Hello, good people of the world! Stability is the characteristic of your drug product to withstand degradation or changes due to environment factors, typically temperature, humidity, and light.
World Health Organisation (WHO) has published guidelines addressing drug stability since 1996. WHO introduced the concept of 4 climatic zones, derived from a scientific paper published in 1993: Grimm, W., Drug Development and Industrial Pharmacy (1993) 19:2795-2830.The definition of the 4 zones is: 1 = temperate (USA, Europe, Russia, etc.), 2 = subtropical (Brazil, China, Japan, etc.), 3 = hot/dry (Iran?), and 4 = hot/humid (Argentina, India, Philippines, etc.).
USP <1150> also addresses the concept.
ICH Q1 addresses the concept in six parts. They are:
- Q1A = Stability Testing of New Drug Substances
- Q1B = Stability Testing: Photostability of New Drug Substances and Products
- Q1C = Stability Testing for New Dosage Forms
- Q1D = Bracketing and Matrixing Designs for Stability Testing of New Drug Substances and Products
- Q1E = Evaluation of Stability Data
- Q1F = Stability Data Packages for Registration Applications in Climatic Zones III and IV
All are available for free download here: ICH Guidelines