Testing the in-use stability of medicinal products

The situation is different for drugs in containers with the possibility of multiple withdrawals. This includes cans, glass containers, pipette bottles, dropper bottles, and tubes.

For the following reasons, medicinal products in multi-dose containers should only be used for a certain period of time after opening:

• After opening, atmospheric oxygen, humidity and light can reach the contents and the existing protective atmosphere is no longer present.
• The medicinal product can come into contact with the skin and the germs (e.g. bacteria, yeasts, fungi) that are present on it.
• Repeated opening increases the risk of contamination and decomposition reactions.
• The storage temperature also has an influence on the shelf life. Medicinal products without preservatives or preparations with particularly sensitive active substances and ingredients are particularly susceptible.

For medicinal products in multi-dose containers, the shelf-life after the initial opening has to be proven through stability studies.

These tests should be performed on two different batches. If different package sizes are marketed, each package size must be tested individually. It is useful to test one batch at the beginning and one batch at the end of the stated shelf life.

The requirements for an in-use stability study are described in the CPMP Guideline CPMP/QWP/2934/99 of the EMA (European Medicines Agency). A concrete test design is not specified here; it depends on the type and application as well as the packaging of the medical product.

The in-use design should simulate the withdrawal by the user. Therefore, the withdrawal mode is adapted to the quantity, frequency and duration of the recommended use.

DSI-pharm will advise you individually and create an opening design for your product that meets your needs. Corresponding in-use stability studies further support you in offering a safe, high-quality drug.

Do you have any questions, or would you like to take advantage of our services? Our expert will be happy to advise you.