University of Strathclyde, Department of Pure and Applied Chemistry, George Street, Glasgow, G1 1RD, UK.
Pfizer Ltd., Ramsgate Road, Sandwich, CT19 9NJ, UK.
Anal Methods. 2022 May 19;14(19):1862-1871. doi: 10.1039/d2ay00471b.
Vibrational spectroscopic chemical imaging is an important tool in the pharmaceutical industry for characterising the spatial distribution of components within final drug products. The applicability of these techniques is currently limited by the long data acquisition times required to obtain high-definition chemical images of a sample surface. Advancements in quantum cascade laser (QCL) technology have provided an exciting new opportunity for infrared (IR) imaging. Instead of collecting a full IR spectrum at each point, it is possible to focus on distinct spectral bands to reduce imaging data collection time. This study explores a laser direct infrared (LDIR) chemical imaging approach that couples QCL technology with rapid scanning optics to provide high-definition chemical images at an order of magnitude faster than traditional imaging techniques. The capabilities of LDIR chemical imaging were evaluated for pharmaceutical formulations and compared with other established spectroscopic chemical imaging techniques including Raman, near-infrared (NIR) and scanning electron microscopy-energy dispersive X-ray (SEM-EDX) spectroscopy with regards to data acquisition time and image quality. The study showed that LDIR imaging provided high-definition component distribution maps comparable to Raman and SEM-EDX at orders of magnitude faster in terms of time. The ability to obtain high-definition chemical images of the whole tablet surface in relatively fast time frames indicates LDIR imaging could be a promising tool in the pharmaceutical industry to rapidly characterise the size and distribution of components within tablets and could help enhance drug product manufacturing understanding.
振动光谱化学成像是制药行业中用于描述最终药物产品中成分空间分布的重要工具。这些技术的适用性目前受到获得样品表面高清晰度化学图像所需的长数据采集时间的限制。量子级联激光（QCL）技术的进步为红外（IR）成像提供了一个令人兴奋的新机会。它可以集中在不同的光谱带，而不是在每个点采集完整的 IR 光谱，从而减少成像数据采集时间。本研究探讨了一种激光直接红外（LDIR）化学成像方法，该方法将 QCL 技术与快速扫描光学相结合，以比传统成像技术快一个数量级的速度提供高清晰度的化学图像。评估了 LDIR 化学成像在药物制剂中的应用，并将其与其他已建立的光谱化学成像技术（包括拉曼、近红外（NIR）和扫描电子显微镜-能谱（SEM-EDX）光谱学）进行比较，涉及数据采集时间和图像质量。研究表明，LDIR 成像提供了与拉曼和 SEM-EDX 相当的高清晰度成分分布图谱，在时间方面快了几个数量级。能够在相对较快的时间框架内获得整个片剂表面的高清晰度化学图像表明，LDIR 成像可能成为制药行业中一种有前途的工具，可快速表征片剂中成分的大小和分布，并有助于提高对药物产品制造的理解。
