Pharmaceutical and Medical Packaging News
Magazine
PMPN Article Index
Originally Published PMPN July 2005
Desiccants
The Changing Shape
of Desiccants
New products help companies contain
costs and extend moisture protection.
by David Vaczek
Senior Editor
 |
| PharmaKeep from Süd-Chemie is an oxygen absorber that works in dry conditions. |
Companies are finding more alternatives in desiccant solutions. New canister and packet products and improved insertion-machine technology have made desiccant use more efficient and address cost concerns.
Vendors have stepped forward with programs for weighing the benefits of packets versus canisters and for calibrating the amount of desiccant needed to meet products’ shelf-life goals.
Products that incorporate desiccants into packaging have allowed companies to eliminate the cost of canister and packet insertion altogether. Some of these solutions provide thorough moisture protection. They include rigid and flexible desiccant-infused films and other desiccant polymers molded as components of devices, such as diagnostic test kits, asthma inhalers, and test strip containers.
Oxygen-Sensitive DRUGS
Many new drugs coming to market are sensitive to oxygen as well as moisture. Nutraceuticals and biotechnology drugs are among products driving industry adoption of oxygen absorbers. Companies are considering packaging solutions for addressing oxygen degradation earlier in the drug development process. For a drug susceptible to oxidation, a drug company could decide to use an oxygen absorber and speed up time-to-market.
“If you address the oxidation issue with the drug’s packaging, you don’t have to worry about it in the formulation. We have been in on the early stages of the drug development process, where these options are being considered,” says Mark Florez, marketing manager, Süd-Chemie Performance Packaging (Colton, CA).
The company’s PharmaKeep oxygen absorber is the first oxygen absorber in a canister, so it is suitable for high-speed line insertion. Since it doesn’t require moisture to activate, it can be used in the low-relative humidity environments that characterize most pharmaceutical packaging. It can even be paired with a desiccant, which is not an option for iron-based oxygen absorbers that work only in higher-moisture areas.
“PharmaKeep has taken off much faster than we thought it would. Many pharmaceutical companies are in the process of validating it,” says Bob Crossno, director of sales and marketing for Süd-Chemie.
“This is a new area for the pharmaceutical industry. We have been told that many of the new biotech drugs are oxygen sensitive. They have not had a product they could use because what has been out there requires moisture to activate,” he adds.
Multisorb’s StabilOx oxygen-absorbing packets are geared for drug products. They work in low equilibrium relative humidity (ERH) environments and activate more slowly to protect products longer. Several drug companies have filed for drug approval using StabilOx. “FDA-approved products using StabilOx will begin appearing in the market shortly,” says Adrian Possumato, business development leader, pharmaceutical market, Multisorb Technologies (Buffalo, NY).
“Pharmaceutical companies are showing much more interest in oxygen absorbers for solid dose pharmaceuticals in high-density polyethylene (HDPE) bottles. They can also be very useful in preventing oxidation of key marker compounds in botanical extracts and other dietary supplements,” Possumato says.
Packets Versus Canisters
 |
| CSP Technologies is working to incorporate a desiccant material into a blister package, as seen in this concept drawing. |
Most companies have used packet or canister solutions for their moisture protection needs. Canister insertion remains the choice for companies that need to maintain high line speeds with rates of up to 500 insertions per minute. For companies with slower line-speed requirements, new systems are making packet insertion more cost-effective. The APA-1000 by Multisorb Technologies, for example, is designed for vitamin supplement manufacturers that do not require high-speed machinery. It inserts desiccant and oxygen absorber sachets at rates of up to 120 per minute. Multisorb provides packet insertion rates well beyond the typical rate of 150 per minute in its Sorbent Savings Program. Multisorb is marketing the program to companies currently using desiccant canisters. Using Multisorb insertion equipment with its StripPax packets, lines can achieve rates of up to 300 packets per minute, at 50% less cost than a canister solution.
