Top marks for novel labelling solution

Regulatory requirements led Abbott UK to seek alternative labelling solutions for its pharmaceutical products

At its pharmaceutical facility in Queenborough, Kent, Abbott UK manufactures and distributes a range of drugs including antibiotic tablets and granules, anaesthetics, drugs for cardiovascular and urological conditions, as well as treatments for HIV. As with all areas of pharmaceutical production, Abbott is bound by strict industry legislation regarding its product labelling details; furthermore, the company is under increased pressure from certain pharmaceutical clients to reduce product packaging. A combination of these pressures led it to consider leaflet labels.

With pharmaceutical industry experience in producing leaflet labels, Inprint, of Ashford, already had an understanding of Abbott's labelling requirements. However, a new development on the production line presented a real challenge for both companies. 'Initially, we worked with Inprint to remove the carton that the product was contained in, while ensuring that the information remained with the product,' said Les Allen, packaging services manager at Abbott Laboratories UK. 'The only reliable way of doing this is with a leaflet label. It removes the cost and effort associated with coordinating the carton, label and produc, saving on the line cost and bringing a definite economic advantage.'

issues arising

Inprint's text folding leaflet labels are printed with all the relevant information, and finished with a polypropylene laminate. Each leaflet label has a blank strip on the cover where the lot number and expiry date of the batch can be applied. Traditionally the variable data has been added by hot foil, but the time taken to change print digits and the requirement to handle hot print blocks led to an investigation of the use of ink jet technology.

Although this overcame most of the issues arising from the use of hot foil, it was at the cost of overall clarity and the quality of the variable print. Abbott, by preference, uses Optical Character Recognition (OCR) on the production line. This led it to look at laser coding, which offered the potential advantages of quick set-up and changeover combined with excellent clarity of print.

A leading manufacturer of laser marking systems, Alltec, was asked to install low power CO₂ lasers on the product line, and early factory trials showed that, although ideal on vinyl substrate, the code lacked the necessary clarity when applied to the polypropylene on the leaflet label.

The adhesives used for making leaflet labels make it impractical to use vinyl so an alternative solution was sought. Alltec suggested that Sherwood Technology might be able to help.

Located in Nottingham Science Park, Sherwood is a technology-based company that specialises in chemically advanced additives, inks and packaging materials. One of the company's developments is a water-based ink that creates a permanent mark when exposed to low-power CO2 laser energy.

Andrew Jackson, applications marketing manager at Sherwood Technology explains: 'A steered beam of low-power laser causes a reaction with the chemistry in our Laserscribe ink to create a clear, permanent, high-contrast image. It is cleanroom friendly and, importantly, it requires no mechanical contact so the risk of smudging is eliminated. As an inert substance, the ink won't react when it's exposed to UV light or solvents either.'

Inprint was supplied with a batch of the Laserscribe ink and applied a coating on the strip of several labels on a flexographic printing unit for trial purposes. Using the Alltec laser coding machine and the leaflet labels supplied by Inprint, Sherwood then carried out trials to see if the ink would provide accurate, permanent coding details. The text on early sample leaflet labels was clear and perfectly legible to the human eye, but was of insufficient contrast for Abbott's OCR reader.

'The intensity of the text is directly proportional to the coatweight of the Laserscribe ink,' said Jackson, 'so if a double "hit" could be applied, then the intensity could be increased.'

extensive trials

Thus Inprint began a series of extensive trials to achieve the correct intensity. Andrew Walker, business development manager at Inprint, commented: 'Inprint immediately began a review of the production units and sample labels were soon delivered to Abbott for testing. Before long, full production capability on the ink-applied leaflet labels was underway with accurate, permanent OCR-readable marking on every label.

'Every application brings with it new challenges and this was no exception. We had to draw on the years of experience we have gained from working with Abbott and other companies within the pharmaceutical industry to deliver a labelling solution to meet this project's specific demands,' he concluded.