PAT: From Western solid dosage forms to Chinese materia medica preparations using NIR-CI

Near-infrared chemical imaging (NIR-CI) is an emerging technology that combines traditional near-infrared spectroscopy with chemical imaging. Therefore, NIR-CI can extract spectral information from pharmaceutical products and simultaneously visualize the spatial distribution of chemical components. The rapid and non-destructive features of NIR-CI make it an attractive process analytical technology (PAT) for identifying and monitoring critical control parameters during the pharmaceutical manufacturing process. This review mainly focuses on the pharmaceutical applications of NIR-CI in each unit operation during the manufacturing processes, from the Western solid dosage forms to the Chinese materia medica preparations. Finally, future applications of chemical imaging in the pharmaceutical industry are discussed.

Effect of Magnesium Stearate Mono- and Dihydrate Dispersibilities on Physical Properties of Tablets

Magnesium stearate (MgSt), an essential lubricant in the manufacturing of tablets, is available in several hydrate forms with different qualities that affect the physical properties of tablets. This study examined MgSt mono- and dihydrates, and their effects on tablet dissolution, disintegration, and hardness. These effects were examined in terms of surface free energy and dispersibility. Dissolution, disintegration, and hardness were evaluated for tablets manufactured from powder mixtures of each MgSt hydrate form and other components, including ethenzamide as an active ingredient, using different mixing times. The surface energy was evaluated for MgSt mono- or dihydrate powder mixtures with a surface tensiometer. For dispersibility, the adhesion states of MgSt hydrates to other components were visually observed via near-infrared (NIR) chemical imaging. The dispersion behavior of MgSt hydrates was examined by quantitative evaluation of skewness and kurtosis of histograms, based on NIR images, and domain size estimated from their binary images. It was found that changes in those parameters related to dispersibility and dissolution differed between MgSt hydrates. This suggests that the quantitative determination of dispersibility of MgSt using NIR chemical imaging is a useful methodology for improving the understanding of tablet manufacturing blending processes.