INTRODUCTION
A key aspect of protecting drugs during storage and transportation is monitoring the environment to which they are exposed. This chapter provides background information about the science and technology of temperature and humidity monitoring over time. It describes the available technologies and performance characteristics and provides recommendations for qualifying their performance. The shelf life of a drug product is a function of the temperature and humidity conditions during storage and transportation, as well as the drug product’s chemical and physical properties. This chapter focuses strictly on supply chain temperature- and humidity-monitoring devices, both electronic and chemical.