Clinical trials are a Critical and well-known portion of the drug discovery, development and approval process, with results frequently featured in the media. Given the significance of drug safety, it is not surprising that there are lots of further testing procedures for the evaluation of drug safety and efficacy. Although these tests aren’t as publicised as clinical trials, they are still quite important. Stability testing is just one such example.An important step in the drug approval Procedure, stability testing assesses how the quality of a drug substance or drug product including its packaging changes with time under the influence of environmental factors, such as temperature, humidity and light. The method determines if any physical, chemical or microbiological changes influence the efficacy and integrity of the final solution, thereby ensuring that a pharmaceutical product is safe and effective, no matter where in the world it will be supplied. Moreover, stability testing determines the shelf life and recommended storage requirements of a finished pharmaceutical product and the retest periods for a drug substance.
Comprised of two phases stability Storage and downstream analytical testing, stability testing ensures compliance with global regulations which form part of the enrolment procedure for a new drug substance or drug product.For the purpose of stability testing, the International Conference on Harmonisation ICH divides the world into five climatic zones based on a combination of temperature and relative humidity RH. This division ensures that the differences in climatic conditions from the varying areas of the world are considered for equilibrium studies. Zone I is described as temperate, zone II as Mediterranean/subtropical, zone III as hot/dry, and zone IV as hot/humid. Moreover, a zone Vibe was introduced relatively recently, which is described as hot/higher humidity and represents ASEAN Association of Southeast Asian Nations testing requirements. The climatic data that defines those areas is linked to the Mean Kinetic Temperature MKT, which is a popular measure from the pharmaceutical sector to express the general effect of temperature changes during transit or storage.
The five climatic zones are duplicated in long-term equilibrium studies to mimic the conditions globally a drug substance or drug product is exposed to. The ICH presents guidelines on the conditions which needs to be included in a stability study, which are often known as ICH conditions. The long-term testing requirements are shown in Table 1.During Stability Testing, a medication Substance or drug product is assessed under the appropriate ICH storage requirements, testing its thermal stability and its sensitivity to moisture. The storage requirements tested and the lengths of the research chosen must pay for the storage, shipment and usage of the item. During the duration of the analysis, the stability of the drug is established through physical, chemical, biological and microbiological tests.