Laser-Marking Technique Improves Tablet Branding

Sherwood Technology (Cheshire, UK, www.sherwoodtech.com) has received a US patent for a tablet-marking method that could offer a new anticounterfeiting solution. The technique combines a color-changing additive and a low-power laser to clearly brand edible pharmaceuticals with trademark symbols, dosage information, or even a bar code.

The "DataLase" additive (in either a dry-powder or wet-solution form) is mixed into a tablet-coating formula and applied to the surface of the tablets. The additive reacts to specific wavelengths of light emitted from low-power CO² lasers and transforms from a clear or white color to black. Similar to a pen-on-paper technique, the coating instantly changes color in the pattern the laser has "written" on the tablets. According to the company, product degradation won't occur because the low-power laser only affects the outer coating of the tablet. "The technique only needs a fraction of the energy, so it's not destructive," says Andrew Jackson, applications marketing manager at Sherwood Technology.

The main advantage, says Sherwood, is that the technique is quicker and produces less waste than traditional tablet-marking processes. For example, embossing methods tend to crack or damage tablets and result in a high level of quality failures and rejections. Other ink spraying techniques require drying-time, which slows down the production line.

"On a pharmaceutical packaging line, it's very undesirable to have such a high level of wastage," says Jackson. The Sherwood technique removes this deficiency and thus, "revenue is consequently enhanced," he notes.

Because of counterfeiting and terrorism concerns, the company believes the US Food and Drug Administration may begin requiring tablet-marking techniques such as this in the future. The laser-color-changing technique can create very precise symbols, and thus, "could be used to make a linear or 2-dimensional barcode on the tablet for encoding information," says Jackson. "The small spot size of the laser beam allows high-quality 'pin-sharp' images to be produced." Conventional nonimpact methods such as inkjets may not be suitable for this application because the spray used to form characters often leaves excess ink on the tablet.

"Aesthetically, this isn't very desirable. But also if it's a code that needs to be read electronically, you're not going to have the proper clarity," notes Jackson.

Sherwood Technology is in discussion with development partners and potential licensees to make the technology available on the US market within the next few months. The company is also in talks with laser suppliers to create an even lower-power device to marry with their technology.

–Kaylynn Chiarello