Stability samples for stability tests in drug research are often stored for several years under defined temperature and humidity conditions in a climate chamber.
Fail-safety, precision, long-term stability, the US Food and Drug Administration (FDA)-compliant data logging and highly accurate reproducibility are the most important properties that the devices must fulfil.
The growing importance of climate chamber stability testing
The requirements for quality, health safety, efficacy and safety of drug products, cosmetics, food and their substances and ingredients have grown steadily over the past decades. With the help of stability tests, manufacturers find out under which conditions the microbiological, chemical and physical stability of products and individual substances changes under constant environmental conditions.
The results can be used, among others, to derive statements on shelf life and consumption dates, as well as storage and transport conditions. For stability sample storage, quality and testing laboratories use climate chambers and walk-in climate chambers for larger volumes. Guidelines and standards such as the International Council for Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) Guidelines, World Health Organization (WHO) Technical Report 953, Annex 2, Association of Southeast Asian Nations (ASEAN) and Good Manufacturing Practice (GMP) ensure cross-national comparability of the required quality tests. The temperature control units are subject to the highest quality requirements.
Simulation of all climate zones
A climate chamber must simulate all climate zones worldwide for stress tests, accelerated, intermediate, long-term and ongoing studies.
Within the ICH quality guidelines, the guidelines Q1A (R2) to Q1E dedicate to the stability testing of new drug products and substances. The most significant factors influencing stability are temperature and humidity. In general, pharmacology is guided in the choice of testing climates by the specifications for five main climatic zones, which take into account the differences in temperature stress and humidity load of drug product exposure during transport or storage. Climatic conditions in Europe, the USA and the UK are pivotal for drug product stability. The climatic conditions in Europe, the USA and Japan predominantly fall into climate zones I and II. Therefore, the ICH guidelines derive from this combined climate zone.
The WHO and regulatory authorities of respective countries deal with determining testing conditions for drug products or substances manufactured in climate zones III or IV.
Qualification according to GMP
As part of the equipment for stability testing, climate chambers must be continuously maintained and qualified, which involves testing the relevant functions and the constancy and homogeneity of temperature and humidity.
The qualification proves and documents that equipment and systems work reproducibly within the specified limit values for temperature and humidity in the entire intended working range. Maximum deviation according to guideline ICH Q1A (R2) is ±5% for relative humidity and ±2°C for temperature.
To ensure temperature and humidity are accurately kept, the climate chamber must connect to an alarm system, and the internal sensors must be calibratable via the control system.
Calibration is the determination of deviations between the values displayed by the chamber and values for temperature and humidity measured in the chamber with a reference measuring device. In deviations beyond these limits, the temperature and humidity control must be readjusted at the measured points.
A climate chamber should also have multiple overtemperature protection, an under-temperature alarm, over-humidity and under-humidity protection, and lockable doors.
Tamper-proof data collection and logging
In today’s world, the following are a matter of course for a climate chamber: network capability, programmability and electronic data logging of all parameters such as date and time, setpoint / actual temperature and setpoint / actual humidity.
In drug research and production, the device software must meet the requirements for electronically stored data records and electronic signatures specified in the FDA Guideline 21 Code of Federal Regulations (CFR) Part 11 and Annex 11 to the European Commission EC Guide to GMP. Fail-safety, tamper-proof data collection of temperature and humidity, protection against loss or damage of data and traceability of all changes are elementary requirements for the device software or IT infrastructure.
Climate chamber efficiency and operating costs
The energy efficiency of climate chambers depends on the unique design, construction, control and, above all, application. Since stability tests are carried out in the vast majority of cases at constant temperatures close to the ambient temperature, Peltier-cooled climate chambers have advantages in energy consumption compared with compressor-cooled units due to technological properties regarding energy efficiency.
Since Peltier units are cooled electrically, they also have more compact dimensions, operate quietly and are practically vibration-free.
Comparison of energy consumption of Memmert constant climate chamber HPPeco with Advanced Peltier Technology (product introduction 2020) with comparable appliances available on the market.
At a glance: the most important requirements for a climate chamber
- Precise maintenance of temperature and humidity via suitable sensors
- Simulation of all climate zones for stress tests, accelerated, intermediate and long-term as well as ongoing studies worldwide
- Chamber with internal calibratable / adjustable sensors
- Tamper-proof data collection of temperature and humidity
- Fail-safe FDA-compliant data logging according to regulation 21 CFR Part 11 of the GMP / FDA
- Locking function and lockable door
- Alarming (visual, acoustic and via central alarm systems)
- Multiple overtemperature protection, undertemperature alarm and over / under humidity protection
- Logging and documentation of all important parameters such as date and time, setpoint / actual temperature
- Setpoint / actual humidity
- Network capability
- Potential-free contacts for connecting external measuring devices and sensors
- Easy to clean
- Plenty of usable space with little space requirement
- Low energy consumption