In the multidisciplinary pharmaceutical industry, photonics plays an increasingly crucial role in the manufacturing process. From quality assurance to marking, the scope of photonics is wide-reaching. Specifically, the use of lasers and machine vision in oral solid dose (OSD) manufacturing is revolutionizing functionality, security and speed while reducing costs and boosting efficiency.
In certain regions of the world, a growing problem concerns medication quality, stemming from poor manufacturing processes. For example, drugs manufactured with a lower dosage of active ingredients than approved by regulators is a dangerous situation that can lead to patients not receiving a medication's full benefit. Worst-case black market scenarios involve nonpharmaceutical-grade or harmful ingredients resembling medication being used as substitutes, such as chalk and talcum powder.
The gray market, on the other hand, manifests itself in several ways, but with reselling, importing and exporting that ultimately can have high costs both for the end consumer and the manufacturer. ("Gray market" goods are also termed parallel imports. This is when someone other than the designated, exclusive importer buys genuine trademarked goods outside the U.S., for example, and imports them for sale in the U.S., in direct competition with exclusive U.S. importers.)
Gray market companies acting as secondary wholesalers are a growing problem within the industry, as well. When a pharmaceutical wholesaler sells to a secondary wholesaler, limited-availability prescription drug pricing can become inflated, with pills passing through the hands of numerous wholesalers. In anticipation of a shortage, these gray market companies incite panic and are able to resell drugs to consumers at higher prices.[3,4]
Pharmaceutical manufacturers should express concern over the gray market, particularly since it most commonly affects their bottom-line profit. When medicine is inexpensive in less-developed countries but moves through the gray market to be resold in countries without drug pricing regulation, such as the U.S., the availability of cheaper drugs in developed markets can take away from a manufacturer's margins and profit. Laser marking of unique product identification, both overt and covert, helps control and promote an orderly supply chain.
LASERS FOR PHARMA
Lasers now are used in several ways for pharmaceuticals, particularly where traceability and security are important considerations. Packaging is being laser-marked with a unique identification number, allowing for manageable tracking through the supply chain. A given product can be traced to a specific manufacturing facility, batch number or manufacturing date, providing transparency and accountability and ultimately boosting consumer confidence. With OSD tablet marking, high-speed lasers have the capability to mark on the fly with a unique identification number, if desired – even down to individual tablet level – without slowing down process speed.
For many years, lasers have been used for tablet drilling, with one of the most important applications of this technology being the osmotic controlled-release oral delivery system. This technology uses osmosis pressure as the driving force to dispense medicine in a controlled time-release manner. This drug delivery system, in the form of a tablet, usually consists of a semi-permeable outer membrane, the medicine and an osmotic core as the driving force that delivers medicine through the laser-drilled hole.
Several other methods for time-release drug delivery exist, with the commonality being a semi- or insoluble outer layer and either single or multiple laser-drilled holes. Recent years have seen a significant increase in demand for improved manufacturing methods for time-controlled drug delivery systems. With the expiration of several primary patents for osmotic pump delivery, the adaptation of this technology has grown. Laser drilling also is used in fast medicine release, not only in slow time-release. In this method, a tablet's protective outer layer is laser-drilled with a multi-hole pattern, causing the outer shell to collapse once the pill comes into contact with water in the digestive system.
As with tablet drilling, direct laser marking has become an important application for lasers in the pharmaceutical industry. Before lasers, OSD forms were traditionally imprinted using one of two methods. In the first method, a mark is molded into a tablet during the compression of the powder in the manufacturing process. This method is limited, however, as it allows only for marks that are simple and large in composition, usually containing two to five characters or an elementary symbol. The second traditional method is offset rotogravure printing, which has significant drawbacks including cleanliness of operation, the use of solvents and extra downtime to clean and maintain equipment. Overall print quality can also be limited.