Medical Device Link.

Originally Published PMPN July 2004

Desiccants

Ben Van Houten

More companies than ever are using desiccants to protect their pharmaceutical products. Whether it’s due to the proliferation of new moisture-sensitive drug technologies or the need to increase shelf life, this trend is currently unmatched in the world of desiccants. 

While all types of desiccants are being used, according to some sources interviewed for this article, the number of companies switching over from canisters to packets is increasing. At the same time, canister providers are seeing new applications emerge.

Ensuring Protection

Most desiccant manufacturers agree that the reasons for using desiccants are obvious. “Desiccants help ensure the integrity of the products they are packaged with. Without desiccant, a product is at risk to mold, mildew, rust, and corrosion,” says Brad Wolk, general manager, Dry Pak Industries (Los Angeles). His company provides 
silica gel, clay, and activated carbon desiccants as well as ethylene and oxygen absorbers and shipping container desiccants.

“Companies will always have problems with moisture in their packaging,” adds Billy Abrams, vice president of business development for CSP Technologies Inc. (Auburn, AL). “Desiccants are the best and easiest solution.”

However, manufacturing costs can be a deterrent, specifically with canisters. “A customer is adding value to their product, but at the same time adding cost as well,” says Wolk. “The cost-to-benefit analysis exercise that each customer performs compares the value of extending the shelf life of their product versus the added costs of using desiccants. Ultimately, the decision to use desiccants and what type of desiccant to use will depend upon each customer’s budget for product stability.”

As a result, cost-consciousness is at the root of new desiccant development. “Cost can play a major issue,” says Bob Crossno, director of sales and marketing–Americas, Süd-Chemie Performance Packaging (Albuquerque). The company manufactures packaged desiccants, absorbents, polymer packaging solutions, and humidity indicator products.

“Clearly, customers are going away from canisters and toward packets,” says Adrian Possumato, pharmaceutical marketing manager for Multisorb Technologies Inc. (Buffalo, NY).

Cost-Saving Solution

To that end, companies like Multisorb and Pechiney Plastic Packaging (Neenah, WI) recently developed desiccant programs aimed at reducing customer costs. Multisorb collaborated with a major pharmaceutical manufacturer on a switch from desiccant canisters to packets that reportedly resulted in line-speed improvements and projected annual savings in the hundreds of thousands in material costs. The pharmaceutical company collaborating with Multisorb had been using three sizes of desiccant canisters and had been experiencing challenges with automated canister insertion into bottles. “It was all about lower cost-per-unit and packet size flexibility,” says Possumato. 

Multisorb also had recent success with its Sorbent Savings Program for desiccant protection. The program combines Multisorb’s StripPax sorbent packets and Active-Pak Automation insertion equipment for a solution that the company says provides up to 50% cost savings over traditional desiccant canisters. “The program provides superior reliability for rollstock desiccant and oxygen-scavenging packet insertion,” says Possumato. 

The Multisorb StripPax sorbents provide consistent packet sizes and seals for accurate separation and insertion, according to Possumato. They also occupy less space inside pharmaceutical packaging. In addition, he reports, the program’s automatic dispenser systems ensure fast and accurate packet separation at speeds in excess of 300 packets per minute. Dispenser equipment is portable for use on multiple packaging lines and can be configured for varying packet types, sizes, and multiple drop applications. “We also offer regulatory checks that verify desiccant placement in every container,” he says. Current users of the program include Merck (Whitehouse Station, NJ) and GlaxoSmithKline (Research Triangle Park, NC). 

Desiccant Films

Pechiney Plastic Packaging’s cost-savings solution is a desiccant film. The company, which manufactures moisture scavenging packaging for diagnostic test strips, pharmaceuticals, and other moisture-sensitive products, recently designed a program for Lifescan (Milpitas, CA), a company that needed a new desiccant approach for its diagnostic test strip packaging. 

“We came up with a foil lamination with a sealant film,” says Rick Merical, Pechiney’s director of product development. “It incorporates a desiccating agent into the heat seal polymer that allows for the elimination of desiccant sachets added to products that are moisture sensitive.”

Lifescan had been packaging diagnostic test strips in a high-density polyethylene bottle. The bottle, which contains five humidity-sensitive test strips, incorporated a molecular sieve desiccant into the bottle’s twist cap. “That packaging was very expensive for the company,” says Merical. Lifescan’s original concept was for a single-use package in a high-barrier tear-open flexible pouch. Merical explains that a long shelf life could not be guaranteed with conventional foil laminations. “We developed an enhanced moisture-barrier option that is still in a cost-effective flexible pouch,” he says. “This flexible package utilizes a desiccating agent blended into the internal polymer sealant layer. It reacts with humidity and moisture and eliminates the need for insertion of desiccating sachets.” 

He adds that the sealant film eliminates the moisture ingress point found in most heat sealable foil high-barrier laminations around the sealed top, bottom, and side edges of the package. “Most importantly, the cost is greatly reduced,” he says. “The customer also saw a 70% drop in total package weight.”