For small-to-medium-sized companies, packets have become more cost-effective, not only with the advent of more-reliable dispensing machines, but also with improved strip packs with less variance in production standards. Süd-Chemie’s Continu-Strip Hole-Punch Packets, for example, feature a hole in each seal to ensure accurate cuts.
“The sensors on packet dispensers are much more reliable, and the machines have improved greatly,” says Brad Wolk, president, DryPak Industries (Studio City, CA).
Süd-Chemie is offering the Desiccant Efficiency System Integration (DESI) program to help companies choose the best desiccant solution. The DESI program reviews variables such as volumes, line speed requirements, and anticipated growth before recommending the correct product, configuration, and insertion equipment.
“Our goal, first and foremost, is to show manufacturers that protecting their products from moisture and oxygen doesn’t have to mean a loss of profits. Second, we want our customers to know that choosing the right desiccant is a complete holistic process,” says Crossno.
For companies using canisters and searching to improve their costs, Multisorb is offering a desiccant that comes in neither a canister nor a packet. Yet it can be used with existing canister-dispensing equipment. The Multiform Coated Solid Form desiccant (CSF) is made of silica gel, activated carbon, or a combination of the two. Multisorb uses tableting, or compressed density, technology to form the material into a high-density solid that delivers twice the absorbing capacity in the same space.
Proprietary binder and coating ingredients prevent dusting, add strength, and create a smooth coating that will not snag on machines.
CSF can be formed into the exact dimensions of a canister, so it can run on the same dispensing equipment without recalibration. Or, it can be formed into any shape and size, such as a 2-g disc snapped into an injection-molded package. Delivered in 1-g and 2-g canister configurations, the product costs from 10% to 20% less than canisters, says Possumato.
Companies can avoid using two 1-g canisters, also known as “double drops,” by using a single 2-g CSF instead of two 1-g canisters containing loose fill. “Multiform CSF gives us access to companies using canisters today who are looking to reduce cost. If they are using 2-g sizes and above, CSF becomes efficient,” says Possumato.
Silgel Packaging Limited (Telford, England) replaces plastic canister caps with Tyvek end caps in its new DRI-MAC 100% nondusting canister. The Tyvek allows “excellent gaseous transmission” without the dusting that the company claims can occur with canister plastic ends impregnated with holes. New assembly technology sonic-welds the Tyvek ends to the canister. Laser-printed health and safety information on the canister eliminates the need for labels or inks. Silgel said that the cost of the product is competitive with that of plastic canisters.
Desiccant Sheets and Films
Süd-Chemie will soon extend its polymer manufacturing capabilities to its site in Belen, NM, due to the products’ growing demand. Historically, the company made its injection-molded components at its plant in France.
“We have the technology to injection mold desiccants into plastics. We are now bringing to the United States the ability to design, manufacture, deliver, and support specialized packaging for individual products,” says Crossno.
With desiccant-infused polymers, suppliers can mold products into practically any shape and size, providing distinctive packaging and new functional elements. Süd-Chemie has launched a desiccant washer that rests in the neck of a pharmaceutical container. The easily removed piece is suitable for powdered drugs that need moisture protection until they are reconstituted with water.
CSP Technologies (Auburn, AL) has partnered with Tekni-Plex (Somerville, NJ) to develop new methods for pairing desiccant material with high-barrier blister packaging. In one application, a strip of desiccant plastic sheet is affixed to the foil lid stock within a strip cavity on the thermoformed blister card. Thermoformed channels run from the strip to each blister cavity.
The companies are devising a second solution where a small island of desiccant film is laminated to the base foil under each well. That approach would ensure that desiccant fixed to unused wells would stay sealed and unexposed to new moisture, said Billy Abrams, vice president, business development, CSP Technologies.
Desiccants are inefficient when used with low-barrier blister material, such as PVC, as the film’s higher moisture-vapor transmission rate saturates the desiccant too rapidly.
Paired with high-barrier material such as a polychlorotrifluoroethylene (PCTFE), the desiccant scavenges residual moisture and works in tandem with the film to increase the duration of moisture protection, Abrams says.
