Inspection Gets Down to Nuts and Bolts

Foil packaging, throughput, and regulations test the mettle of packaging lines.
By John Conroy

X-ray inspection systems from Eriez can call out errant bits of metal, even in foil blisters.

Metal shavings, screen bits, nuts, bolts. When a doctor tells a patient that he or she should get more iron, it’s a safe bet that these items are not what the physician means.

However, the possibility that these contaminants could find their way into over-the-counter (OTC) and prescription drugs is one reason that manufacturers of x-ray inspection systems say they’re drawing increased interest from drug manufacturers. In addition, several makers of machine vision systems and bar code readers maintain that customer concerns about foil packaging, regulations, labeling, and high-volume throughput make effective inspection regimes as important as ever for both pharmaceutical and medical device manufacturers.

Foil-packaged pharmaceuticals are particularly susceptible to contamination and miscounts, says Oscar Jeter, national sales manager for Mettler-Toledo Safeline (Tampa, FL). Many packages combine foil and plastic laminate that show the contents. But sometimes, he says, “it’s a foil-on-foil package so that you can’t even see [what’s inside] them.”

In any case, both types of packages are placed in a master carton usually containing two or three blister pack sheets, Jeter says. “In fact, almost all of the over-the-counter medicines today are in these blister packages. X-ray [inspection] is one of the only things we know of that can look inside the closed carton and determine that the right number of tablets are in each blister [pack].”

Missing tablets, broken tablets, and packages with the incorrect number of capsules also tax inspection capabilities, he notes. Faulty counts present problems for packages requiring different dosages and even different formulations for morning and evening. These dosage requirements make it imperative that each blister pack contains the right number of capsules, gel tabs, or tablets, Jeter points out.

“When you think about all of the processing equipment, metals, mixers, blenders, sieves, strainers, and presses—almost everything that touched the product is metal,” Jeter says. “You also have to consider that some of these ingredients are coming from Third World countries where all the [proper] procedures are not necessarily in place. So you might be getting contamination in the shipment from the supplier.”

Testing has shown that low-energy x-rays have no effect on the efficacy of the drugs under inspection, says Ray Spurgeon, product manager, x-ray inspection systems, for Eriez (Erie, PA). The risk is even particularly lowered on rapidly moving lines where packages zoom past the 2–3-mm beams in milliseconds. High-speed lines can run “some 800 to 1000 packs per minute,” Spurgeon says.

Additionally, irradiating products requires a high-energy beam in the million-electron-volt range. Eriez systems operate in the KeV, or thousand-electron-volt range, “nowhere near close” to harming products, he notes.

Systech’s machine vision product, Sentri, can inspect syringe labels.

In June, Mettler-Toledo Safeline introduced the PowerChekPlus, which is designed to detect contaminants and provide quality assurance in pharmaceutical manufacturing. The company’s x-ray systems cost between $40,000 and $150,000. Eriez’s E-Z Tec XR inspection systems range from $40,000 for “a vanilla system” to more- sophisticated systems costing $60,000 to $100,000. A case inspection system, which “looks similar to an x-ray machine at the airport,” can cost up to $115,000. Both the Eriez and Mettler-Toledo systems feature a 15-in. touch screen, full-color displays, and software programs for real-time inspection.

The Eriez systems can detect foreign objects as small as 0.8 mm, Spurgeon says, adding that this is about the size of a fine pen ink dot. From raw materials arriving on the loading dock to shipment of finished product, the manufacturing process entails the use of machinery with “millions of parts moving all at once,” Spurgeon says. A nut or a bolt should be easy to spot, but if metal slivers or a bolt did make it through the inspection process, the fear is that “someone pops a pill” into his mouth and gets a headache of a different sort.

X-rays work better than a metal detector on foil-seal blister packs, Spurgeon asserts. “You can’t take that metallized foil and pass it through a metal detector and expect any sort of reasonable performance,” he says.

The typical blister production line has five main inspection points, says Jeff O’Neill, director of the Laetus equipment division for Hapa & Laetus (Rockaway, NJ). These include inspection of all tablets before sealing to ensure correct color, size, and shape as well as 100% inspection of the printed lid stock foil for the blister packs. The latter requirement covers 100% inspection of all printed matter and “unlimited inspection windows” for all printed bar codes such as GS1 Databar. It also covers the unlimited ability to inspect human-readable lot and expiration print.

For drug and device manufacturers, the two most challenging applications for vision systems are full web scan capability and grading of bar codes at production line speeds, O’Neill says. Issued in 2004 to reduce hospital medication errors, FDA’s new bar code regulation “has created the need for a full web scan system for blister packaging machines,” he says. The rule requires that medication taken in single units or dosages have a bar code that includes, at a minimum, the National Drug Code (NDC) number and in most cases the lot number and expiration date.

The Laetus Argus Inspect wt System from Hapa & Laetus can verify all symbologies.

The company director says the new generation of web technology from Laetus uses an Internet browser to communicate with all server-based inspection devices on a standard Ethernet network. The system’s color touch screen complies with 21 CFR Part 11, and the network gives the system the flexibility to connect to an almost unlimited number of inspection devices. A typical vision system application, depending on the web size, “can range from $75,000 to $115,000.”

