Product Update
Safe-and-Secure Shipping Materials &
Containers
These materials are designed to protect products throughout
the rigors of transportation.
Durable Transport Containers
Durable insulated containers can be custom designed, tested,
and qualified to protect perishable goods during transportation.
The systems tightly seal payloads, maintaining frozen temperatures
(-75 to 20 degrees C) as well as refrigerated temperatures (2
to 8 degrees C or 1 to 10 degrees C). Options include FLX-SEAL
flexible doors, false floors, cargo stabilizers, casters, drains,
shelving, 1- to 3-in. urethane foam walls, and corporate logo
graphics molded into the containers. The latest container in development
is a customizable bulk transporter that accommodates pallet-sized
loads while secured to its own 40 x 61-in. aluminum pallet. An
inlaid thermometer visible on the front door monitors internal
payload temperatures. These temperatures are maintained by circulating
air vented from a bunker that can store dry ice or gel packs.
The shippers can be prequalified through testing and qualification
services. ThermoSafe Brands, Arlington Heights, IL; 800/323-7442;
www.thermosafe.com.
Shipping Containers
 |
A firm offers five different transport solutions for protecting
temperature-sensitive products. Using only frozen gel packs, pallet-sized
BioSphere maintains healthcare products at 2° to 8° C
for 96 hours in hot and cold environments. Premolded Conduction
Blocks can reduce temperature pockets in specific areas of the
shipping container to consume energy from its source before it
reaches the product load. A Sliding Ice Tray separates coolant
from the product while controlling thermal conduction and directing
thermal convection. The Convection-Engine design uses engineered
shapes, cavities, and channels in various places throughout a
container to use thermal convection to move and disperse energy
within the container. Finally, Air-Lock interlocking walls, lids,
and bases reduce thermal convection between the external and the
internal environments. These offerings can be combined to provide
a custom-designed shipping container. EnviroCooler, Huntington
Beach, CA; 714/891-5035;
www.envirocooler.com.
Perforated Bagging System
A packaging company has introduced a new shipping system that
eliminates the need for corrugated shipper boxes. The PERFect
Pack system uses layers of perforated plastic bags to form a brick
of bagged bottles that can be stacked onto a pallet for economical
and convenient shipping. The system also features a unique stacking
method that eliminates wasted head space in corrugated shipper
boxes. This enables companies to fit more bottles into limited
warehouse space and results in better stacking strength for each
pallet. It also offers improved ergonomics for plant floor personnel
so they can handle each layer of bottles separately instead of
handling the entire contents of a 30-lb shipper carton at one
time. Alpha Packaging, St. Louis, MO; 800/421-4772; www.alphap.com.
Copyright ©2004 Pharmaceutical &
Medical Packaging News
===
Transportation Packaging
Phase-Change Materials Cut the Ice
Water-based gels are the workhorses of temperature control
in the shipment of temperature-sensitive products. For esoteric
applications, however, phase-change materials make it possible
to hold a wider range of temperatures than ever before.
Jenevieve Blair Polin
Contributing Editor
 |
TCP
Reliable’s Phase 5 phase-change material is packaged
using a thermal
control panel that allows for a 72-hour shipping range with
standard
insulated shippers. |
TCP Reliable’s Phase 5 phase-change material is packaged
using a thermal control panel that allows for a 72-
hour shipping range with standard insulated shippers.
For decades, those shipping refrigerated temperature-sensitive
products had their choice of two phase-change points: 0°C
(water) or –80°C (dry ice). Recently introduced phase-change
materials (PCMs) offer the tantalizing promise of customized phase
change, at any temperature the payload product requires. However,
PCM manufacturers are the first to admit that much research and
development remains to be done before the perfect PCM comes to
market.
Giving Water a Run for the Money
The drawback of water-based gel as a refrigerant is the need
to isolate it from product that requires a temperature range of
2°–8°C and that can’t tolerate freezing. “That
meant a lot of design work,” laughs Sanford L. (“Sandy”)
Cook, CPP, president of Thermal Packaging Solutions LLC
(Ocean, NJ). “You had to put expanded polystyrene, urethane,
bubble pack, or some other insulation between the gel packs and
the payload. That made the package heavier and bigger and more
expensive to ship.”
