New HERMA adhesive for pharmaceutical labels - Tackling small radii whilst stopping migration

• The new pharmaceutical adhesive 63Mps makes the labelling of cylindrical pharmaceutical products with small diameters considerably safer.
• Its excellent initial tack immediately counteracts critical restoring forces.
• Thanks to multi-layer technology, the adhesive reaches the optimal migration level – an important factor in use with plastic packaging.

It is extremely migration-safe, tackles very small radii, and provides reliable tack even in cool environments: HERMA’s new multi-layer pharmaceutical adhesive 63Mps solves many challenges in the labelling of delicate tubes, bottles, and ampoules. With small diameters of 15 millimetres or less, huge restoring forces act upon the adhesive. As a result, labels can unintentionally peel off, stick together, or even fall off. Additional obstacles in pharmaceutical labelling are cool environments and the fast application of labels by means of high-speed systems. Excellent initial tack is therefore essential. 

Unique combination

Due to a sustained trend in the pharmaceutical industry that favours plastic containers – which unlike glass are not a reliable barrier – the topic of migration is becoming increasingly important for pharmaceutical packaging. The adhesives employed in these tasks are approved for use in the pharmaceutical industry and do not represent any health hazards. Nevertheless, pharmaceutical manufacturers place great value on making sure that no adhesive components can “migrate” into their products. In a manner that may well be unique in the world, HERMA’s new 63Mps adhesive combines the extreme (initial) tack required for such wrap-around applications with the optimal correction level regarding migration. This factor measures the quantity of constituents that can migrate from the adhesive under defined testing conditions. It ranges from correction factor 2, the best value, to correction factor 5. As a rule, most standard dispersion adhesives already have difficulties complying with correction factor 5. Typical hot-melt adhesives that are often used for specialized applications usually display even more critical characteristics. HERMA’s new 63Mps adhesive reaches correction factor 2 – the best possible result in terms of correction factors. 

Extremely accurate adhesive application

In order to make an adhesive migration safe, one can reduce the percentage of additives up to a point. But this results in the adhesives losing some of their characteristics, such as adhesive force or resistance to external influences like heat or cold. “This is therefore not an option especially in the case of sensitive pharmaceutical products”, explains Dr. Ulli Nägele, Head of Adhesive Material Development at HERMA. For that reason, HERMA has developed the multi-layer technology which allows for the simultaneous application of two adhesive layers. It is also used for the new 63Mps adhesive. “The two distinct layers do not mix but instead remain stable – even if the self-adhesive material or the label is stored for a long time or subjected to very high pressure”, says Dr. Nägele. “Thereby, we succeed in resolving the contradiction between two qualities that used to exclude each other – e.g. excellent migration characteristics and very good adhesive properties.” Another advantage of the multi-layer technology: the adhesive application is extremely even. “It is important to prevent fluctuations in adhesive application, especially in tasks as demanding as pharmaceutical labelling. If not enough adhesive is applied, the tack is no longer sufficient”, explains Dr. Nägele. The new 63Mps adhesive is available in combination with a wide range of white paper and film materials – amongst them materials that optimally support reliable wrap-around labelling thanks to their great suppleness.