From Smart Tags to Brilliant Tags: Advances in Drug Stability Monitoring

Nov 01, 2005
Volume 18, Issue 11

A suitable microprocessor can be linked to an RFID chip to construct a battery-assisted RFID tag. This type of tag is a cross between a passive RFID tag not powered when not operational, and an active RFID tag that uses battery power to send and receive radio signals. A battery-assisted RFID tag remains continually powered, but saves battery energy by utilizing the reader's energy source to transmit back an RFID signal.

Thus, in volume, modern electronics is presently capable of producing drug stability monitoring "brilliant" tags for around $1.00 to $2.00 per unit.


Although the technology is available today, there are a number of significant manufacturing, regulatory, and legal issues that must be addressed before this "brilliant tag" approach can become widely used for drug stability monitoring.

To program a "brilliant tag" accurately, stability characteristics of the drug must be precisely determined. This will likely require drug manufacturers to pay increased attention to their drug stability testing procedures. Fortunately drug companies typically conduct much more stability testing than is usually published, and much of this needed extra information is likely to be available. Here "brilliant tags" act to liberate this detailed information, which otherwise would go unused, and make it available to the end user in a convenient, timely, and easy-to-use format. The net effect is brilliant tags enable the company to send its stability experts to monitor the status of each unit of drug in the field.

An additional advantage from a manufacturing perspective is that brilliant tags enable a pharmaceutical company to have more strategic options during product development. Consider a promising drug in late-stage development that has marginal stability. Without brilliant tags, a manufacturer would have to decide between two undesirable options: terminate the drug or launch the drug with suboptimal storage dating. With brilliant tags, a third option is created: design an appropriate stability label that will flag any drug that has been improperly stored.

Brilliant tags are new, and regulatory policies concerning these tags have yet to be formulated. One possible regulatory policy may be to permit brilliant tag use on the stipulation that all existing storage regulations remain, and that the tags should never extend beyond a printed expiration date. In this instance, the tag would always indicate an expiration date less than or equal to the printed expiration labeling and serve as a secondary fail-safe device rather than as a primary process control device.

Legal considerations also are important. Brilliant tags transfer some of the burden of deciding when a drug is acceptable from the end user to the manufacturer. Although this is sound policy from both a safety and information-ownership perspective, it places a higher burden of the responsibility on the manufacturer. Mitigating this higher burden is the fact that a fair number of presently inexplicable adverse drug reactions may now become explainable and attributable to end-user failure to respond to appropriate stability warnings. This would tend to considerably reduce the manufacturer's legal burden.

One interesting issue is the concept of "standard of practice." After it becomes clear that a new "standard of practice" is available to minimize problems, legal considerations tend to favor manufacturers that adhere to the new standards.


Most drugs deteriorate gradually as they age beyond their expiration conditions. Fortunately, a slight loss in potency usually has only a small effect relative to overall physiological variation. As a result most drug deterioration is harmless and goes completely undetected.

There are exceptions, however. Drugs stored in a liquid form generally deteriorate much more rapidly than drugs stored in a dry form; and poor storage of liquid drugs can significantly compromise effectiveness. Some commonly used drugs such as beta-lactam antibiotics are particularly unstable, deteriorating after only a few hours of higher temperature exposure.

Drugs stored in non-temperature controlled environments such as ambulances also have many stability issues. Ambulatory infusion situations are particularly problematic because the drug is both in an unstable liquid form and subjected to uncontrolled temperatures.

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