With pearlescent coatings, a rainbow of colors is possible. These colors can only be duplicated by knowing the specific pigment grade combination and the detailed processing procedures used in the drug's manufacture; they cannot be duplicated by using analytical or reverse-engineering techniques. Several products using this technology are in clinical trials and should enter the market by 2007.

Any number of colors and images can be achieved with the same chemically stable, inert, light-refracting ingredient, both qualitatively and quantitatively, by controlling processing variables. Various coating systems are available that can give the same pearlescent effect while meeting each country's regulatory requirements.

As an additional benefit, the ease of visual identification by caregivers, pharmacists, and patients can reduce medication errors by ensuring that the right tablets are taken appropriately. Although the current FDA bar code regulation only addresses medication errors that occur in the hospital, visual identification methods are effective throughout the supply chain, right to the patient at home.

Electronic ID Innovative electronic technology now allows manufacturers to use common, edible inks to apply two-dimensional (2D) Datamatrix bar codes directly on the tablet surface. Smaller than their linear counterparts, 2D bar codes can be used to code specific information such as National Drug Codes, which provide identification control all the way from the manufacturing plant to the bedside. Plus, the unique bar code technique used in this process cannot be easily duplicated.

Tablet bar coding restricts the potential for error even after the tablet has been removed from the packaging, either for delivery to the patient's bedside or for repackaging. During bulk repackaging operations, bar code GMP controls can now be implemented to assure that there is no chance for mix-up, either in the packaging or the dispensing.

High-resolution imaging now provides a wide range of new identity options. Tablets can contain images with bar codes as small as 2.5 millimeters that are readable by typical high-resolution bar code scanners. For easy identification by patients, readable numbers, codes and logos can be combined with bar codes. With high-definition imaging technology, coded images can be designed into logos, acting as fingerprints that make tablets very difficult to duplicate. These images may also be made scannable to provide visually appealing electronic identification.

High-definition imaging can also be combined with number codes to make tablets highly recognizable and even harder to counterfeit. Multi-coded tablets can be easily traced through the supply chain, and pharmacists and physicians can readily identify individual drugs that patients present for verification. Some products currently in Phase II are being developed with this technology.

Chemicals, Flavors, Aromas Incorporating covert chemical markers into the film coating of tablets adds even greater security against replication. Taggants—simple, stable, inert, organic chemicals that are present in the product in trace quantities—can be added to film coating solutions under tight security during product manufacture. Undetectable by the human senses, taggants are also difficult, if not impossible, to detect through normal analytical techniques and cannot be copied or removed from the dosage form. Available with wide regulatory acceptance, manufacturers can include taggants in new products or incorporate them into existing products with minimal regulatory requirements.

Because they are detected through the use of a specific recognition molecule and can be quantitatively measured using inexpensive equipment, taggants are also being used as chemical bar codes. With this methodology, manufacturers can provide additional information (such as manufacturing location) that goes beyond the data available in the 2D electronic bar code on the tablet surface. Robust taggants provide immediate chemical authentication when tested by pharmacists or customs agents using in-field testing kits.

Specialized flavors and aromas incorporated into tablet film coating systems can also provide unique characterization profiles identifiable by patients. In addition, they act as covert forensic fingerprint profiles that can be tracked and traced. Flavors and aromas can be difficult to duplicate because oxidation can change the sensory profile if counterfeiters do not use the same stable grade that is in the genuine product. And it is difficult to identify the specific grade used in an individual drug.