Protecting the Cold Chain

August 2, 2007
Hallie Forcinio
Pharmaceutical Technology

Volume 31, Issue 8

Makers of temperature-sensitive products constantly seek to ensure proper conditions during shipping and storage.

Drugmakers have an ever-increasing array of protective materials and devices to monitor conditions and maintain sensitive products at the appropriate temperatures. The ideal innovation combines high efficiency with low cost. Options include time and temperature indicators, data loggers, and insulated packaging and refrigerants.

Hallie Forcinio

Indicator labels

Indicator devices, primarily labels, reveal the passage of time, temperature excursions beyond acceptable limits, or both. Many of these devices have been designed for the food industry but have potential applications in the pharmaceutical supply chain.

One temperature indicator designed to protect red blood cells is attached to the blood bag with a handheld activator. After preconditioning, activation, and application, phase-change material in the label irreversibly turns from white to red if the temperature of the contents exceeds a preset threshold ("Check-Spot" label with "Spot-Gun" handheld activator, Harald H. Temmel KEG, Gleisdorf, Austria).

For products that can't be frozen, a freeze indicator provides assurance that no accidental freezing events occurred ("iStrip," Timestrip plc, Miami, FL).

As time passes, a spot of color on the "Timestrip" label darkens to show how much shelf life remains.

Some labels monitor time rather than temperature. One technology that can be supplied as an external label or integrated into the packaging is particularly useful for products such as eyedrops, which must be used within a specific time frame. When activated, an edible oil travels across the label at a consistent rate and provides a visible indicator of how long the product has been open or in use ("Timestrip" label, Timestrip plc).

Another time-tracking option is a small, battery-equipped digital counter with a magnetic or suction-cup backing for easy mounting ("Days Ago" digital day counter, double u products, Inc., Cupertino, CA).

An indicator that registers both time and temperature consists of a clear pressure-sensitive label with a coating of food-grade microorganisms that simulate the degradation of the product. When the label is activated and applied over the barcode of the product, it slowly changes color as time passes or temperatures exceed its threshold. When the label becomes so opaque that the barcode is unreadable, the product is no longer safe to use ("Traceo" label, Cryolog, Gentilly, France).

For storage facilities, monitoring systems can provide alerts if temperatures warm or chill too much or the power fails. Light-emitting diodes on a sealed, weatherproof, lockable enclosure display alarm and status conditions for at-a-glance monitoring. Capable of measuring temperatures as low as –85 °C, the monitoring system automatically calls as many as eight numbers when a problem occurs. The unit also can trip an on-premises warning device ("Sensaphone 1400" and "Sensaphone 1800," Sensaphone, Inc., Aston, PA).

Data loggers and RFID

For cold-chain applications, data loggers help ensure products remain within storage parameters during shipment by providing a record of the conditions experienced. Some of today's units are low-cost enough to be used for a single trip and often incorporate radio-frequency identification (RFID) technology to automate data transmission.

A data logger with an integral USB port and PDF report generator presents data collected during the journey as a PDF file, thus eliminating the need for installing and qualifying specific software. Once the unit is plugged in, the report may be viewed, printed, e-mailed, or stored on a network. An "X" or check mark in the corner of the screen instantly shows whether a product is acceptable or unacceptable. The USB port also is used to configure the unit. The system monitors multiple trips during a 400-day period, captures 16,000 temperature data points between –35 and 70 °C, and supports compliance with 21 CFR Part 11 requirements ("Libero PDF" data logger, Elpro Services Inc., Marietta, OH).

Monitoring in real time is possible with a system that combines a disposable, credit-card-size pallet tag, hardware, and software. During the trip, the tag monitors shipment temperature and wirelessly transmits data to a server that supplies reports and alerts by e-mail or mobile phone ("Smart-Trace Online" monitor, Ceebron Pty. Limited, North Ryde, New South Wales, Australia).

A monitoring system using a battery-assisted passive RFID tag integrates a temperature sensor with data-logging capability, encryption technology, and electronic product code (EPC) data to enable product authentication and provide product information and environmental data ("Lightweight Multistream Encryption" EPC tag with integrated temperature sensor, SecureRF, Westport, CT).

Another data logger that relies on RFID uses a thin, lightweight, passive 13.56-MHz tag that measures 2 in.2 and logs as many as 64,000 readings per trip. Available in disposable and reusable versions, the tag can be programmed to read in increments from ± 0.1 to 1 °C. A handheld scanner programs units and retrieves data ("Logic Temperature Tracker" with "CertiScan" wireless scanner, Intelligent Devices subsidiary of Information Mediary Corp., Ottawa, ON, Canada).

A credit-card-size temperature monitor that consists of a 13.56-MHz RFID chip, a temperature sensor, and a printed battery and antenna records temperature data at intervals ranging from 6 s to 12 h. A reader connected to a laptop provides two-way data transmission and can be used to set the tag's temperature parameters between –20 and 50 °C. Data can be downloaded from the card without opening the package. Software developed to meet the requirements of 21 CFR Part 11 stores data in a password-protected database to generate charts and reports. Information also can be exported for use in Excel spreadsheets ("e-temp-label," Schreiner MediPharm, Oberschleissheim, Germany).

An active Wi-Fi tag incorporates a temperature monitor and motion sensor. The former triggers a remote alert if the temperature exceeds a preset threshold. The latter tracks product movement. Three colored light-emitting diodes can be incorporated in the tag to provide a visual display of product status ("AeroScout T2" tag, Aero-Scout, Inc., San Mateo, CA).

