This study investigated the effect of temperatures and relative humidity of air during the storage of raw Artemisia on its artemisinin content. It was concluded that the raw material needed to be dry before storage and should be stored as leaves, not powder; that high temperature and high relative humidity tended to cause losses; that at 20°C high humidity did not matter but at 40°C there were significant losses after a year even at low humidity; and that higher temperatures could cause significant losses even after only a few days.
Simonnet, X.; Quennoz, M.; Cutler, M.; Bathurst, I. iArtemisia annuai L. How the storage can affect the artemisinin content? Presented at WHO/MMV Artemisinin Conference 2009 - Ensuring Sustainable API Supply to Meet Global ACT Demand. Mumbai, India, 28-30 September 2009. Medicines For Malaria Venture, Geneva, Switzerland (2009) 12 pp.