Preventing drug wastage through temperature stability
Mike Butt, managing director at Lec Medical discusses the importance of temperature stability in clinical environments to prevent drug wastage.
Pharmaceutical waste is a universally accepted problem within the NHS and, while there are many contributing factors to the problem, the safe storage of temperature sensitive products remains one of the most important – but one which is sometimes overlooked.
The safe storage of medicines in hospitals and pharmacies is paramount to reducing waste and costs for the NHS. The rising price of medicines is a major focus for a healthcare sector that is struggling with financial challenges. The most recent figures from NHS Digital report that NHS spending on medicines rose from around £12bn to £18.2bn in the seven years up to 2017/18. So why is storage so important?
The active chemicals in any medication can change in molecular form when exposed to different temperatures, potentially resulting in decomposition of the medication. This can make medications less effective and may even result in new or dangerous effects. As a result, temperature sensitive medication which has ‘spoiled’ due to incorrect storage must be disposed of.
Vaccines may lose their effectiveness if they become too hot or too cold at any time. They naturally biodegrade over time and being stored outside the recommended temperature range may speed up loss of potency. This impact cannot be reversed and a vaccine may then fail to create the desired immune response and give protection. Vaccines cost the NHS around £200 million a year, so wastage from inappropriate storage must be avoided at all costs.
In addition to vaccines, biologic drugs - such as insulin - and drugs to treat conditions such as rheumatoid arthritis, inflammatory bowel disease, psoriasis and various forms of cancer are often sensitive to temperature extremes and, if compromised, may put patients at risk. Biologics represent an innovative and rapidly expanding category of drugs – by 2022, it is estimated that sales from biologics will account for roughly 30% (or $326 billion) of prescription drug sales globally. However, maintaining the safety and efficacy of these cutting-edge therapies can present unique challenges. Patients who use medicines whose potency has been reduced or even destroyed by incorrect storage may experience clinical setbacks, recurring symptoms and other adverse events.
Following manufacture, vaccines and biologics need to be shipped and stored at lower than ambient temperatures to assure their quality and efficacy. They are often referred to as “cold chain products” or “fridge lines” and they come with strict temperature requirements. Failure to store medicines according to manufacturers’ recommendations can invalidate the expiry date and cause manufacturers to disclaim responsibility for any apparent failure of the medicine as the safety and effectiveness of such medicines can be significantly compromised or unknown. This can cause avoidable waste, often at considerable expense.
In any clinical setting where temperature sensitive medicines are stored, there must be named individuals responsible and accountable for the receipt and storage of vaccines/heat sensitive medicines, and the monitoring and recording of fridge and ambient room temperatures.
Crucially, refrigerators used for the storage of medicines must be designed specifically for that purpose. Standard domestic refrigerators cannot be used for storing cold chain products for a number of reasons, including an uneven temperature distribution (as a result of minimal air circulation) and a normal operating range of between 0°C and 10°C. Medical-grade refrigerators offer a lot more than a standard fridge. Firstly, they maintain a more consistent temperature, which is vitally important for storing sensitive things, like vaccines and samples, that can be damaged by fluctuations. Medical grade refrigerators also feature visible and audible alarms to alert staff to any issues or faults. These alarms might go off if the door isn’t closed all the way, or if the temperature goes up or down unexpectedly, allowing medical staff to act quickly to avoid damage and dangerous changes to the medication contained within. In addition, the fridges can be locked and glass doors allow quick and easy stock checks.
The medical refrigerator used must also be of an appropriate size for the quantity of stock to be stored i.e. filled to no more than 75% capacity to allow adequate air circulation. It must also be reserved exclusively for the storage of vaccines and other pharmaceutical products and not used to store food, blood, milk, drink or anything else representing a contamination risk.
Care must also be taken to ensure the refrigeration unit is sited in a well-ventilated room maintained between 10°C and 25°C, away from external windows and all heat sources e.g. radiators or direct sunlight, and at least 5-10 cm from walls and other units. To ensure its ongoing effectiveness, any pharmacy refrigeration unit must be serviced according to its manufacturer’s instructions and have its integral thermometer independently calibrated to ensure readings are true. Finally, the medical refrigerator must be cleaned regularly and the internal stock should be stored according to first expiry.
Industry predictions said that the cold chain industry would increase by 65% by the end of 2020, as temperature-sensitive pharmaceutical products continue to elevate. This prediction was made before the arrival of Covid-19, for which we anticipate – and hope for – a vaccine. Once a vaccine arrives, the effectiveness of refrigerated storage will become vitally important to avoid waste and get a life-saving medicine to the public. The vaccination required to protect us all will require a feat of mass manufacturing and will put pressure on cold chain logistic capabilities. While the world is waiting for a vaccine, ask yourself: when you get it, where will you store it?
Editor's note: This article was submitted before news relating to the efficacy of certain Covid-19 vaccines had been released.