This problem prompted Cook’s firm to work with packaging
manufacturers and suppliers and biopharmaceutical companies to
develop high- and low-temperature PCMs, including those incorporating
paraffin.
“If you put a match to a candle, it phases—liquefies—at
a much higher temperature than water, and it solidifies at room
temperature,” explains Cook. “So we took advantage
of that characteristic to raise the phase point of a gel pack.
Since the mean temperature for refrigerated biologics was 2º
to 8ºC, we shot for 5ºC as the nominal. Now, you don’t
need to insulate the gel packs from the precious biologics. You
can wrap the product in gel packs and keep them at the right temperature.
Hence the package is smaller and lighter weight.”
“Paraffins,” adds Larry Gordon, president of Cold
Chain Technologies Inc. (Holliston, MA), “are composed
of long carbon molecules that can be manipulated to alter their
molecular weight. In doing so, one can create a paraffin solution
to change phases at just about any temperature desired.”
Last fall, TechPak Solutions—now Life-Like Products,
Northeast (Peabody, MA)—introduced the Guardian PCM 4C,
which changes phase at 4ºC. Bruce Truesdale, general manager,
explains the firm’s hybrid approach, which controls both
cost and temperature. “We can use water-based gels for the
bulk of the work of absorbing heat inside an insulated container,
at about a 2:1 ratio of water-based gel packs to PCM 4C packs.
The 4C acts to buffer the extreme cold of the frozen water-based
packs, but it also has a second benefit in that it partially phases
when it’s protecting against that very cold temperature.
You get a kind of bonus at the end of the trip, when you still
need BTU absorption (to keep it in that 2º to 8ºC range).
The PCM 4C has, in a sense, become another gel pack, helping you
get more hours out of your package,” Truesdale says.
The U-tek line of PCMs from SCA ThermoSafe incorporates hydrated
salts, which helps control costs.
 |
| The
U-tek line of PCMs from SCA ThermoSafe incorporates hydrated
salts, which helps control costs. |
Cold Chain manufactures paraffin-based PCMs, but Gordon acknowledges
that their biggest drawback is price. “They are an order
of magnitude higher in price than a standard refrigerant gel.
As a result, we have found that we are often able to meet the
needs of our customers in a more effective and economical way
without the use of paraffins.”
TCP Reliable Corp. (Edison, NJ) has a different
view. “PCMs maintain narrow temperature ranges and generate
multiple benefits to the end-user,” says president/CEO Maurice
Barakat. “Our engineers had to rethink the package design,
and they created Thermal Control Panels (TCPs) to allow customers
to envelope the payload area and maximize the effectiveness of
the PCMs. This design allowed us to extend the shipping range
to 72 hours using standard insulated shippers, and they can be
used for multiple temperature ranges.” This design won the
Ameristar and Worldstar Packaging Awards in 2004.
Cold Ice Products (Oakland, CA) is another company
investing in water-based PCMs. “We offer multiple phase-change
refrigerants,” says Raymond Wilhelm, Cold Ice’s president.
“We can custom formulate these products for different companies.”
The Cold Ice product line includes PCMs for products requiring
temperatures of 0° to –23°C.
Similarly, AcuTemp (Dayton, OH) offers a wide
range of PCMs. “Water-based PCMs are the cheapest and easiest
to use,” says Mike Sieron, the company’s sales and
marketing manager. “We supply paraffin-based, nontoxic PCMs
that can be blended to achieve the proper temperature. These are
the best choices for use in closed shipping cycles where the product
is returning.”
Sieron also adds that AcuTemp is aggressively targeting the pharmaceutical
industry. “FDA is really starting to put some teeth into
its transportation regulations,” he says. “Companies
will need the proper shipping materials more than ever, and it’s
a great opportunity for suppliers of PCMs.”
