Hyperspectral Raman Line Mapping as an Effective Tool To Monitor the Coating Thickness of Pharmaceutical Tablets

Abstract

Protective chemical coatings are deposited on drugs during the manufacturing process for the purpose of controlling the pharmacokinetics of active pharmaceutical ingredients (APIs). Although manufacturers attempt to coat all the tablets uniformly, the film thickness of an individual drug is statistically different and depends on the measuring position of the anisotropic structure, and analytical methods for measuring coating thickness must be robust to statistical and geometrical aberrations. Herein, we demonstrate that a spatially offset Raman-spectroscopy-based line mapping method offered excellent calibration and prediction of the coating thickness of 270 acetaminophen (N-acetyl-para-aminophenol, paracetamol) tablets. Raman-scattered light resurfaced back from the coating and APIs, and offset-resolved spectra were projected according to the vertical positions in an imaging sensor. The Raman intensity ratio between the coating substance and the inner APIs is a key parameter in the analysis, and its variation with respect to the spatial offset is proportional to the coating thickness and duration. The results of this study have implications for the rapid spectroscopic thickness measurement of industrial products coated with transparent or translucent materials.

Potential of Spatially Offset Raman Spectroscopy for Detection of Zebra Chip and Potato Virus Y Diseases of Potatoes (Solanum tuberosum)

“…In other cases, the variation between spectra can be subtle shifts in band position and/or intensity, requiring statistical methods, such as multivariate statistical analysis, to differentiate them. The potential of RS coupled with multivariate statistical analysis was previously demonstrated in many fields including forensics, art, and medicine. − Our group has demonstrated the potential of RS coupled with multivariate statistics for the detection of fungal, viral, and bacterial diseases on a broad spectrum of plants. − Specifically, we showed that RS could be used for the detection of Candidatus Liberibacter asiaticus that causes Huanglongbing, or citrus greening, on orange and grapefruit trees. , While Raman is quite powerful in detecting distinct chemical groups on a sample surface, its ability to probe deeper layers is limited.…”

Raman imaging for measuring homogeneity of dry binary blend: Combining microscopy with spectroscopy for technologists

“…Therefore, Raman chemical mapping can be a better solution to handle this challenge as materials may be distinguished by spectroscopy based on their mineralogical or chemical characteristics, and the same can be mapped for being used as readily available in image form for technologists or engineers. This technique is being extensively explored in the field of pharmaceutics and food industry for quality control‐related applications in the manufacturing of medicinal tablets and instant food mixes 28‐30 . This technique has been evaluated as a process analytical tool to determine the end point of the mixing for pharmaceutical blends 31 .…”

A Review of Pharmaceutical Robot based on Hyperspectral Technology

“…Therefore, the detection of drug surface coating thickness is an important content that cannot be ignored in drug detection by Raman hyperspectroscopy [63][64][65]. Figure 6 shows the detection of the coating thickness of tablets with the Raman spectroscopy method [66]. Song et al, [66] innovatively proposed a line mapping method based on space-shifted Raman spectroscopy to solve the problem of thickness detection and analysis of protective chemical coatings for drug deposition.…”

“…Figure 6 shows the detection of the coating thickness of tablets with the Raman spectroscopy method [66]. Song et al, [66] innovatively proposed a line mapping method based on space-shifted Raman spectroscopy to solve the problem of thickness detection and analysis of protective chemical coatings for drug deposition. It has achieved signal calibration and thickness prediction in terms of coating thickness of acetaminophen.…”