Stability testing of pharmaceutical products is an essential method of determining “shelf life” (i.e. expiration dates) and storage conditions. A stability test period can range 6 to-12 months depending on the protocol. The test period including the temperature and humidity (RH) conditions are determined based on ICH (International Conference of Harmonization) guidelines. ICH test conditions can be one of the following: 25 C / 40% RH, 25 C / 60% RH, 30 C / 65% RH or 40 C / 75% RH. ICH requires conditional tolerances of +/-2 C and +/- 5% RH.
Stability chambers can be refrigerator size or large “walk-in” types. Mapping these chambers with a thermocouple based system is time intensive because the “wires” must be carefully fed through sealed ports or door seals. Also, separate RH sensor assemblies must be installed and connected to the system.
Using a thermocouple based system may be the only alternative if “seeing live data” is important. However, for most chamber mapping work, using wireless dataloggers is by far the best alternative.
The XpertLog wireless dataloggers were designed for stability chamber mappings. The temperature datalogger has a range of -60 C to 150 C with a calibrated accuracy of +/-0.1 C. The RH datalogger has a calibrated range of 20% to 90% with an accuracy of +/- 2%. The XpertLog RH datalogger is uniquely calibrated for all ICH temperature points*.
*Note: RH measurements vary with temperature so calibration at specific ICH temperature points are necessary to maintain accuracy. Most other RH dataloggers are only calibrated at 25 C. If used for 40 C stability studies then a special calibration is required. Otherwise, the RH measurement error can easily exceed the ICH limit of +/- 5%.
In summary, the XpertLog dataloggers save considerable time for stability mapping work. Also, they can be easily used to monitor the chamber throughout the study. For critical studies, this can insure that the exposure conditions were in tolerance throughout the chamber.