Stability Chamber Validation
Stability chambers are ideal for testing storage, shelf life, packaging and stability. Stability chambers are available in temperature only or with temperature and humidity. Sizes range from reach-in to walk-in and most chambers feature a temperature range of -30°C to 80°C and an optional humidity range from 10% to 95% RH.
Stress testing is likely to be carried out on a single batch of the drug substance. It should include the effect of temperatures in 10°C increments (50°C, 60°C, etc.). Increments may be greater for accelerated testing. Stress testing for humidity typically is performed at 75% RH or greater (where appropriate).
Other tests can include effects of oxidation and photolysis. Stress testing of the drug substance can help identify the likely degradation products, which can in turn help establish the degradation pathways and the intrinsic stability of the molecule. It can also validate the stability indicating power of the analytical procedures used. The nature of the stress testing will depend on the individual drug substance and the type of drug product involved.
Most stability chambers are designed with outside air intake, followed by heating and uniform distribution of the air throughout the chamber to secure even impact on samples placed on shelves anywhere in the chamber volume. Exhaust air is vented to the outside through a port. The parameters of interest are temperature and humidity.
Temperature range is typically -30 to +70°C and humidity range is 50-80% RH.
Typical examples of stability testing of drug substance for various storage conditions is available here
Validation of stability chambers typically does not pose any special challenges as the parameters that are controlled are relatively easy to match. The temperatures are modest and no pressure measurements are needed. This range of temperature and the temperature/RH% also allows Ellab TrackSense LAB loggers to be used. To simplify the operation, the LED indicators on the LAB loggers will provide the operator with instant information on logger status. The LAB loggers can be matched with the SKY option for real time data transmission. For very small chambers that include an access port(s), using thermocouples could be advantageous to reduce impact and ensure chamber integrity.
For the approval of pharmaceuticals and for providing evidence of stability tests, numerous steps must be taken to ensure that the stability test chambers function correctly. For example, the fluctuations in temperature and humidity need to remain within the stipulated range and the chamber needs to maintain this over relatively long periods of time.
All stability chambers should meet ICH Q1A guidelines for pharmaceutical stability testing which provides recommendations on stability testing protocols including temperature, humidity and trial duration. Validation must be carried out regularly to ensure that an environmental room or cabinet is capable of accurate and repeatable performance.
Validation of a stability chamber consists of various steps regarding Installation Qualifications (IQ), Operational Qualifications (OQ) and Performance Qualifications (PQ).
The IQ is conducted to demonstrate that the stability chamber is inspected and contains all the required parts for its proper functioning.
In the OQ, the performance of the stability chamber and its operational procedure are verified. The OQ consists of temperature and /or humidity mapping of the empty chamber and it is performed to confirm that the empty chamber works within the specified limits throughout the chamber. The OQ also contains information about calibration of measuring equipment and defines the location of the thermocouples or the data loggers in the stability chamber.
The PQ verifies that the loaded stability chamber is capable of reaching and maintaining the target temperature range. The PQ confirms that the loaded chamber works within the specified limits of temperature and/or humidity throughout the chamber.
The typical number of measuring points on small to medium sized stability chambers is 5 (4 corners + center) on the lower as well as the top shelf. During the OQ, the loggers or thermocouples are fixed directly on the shelves in the empty chamber and during the PQ they are loaded into samples. For larger chambers it is recommended to place 5 measuring points on a minimum of 3 layers or even on each layer with sample readings every 1- 5 minutes during 24,48 or 72 hours.
As an example, the acceptance criteria for a standard stability chamber with set point of +37°C is that all measurements throughout the chamber do not individually differ by more than 2°C.
Typical validations include:
- Up to 15 temperature points logged over 24 hours
- Up to 12 humidity points logged over 24 hours
Ellab’s wide variety of wireless data loggers are ideal for most standard stability chambers. Even with stability chambers with access port(s), the setup and take down can be time consuming and cables can disturb the integrity of the chamber’s atmosphere.
For most pharmaceutical and medical device applications, this will require the use of Ellab’s advanced software ValSuite™ Pro with its 21 CFR Part 11 compliance and sophisticated reports/features. When not requirering electronic records, ValSuite™ Basic can provide all the necessary functionality.
For validation purposes, creating a Unit that demonstrates the exact position of each measuring point documented by pictures is advantageous when handling many sample points. Furthermore, creating a Profile which includes a Limit Report and a Statistical Report is useful and produces time savings.
At the end of each study report(s) can be signed by Electronic Signature(s), stored, printed, and distributed in a secure and locked PDF format.
Using the built-in calibration functionality, users can calibrate the Ellab sensors at regular intervals. The ValSuite™ Pro software generates an easy to read calibration report that includes all measurements and tolerances that are defined by the user. It is recommended that Ellab sensors and probes are sent in at least once a year for factory calibration (which includes a traceable calibration certificate).