Mike Soborski, central engineering director for Systech International (Cranbury, NJ), which makes machine vision and line and plant management products, says his clients’ major concerns “are driven by FDA regulations and their own internal quality assurance initiatives.” These include critical- copy verification of product packaging, label positioning, label skew, logo print quality, FDA-mandated inspections, and “anything the manufacturer’s quality assurance or marketing staff think are important for brand integrity.”

The Systech Advisor line management and Sentri vision inspection products are designed to work in tandem in order to help device and drug manufacturers put inspection data “into a format to better manage the packaging performance of the entire operation,” Soborski says. With the drug pedigree requirements of 21 CFR Part 203 in force, manufacturers can benefit from the capabilities of the twinned systems, he insists. “This new pedigree requirement gives us another way in which to use the data that our product contains,” Soborski notes. “It’s not that we’re inspecting anything new. It’s what we’re doing with the data that are already there.”

A single-camera Sentri system costs in the $20,000–$30,000 range. A full Sentri and Advisor automation combination covering a very large line of packaging equipment costs “hundreds of thousands of dollars,” he says.

Reducing the amount of expensive factory-floor real estate is causing packaging lines “to get smaller and smaller,” says Blake DeFrance, hardware product manager, In-Sight products, Cognex (Natick, MA). That trend has helped the development and of In-Sight’s “smart” cameras, which are picking up more interest from drug and device producers.

“We’re determining that there is a real need for smaller smart cameras. That’s where a lot of our growth is going to be in the next few years,” DeFrance says. The cameras operate at 60 frames per second, “but what really matters is the processing time. We have a couple of different flavors of processors in there. It all depends whether you’re trying to eat the hamburger all at once or take it a bite at a time.”

Inspecting Datamatrix codes, Systech’s Sentri minimizes false rejects.

The new In-Sight 5600-series code readers have drawn a lot of interest in the last few months from medical device manufacturers, DeFrance notes. “One customer was performing roughly 27 inspections on a medical device, like a plastic film canister with a desiccant impregnated in it. That’s big business. That’s trying to eat the hamburger, plus the pickles, lettuce, onions, and everything you had on there.” He says he’s seeing what he calls “spec creep” from some customers with 21 CFR Part 11 compliance concerns. In addition, business is increasing with the growing sales of consumer products such as stop-smoking cures and weight-loss products. Another notable trend is an increase in “market segmentation with drugs of different sizes and flavors,” DeFrance says.

Cermex used a Cognex Checker sensor to count flasks in cartons and an In-Sight 5100 vision sensor to verify document presence.

With major drug and device manufacturers as customers, Integro Technologies (Salisbury, NC), a machine vision integrator launched in 2001, uses a Cognex line-scan system to check the quality of surgical tubing for one installation. “Machine vision can check much more than a laser can check. Another line-scan vision use identifies defective labels,” asserts Shawn Campion, principal application engineer.

Laser-based inspection is the traditional norm for tube inspection, Campion says. Defects in tubes include closed or pinched interior diameters from foreign debris and blockages. One of the machine vision systems operates at more than 600 ft per minute, he says. The systems inspect tube OD and ID to check for blockages and proper diameter. They also confirm the opaqueness of the frosting level. Frosting adds strength, he says, but it’s undesirable for the end-user because it makes it difficult to see what’s going through the tube.

“There are many difficult applications in these industries, particularly in the vacuum or pneumatic conveying systems where the product can be moving extremely fast and product rejection has to take place both quickly and without affecting the integrity of the inspection system,” says Richard Lines, vice president, S+S Inspection (Tucker, GA). “S+S deals with this by the special designs of reject containers with fast-acting valves to quickly operate reject flaps and diverters, as well as by using secondary chambers to isolate the rejected product and maintain system integrity.”

Systems are integrated into the production line or process to ensure 100% coverage, Lines says. Because the reject systems rapidly remove contaminated products, fast throughput is maintained without interrupting process flow. The company’s GF series systems are used for metal detection of granulated products in vacuum or pneumatic lines, common methods for moving bulk materials in pharmaceutical production and for moving granular plastics used in blow molding or injection molding of medical devices, Lines says. Based in Germany, the company recently launched its first product in the United States, a second-generation x-ray inspection system called Raycon.

See Sidebar: Verification System Debuts for Cost-Conscious Manufacturers

In many cases, the risk factor dictates how rigorous the inspection regimen is for different products—an OTC painkiller as opposed to a controlled substance, for example, notes Bob Taplett, application engineering manager, Microscan Systems (Renton, WA). He says that a packaging line running 1000 or 5000 pieces could sample every piece, and line production wouldn’t necessarily need to stop if the system missed one. However, if the readers miss three in a row, workers may stop the line to check the problem—a missing bar code, perhaps, or an incorrectly oriented bottle. “When you’re running really high volumes, sometimes you get into a trending level,” Taplett says. “You don’t have to inspect everything, but you want to be notified if there’s a problem going way beyond the norm.”

The fastest inspection throughput, usually in document handling, is 100 to 120 in. per second, “which is really moving fast,” says Taplett. Pharmaceutical products run “typically somewhere between 25 to 60 in. per second.” Another trend he’s spotted is the use of bar code imagers to check product color, dimensions, and other value-added applications. “Engineers may determine it’s more cost-effective to use the bar code imager, or it may be more cost-effective to use two different subcomponents,” he concludes.


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