Novel approach to pharmaceutical quality control

Researchers at Fraunhofer IAF have developed a system for the rapid and contactless control of pharmaceuticals. The measurement system is based on the combination of infrared spectroscopy and artificial intelligence (machine vision and machine learning) and provides 100 percent verification of blister contents within a few milliseconds. The approach can be further developed for integration into the industrial production process, making it an important tool for end control in the pharmaceutical industry. The scientific paper was recently published in the IEEE Sensors Journal.

Pharmaceutical production is subject to strict guidelines and controls. These are necessary to ensure that the safety, quality and efficacy of the drugs produced are given. In the production of pharmaceutical blisters, qualified personnel often carry out the final inspection by performing a final visual check of the blister contents. Researchers at Fraunhofer IAF have developed a measurement system that can support this step of final content control in the ongoing production process and provide fast, non-contact and precise identification of each individual tablet in the blister.

This infrared spectroscopy measurement system is designed to help pharmaceutical companies make quality assurance and process controls more reliable and at the same time more efficient. The approach can be further developed for integration into existing plants and enables a 100 percent verification rate. The results are based in part on a project carried out jointly with Fraunhofer CAP.

Picture of the demonstrator of a QCL-based measurement system
© Fraunhofer IAF
Fraunhofer IAF has developed an integrable measurement system for fast testing applications in the pharmaceutical, chemical and food industries.

Spectroscopy combined with artificial intelligence

The measurement principle is based on backscatter spectroscopy in the mid-infrared (MIR). The wavelength ranges from 4 to 12 μm could be covered in principle. A core component of the system is a broad-emitting and spectrally fast-scanning laser module consisting of quantum cascade laser (QCL) and micro-opto-electro-mechanical grating scanner (MOEMS). The high brilliance of the light source and the unique properties of the MOEMS scanner enable infrared spectroscopy at a rate of one kilohertz. Such a laser source (spectral tuning range of about 300 cm-1) is integrated in the developed technology demonstrator. However, several individual MOEMS EC QCLs can also be combined with each other so that a much wider bandwidth can be covered with the same measurement time.

The researchers have now combined the core technological components of the system with artificial intelligence (machine vision and machine learning) to enable content verification in the running (inline) process that is both fast and characterized by high confidence. Within 300 milliseconds, a blister consisting of 12 tablets is scanned by spectrally measuring each individual tablet. The acquired measurement data (MIR backscatter spectra) are evaluated in real time.

The scientific results have now been published in the paper titled “Point of Interest Mid-Infrared Spectroscopy for Inline Pharmaceutical Packaging Quality Control” in the IEEE Sensors Journal:

DOI: 10.1109/JSEN.2023.3281972

Further information


Point of Interest Mid-Infrared Spectroscopy for Inline Pharmaceutical Packaging Quality Control


Application laboratory infrared lasers

In our application laboratory, we offer spectroscopic measurements with our fast tunable quantum cascade lasers (QCLs).