Suggestions on Storage of Insulin Preparation under High Temperature Environments

Abstract

Diabetes care education entails paying attention to patients’ convenience and levels of applicability, describing the points that should be considered when an insulin preparation is stored: “as a rule, the preparation should be kept at a temperature between 2°C and 8°C before use (place it in the refrigerator, avoid freezing); the preparation should be kept at room temperature once usage has started (do not place it in the refrigerator.)” However, in recent years, urban heat islands and climate change are contributing to a rise in environmental temperature all over the world. Being concerned about proper storage of preparations under high temperature environments, patients are apparently struggling to maintain the quality of the preparations while paying attention to the storage temperature of the preparations. Fundamental studies could not rule out the possibility of changes in the three-dimensional structure of insulin preparations in high temperature conditions and a resulting reduced pharmacological activity. Thus, it is recommended that insulin preparations be stored under refrigeration at a temperature as close as possible to 4°C. In recent years, the number of days on which the temperature has risen above 30°C (a real summer day) has been and increasing and will increase further. Therefore, as a countermeasure against high temperature, we recommend the following: if the room temperature is above 30°C, any prefilled (kit) insulin preparation in use should be kept in the refrigerator (after removing the syringe needle); the preparation should be before injection to be returned to approximately normal air temperature (between 15°C and 25°C). This countermeasure is based on the premise that the possible problems that were previously pointed out of storing an injection syringe in use in the refrigerator should be fully taken into account.