Quality Control Advances

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

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).