Hernández Eduardo, Pawar Pallavi, Rodriguez Sandra, Lysenko Sergiy, Muzzio Fernando J, Romañach Rodolfo J
Department of Chemistry, University of Puerto Rico, Mayaguez Campus, Mayaguez, Puerto Rico
Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, New Jersey, USA.
Appl Spectrosc. 2016 Mar;70(3):455-66. doi: 10.1177/0003702815626669.
This study describes changes observed in the near-infrared (NIR) diffuse reflectance (DR) spectra of pharmaceutical tablets after these tablets were subjected to different levels of strain (exposure to shear) during the mixing process. Powder shearing is important in the mixing of powders that are cohesive. Shear stress is created in a system by moving one surface over another causing displacements in the direction of the moving surface and is part of the mixing dynamics of particulates in many industries including the pharmaceutical industry. In continuous mixing, shear strain is developed within the process when powder particles are in constant movement and can affect the quality attributes of the final product such as dissolution. These changes in the NIR spectra could affect results obtained from NIR calibration models. The aim of the study was to understand changes in the NIR diffuse reflectance spectra that can be associated with different levels of strain developed during blend shearing of laboratory samples. Shear was applied using a Couette cell and tablets were produced using a tablet press emulator. Tablets with different shear levels were measured using NIR spectroscopy in the diffuse reflectance mode. The NIR spectra were baseline corrected to maintain the scattering effect associated with the physical properties of the tablet surface. Principal component analysis was used to establish the principal sources of variation within the samples. The angular dependence of elastic light scattering shows that the shear treatment reduces the size of particles and produces their uniform and highly isotropic distribution. Tablet compaction further reduces the diffuse component of scattering due to realignment of particles.
本研究描述了在混合过程中，药物片剂在经受不同程度的应变（剪切作用）后，其近红外（NIR）漫反射（DR）光谱中观察到的变化。粉末剪切在粘性粉末的混合中很重要。通过使一个表面在另一个表面上移动，在系统中产生剪切应力，从而导致在移动表面方向上的位移，并且是包括制药行业在内的许多行业中颗粒混合动力学的一部分。在连续混合中，当粉末颗粒持续移动时，过程中会产生剪切应变，这可能会影响最终产品的质量属性，如溶出度。近红外光谱中的这些变化可能会影响从近红外校准模型获得的结果。本研究的目的是了解近红外漫反射光谱中的变化，这些变化可能与实验室样品混合剪切过程中产生的不同程度的应变有关。使用库埃特池施加剪切力，并使用压片模拟器生产片剂。使用近红外光谱仪在漫反射模式下测量具有不同剪切水平的片剂。对近红外光谱进行基线校正，以保持与片剂表面物理性质相关的散射效应。主成分分析用于确定样品中变化的主要来源。弹性光散射的角度依赖性表明，剪切处理减小了颗粒尺寸，并使其分布均匀且高度各向同性。片剂压实由于颗粒重新排列进一步降低了散射的漫射成分。