Similarly, CSP Technologies offers desiccant films that can be fused to the inside of foil pouches. “We typically put the desiccant into the package by embedding desiccant par- ticulates in a polymer matrix,” says Billy Abrams. 

New Drug Development

The development of new drug technologies is also responsible for an increase in new desiccant applications. Moisture-sensitive drugs, for example, are on the rise. “There are many new AIDS and cancer drugs that appear to be more sensitive to moisture and oxygen,” says Crossno of Süd-Chemie.

“There is no doubt that the new drugs are more sensitive to oxygen and are much more moisture sensitive,” adds Multisorb’s Possumato. “A lot of these new formulations require an obscene amount of desiccant. As that is happening, companies will have an even bigger need for reduced-cost desiccants.” He specifically points to a new cholesterol drug currently in production. “That product is supposed to be coming out with 2, 5, and 7 grams of silica gel,” he says. “That will not be launched using canisters, because of the amount of desiccant required. Not to mention the cost. I believe that is a trend that will continue.”

Dissolvable films and tablets are two technologies that require different desiccant solutions. “We’re seeing much more interest in packaging for effervescence and for pharmaceutical powders,” says Abrams of CSP. 

“I am definitely seeing more effervescence,” adds Possumato. “With more powder-form drugs coming on the market, customers will need special types of caps and inserts with new desiccants. It’s probably one of the biggest trends going on right now.” He also mentions new sorbent technologies, which invariably require more desiccants. “There has been an increased use of sorbent materials for blister packaging, for example,” he notes. “So there will be a continued greater interest in desiccants for blister packaging in the form of capsules or even flat canisters.”

Süd-Chemie offers technology that allows the company to injection mold desiccants directly into components, another potential trend. “For example, the desiccant can be part of the plastic of the bottle, saving both space and insertion time,” says Crossno. 

The company also is investing in its desiccant polymer tubes. The tubes have desiccant protection injection molded into the polymer itself, adding volume and functionality to an advanced form of diagnostics protection, according to Crossno. “It combines the rigid protection and ergonomic design of traditional polymers with the benefits of moisture protection,” he says. 

As pharmaceuticals continue to be packaged and distributed globally, more companies are striving for ways to desiccate those products with a focus on increased shelf life. “More and more companies are using des-iccants as global trade increases,” says Brad Wolk from Dry Pak. “As goods travel via air and ocean between countries, the need for desiccants will also increase in proportion.”

As will the need for tamper-evident technologies. “Tamper evidence is on the rise, obviously,” says Crossno of Süd-Chemie. “I expect much more of a focus there as time goes on.”

Canisters Continue

Süd-Chemie offers a wide range of desiccant solutions, including polymer technology, canisters, and packets.

Some companies are finding new ways of using desiccant canister technologies. The use of oxygen-absorbing canisters, for example, is a trend on the rise. “That technology protects a product from oxidation, and it works really well at low relative humidities,” says Crossno. “It’s a technology that is set to break out, in my opinion.”

To that end, Süd-Chemie recently launched a partnership with Mitsubishi Gas Chemical Company, Inc., that resulted in PharmaKeep, an 
oxygen-absorbing canister that protects against oxygen degradation. Designed for use with high gas barrier, non-oxygen-permeable packaging, the canisters are currently available in 1-g configurations. “It’s an important development for us,” says Crossno. “Pharmaceutical companies can address oxygen degradation with packaging rather than at the drug formulation stage. That saves development and launch time and tends to increase the bottom line.” 

Desiccare Inc. (Pomona, CA) is another company continuing to work with canisters. The company just introduced a new desiccant canister, the Dri-Mac. Used for high-speed automatic insertion, the product contains Tyvek ends that are 100% nondusting, according to Virginia Velazquez, a Desiccare spokesperson. The canister is designed to eliminate moisture and odor from packages. “It ensures that the pharmaceutical tablets and capsules in the container are easily differentiated from the canister. This prevents accidental ingestion,” says Velazquez. 

Dri-Mac’s features include sonically welded ends for product integrity and the ability to withstand irradiation or sterilization. The canisters are available with silica gel, activated carbon, molecular sieve, or various mixture fills.

Whatever transpires in the future for desiccants, it is agreed that technology will lead the way. “Everything that’s going on in drug manufacturing is related to new technology, whether it’s dissolvable films or tablets,” remarks CSP’s Abrams. “Those developments are all going to require desiccants that involve more than just the traditional canisters and packets.”

He predicts that CSP’s desiccant polymers will translate into other packaging forms, such as active dispensers that dispense single doses. “That has to do with convenience,” he says. “There will be more interest in dispensing one edible film strip at a time, for example. Resealing the package and incorporating desiccant will play a key part.” 

Copyright ©2004 Pharmaceutical & Medical Packaging News