“High-barrier transparent blisters will allow only very small amounts of moisture to enter the pack when exposed to accelerated ICH stability climatic chambers. By integrating a desiccant into the package, that small amount of moisture can be scavenged, and the headspace relative humidity can be kept at around 5% for a
pre-specified amount of time,” says Michiel van den Berg, director of global pharmaceutical package development, Tekni-Plex.
A manufacturer of an integrated blood glucose meter and test strip device has adopted CSP Technologies’s proprietary solution for combining desiccant into polymers for injection molding, says Abrams.
A component of the device is made of the desiccant-infused polymer. The plastic compound is composed of the desiccant, a polymer, and a channeling agent. The channeling agent creates a channel structure made, in this case, of a hydrophilic polymer through which moisture vapor can diffuse. Desiccants in particulate form capture the vapor.
Alcan Packaging (Bethlehem, PA) produces a flexible desiccant-infused film for use in pouches and rollstock packaging. A chemical desiccant is incorporated into the sealant layer of the five-layer heat-sealable film. It is suitable for pharmaceutical and diagnostic devices requiring a high level of dryness, says Rick Merical, director of research and development for medical flexibles, Alcan Packaging.
Companies making diagnostic test kits and numerous other moisture-sensitive devices are verifying the efficacy of the high-barrier lamination film, reports Merical. Companies using the film can avoid the product, insertion, and inspection costs associated with sachets and canisters. Also, it is an efficient alternative to pressure-sensitive desiccant film patches that require a secondary production line step for application. The film creates an “active package” providing 360-degree product coverage. “In most cases, the entire pouch is composed of the heat-sealable film. A sachet might end up at the bottom of the package, causing moisture to pass through the package to get to the desiccant,” Merical says.
The chemical desiccant eliminates the potential for moisture release back that can occur when physical desiccants such as silica gels are subjected to high pressure or temperature. “We drive the headspace relative humidity to less than 10% within 24 hours, and hold it at less than 10% for as long as the desiccant is available,” Merical says.
Insertion Flexibility
Contract packagers looking for more versatility in insertion machinery are one audience for Palace Packaging Machines Inc.’s new Loose Pouch and Desiccant Canister Feeder. The Model DF-OT offers two breakthrough functions. Packets can be loaded in single form rather than from a rolled strip. And, with a simple software command and parts changeover, the machine can switch from packet to canister delivery. The machine employs a two-lane, v-grooved oscillating tray to singulate packets that are control-fed from loose bulk quantities. Singulation is then maintained, ensuring uniform delivery.
By delivering the packets in loose form, the machine allows companies to eliminate the downtime that arises from miscuts due to variances in strip rolls and misreads by the sensor that occur with strip-fed packets.
The Model DF-OT performs multiple insertions into single containers, or single insertions into multiple receivers such as multiline assembly systems. “We can discharge 12 packets in 12 lines at one shot,” says Stephen Tarashi, Palace Packaging’s vice president at the Downington, PA, based company.
The system can act in stand-alone mode or be fitted onto existing packaging lines. “Contract packagers are looking for machines that can do everything in one line,” Tarashi says.
Wrapping Up
Forces other than the susceptibility of many new products to the effects of moisture and oxygen are driving use of atmospheric modification products. Increasingly, companies need to extend the shelf lives of products being shipped to global markets, says DryPak’s Wolk.
And desiccants provide a competitive edge in other ways. “Many buyers at big companies won’t purchase products without desiccant protection. There has been wide acceptance by consumers who see it as a value-added feature,” Wolk says.
Süd-Chemie is addressing the opportunity to provide companies with more functional and marketable packaging along with desiccant protection. This can be accomplished with injected-molded device parts that are easier to hold, open, and use in dispensing. In keeping with that goal, the company is launching a line of scented packaging solutions for pharmaceuticals and nutraceuticals. Scents, including orange, lemon or customized odors, are incorporated into desiccant or nondesiccant canisters, packets, stoppers, and injection-molded polymer parts.
Copyright ©2005 Pharmaceutical & Medical Packaging News
