Medical Device Link.

Originally Published PMPN October 2001

SPOTLIGHT

Vision systems and complementary technologies are working together to verify text, color, and even chemical composition.

Erik Swain, Senior Editor

Images of a color label inspection system courtesy of Advanced Vision Technology Inc.

Vision systems, once considered an exotic item, are now common on pharmaceutical packaging and labeling lines. Go into a packaging facility at any drug or device company or any facility at a contract packager or labeling supplier, and chances are that you will see a vision system in use.

Most firms use vision systems to proofread labels and date and lot codes. But thanks to advances in technology, vision systems can be used much more widely at an affordable price. These systems can find errors, communicate the location of errors, and help other systems correct or reject errant products.

For instance, The Nosco Printing Group (Waukegan, IL), a printer of pharmaceutical and healthcare cartons, labels, blister cards, and other printed packaging, uses a single system to slit, rewind, inspect, and code labels. The Flytec 2000, which is distributed by Omega Systems, a division of Burton Group Inc. (Danbury, CT), searches for label flaws, stops and reverses the label web if it finds any, and positions the problem areas on an inspection table. There, the operator decides whether something needs to be corrected or whether the run can proceed.

Kregg Albrecht, Nosco's director of business development, reports great success with the system. "One of the great benefits is the ability to inspect 100% of the multiple lanes of labels in one single machine pass," he explains. "We can now accomplish an advanced level of inspection in considerably fewer machine passes."

Such capabilities mean that even in slow market conditions where most firms are unwilling to invest more in capital expenditures, some firms are realizing that versatile and reliable vision systems can help root out errors and improve company bottom lines.

Vision systems are also becoming more advanced. "There are more challenging [vision] applications such as [inspecting] color variances and top and bottom webs," says Steven Antonacci, vice president of engineering at I.C. Technologies Inc. (Tampa, FL). "There are better lighting technologies and higher resolution cameras. I find that more companies are replacing antiquated systems with new, updated systems and new technologies for existing applications. They are more concerned with the reliability of the equipment than with the cost."

In many cases, advances in software and programming have accounted for these breakthroughs. "Before, there were about 40 suppliers, and now that has been trimmed to about a handful. People had problems when the technology was not dynamic and [when it] operated in a small window," says Paul E. Schaa, president of AC Compacting LLC (North Brunswick, NJ), which is the U.S. distributor for Covan Vision Systems and Proditec. "Now, vision system companies are writing their own software to make it very specifically oriented to packaging. We are starting to see software that is reliable and validatable enough to put into a real system. For example, there is now enough programming capability to do OCR/OCV [optical character recognition and optical character verification] effectively. It requires a tremendous amount of computational power in the hardware system. With inspecting blister packs, there is the issue of speed and capability. Now, the hardware and special applications software are able to handle the computational speed necessary to make these systems usable in the real world." (For more information on OCV, see Evaluating OCV Technology.)

COLOR INSPECTION

The most prominent change in the market in recent years is the increased use of vision systems for color-related inspection. "The pharmaceutical packaging business is using more color and more graphics. Quality demands for graphics continue to increase as companies compete for shelf space," says Lance Shumaker, president of Advanced Vision Technology Inc. (Atlanta). "Pharmaceutical customers continue to look for consistent quality, particularly in process color, which is being used more. So systems are becoming more color relevant. Copy has always been a key [focus], but now there is more emphasis on the color aspect and the integrity of the image."

The main barrier to extensive use of vision for color-related inspection has been cost, but Ali Zadeh, PhD, senior R&D engineer of DVT Corp. (Norcross, GA), says his firm has found a way to make it cost-effective. DVT's solution is a new system that costs about one-fourth that of traditional color systems, while offering unlimited color selection capabilities. Its chief application will likely be distinguishing the color and features of labels and package decorations to make sure the correct ones are being applied to the correct products. "With other color systems, you need to buy off-the-shelf hardware components—the frame grabber, the camera, the PC, the illumination system—and put them together before adding the software," he says. "All these things add up to one expensive system. We have one small unit with all of these [elements] integrated. The camera, the frame grabber, and the software are all right in there."

Another application with potential is the use of a vision system on the press before color labels are printed, Shumaker says. "Substrates are becoming more and more expensive, which [means that] reducing waste and continuing to monitor quality are important priorities. Much monitoring has been done on the rewind, as a quality control measure before the product goes out the door. Now, firms want to make sure they find a defect before it becomes waste, so defect detection is coming to the presses," he says. "Companies are not leery of spending money, because such systems not only provide them with the assurance of good quality, but also a dramatic reduction in waste, particularly on the press. The return on investment happens quickly—in less than 12 months in some cases—and that gets people's attention."