Polar Tech Industries (Genoa, IL) also manufactures temperature-sensitive
packaging and shipping products, such as its Ice Brix line of
gel refrigerant packs. “When it comes to surrounding your
product effectively, you have to use ice,” says Don Santeler,
the company’s president. “Phase-change materials can
be an excellent solution, but they’re not for everyone.
I’d say they’re good for only 1–2% of the pharmaceutical
market.” Polar Tech’s Ice Brix line keeps products
at a constant and desirable temperature for days at a time, according
to Santeler.
Holding Heat
 |
| Laminar
Medica’s new PCMs (right) offer multiple individual
phase changes over a range of temperatures. |
Laminar Medica’s new PCMs (right) offer multiple individual
phase changes over a range of temperatures.
Much less expensive, and therefore of great interest, are PCMs
that incorporate hydrated salts. SCA ThermoSafe Brands
(Arlington Heights, IL) has been supplying PCMs using various
hydrated salts under the U-tek brand name for more than 30 years.
Recently, ThermoSafe began selling microencapsulated paraffin-like
PCMs rated at 28°C and 35°C, as additions to its U-tek
product line. The 35°C material has been particularly successful
in a custom-designed configuration maintaining 36°C ±
3°C for a human cell–infused medical device in transit.
This package replaced the customer’s own design that had
used 25 or more units of warmed sterile saline to increase the
thermal mass. According to SCA ThermoSafe, microencapsulation
simplifies the packaging process for these materials and provides
important flexibility for thermal engineering. It also brings
to the market unconventional PCMs in a reliable pouch format that
is more familiar to customers.
TCP Reliable also offers a broad range of PCMs, such as the Phase
5 and Phase 22. “We just completed a project with a large
Canadian blood supply organization that had tried to maintain
narrow temperature ranges [2°–8°C and 20°–24°C]
in very demanding conditions,” explains Barakat. “Their
final design—actually the only one that worked—is
based on our PCMs, and we hope to implement it this spring.”
This customer, Barakat explains, has developed and validated every
step of the blood transit system from collection to the final
destination in the hospital.
“We have supplied thousands of Thermal Control Panels for
various temperature ranges without significant packaging performance
issues,” continues Barakat. “PCMs require a formal
quality assurance program to ensure that the containers are leakproof
and reusable and that the phase change performance is repeatable.
We are able to target very precisely most of the temperature ranges
from –20° to 27°C and work with various chemical
formulations, including eutectics and hydrocarbons. Our design
approach allowed us to reduce the size and weight and simplify
the conditioning of the packs and package qualification. This
created a savings in freight and handling that will more than
pay for the increased cost of the packaging.”
Life-Like’s Guardian PCM 28C—which holds temperature
around 28ºC—was developed in response to a customer’s
request. The customer, Organogenesis (Canton,
MA), was shipping its Appligraf laboratory-grown living human
skin in a custom-engineered package developed by Source
Packaging of New England Inc. (Warwick, RI). (See the
article “Smaller Boxes Spell Savings,” in the February
2003 issue of
 |
A
blood shipper
from SCA ThermoSafe features the company’s PCMs with
hydrated salts. |
Pharmaceutical & Medical Packaging News, for details on the
original package.) The company was limited to shipping in this
package only via overnight air freight.
A blood shipper
from SCA ThermoSafe features the company’s PCMs with hydrated
salts.
“Their customers could schedule surgeries only Tuesday
through Thursday, because Organogenesis couldn’t ship its
product over the weekend. So they were really searching for a
different kind of phase-change material, which would essentially
grow their sales,” Truesdale explains. “They were
looking for a 72-hour shipping window, and they couldn’t
do that with standard phase-change materials. Now they actually
get up into the low-80-hour window using the air-insulated box
and this new PCM,” he adds.
Laminar Medica (Tring, Hertfordshire, UK) offers
inorganic hydrated salt–based PCMs. The company is currently
in the process of launching a completely new range of PCM solutions,
based on these salts, called Medisorb and Mediphase.