Wi-Fi tags also can be integrated with logistics software, specially equipped trailers, global-positioning systems, and central servers to track product paths in real time using a web browser ("AeroScout T2" tag, AeroScout, truck-based "Microlise Tracking Unit" and "Microlise Transport Management Centre" software, Microlise, Eastwood, UK; third party logistics provider, DHL, Bonn, Germany).

Insulated packaging

Sensitive products generally require specialized packaging that may also include provisions for ice, dry ice, or gel packs. One new option designed for blood-platelet shipments features vacuum-insulated panels and liquid-refrigerant packs to maintain the US Food and Drug Administration's required temperature range of 20–24 °C for two days in both summer and winter conditions. The result is a shelf life that is at least three times that achieved with traditional insulated shippers ("Golden Hour Platelet Shipper," Minnesota Thermal Science, Plymouth, MN).

Vacuum-insulated panels and liquid refrigerant packs help the "Golden Hour Platelet Shipper" triple the length of time contents remain at the proper temperature.

A prequalified insulated shipping container maintains a temperature range of 2–8 °C for 24 h and conforms to summer and winter weather shipping-condition requirements set by the International Safe Transit Association (ISTA, East Lansing, MI) in its ISTA 7d standard. For more stringent applications, 48-, 72- and 96-h versions are available ("TimeSaver 24," TCP Reliable, Edison, NJ).

Another prequalified thermal shipper capable of maintaining 2–8 °C conditions combines polyurethane construction with refrigerants to provide protection for as many as five days and a 2744-in.3 payload ("Large-Capacity KoolTemp GTS-120" insulated container, Cold Chain Technologies, Holliston, MA).

To minimize environmental impact and reduce waste, Talecris Biotherapeutics, Inc. (Research Triangle Park, NC) specifies a shipping container that combines a recyclable corrugated box with interior insulation panels made of several natural minerals that are heated, spun into a fiber, and encapsulated in biodegradable plastic. "The integration of 'Control Temp Blue' containers into our supply chain will enhance the integrity of our products and minimize any environmental impact from packaging and shipping," says Jim Bacon, director of global demand planning and customer operations at Talecris. Besides the environmental benefits, the new containers offer longer temperature maintenance per inch of insulation, enhanced cushioning, and shock protection for Talecris's glass-packed products ("Control Temp Blue" container, R.N.C. Industries, Inc., Norcross, GA).

Several firms offer insulated bags that maintain product temperature for several hours. Generic insulated medical pouches rely on a three-layer structure consisting of reflective film, polyethylene foam, and food-grade film. The pouches are available in five stock sizes ranging from 12 X 10 in. to 21 X 21 in. This construction also blocks potentially damaging ultraviolet light. Custom designs of the washable, reusable, and recyclable bags can be printed in 10 colors. For added protection, a gel pack can be built into the bag ("Medtraveller" thermal bags, Coldkeepers, LLC, Thomasville, GA).

Another supplier of insulated bags and pouches recently installed a production machine that handles narrow webs of material to meet rising demand for smaller sizes. Bags and pouches are not only certified to be made of food-grade materials, but also provide unit-level traceability because each one carries a unique identification number ("Criomed" and "Criomed Plus" insulated bags, Termika US, Roswell, GA).

Temperature-sensitive shipments typically include wet ice, dry ice, or gel packs to help maintain refrigerated or frozen conditions inside the container. Wet ice is messy, and dry ice can be dangerous because it can burn exposed skin. All three traditional refrigerant options are relatively heavy and offer no cooling action once thawed. More active cooling is available from a gel-equipped fabric that is conditioned with water and frozen before packing in a process that can be automated for high-volume requirements. An active polymer in the gel holds water in suspension for 6–8 days and stays frozen for 25% longer than an equal mass in a gel pack. Even after thawing, the water sublimes through the fabric and continues to provide evaporative cooling to maintain safe product temperatures for twice as long as traditional refrigerants. The flat, flexible fabric also distributes cold more evenly through the container than wet ice, dry ice, or gel packs ("ThermaFreeze" refrigerant pads, ThermaFreezeProducts Corp., Theo-dore, AL).

Hallie Forcinio is Pharmaceutical Technology's Packaging Forum editor, 4708 Morningside Drive, Cleveland, OH 44109, tel. 216.351.5824, fax 216.351.5684, editorhal@cs.com.

Company websites

The following is a list of websites for the companies mentioned in this column:

AeroScout, Inc.,www.aeroscout.com

Ceebron Pty. Limited,www.smart-trace.com

Cold Chain Technologies,www.coldchaintech.com

Coldkeepers, LLC,www.koldtogo.com

Cryolog,www.cryolog.com

DHL,www.dhl.com

double u products, Inc.,www.howmanydaysago.com

Elpro Services Inc.,www.elpro.com

Harald H. Temmel KEG,www.temmel-austria.com

Information Mediary Corp.,www.log-ic.biz

International Safe Transit Association,www.ista.org

Microlise,www.microlise.com

Minnesota Thermal Science, http://goldenhourtechnology.com

R.N.C. Industries, Inc.,www.rncinc.com

Schreiner MediPharm,www.schreiner-medipharm.de

SecureRF,www.securerf.com

Sensaphone, Inc.,www.sensaphone.com

Talecris Biotherapeutics, Inc.www.talecris.com

TCP Reliable,www.tcpreliable.com

Termika US,www.termika.us

ThermaFreezeProducts Corp.www.thermafreeze.com

Timestrip plc,www.timestrip.com