These systems, he adds, also have the potential to increase productivity. "Most press operators do not run the presses at full speed. Part of that has to do with drying times, but much of it is because the operator reaches a comfort zone where he knows he can get good and consistent quality," Shumaker explains. "On-press detection systems allow them to get more comfortable with higher speeds and run a bit faster. If it's as little as 5% faster, that makes a huge impact on a run of 7–10 presses, and a huge impact to the bottom line for increased capacity. Even a complex color job will be better if it will allow them to do on-line color monitoring throughout the run."

VISION COMPLEMENTED

The ability of vision systems to work in synergy with other systems has also made healthy progress in recent years. For example, Micron Automation Inc. (Tampa, FL), which distributes the Scanware line of blister inspection systems, has been incorporating aspects of motion control into their machines.

"You can now stop the machine if the vision system can't identify the product," says Peter Buczynsky, Micron's president. "One company was looking for a vision system that could stop the feeder when the product was bad."

Other advances, Buczynsky notes, include enhanced magnification technology that can detect tiny pieces of crushed product within the sealed area of a blister and advanced lighting systems that allow for uniformity of light.

"Before, with the slightest contrast on the camera, you could have the system rejecting good product," he says. "Now, you don't have to adjust the camera for the proper light or focus. The system is electronically controlled and all the settings are stored electronically. You can pull up a product format that's a year old and it will work. And it's fully validatable because all settings are electronic."

Buczynsky says that it is also important to help users meet the regulations imposed by 21 CFR Part 11. System suppliers should provide appropriate documentation and reporting features in conjunction with the latest access control technologies to record changes in system settings and crucial operator actions in a log file.

Another example of complementary technology is the QualitySpec TI, a near-infrared spectrometer from Analytical Spectral Devices Inc. (ASD; Boulder, CO). While vision systems can identify color, size, and shape, they cannot see chemical composition or concentration to ensure that an errant tablet or capsule with a look similar to the right drug is not going into the wrong package. In those cases, firms might want to use a near-infrared spectrometer to identify the tablets or capsules by chemical composition.

"We are starting with clinical manufacturers because all their products look alike. Let's assume a clinical manufacturer wants to package a placebo, a 10-mg dosage, and a 20-mg dosage in the same blister. They must ensure that those tablets are never switched," says John Enterline, ASD's director of sales and marketing. "Vision systems can't do it but near-infrared can. Right now, it is only for blisters, though there has been talk about using it with bottles and slat-filling machines."

Optel Vision (Quebec City, QC, Canada) has a laser scanner that checks for proper label positioning and can be used alone or in conjunction with Optel's conventional vision systems. "As the laser beam scans the bottle, a special mechanism detects the position of the label on the bottle surface. Even a white label on a white container can be detected," says Jean-François LaFortune, Optel's production manager. "If we add a second optical head on the system, two labels or a complete wrap-around label can be inspected. You can set your acceptance criteria. It is a very simple system used to reject product with missing, high, low, and skew labels. It allows customers to verify the position of their labels without putting any UV coating on them."

EMERGING COMPETITION

X-ray systems could soon find their way into pharmaceutical packaging. In applications in which inspection through an opaque package is needed, x-ray systems could prove useful, says Erik Brainard, x-ray product manager, Loma Systems Inc. (Carol Stream, IL).

"If you have a stacked package, like a Sucrets case, x-ray systems can look for contaminants in the foil package or look for missing or broken products. It may be more sensitive than a checkweigher. To perform these functions, vision systems need a clear side to the package. X-ray systems, however, do not. With labeling, x-ray can look through metallized labels for contaminants. Other uses include the inspection of metal, glass, PVC, and Teflon."

Schaa agrees that x-ray has potential in the pharmaceutical packaging market, but even though it "is still vision, just not in the visible light range," it will never take the place of light-and-camera-based vision systems.

"For conventional appearance issues, the visible spectrum is fine. But if you are looking at opaque packaging for content or contamination, you might want to use x-ray," Schaa says. "When inspecting solid dosages, if you have problems with foreign matter, x-ray could work. But other than looking for the presence of particle contamination, there is no real advantage to it."

Copyright ©2001 Pharmaceutical & Medical Packaging News