Stability of thermolabile drugs at room temperature. A review

The aim of this study was to review and compile the available information, in an easily accessible format, regarding the stability of thermolabile drugs at room temperature (22-25 °C), according to information contained in summary of product characteristics (SmPC), published literature, and information provided by the manufacturing pharmaceutical companies.

Drugs included in our hospital that required storage at a temperature between 2 and 8 °C were selected. Medications used in clinical trials, frozen drugs, and compounded formulations were excluded. The first source of information consulted for stability data was the SmPC. In case of no information available, published literature and gray literature were reviewed. If information was not found through these sources, the manufacturing laboratory was contacted. The results are shown in table format to make the information more manageable. The table contains the following information: Drug product, trade name, brand name (manufacturer), maximum stability at room temperature, and information source. Stability data from SmPC were included for all medications, and for those with additional information obtained through the sources used in the study, this was included in a separate column.

A total of 203 thermolabile drugs were selected. Thirty seven (18.2%) had a stability of 24 h at room temperature, 36 (17.7%) had a stability of 48 h-1 week, 63 (31%) had a stability of 1 week-1 month, and 52 (25.6%) had a stability of more than 1 month. However, 12 drugs (6.3%) had a stability of less than 24 h, and 3 drugs (1.4%) had other stability data at room temperature. Stability information for 95 (46.7%) drugs was obtained from the SmPC, 56 (27.5%) from published literature, and 36 (26.2%) from manufacturers. In 21 of these cases, the stability information was valid exclusively for a specific case, with particular storage conditions and for a specific batch of the product.

The number and impact of thermolabile drugs have increased exponentially in recent years. The vast majority of these drugs maintain adequate stability at room temperature for an acceptable period of time, with some remaining stable for relatively long periods. To date, our study presents the largest dataset on the stability of these drugs. Therefore, the results of our study constitute a highly useful and up-to-date tool for saving time and money in hospital pharmacy units. Pharmaceutical manufacturers should consider publishing stability study results under non-recommended storage conditions in the SmPC.