The virtues of these new PCMs, says Laminar’s Katrina Bray,
include storage and release of latent heat energy at nearly constant
temperatures, making them similar to water. “Inorganic PCMs
also store much denser values of latent heat energy in comparison
with the organic variety, and therefore packaging performance
with 0ºC systems is achievable,” says Bray.
Laminar claims that hydrated-salt PCMs can control temperatures
ranging from –40º to 120°C. Laminar expects the
new PCMs to impact package design for temperate product shipping.
Given the changes in ambient temperatures when transporting platelets,
for example, at 20°–24°C, a package may have to
cope with significant periods of positive and negative temperature
stress. “If a single-phase material were used,” Bray
comments, “the package design would need to incorporate
a combination of solid- and liquid-phase PCMs. The former prevents
the payload from getting too warm and the latter from getting
too cold. Sure, the necessary stability is achieved, but assembling
the shipper becomes more complex and payload space is much reduced.
With one of Laminar’s new-generation PCMs, however, multiple
individual phase changes are offered over a range of temperatures
using one preparation.”
One drawback of hydrated-salt solutions is their potential corrosiveness.
“I’ve personally seen corrosive damage in testing
a room-temperature PCM in our lab,” says Tom Pringle, acting
technical director for ThermoSafe Brands. “The material
leaked from the bags, and where it leaked, it actually removed
the coating on the metal floor of our test chamber.”
 |
| Figure
1. Comparison of the phase-change time of low-temperature
gels (–20°C and –50°C) with dry ice and
water-based 0°C PCMs (phase-change materials). The test
method involved using 1-lb PCMs frozen 10°C lower than
their rated temperature and 1 lb of dry ice, all held at 30°C
ambient temperature with no insulation. (10 lb of dry ice
has a 24-hour sublimation rate.) The chart values should be
viewed respective to the phase temperature of each of the
PCMs (i.e., 0°C PCMs would not be used for a -20°C
application). Insulations will extend phase time at variable
rates based on their K value. Source: Thermal Packaging
Solutions (Ocean, NJ) (click to enlarge). |
Cold Chain’s Gordon reports a similar experience. “As
a company, we have avoided hydrated salts, because they are such
a mess. One customer gave us their hydrated salt and wanted us
to test the package. The hydrated-salt solution leaked and dripped
on the aluminum floor in our thermal chamber and corroded the
surface. I just don’t want to introduce anything corrosive
in my plant,” Gordon stresses.
Figure 1. Comparison of the phase-change time of low-temperature
gels (–20°C and –50°C) with dry ice and water-based
0°C PCMs (phase-change materials). The test method involved
using 1-lb PCMs frozen 10°C lower than their rated temperature
and 1 lb of dry ice, all held at 30°C ambient temperature
with no insulation. (10 lb of dry ice has a 24-hour sublimation
rate.) The chart values should be viewed respective to the phase
temperature of each of the PCMs (i.e., 0°C PCMs would not
be used for a -20°C application). Insulations will extend
phase time at variable rates based on their K value. Source: Thermal
Packaging Solutions (Ocean, NJ) (click to enlarge).
Hydrated-salt-based PCMs are often available only in rigid bottles,
for good reason. “In solid form, these are salt crystals,”
Gordon points out. “They have very sharp edges that will
rip right through a plastic pouch.”
With proper packaging, however, these PCMs may be manageable.
“We have shipped a large number of units—probably
50,000 plus—to various customers without any leakage problem,”
says TCP’s Barakat.
Laminar produces hydrated-salt PCMs in both rigid bottle packs
and flexible, tough laminate materials. “Provided the proper
control procedures are observed, disposal and spillage issues
are, for all practical purposes nonexistent,” says Laminar’s
Bray.
Another problem, though, according to Gordon, is that “hydrated
salts tend to be unstable. If you run them through a phase change,
they do not always perform the same way the second or third time
around. This makes for some difficult reproducibility when considering
qualification testing for pharmaceuticals. One reason is their
tendency to precipitate, meaning that the solids of the salt reform
and come out of solution.” Precipitation changes the molarity
of the solution and thus alters the temperature at which phase
change occurs.
