A guide to pharmacy fridge temperature monitoring
Laboratory automation: Become more efficient
What is Pharmaceutical Stability Testing?
Pharmaceutical stability testing is used to help manufacturers assess how the quality of a drug will be upheld when placed under a variety of environmental conditions. Manufacturers will use stability chambers to assess factors such as temperature, humidity, and light exposure. Regulatory measures ensure that pharmaceutical stability testing must be conducted before a drug is made available to the market.
The ICH (The International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use) has provided guidelines for pharmaceutical stability testing, to ensure that the process is correctly implemented by pharmaceutical manufacturers. The ICH is an organisation that connects regulatory authorities and the pharmaceutical industry to discuss scientific and technical aspects of pharmaceutical product development and registration.
The Pharmaceutical Stability Testing process
Testing the quality of a drug requires a stability chamber, utilised for a specified period of time to implement controlled set temperature and humidity environments. Drug samples are then checked periodically to analyse any potential impact on quality.
Pharmaceutical stability testing time frames can vary, with studies ranging from one week all the way up to a year or more.
The other type of pharmaceutical stability test is photostability. This tests how the drug is affected by differing levels of light and UV over time. For photostability tests, ICH stability guidelines state that stability chambers must have the capacity to emit the required light and UV over the desired time period.
Unlike stability testing for temperature and humidity, photostability testing can be completed in as little as one week. Specific units can be programmed so that the light shuts off when the required exposure has been achieved.
ICH Guidelines
The ICH guidelines for stability testing are followed by regulatory bodies worldwide. Six of the ICH stability guidelines (Q1A to Q1F) provide the specific details for adequate testing. The ICH guidelines are very specific and require precise temperature stability of the chamber with less than 2 or 3°C deviation. Humidity conditions must also not fluctuate by more than 5%.
Stability chambers used for photostability testing must provide standardised light emissions to meet the requirements of section Q1B of the ICH stability guidelines. The chambers must maintain light exposure of over 1.2 million lux hours and emit more than 200 watts of UV energy to samples.
There are 5 different climatic zones for stability testing that are universally used. These are the temperature and humidity storage conditions tested, depending on the climatic conditions of the country in which a new drug will be sold:
Climatic Zones
- Zone I Temperate: 21°C/45%RH
- Zone II Mediterranean/Subtropical: 25°C/60%RH
- Zone III Hot, Dry: 30°C/35%RH
- Zone Iva Hot Humid/ Tropical: 30°C/65%RH
- Zone IVb Hot/ Higher Humidity: 30°C/75%RH
What to look for in a Stability Chamber
The precise ICH stability guidelines mean that high-quality stability chambers must be used for pharmaceutical stability testing. Stability chambers must be durable, and their long-term performance needs to have been tested meticulously.
Due to the potentially extensive time ranges of pharmaceutical ICH stability tests, the pharmaceutical laboratory could potentially lose months of work if the stability chambers malfunction.
Uniformity is also very important for stability testing and the performance of a stability chamber in this area must be adequate. Any inconsistency in temperature throughout the unit could compromise the results and efficiency of the stability test.
High and low temperature alarms are a highly beneficial feature of stability chambers, as users will be warned when the temperature is diverging. 24/7 remote monitoring systems also allow users to assess temperature conditions when away.
The size of the chamber required will be important based on the volume of drugs tested; a large chamber or even a custom-built walk-in solution may be best suited. Consideration must also be given to the power usage/supply and water feed for the humidity.
Loading aspects differ with each product (everything from tablets to vials to bottles of liquids) which will indicate internal fixtures such as shelves or containers, heat dissipation from refrigeration systems, and maintenance aspects. Another important aspect of a chamber is to have dual refrigeration systems. This will ensure double redundancy for critical backup; if one refrigeration system fails the other kicks in, ensuring zero downtime.
Service and Validation of your chamber
As mentioned previously, the reliability of the stability chamber is incredibly important for pharmaceutical stability testing studies, due to the length of the testing periods. Therefore, regular maintenance and validation of the unit is required, to ensure that the chamber continues to provide accurate results and reliable performance.
It is important when choosing a stability testing unit that you consider service and validation options available.
Withnell Sensors supply precise and reliable stability chambers for pharmaceutical stability testing. We have stability chambers available from two prestigious brands Kambic & ALS. Better yet, the chambers we supply from these brands can be continually serviced and validated by our trained engineers.
Get in touch with Withnell Sensors to find the perfect solution for your ICH stability testing needs.
