Packaging Forum

Cold Chain Concerns - continued

Added benefits RFID advocates claim RF-enabled temperature monitors are more accurate than color-changing labels or strip charts. Fewer shipments are destroyed because in marginal cases, the data stream allows quality engineers to decide whether the product is still potent. It also cuts out fingerpointing because it provides proof of when and where temperature limits were exceeded. For fragile products, shock and vibration sensors can be added. Finally, RF-generated information can help logistics managers save on coolant and attendant dead-weight shipping costs because packaging can be closely matched to the conditions the shipment is likely to face. Preventing product loss can add up to real money. “In one real-world case I’m aware of,” says Henry Ames, director of life sciences marketing at Sensitech, “an entire shipment of biologics was frozen, causing an $8-million loss.” CSL (Parkville, Victoria, www.csl.com.au), Australia’s biggest pharmaceutical company, is using an RFID-based temperature-sensing system that features a read–write, credit-card-size, 13.56 MHz active tag, which can be attached to or inserted in shipments. Other components include RF readers, software, and a Web portal to a secure database. The tag can be programmed to register temperatures within a certain range at specified intervals or locations and can be set to log all data points or just exceptions. Alerts are provided whenever data are uploaded or an exception occurs so that corrective action can be taken. The active tags reportedly cost less than traditional data loggers and may be reused for 12 months or until battery power is depleted. Future tag designs may measure additional environmental conditions such as humidity, shock, and vibration (x_Tract Consignment Monitoring Service, Global Licensing & Innovation, a Carter Holt Harvey Co., Reservoir [Melbourne], Victoria, Australia, www.glandi.com). Other cold chain management solutions Using RFID is not the only way to protect temperature-sensitive products. Other options include implementing data loggers, color-changing labels, and insulated packaging (see Pharmaceutical Technology, March 2004, p. 36). Data loggers typically require downloading to a personal computer. One reusable, button-shaped digital logger, however, simplifies data transfer by interfacing with a low-cost reader. The reader, in turn, transmits data directly to a printer to generate a one-page shipment history (model PT Instant Certificate Maker, Photologic Ltd., Cobourg, Ontario, www3.sympatico.ca/photologic/cdw.htm). Another system combines a data logger with a proprietary, reusable insulated shipping container. The vacuum-insulated panel construction of the container maintains shipment temperatures in the 2–8 °C range or <0 °C for five days while an “onboard” computer monitors conditions. The system also relies on a turnkey logistics service and an e-commerce Web site that provides access to shipment data (Cold Chain Shipping Container, Kodiak Technologies, Inc., Kingsville, Texas, www.gokodiak.com). Insulated containers are available in various formats including box liners, pallet covers, and pouches. The seven-layer structure includes aluminum foil to reflect heat, polyethylene for strength, and bubble material to block heat flow. The thin, light-weight material can be customized to match temperature-control requirements. It also can be reused and can be stored in 85% less space than EPS foam insulating material (TempShield thermal insulating material, Reflectix, Inc., a subsidiary of Sealed Air Co., Markleville, IN, www.reflectixinc.com). Color-changing labels include various structures such as irreversible temperature-indicating labels and time temperature indicators (TTIs). Irreversible temperature-indicating labels provide a permanent record of temperature abuse. Typically, these labels are designed to register across a span of temperatures and are inexpensive and easy to use (Thermostrip Irreversible Temperature Indicating Labels, Hallcrest, Inc., Glenview, IL, www.hallcrest.com; Thermax Indicators/Strips, Thermographic Measurements Ltd., Flintshire, UK, www.t-m-c.com). A simpler version consists of a spot label that changes color and sometimes reveals a message if its designated temperature is exceeded, providing “good/no good” information at a glance (Clearing Point Label, Hallcrest; Chill Checkers, Thermographic Measurements). A newcomer to the TTI field offers a two-stage pressure-sensitive label construction, which activates with the application of a spot activator label over the indicator printed on the base label. These labels change color over time as shelf life winds down or if the product is temperature abused. Currently in use in the seafood industry, this two-stage construction eliminates the need to store the labels in a refrigerator or freezer before use, a typical requirement for color-changing TTIs. Three standard labels address various temperature requirements, and custom structures also are available (TT Sensor, Avery Dennison Industrial Products Division, Strongsville, OH, www.industrialabels.averydennison.com). These are still early days for cold-chain management. But with the sale of temperature-sensitive biologics growing at a healthy clip, it’s a safe bet that technological innovation will continue and that temperature-controlled packaging will come under increased regulatory scrutiny. PT