Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana 47907, USA.
J Pharm Sci. 2012 Jun;101(6):2066-73. doi: 10.1002/jps.23099. Epub 2012 Mar 2.
The applicability of nanoscale mid-infrared (mid-IR) spectroscopy for the study of the micro- and nanostructure of pharmaceutical drug-polymer systems was explored. Felodipine-poly(acrylic acid) (PAA) blends were used as model systems. Standard atomic force microscopy evaluation as a function of drug-polymer composition suggested limited miscibility, in line with previous findings. Localized spectra on a 50:50 (w/w) felodipine-PAA dispersion revealed that the discrete submicrometer domains formed corresponded to an amorphous felodipine-rich phase while the continuous phase tended to be rich in PAA. Further, spectroscopic imaging at selected wavenumbers, enabling discrimination between both constituents, confirmed this finding and made it possible to chemically image differences in composition between each phase with submicrometer resolution.
本研究旨在探索纳米级中红外（mid-IR）光谱在药物-聚合物体系的微观和纳米结构研究中的适用性。采用非洛地平-聚丙烯酸（PAA）共混物作为模型体系。根据药物-聚合物组成的标准原子力显微镜评估表明，其混溶性有限，与之前的研究结果一致。在 50:50（w/w）的非洛地平-PAA 分散体上进行局部光谱分析表明，形成的离散亚微米域对应于无定形的富非洛地平相，而连续相则倾向于富含 PAA。此外，在选定波数下进行的光谱成像能够区分两种成分，进一步证实了这一发现，并能够以亚微米分辨率对各相之间的组成差异进行化学成像。
