Should medication still be used after the expiry date, Emre Çörek?
Text: Emre Çörek, Toxicologist
Rising healthcare costs and bottlenecks in the supply of certain medicines are leading to discussions of whether expired drugs can — and should — continue to be used. Answers from a regulatory perspective.
When discussing the dilemma of using medicines after their expiry date, it’s worth taking a closer look at how exactly this date is defined. Around the world, medicines for human use undergo an authorization procedure before they reach the market. As part of this process, medicines are also assigned a region-specific shelf life to ensure patient safety.
The shelf life and optimum storage conditions are stipulated by the manufacturer based on stability tests, whose requirements are described in official guidelines from the International Council for Harmonisation of Technical Requirements for Registration for Pharmaceuticals for Human Use (ICH) and the World Health Organization (WHO).
The guidelines set out the test conditions for three European regions, Japan and the USA, taking account of the different climatic zones. For European marketing authorization, medicines are tested in conditions that reflect their stability in real time (12 months, 25°C, 60% relative humidity) as well as under slightly accelerated (6 months, 30°C, 65% relative humidity) and strongly accelerated degradation conditions (6 months, 40°C, 75% relative humidity).
Furthermore, the guidelines require stress tests in order to determine the degradation products and the influence of very high temperatures, high atmospheric humidity (75% or more), contact with air and exposure to light, as well as other chemical reactions. In the case of combination products containing multiple active pharmaceutical ingredients (APIs), it is also vital to consider interactions between the APIs and between the products of their degradation.
Experts then review the test results, taking account of clearly defined limits for individual and total degradation products. From these results, they derive information on the shelf life and recommended storage conditions, based on the most vulnerable API, in order to ensure the safety and efficacy of the medicine.
There are cases where the shelf life has been changed following authorization as additional data became available. One example is the “Comirnaty” Covid-19 vaccine from Pfizer/BioNTech. At the time of authorization in late 2020, there was a lack of comprehensive and empirical data on the shelf life. When the manufacturers were able to present this data in 2022, an extension of the shelf life was approved by Swissmedic, the Swiss licensing authority for therapeutic products.
From a regulatory perspective, we can therefore say that the current guidelines are based on scientifically sound data and ensure optimum patient safety.
At the same time, they provide a clear framework for the testing of medicines. This is hugely important for manufacturers, because it makes it easier for them to plan and to reliably estimate costs.
In the future, there may be a need for additional regulations — further stability tests, for example — in order to address existing challenges such as rising healthcare costs and worsening drug shortages. It is vital, however, that the guidelines for additional tests be based on scientific consensus and provide a clear framework for manufacturers.
Emre Çörek obtained a doctorate in pharmaceutical sciences at the University of Basel and works as an expert in regulatory toxicology in Professor Ellen Fritsche’s group at the University of Basel and at the Swiss Centre for Applied Human Toxicology, a joint institution of the Universities of Basel, Geneva and Lausanne and the University of Applied Sciences and Arts Northwestern Switzerland.
More articles in this issue of UNI NOVA (November 2024).