Pringle points out another shortcoming of novel PCMs. “The
staging of these materials above or below their phase point (solid
or liquid phase) is inconvenient compared with using water-based
gels that are staged in conventional refrigerators or freezers
at refrigerated or frozen temperatures,” he explains.
This applies to both paraffins and hydrated salts. Explains Pringle:
“Take, for example, a 4°C PCM. For summer shipments
you have to stage it below its phase point to take advantage of
its energy-absorbing characteristics. It goes from a solid to
a liquid as it absorbs heat at 4°C. Conversely, in the winter
you have to stage the 4ºC PCM above 4°C to gain the most
benefit, as it gives off heat converting from a liquid to a solid
at 4°C. There is no convenient staging equipment at constant
8°C or 2°C.”
Inefficiency is another negative aspect of PCMs. “Cost,
hazard class, and convenience aside, the latent heat energy released
as these materials solidify, or absorbed as they liquefy, is far
less than that of plain water. Water solidifies in a unique way
compared with most other materials,” Pringle points out.
“As these other materials change from a liquid to a solid,
their molecules stack up like cord wood. Water molecules actually
form a crystalline structure that is the primary reason for their
latent-heat advantage. Therefore, until new materials are identified
and developed to overcome the disadvantages noted above, water-based
gels used at various temperatures are still the temperature stabilizer
of choice for shipping most temperature-sensitive pharmaceutical
products.”
All components of a cold chain solution should be evaluated on
an individual basis, adds Rod Derifield, CEO of EnviroCooler
(Huntington Beach, CA). “EnviroCooler believes that the
critical aspects of each component that affect performance should
be characterized to understand why a particular solution performs
in a certain way,” he says. “Specifically, this information
is used for quality control and incoming inspection of each component,
as well as component qualification (CQ) prior to qualifying or
validating the entire process as part of operational and performance
qualification. For gel packs, we believe such characteristics
include the freezing point and melting point, rate of change,
and total energy stored. In our view, understanding these product-impacting
parameters is the foundation of a science-based approach to solving
cold-chain problems in a consistent, repeatable, and controllable
manner.”
Rivaling Dry Ice
At the other end of the temperature spectrum are PCMs that change
phase at subzero temperatures. “We just finished a validation
for a major healthcare products distributor in which we had to
hold –20ºC as the high temperature and –40ºC
as the low temperature,” Cook mentions. “So we worked
with a company to develop a PCM that would hold it at –30ºC,
and it was very successful.” The distributor has been using
the low-temperature PCM since the middle of 2003 for many pharmaceutical
shipments globally.
Since 1998, TCP Reliable has sold DICE products that hold –50ºC.
“We have since developed custom formulations that maintain
the internal temperature within the deep-freeze temperature range,”
says Barakat.
Last year, SCA ThermoSafe Brands introduced a –50°C
U-tek gel pack, the Model 760, which serves as an alternative
to dry ice. Like its brethren, this PCM is not as efficient as
its archetype. “No gel pack can match dry ice pound for
pound,” explains Kevin Grogan, the company’s director
of marketing and business development.
“The thing about dry ice is that it makes a double-phase
change. It goes from a solid right to a gas, and skips liquid.
As it sublimates, it releases a tremendous amount of energy. But
what we’ve managed to do is offer something that gets down
to within the desired temperature range, –50°C. It’s
not –80°C, but it’s as close as we’ve been
able to come while still offering a strong latent heat characteristic.
In so doing, it can often eliminate dry ice altogether.”
What makes this option attractive? Some airlines now limit the
amount of dry ice aboard each plane. “Because the cargo
hold in most planes is sharing the same air with the cabin, if
you had too much dry ice in the cargo hold, you can seriously
degrade the air quality in the cabin,” Grogan explains.
Such a restriction on the use of dry ice in transport could cause
a disastrous delay for a temperature-sensitive product. “The
way you get around that if you’re in our industry is you
make very efficient boxes that use a small amount of dry ice.
We do that. Or you make dry-ice substitutes, like our –50°
U-tek,” Grogan adds.
Copyright ©2005 Pharmaceutical &
Medical Packaging News