Quality Control Advances

Highly automated and sensitive quality-control equipment quickly identifies product faults.
Aug 02, 2012
Volume 36, Issue 8

Hallie Forcinio
Quality control requires constant attention on pharmaceutical packaging lines, but it doesn't have to cause sleepless nights for operators and managers. Today, faster and more sensitive quality-control equipment provides continuous online vigilance. Data-collection capabilities are more robust too, which increases automation of record-keeping and validation. Vendors also are providing tools to help match quality-control systems to applications. Quality-control machines, introduced in the past year or so, are indicative of the technology available today and include systems for visual inspection, leak detection/seal integrity confirmation, checkweighing, and contaminant detection.

Visual-inspection systems

Visual-inspection systems, such as vision sensors, smart cameras, and camera-based vision systems, confirm the presence and position of caps, lids, and labels and check for particulates, label accuracy, and surface imperfections.

For the most demanding applications, full-scale machine-vision systems provide the highest level of programming flexibility. Although machine-vision systems are still the most complex to set up and configure, software and operator interfaces streamline configuration and simplify operation.

In the mid-range of functionality and ease of use, smart cameras combine a camera with onboard intelligence and an array of software tools that offer considerable flexibility for application programming.

The simplest and easiest to implement system, the vision sensor, also combines a camera with onboard intelligence and is optimized for optical-inspection tasks. A vision sensor can be taught to compare a captured image to a good sample and/or check for specific defects. Its capabilities are sufficient for many packaging-line inspection tasks (1).

Software is designed to be intuitive even for users who are not vision experts, said Jim Anderson, product manager for machine vision at SICK, in a company publication (1) (vision sensors, smart cameras, vision systems, SICK).

For pharmaceutical packaging applications, one robot-supported inspection machine handles almost any cylindrical container with a volume between 1 mL and 100 mL, including vials, syringes, ampuls, cartridges, cylindrical blow–fill–seal containers, and inhalers. The six-axis robot arm moves up to 15 containers per minute through three machine-vision inspection stations equipped with different camera, lighting, and container positioning options. In some cases, more than one inspection is performed at a single station. The system can check for the following: particles from a bottom or side view; proper cap application; dirt or cracks at the shoulder of the container; scratches, cracks, or chips on the neck, shoulder, or sidewall; cracks at the heel; flaws on the bottom of the container or heavy particles in suspension; and particle or cosmetic defects. The compact system is compatible with isolator enclosures and particularly well-suited for toxic or highly potent products (Seidenader RIM inspector with robot arm from Stäubli Group, Körber Medipack).

Another multiple-camera, machine-vision system examines tablets from six angles to confirm surface quality. Laser-slit lighting and three-dimensional images improve identification of chips and embossing flaws, while color cameras and filters detect subtle color variations. Simulation modes shorten set-up time, and fewer, lighter change parts reduce changeover time. The system runs up to about 5800 tablets per min (Viswill TVIS-EX3-CD visual inspection system for tablets, Daiichi Jitsugyo America).

A print quality inspection and barcode verifier for thermal and thermal-transfer printed labels performs a variety of inspections. Functions include master-to-label comparison (i.e., blemish detection), one- and two-dimensional barcode verification and validation, optical character recognition, optical character verification, field matching, and number/data validation. Additionally, the software includes automatic setup for quick label and field identification, job retrieval for recall of previous runs, and a robust alarm matrix for user-defined input/output interaction with peripheral devices. The rugged design of the read head and mounting plate simplify integration with thermal label printers and other slow-speed roll printing applications. The system is 21 CFR Part 11 compliant-ready, offering multiple security levels and comprehensive data management and reporting options (LVS 7500 inspection system, Label Vision Systems).