The risk of label edge lifting in pharma applications
Small diameter injectables containers are very common in pharmaceutical packaging types including labels for vials, syringes, pre-filled pens, etc. When labeling small diameter injectables containers, there can be challenges with performance including label edge lifting. Label edge lifting can pose a risk to the safety of the products as labels contain critical information for pharmaceutical packages such as dosage instructions, expiration dates and more.
Based on our years of experience and industry knowledge, we have defined limits for container diameter size where edge lifting is most likely to happen. A container between a diameter of 7 to 23 mm and volume of 1 to 50 ml, depending on the container, is considered a small diameter container. The containers most at risk to experience label edge lifting within that range are those with a 7 to 12 mm diameter range.
What is edge lift?
First things first, what is edge lift? This term refers to one or more of the outer edges of a label lifting from the surface onto which it has been applied. Although it can occur on any type of surface, it most frequently occurs when labels are applied onto curved surfaces. Naturally, the tighter the diameter curve then the higher the risk of label edge lifting. When the edge of the label lifts it can cause the label to come off and get stuck on other packages or to the labeling line.
Challenges with labeling syringes and other small diameter packaging types
Most syringes have a diameter starting below 7mm though other package types fall into this category as well as previously mentioned. For example, an injectable vaccine may be 1ml or 3ml syringes and a diameter of those containers is below 10mm. So, for these package types it is extremely critical to select the right label material to avoid edge lifting.
Factors to consider when trying to decrease the risk of label edge lifting
Adhesive
There are two factors to consider with the label adhesive:
- The tight mandrel hold performance of the adhesive
- The surface on which the adhesive is applied
The solution for label edge lifting could be as simple as switching to an adhesive specifically designed and pre-tested to offer tight mandrel performance but there are other factors to consider. Another solution could be to overlap the label materials so that the label sticks to itself in addition to sticking to the container. When in doubt, consult with the subject matter experts from your supplier.
Face material
A common misconception is that simply changing the adhesive will solve your label edge lift problem. However, the whole label combination works together to ensure peak performance and creates the full mandrel hold. Thus, the face must also be taken into consideration. Due to the small diameter range of injectables you may need to use special, thin papers and very conformable, flexible films.
Finding the right label materials for tight mandrels and small diameters is challenging. In addition to the factors mentioned above there could be a variety of other factors influencing the overall performance of your label as well including:
- Sterilization method
- Label size and format (overlapping, non-overlapping)
- Chemical exposure that may affect print legibility
- Substrate of the container (plastic vs glass)
- Surface treatments
- Temperature and moisture levels during application
- Temperature and moisture levels during storage (freeze-thaw cycles)
Ultimately, small diameter injectable containers require specialized label materials to ensure tight mandrel hold and extreme durability. In the pharma industry it is critical to ensure the label doesn’t compromise getting the pharmaceutical product and critical information to the patient. Knowing it’s not easy to choose the right materials, we strive to help you make the best selection for your pharmaceutical product. For guidance in selecting the right label material, check out our pharma specification guide.
