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Pharmaceutical shipments chill out from within

Superior Pharmaceutical is among the first to use a powdered polymer within a flexible material to keep overnight shipments cool, but not frozen. The material yields cost advantages, as well as freight and space savings.
FILED IN:  Machinery  > Filling/sealing  > Dry filling

Packagers needing to keep products cold during shipping have traditionally relied on insulated containers dry ice or gel/freezer packs or a combination of these. Now however an unusual alternative is being used commercially for pharmaceutical and food applications. Cincinnati OH-based Superior Pharmaceutical is among the first users of ThermaFreeze® Refrigerant a patented product made up of powdered polymer trapped within the cells of a flexible material that consists of a layer of polyester film on one side and spun-bonded nonwoven polypropylene on the other. It's marketed by ThermaFreeze Inc. (Mobile AL). Superior uses ThermaFreeze for overnight shipments of pharmaceuticals that must be kept cold but not frozen such as insulin and flu vaccines. Glass vials are typically packed by hand inside a small box. A sheet of ThermaFreeze is wrapped around the box before loading into a corrugated case for shipment to pharmacies professional offices hospitals or to wholesale outlets nationwide. Another shipping case may contain 50 to 100 boxes of vials. In this instance several sheets of ThermaFreeze are used. These items are then packed in a corrugated case lined with a metallized film bag. This bag is called ThermaBarrier® and it provides a thermal barrier within the shipper. It too is made by ThermaFreeze. "We're a nationwide distributor of pharmaceutical products" notes Lore Breetz Superior's general manager. "We ship about twenty-five different products that need to be kept cold." ThermaFreeze keeps the pharmaceutical shipments at temperatures between 36°F and 46°F for up to 48 hours to help maintain product efficacy. How it works The supplier ships ThermaFreeze in roll form to Superior. Workers at the Cincinnati facility cut sheets of the material as needed hydrating them in warm water within a sanitary tub for about three minutes. After drying the surface of the sheets sheets are placed in a freezer overnight for use with the next day's shipments. The material permits the absorption of water by the polymer refrigerant described by ThermaFreeze as an ionic chemical composition. The water freezes to help hold the necessary cold temperatures. But rather than melting into a liquid ThermaFreeze evaporates as a vapor or sublimates as it thaws much like dry ice but without being harmful to touch. It stays frozen longer than water ice and frozen gel packs and its structure prevents water exiting as a liquid when the ice melts. "We began using ThermaFreeze about three years ago" says Breetz. For much of that time the product "was in a research and development testing process" says Joseph Murray ThermaFreeze president. "Only now are we moving into the commercial area after improving on the sealing characteristics of the structure." Murray credits suppliers Amoco Fabrics and Fibers (Atlanta GA) and Ropak Intl. Packaging (Roselle IL) with advancing the product to its present commercial status. Amoco's RFX(TM) nonwoven polypropylene permits the absorption of water into the product during hydration without letting powder or water escape. Ropak's proprietary four-layer 1-mil polyester film is designed to heat-seal to the RFX and enable the frozen structure to withstand repeated drops. "The clear polypropylene film gives us strength characteristics at both standard and cold temperatures" says Murray. Machine development ThermaFreeze developed the production machine that makes the ThermaFreeze sheet. The 60"-wide clear polyester film rollstock unwinds to form a base layer. The powdered polymer material is released from a hopper downward to a roller containing dimples or pockets each holding less than 1g of the polymer. As this roller revolves the dimples deposit the powder across the web. From a separate unwind above the nonwoven PP then descends onto the film base layer. The two structures are mated and sealed together via heat and pressure as they pass between a rubber-coated pressure roller and a "waffle" roller that revolve in opposite directions to one another. The latter roller is etched with a waffle-like pattern. When the material passes between the rollers the waffles create roughly 21/4" x 2" pockets or cells that contain the powder. A standard 100-yard-long roll contains 9 of these pockets. Master rolls are typically slit into four 15"-wide rolls for Superior Pharmaceutical. Superior benefits Superior's Breetz points out there are several advantages to using ThermaFreeze. "ThermaFreeze keeps our product cold as well as if not better than the alternatives" she says. "Cost was another important reason why we selected ThermaFreeze" she continues. "We were quoted prices for cooler boxes and the freezer packs that were very high. And because ThermaFreeze is shipped to us in a dry state it is lightweight. That saves us on inbound [freight charges]." Even after ThermaFreeze is hydrated it still weighs less than insulated boxes with freezer packs. "We pay shipping costs not our customers" Breetz tells PW "and there are cost savings for us for outbound shipments using ThermaFreeze." She declined to provide specific savings. ThermaFreeze's cell design and flexible materials enable users to cut in seal areas between the cells to custom-size sheets. These sheets can be layered between products within a shipment or wrapped around products as necessary. Yet another advantage of ThermaFreeze Breetz says "is storage space savings. We only need a corner of a table to store a couple of boxes of this material." Savings offset labor Breetz estimates that Superior uses ThermaFreeze for more than 1 boxes a year that contain mostly vials of liquids. Although it's not a high-volume application it is important to Superior Pharmaceutical. "It takes maybe an hour or hour-and-a-half to hydrate the sheets we need for the next day's shipments then put them into a freezer overnight for use the next day. It's not a lot of labor. Even when you factor in the new freezer that we purchased for ThermaFreeze we're still ahead economically compared to paying for cooler boxes and ice packs and the costs to ship and receive them" Breetz concludes.

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