Control of indelible labelling in the laboratory

Information addressed for MAH

On medicinal products marketed in Denmark all text in the labelling must be indelible¹. No standardised test or guide for indelible at medicinal packages exist. Therefore, the laboratory at the Danish Medicines Agency publish our own test method for the control of indelible labelling.

Test method:

• For 20 seconds, hold the sample in your hand so that batch and expiration date are covered.
• A finger is rubbed (moderate pressure) across the print with the batch and expiration date 10 times.
• The test is documented with pictures and observations are noted.

An assessment is always made to determine whether the method is relevant for the specific medicinal product and whether additional tests need to be conducted.

Experiences of the laboratory show that extra focus should be concentrated on the indelibility of information such as batch number and expiration date. This information is often printed later in the production process. Therefore, companies must be aware that the information should be printed with ink or toner of sufficient quality for the surface being printed on.

Experiences of the laboratory also show that heat and oils from the palm of your hand may contribute to the ink or toner being dissolved, making it easier to smudge. The user of a medicinal products must be able to handle the packaging without the labeling disappears. Therefore, we focus on keeping the medicinal product in our hand before the mechanical test of rubbing over the labeling.

Medicinal products of special considerations

The laboratory of the Danish Medicinal Agency has not described our control method for medicinal products used under special conditions. In the event that these drugs are brought in for control, a specific assessment will be made regarding how the control should be carried out.

The guideline to the labeling regulation¹ states that "By indelible labeling, it is understood that the labeling must withstand the intended handling of the medicinal product throughout the entire period of use; for example, turbohalers should be able to be stored in a pocket and shampoos should be stored/used in connection with water, without the labeling disappearing." Therefore, there may be increased requirements for the durability of the labeling if the medicinal product is handled in special ways or in special situations. The labeling must still be impossible to erase, even under these special circumstances.