Laser triangulation as a fast and reliable method for determining ribbon solid fraction; focus on accuracy, precision, and measurement time.

Roller compaction and dry granulation represent well-established unit operations in the pharmaceutical industry. The ribbon solid fraction is classified as a critical quality attribute, that directly impacts final product quality and performance. The development and evaluation of novel methods measuring ribbon solid fraction represent a subject of current research, since novel analyses strategies need to be established for at-, on-, or in-line process monitoring to overcome limitations of end product testing and to set the course for continuous manufacturing. In this study, a novel analytical device, using the principle of laser triangulation, was investigated to asses its potential being used as at-line process analytical technology tool during a roller compaction process. To this end, the laser triangulation device was compared with X-ray micro-computed tomography and powder based volume displacement measurement techniques using different statistical evaluation methods. Special focus was given to accuracy, precision, and total measurement time. The laser triangulation device was confirmed as highly accurate and precise, enabling the shortest total measurement time compared to the other methods. The findings of this study support the idea of implementing the laser triangulation device as a novel at-line process analytical technology tool into a roller compaction process.

UV-VIS spectra as potential process analytical technology (PAT) for measuring the density of compressed materials: Evaluation of the CIELAB color space.

Measurement methods for determining the density of compressed materials, being a critical quality attribute, provide an important parameter for successful processing. In this study, a novel approach was developed for determining the density of compacts using ultraviolet-visible spectrophotometry. The assumption within this context was that a change in density affects the corresponding color information of the compact. From the obtained spectra of the visible range, the color information of the compact was calculated which turned out to be directly proportional to the density of the compact. In comparison, the obtained spectra were analyzed using partial least square regression. The results of this study showed that both methods could be used predicting the density of a compact from the corresponding visible spectrum at identical accuracy. In contrast to the partial least square regression, the correlation of the color information as a direct output parameter of the spectrophotometer with the density required no excessive data pre-processing. Subsequently, the easier and faster data processing of the color information over the partial least square regression, conceives using this novel approach as potential process analytical technology tool for implementation into a compression process e.g., tableting or roller compaction.