dioxide as it becomes a supercritical state is very easy to see with this instrument. In spite of its rugged construction, the vessel is pressurised and depressurised slowly in use to prevent undue stress on the components. 

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