Ambient temperature can impact the rate of degradation of medicines. When medication is exposed to temperatures outside that specified by the manufacturer, it may reduce its effectiveness. A product that is stored outside of its recommended range can be said to have undergone a ‘temperature excursion’.
All medications have storage requirements listed by their manufacturer. Certain products may be sensitive to heat, for example, ointments or creams where the consistency may be impacted. The NHS advises patients that some products should not be used if they freeze, for example, insulin. [1] Dispensing and supplying medicines that have been stored within their specified range is therefore an essential component of good practice.
Storage
It is important to store medication appropriately within the range specified by the manufacturer. Most medicines are stored at ambient temperatures between 8ºC and 30ºC.
Pharmacies should have a temperature monitoring system in place to detect any changes in temperature that may occur. This can include using thermometers or temperature data loggers to record the temperature in different areas of the pharmacy, such as the storage room, dispensing area, and delivery area. Pharmacies may fail a regulatory inspection if they cannot demonstrate that medicines are being stored appropriately. [2]
Transportation
It is important that when mailing medication, a shipping method that will protect it from temperature excursions is used. This can include using express shipping or packing the medication with appropriate coolants and following the manufacturer’s instructions.
For patients, medication must also be transported appropriately, for example, patients travelling with medication may need to keep these in an insulated bag or cooler to protect from extreme temperatures.
In addition to protecting medication from temperature excursions during storage and transportation, it is important to consider the temperature of the medication during administration. For example, some medications, such as insulin, should be stored in a refrigerator but should be allowed to reach room temperature before being administered.
Medicines exposed to temperatures outside of their recommended range
It is important to have a protocol in place for handling medication that has been exposed to temperatures outside of their recommended range. This may include discarding any such medication as well as informing patients who may have received affected medication.
The specialist pharmacy service [3] has a number of webpages around temperature management including managing temperature excursions.
Determining the effects of ambient temperature excursions on medication can be a complex process. The key steps that can be taken to assess the impact of changes in temperature on your medication include:
- Review the manufacturer’s storage guidelines. Many medications have specific storage guidelines that indicate the ideal temperature range for maintaining the medication’s potency and safety. Reviewing these guidelines can provide a starting point for assessing the impact of temperature excursions on your medication.
- Check the appearance of the medication. A change in the appearance of medication may indicate that a temperature excursion has occurred. For example, if a tablet or capsule appears to be discoloured, disintegrated, or has changed shape may indicate a temperature excursion.
- Keep records of temperature excursions. To better understand how temperature excursions can affect medication, it is important to keep records of any incidents. This can include the date, time, and location of the temperature excursion, as well as the medication involved. This information can be used to identify patterns and trends and to take preventative measures in the future.
- Consider the impact of a temperature excursion on the medication’s potency. In general, isolated and short-temperature excursions of a few centigrade medicines stored at ambient temperatures is unlikely to have a significant impact. However, for medicines with a short shelf life and which need to be stored within a narrow temperature range the impact may be more significant.
Calculating the degradation of individual medications due to temperature excursions is a complex process, however, there are some steps that you can take to determine the impact.
- Review the manufacturer’s stability data. Many medications have stability data available that indicates the rate of degradation at specific temperatures. Reviewing this data can provide a starting point for calculating the extent of medication degradation due to a temperature excursion.
- Measure the temperature excursion. To calculate the extent of medication degradation, it is important to measure the temperature excursion. This can be done by using a thermometer or temperature data logger to record the temperature at the time of the excursion.
- Determine the length of the excursion. In addition to measuring the temperature excursion, it is important to determine how long the medication was exposed to extreme temperatures. The longer the exposure, the greater the potential for degradation.
- Compare the results to the manufacturer’s stability data. This will help to determine the extent of medication degradation and the potential impact on the medication’s effectiveness.
These steps are based on the assumption that the manufacturer has provided stability data for the affected medication, if not, it will be difficult to calculate the degradation of the medication. The appropriate formula should be used to determine the extent of degradation caused by the temperature excursion.
Summary
The Specialist Pharmacy Service recommends that “where temperature excursions occur, follow a defined process to manage and mitigate the effects on medicines.” [4]
Any premises that handles, stores, or supplies medicines must have such a process (i.e. a SOP) in place which is tailored for the medications handled within those premises. This will then inform the next steps and the decisions that need to be taken.
By community pharmacist and Chair of PDA’s Southeast Regional Committee, Nav Bhogal
Learn more
- Focus on the safe and effective management of medicines: our findings from inspections
- Storing and travelling with rapid-acting insulin
- Temperature management
- Managing temperature excursions
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