Global Comparison of Stability Testing Parameters and Testing Methods for Finished Herbal Products

Quality consistencies of drug products are essential to guarantee expected therapeutic activities, and achieving consistent qualities for herbal products is challenging because of their physicochemical complexities and inherent variabilities. Regulatory authorities worldwide have issued regulations or guidelines for stability testing parameters and testing procedures for herbal products stored in proposed conditions. These testing parameters and methods for finished herbal products are detailed in the guidelines and regulations issued by 5 global authorities and 15 countries, that is, the Association of Southeast Asian Nations (ASEAN), the Eurasian Economic Commission (EEC), the European Medicines Agency (EMA), the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH), the World Health Organization (WHO), Australia, Brazil, Canada, China, Egypt, Hong Kong, India, Japan, Kenya, Republic of Korea, the Philippines, Qatar, Switzerland, USA, and Zambia. Physical, chemical, and biological stability tests were compared between different dosage forms, and the testing conditions (temperature and relative humidity) used for long-term, accelerated, or intermediate testing were included in the guidelines and regulations. Comparisons of global regulations and guidelines addressing stability testing are fundamental for the international harmonization of herbal product quality assessments. This review aids understanding of the global situation regarding the testing of herbal product quality with respect to storages.