Entropy Solutions Inc. believes its box packs quite a punch. Not to mention blood, vaccines, human organs and even ice cream.¶ The Eden Prairie-based start-up has developed a high-tech packaging system that can maintain pre- programmed internal temperatures to protect perishable products like food and medical supplies for five days, long enough to reach most destinations around the world. Dubbed the "Green Box," the system, which consists of an outer shell, insulation panels, and packs of special "phase changing" materials, can be reused many times, the company says.

"Green Box will never find its way into a landfill," said Entropy President Eric Lindquist.

Entropy's customers include Wal-Mart Speciality Pharmacy, Medtronic Inc. and Memorial Blood Centers. The company, which did not disclose revenue figures, has not yet sought the venture capital that it will need to expand. But some investors say the technology appears to fill a pressing market need.

"It has the ability to solve a problem related to shipping temperature-sensitive materials over distances that cannot be solved by today's current solutions like couriers and overnight shipping," said Peter Birkeland, chief financial officer of Rain Source Capital, a St. Paul-based network of angel investors. "The question is ... 'is the market large enough to make the business a commercial success?'"

Founded in 2003, Entropy was the brainchild of Mark Wallace, a chemical engineer. Wallace, who worked at Cub Foods, was frustrated to see shipments of ice cream arriving at supermarkets already melted. He began to work on packaging that could better protect food.

Wallace died in 2006 and Entropy eventually shifted its focus to the transportation of biological, medical and pharmaceutical products, a $62 billion market "where we felt we can make the biggest difference in the short term," Lindquist said.

The company's main challenge is to explain the technology and its benefits to customers, Lindquist said.

Experts say drugs and vaccines often spoil due to extreme temperature variations during shipping. This waste costs the federal Vaccines for Children Program $20 million because of bad refrigeration, expiration, and shipping damage.

With vaccines for one infant visit running near $300, "loss of vaccine potency due to improper storage conditions is a costly mistake," according to the Centers for Disease Control and Prevention.

That's why Steve Skallerud, Entropy's vice president of sales and marketing, said it "makes sense to align [our technology] against someone who has high-value, critical payloads."

Green Box boasts three layers of thermal defense to keep out heat or cold. The first is a high-density polyethylene outer container. The second layer consists of "Thermal-Lok" insulation panels. Using nanotechnology, Entropy manipulates the microscopic pores in the panels so energy cannot easily pass through.

The third layer is what Lindquist calls the company's "secret sauce." Entropy developed packs of patented materials made from vegetable oils that change states of matter depending on certain temperatures. Outside energy that seeps into the box bounces between the packs as the materials phase back and forth between solid and liquid states, creating in effect an internal thermostat within the box that can handle settings ranging from minus-4 to 122 degrees.

Phase-changing materials are not new, but Entropy's patented system makes it possible to maintain temperatures across such a broad range in the box for long periods of time even under extreme outside temperatures, said Dr. Rafik Bishara, chairman of the pharmaceutical "cold chain interest group" at Paternal Drug Association, an industry group based in Bethesda, Md.

"From what I've seen, it performs well," said Bishara, a former director of quality knowledge management and technical support at drug maker Eli Lilly and Co. Bishara, though, says more data is needed as Green Box gains additional customers.

Lindquist says Green Box can also help customers save money because one system can be reused more than 100 times. People who receive the boxes simply send them back to one of Entropy's reclamation centers. Companies also cut shipping costs by choosing ground delivery, knowing the products will stay fresh during the trip.

Wayne Williams, executive director of Cold Chain Technology Services, said Green Box has cut shipping costs by as much as 60 percent. Based in Spring Branch, Texas, Cold Chain advises the federal government and companies on how to ship sensitive products like drugs and blood.

"This is the way of the future," Williams said.

Thomas Lee • 612-673-7744