So vital to smooth, wrinkle-free skin, moisture can be a packager's nemesis, especially when it comes to effectively containing sophisticated medical diagnostic devices. Even the slightest wrinkle or imperfection in package seals can provide a path for moisture to invade, possibly disabling the device. But a validatable four-side-seal pouching machine, used to package assorted moisture-sensitive medical diagnostic test kit instruments in a barrier foil / film wrap, proved the right shot in the arm for San Diego's Quidel Corp.

The company's Model 4SS pouch sealers from Doyen Medipharm have cut changeover time from one pouch size to another by over five hours per change, drastically reducing packaging material waste, downtime and eliminating the risk of moisture transmission to the pouched test device.

Designed for continuous-motion operation, the 4SS machine pouches a variety of injection-molded cassettes used in immunoassay tests for point-of-care detection of various conditions and illnesses. The sealed test cassette pouches must provide a zero moisture vapor transmission rate; moisture makes the viewable test strips within the cassette housing unusable.

Quidel's Jay Strandberg, Material Specialist and Warehouse Group Leader, explains that the Food and Drug Administration currently requires these non invasive products to have 100-percent validatable package seals or validated packaging equipment. "Because the four-side sealer can validate seal integrity, we're ensured the pouch seals out moisture."

Sophisticated temperature control systems on all heating elements ensure that actual and programmed temperatures are the same within tight tolerances. The sealing surface is ensured to remain at the set temperature - essential Quidel notes, considering that if temperatures are not maintained, seal integrity cannot be assured.

"Not only do Quidel's 4SS machines keep tabs on and measure temperature of the sealing surfaces when running, pressure can also be validated and accurately measured," points out Doyen's Sales VP Mark Mosher.

"To provide extremely consistent sealing pressure at the seal point, we have a fixed-interference gap between the two heated pairs of side seal wheels. The gap doesn't rely on air pressure or spring tension to provide pressure at the seal point. It's a fixed point; the pouch material sort of squeezes through, ensuring consistent pressure down to the final dimension," Mosher went on to comment.

Built to FDA, GMP, ISO, CE and other worldwide standards, the servo-driven 4SS four-side sealer can produce packages at speeds up to 250 packs per minute.

Pre-stored product data can be recalled and set up in less than five minutes. A completely new package setup can be created and stored in less than 20 minutes.

"These are vast improvements from the past", Strandberg says. "Our former equipment took between two and six hours to change over from one package size to the next." "Considering the many package stock stockpilings, this cost the firm plenty in downtime." "Today, we save days' worth of downtime," Strandberg says.

In some cases, Quidel's machines could be changed over as often as three or four times a day depending on schedules and on what was being changed. "We've regained much of that downtime capacity," Strandberg continues. "Now it takes seconds to call up something in memory."

There were other equipment choices available, Strandberg tells PD. "We looked at form / fill / seal equipment and tested some other flow wrap machinery with our pouches. The test pouches leaked or didn't prevent adequate moisture vapor transmission. One reason we chose the 4SS machine was that it was the only one that could hold the seal integrity we were after." "Maintaining the 18- to 24- month shelf life of the kits, the pouches prevent almost all moisture penetration." "We haven't had a 'leaker' with this machine," Strandberg adds. "We're very impressed because of the high degree of validation the machine provides. It can validate all sealing parameters. The seal integrity is vastly improved on these packages."

Building new strategies, Quidel is poised to take advantage of trends in healthcare management, such as more rapid in vitro diagnostics products for decentralized point-of-care sectors. Additional packaging equipment will be needed soon, Strandberg says, prompted by increased sales and a mission to improve performance of existing operations. "We have much to consider first, but every time we need something, Doyen can customize it for our needs."

Published in: Packaging Digest, Cahners Business Information, August 1999