Principles of the Stability Test Chamber

In Stability Testing - Overview, we look at Stability Testing Requirements - Chamber Selection, Validation Requirements, IQOQPQ and IPV Considerations.

In order to demonstrate the shelf life of a drug in a certain market, the manufacturer must store it for a specified period of time at the relevant temperature and humidity. This is done in a stabilization chamber, also known as a stabilization cabinet.

Regulators in each market, such as the FDA in the US, HPRA in Ireland, specify the temperature and humidity conditions that should be used and the storage time of samples, such as a minimum of 6 to 12 months. During this time, the samples were tested and their potency and degradation were measured and recorded. This is called a stability test.

The most common conditions are 25°C/60%RH. For new products, accelerated conditions may be 40°C/75%RH. Other conditions include 30°C/65%RH, 30°C/35%RH and 25°C/40%RH.

Another condition is 5°C ±3°C for products intended to be stored in the refrigerator. For products intended to be stored in the refrigerator, test conditions are -20°C ±5°C.

Intangible Cultural Heritage
ICH, the International Conference on Harmonization of Technical Requirements for the Registration of Medicinal Products for Human Use, develops rules for operational stability testing. ICH Q1A states that conditions should be held constant at ±2°C and ±5%RH during stability testing.

Additionally, if these conditions are not met for more than 24 hours, the exam may have to be extended, resulting in a lot of paperwork. If conditions deviate from ±2°C/±5%RH, even for a short time, this should be stated. This may be due to the door opening to "pull" the sample. Such events are usually recorded in the room log.

If there is no obvious explanation, it may be necessary to seek help from a service engineer. If the chamber fails, a quick response from the supplier is required, and although he is expected to stock major spares, the auditor also likes the site to stock some. It is also recommended to have redundancy, i.e. have another chamber on site as a backup. The chamber must be fully validated and ready to use.

Photostability Test Chamber
To demonstrate shelf life under ambient light conditions, samples may be exposed to precise doses of UV and visible light in specially designed chambers. ICH Q1B specifies that temperature should be controlled to prevent localized hot spots.

Surveillance and 21 CFR Part 11
Indoor conditions should be independently monitored. This usually requires temperature and humidity transmitters connected to the recording system. In the light stabilization room temperature, UV and visible light intensity will be recorded.

The system must comply with US 21 CFR Part 11 regulations, whether it is a paper recorder or a computer system. 21 CFR Part 11 states that all relevant data collection and storage systems must be designed to prevent counterfeiting, corruption, untraceable changes, or data loss. For computer systems, formal testing (IQOQ-Installation Qualification, Operation Qualification) should be performed to demonstrate compliance.

Chamber of Commerce Qualification
Likewise, formal testing of the new chamber (IQOQ and PQ performance certification) is mandatory. During its lifetime, it should be regularly maintained (usually an annual preventive maintenance service with calibration checks) and preferably mapped with multiple probes per year (IPV - Instrument Performance Verification).

PQ and IPV typically require at least one 24-hour monitoring run, unloaded, loaded, or both. During this run, the display conditions must remain at the set point ±2°C, ±5%RH. Test equipment for these tests must be traceable calibrated at least annually and meet the IQOQ standard of 21 CFR P11.

Stability Test chamber Selection Considerations
The following factors need to be considered:
Reliability; is it known, used and trusted?
There should be low fluctuations in temperature and humidity
capacity; planning for future needs as well as current needs
footprint; footprint may be limited
Do you offer local service with quick response, spare parts inventory and refrigeration repair certification?
The chamber shall have integrated controls including temperature limiters and error message logging
It should refill automatically.
Low user maintenance
Almost no consumables required
Sterile moisture is generated. Microorganisms must not be injected into the chamber
It should be possible to lock the keyboard
There should be an output when an error occurs, which can be monitored by the building management system

Should be designed in accordance with GAMP; good automated manufacturing practice

IQOQ, PM and IPV have traceable calibration, are 21 CFR Part 11 compliant and should be obtained from the supplier Thchamber.